CN115398036A

CN115398036A - Device, system and method for generating nitric oxide

Info

Publication number: CN115398036A
Application number: CN202180027930.4A
Authority: CN
Inventors: 封志纯; 毛雯; 张煜彦; 耿翔; 陈涛; 赵杨波; 吴清
Original assignee: Nanjing Nuoling Biotechnology Co ltd
Current assignee: Nanjing Nuoling Biotechnology Co ltd
Priority date: 2020-12-18
Filing date: 2021-12-17
Publication date: 2022-11-25
Anticipated expiration: 2041-12-17
Also published as: CN117568825A; CN115398036B; CN117802515A; CN117070962A

Abstract

Embodiments of Nitric Oxide (NO) generating devices, systems, and methods are provided. In some embodiments, the NO generation apparatus may include a reaction chamber having a liquid region and a gas region. The liquid region may be configured to contain a reaction medium, while the gas region may be configured to contain a product gas comprising NO. The NO generation device may further include a plurality of electrodes disposed in the reaction medium and may include an energy source electrically connected with the plurality of electrodes and configured to apply a predetermined voltage or a predetermined current to at least one of the plurality of electrodes to generate NO. The NO generation apparatus may further comprise an inlet circuit configured to receive the carrier gas, and the NO generation apparatus may comprise at least one sparger in fluid communication with the inlet circuit and configured to emit bubbles of the carrier gas in the reaction medium.

Description

Device, system and method for generating nitric oxide

Cross Reference to Related Applications

Chinese patent application No.202011502839.7 filed on 12/18/2020, chinese patent application No.202011502846.7 filed on 12/18/2020, chinese patent application No.202011502862.6 filed on 12/18/2020, chinese patent application No.202011508948.x filed on 12/18/2020, chinese patent application No. 023064800.x filed on 12/18/2020, chinese patent application No. 202064847.6 filed on 12/18/2020, chinese patent application No. 202023060234866.9 filed on 12/18/2020, chinese patent application No. 023072485.5 filed on 12/18/2020, chinese patent application No. 202072503.x filed on 12/18/2020, chinese patent application No. 2020231833.0 filed on 2/18/2020, chinese patent application No. 20212044.8/3.4 filed on 2/18/2020, and the japanese patent application No. 2023612044/3.4 filed on 12/18/2020 are incorporated by reference in their entireties.

Technical Field

The present disclosure relates to devices, systems, and methods for generating and/or delivering nitric oxide, and more particularly, to devices, systems, and methods for generating and/or delivering nitric oxide on demand.

Background

Nitric Oxide (NO) is a gaseous signaling molecule that plays an important role in many physiological and pathological processes. NO can diffuse through the cell membrane without an intermediate transport mechanism and can therefore signal adjacent cells or tissues in an efficient and rapid manner. For example, NO produced by vascular endothelial cells may signal relaxation of the surrounding vascular smooth muscle, resulting in vessel relaxation and increased blood flow. NO may also be involved in electron transfer and redox reactions in biochemical events in human cells. NO can cause various physiological effects such as endothelium-dependent vasodilation by activating guanylate cyclase.

Inhalation of NO can improve the body's oxidative capacity and reduce the need for high risk extracorporeal cardiopulmonary support in critically ill patients. Controlling the administration of an appropriate amount of inhaled NO may reduce pulmonary arterial hypertension and improve oxygenation. The U.S. food and drug administration has approved inhaled NO as a drug for the treatment of neonatal persistent pulmonary hypertension. NO inhalation therapy has also been used in various disease or clinical medicine fields such as neonatal respiratory disorder, intensive care medicine, cardiothoracic surgery, acute respiratory distress, and anesthesiology.

In a clinical environment, high pressure gas tanks or cylinders are used to provide NO. Such gas tanks are large in size and weight and are typically mounted on wheeled conveyors or carts, often placed at the bedside of crowded intensive care units. The use of such heavy and large cylinders may present a safety risk to the patient and the medical staff. For example, patients and healthcare personnel may be exposed to toxic nitrogen dioxide formed during system setup or due to potential NO leaks from damaged regulators, valves, or supply lines. Medical personnel may also suffer physical injury by moving or replacing the cylinder. Accordingly, there is a need to overcome and/or address one or more of these disadvantages. The present disclosure relates to a tank-less or "tankless" system and method that can generate NO on demand, without the need to store large amounts of pressurized NO.

Disclosure of Invention

According to some embodiments of the present disclosure, there is provided an apparatus for generating Nitric Oxide (NO). In some embodiments, the apparatus may include a reaction chamber having a liquid region and a gas region. The liquid zone may be configured to contain a reaction medium. The gas zone may be configured to contain a product gas comprising NO. In some embodiments, the apparatus may include a plurality of electrodes disposed in the reaction medium. The plurality of electrodes may include a cathode. In some embodiments, the apparatus may include an energy source electrically connected to the plurality of electrodes. The energy source may be configured to apply a predetermined voltage or a predetermined current to the cathode to generate NO. In some embodiments, the apparatus may include a sparger disposed in the reaction medium. In some embodiments, the apparatus may include an inlet circuit. The inlet circuit may be in fluid communication with the sparger and configured to deliver the carrier gas to the sparger. In some embodiments, the apparatus may include an outlet circuit. The outlet loop can be in fluid communication with a gas region of the reaction chamber and configured to convey the product gas from the reaction chamber. In some embodiments, the apparatus may include a first circulation loop configured to circulate a first fluid flow relative to the reaction chamber. The first circulation loop may include a first inlet in fluid communication with the gas region of the reaction chamber, a first outlet in fluid communication with the sparger, and a first pump configured to create a first fluid flow from the first inlet to the first outlet.

According to an embodiment of the present disclosure, a method of generating nitric oxide is provided. In some embodiments, the method may include applying a predetermined voltage or a predetermined current to one or more of the plurality of electrodes by the energy source. A plurality of electrodes may be disposed in the reaction medium contained in the reaction chamber to generate NO. The plurality of electrodes may include a cathode. The reaction chamber may include a gas region and a liquid region. The liquid region can be configured to contain a reaction medium. The gas zone may be configured to contain a product gas comprising NO. In some embodiments, the method may include receiving a carrier gas through an inlet loop. The inlet loop may be in fluid communication with a sparger disposed in the reaction medium. In some embodiments, the method may include emitting bubbles of the carrier gas in the reaction medium through a sparger. The gas bubble may be swept across a surface of one or more of the plurality of electrodes. In some embodiments, the method may include circulating a first fluid stream relative to the reaction chamber in a first circulation loop. The first fluid stream may comprise a product gas stream. In some embodiments, the method may include passing the product gas from the reaction chamber through an outlet loop. The outlet loop may be in fluid communication with a gas region of the reaction chamber.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosed embodiments, as claimed.

The accompanying drawings form a part of the specification. The accompanying drawings illustrate several embodiments of the disclosure and, together with the description, serve to explain the principles of certain disclosed embodiments as set forth in the appended claims.

Drawings

Fig. 1 is a schematic diagram of a NO system according to some embodiments of the present disclosure.

Fig. 2 is a schematic diagram of a NO generation apparatus, according to some embodiments of the present disclosure.

Fig. 3A is a schematic diagram of a first electrode, a second electrode, and a sprinkler, according to some embodiments of the present disclosure.

Fig. 3B is a perspective view of a sprinkler according to some embodiments of the present disclosure.

Fig. 4A is a graphical representation of the concentration of NO in the product gas generated by the NO generation device versus the current applied to the electrodes, according to some embodiments of the present disclosure.

Fig. 4B is a graphical representation of the concentration of NO in the product gas generated by the NO generation apparatus as a function of time, according to some embodiments of the present disclosure.

Fig. 4C is a graphical representation of the concentration of NO in the product gas generated by the NO generation apparatus during multiple stages, according to some embodiments of the present disclosure.

Fig. 5A is an exploded view of a filtration device according to some embodiments of the present disclosure.

Fig. 5B is a cross-sectional perspective view of the filter device of fig. 5A.

Fig. 5C is a cross-sectional view of the filter device of fig. 5A.

Fig. 6A is a perspective view of a pressure vessel according to some embodiments of the present disclosure.

Fig. 6B is a cross-sectional perspective view of the pressure vessel of fig. 6A.

Fig. 6C is another cross-sectional view of the pressure vessel of fig. 6A.

Fig. 7A is a top perspective view of an exhaust treatment device according to some embodiments of the present disclosure.

Fig. 7B is a bottom perspective view of the exhaust treatment device of fig. 7A.

FIG. 7C is a cross-sectional view of the exhaust treatment device of FIG. 7A.

Fig. 8A is an exploded view of a gas converter according to some embodiments of the present disclosure.

Fig. 8B is a schematic diagram of a gas converter according to some embodiments of the present disclosure.

Fig. 9 is a schematic diagram of a ventilation circuit for delivering NO to a patient, according to some embodiments of the present disclosure.

Fig. 10A is a perspective view of a moisture trap, according to some embodiments of the present disclosure.

Fig. 10B is a partial perspective view of the moisture trap of fig. 10A.

Fig. 10C is another partial perspective view of the moisture trap of fig. 10A.

Fig. 11A is a schematic illustration of a sampling process of a gas monitoring device according to some embodiments of the present disclosure.

Fig. 11B is a schematic illustration of an initialization process of a gas monitoring apparatus according to some embodiments of the present disclosure.

Fig. 11C is a schematic illustration of a cleaning process of a gas monitoring device according to some embodiments of the present disclosure.

Fig. 11D is a schematic diagram of a calibration process of a gas monitoring device according to some embodiments of the present disclosure.

Fig. 12 is a flow chart illustrating a NO generation method according to some embodiments of the present disclosure.

Detailed Description

Reference will now be made in detail to the disclosed embodiments, taken in conjunction with the accompanying drawings. Unless defined otherwise, technical or scientific terms have the meaning commonly understood by one of ordinary skill in the art. The embodiments disclosed are described in sufficient detail to enable those skilled in the art to practice the embodiments disclosed. It is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the disclosed embodiments. Thus, the materials, methods, and examples are illustrative only and not intended to be necessarily limiting.

The present disclosure provides devices, systems, and methods for generating NO from one or more electrochemical reactions. According to one aspect of the present disclosure, an embodiment may output a product gas including NO. NO in the product gas may be generated or delivered at a predetermined concentration and/or flow rate. For example, some embodiments may output a product gas with a clinically relevant concentration and/or flow rate of NO for inhalation NO therapy. The concentration and/or flow rate of NO in the product gas may be adjusted. For example, the concentration of NO in the product gas may be in the range of about 0 to about 20000 ppm.

Dimensionless units "ppm" used in this disclosure to describe gas concentrations refer to volumes of parts per million and can be converted to other concentration units such as parts per million moles or milligrams per liter (mg/L). The dimensionless units "%" or "volume%" used in this disclosure to describe gas concentrations refer to volume percentages and may be converted to other concentration units, such as weight percentages or molar concentrations. As used herein, "about" in a numerical range means that the numerical range covers normal industry and subject variations or tolerances for manufacturing and/or operation. As used herein, the phrases "less than," "greater than," "between one value and another value," or "from one value to another value" in a numerical range include the endpoints and all values within or between the endpoints.

According to another aspect of the present disclosure, embodiments may allow for the generation of NO in a phase comprising at least one operating cycle. The concentration and/or flow rate of NO in the product gas may reach and/or remain at a steady state during the operating cycle. As described herein, the concentration and/or flow rate of NO in the product gas at steady state may deviate from a certain value or a certain range due to steady state errors. For example, the steady state error may be in the range of about 0 to about 10%. The operating period may, for example, last up to about 60 hours or more.

According to another aspect of the disclosure, embodiments may allow for NO to be generated in a phase comprising at least one ramp cycle. As described herein, a ramp period may refer to a transition period during which the NO concentration of the product gas may increase or decrease from an initial concentration to a predetermined steady-state concentration. The ramp period may be a ramp-up period or a ramp-down period. For example, the ramp period may range from about 2 minutes to about 10 minutes. The ramp period may be predetermined or adjusted to allow a more rapid or immediate provision of a steady flow of NO, such as may be required in an intensive care unit.

According to another aspect of the disclosure, embodiments may allow for the generation of NO in multiple stages. Multiple stages of NO generation may provide NO to treat the same patient or to treat different patients over time. One or more parameters for generating or delivering NO by some embodiments of the present invention may be predetermined and/or adjusted. For example, the number of stages, the number of operating cycles in a stage, the start and/or end times of an operating cycle, and/or the concentration and/or flow rate of NO in the product gas during an operating cycle of a stage may be predetermined and/or adjusted.

According to another aspect of the present disclosure, to reduce exposure to health risks, embodiments may reduce or remove one or more toxic impurities, such as nitrogen dioxide, that may be present in the product gas.

Various devices, systems, and methods for generating NO consistent with the present disclosure are described below.

Fig. 1 is a schematic diagram of a NO system 10 according to some embodiments of the present disclosure. As shown in fig. 1, in some embodiments, system 10 includes a NO generating device 100. The NO generating device 100 generates NO using one or more electrochemical reactions. In some embodiments, the system 10 includes a carrier gas source 200 disposed upstream of and in fluid communication with the NO generation device 100. The carrier gas source 200 may generate or supply the carrier gas 122. The carrier gas 122 may be supplied to the NO generation apparatus 100 to transport the generated NO out of the NO generation apparatus 100. For example, the carrier gas 122 may sweep, purge, and/or entrain the generated NO from the NO generation apparatus 100.

The NO generation apparatus 100 may output NO generated in the product gas. The product gas may include one or more components. In some embodiments, the product gas comprises a carrier gas. The product gas may flow from the NO generation facility 100 to one or more downstream systems or devices. One or more downstream systems or devices may transport, process, and/or store the product gas from the NO generating facility 100. For example, the product gas may include one or more impurities, such as moisture, one or more toxic gases, and solid matter. In some embodiments, system 10 includes one or more filtration systems or devices to reduce or remove one or more impurities in the product gas. In some embodiments, system 10 includes a ventilation circuit to deliver NO to the patient aerobically or anaerobically. Various embodiments of the system 10 and methods of generating NO using the system 10 are described below.

Electrochemical generation of NO

Fig. 2 is a schematic diagram of a NO generation apparatus 100, in accordance with some embodiments of the present disclosure. The NO generating device 100 is configured to generate NO from one or more electrochemical reactions in the reaction medium 112. As shown in fig. 2, in some embodiments, the NO generating device 100 includes a reaction chamber 102 and a plurality of electrodes. In some embodiments, the reaction chamber 102 includes a liquid region 108 and a gas region 110. Liquid region 108 is configured to receive reaction medium 112. Gas zone 110 is configured to receive gases generated in and/or transported from reaction medium 112.

In some embodiments, the reaction chamber 102 has a first side 104 and a second side 106. The first side 104 may be a top side of the reaction chamber 102. The second side 106 may be the bottom side of the reaction chamber 102. The first side 104 and the second side 106 may extend parallel to each other. For example, the first side 104 may have a surface that extends parallel to a surface of the second side 106. The liquid region 108 may be disposed adjacent to the second side 106. The gas region 110 may be disposed adjacent the first side 104.

As shown in fig. 2, in some embodiments, the NO generation apparatus 100 includes an inlet circuit 120 and an outlet circuit 124. The inlet loop 120 is disposed downstream of and in fluid communication with a carrier gas source 200. In some embodiments, the inlet circuit 120 has at least one outlet 144, such as an opening, in the liquid region 108. The inlet circuit 120 may receive a carrier gas 122 and transport the carrier gas 122 to the liquid region 108. The outlet loop 124 is disposed downstream of and in fluid communication with the gas region 110 of the reaction chamber 102. In some embodiments, outlet circuit 124 has at least one inlet, such as an opening, in gas region 110. For example, the carrier gas 122 may carry generated NO out of the NO generation apparatus 100 from the gas zone 110 through the outlet loop 124.

In some embodiments, the NO generation apparatus 100 may include one or more NO sensors (not shown) configured to detect the concentration of NO in the product gas. The NO sensor may be located at any suitable location. For example, the NO sensor may be placed in contact with the product gas in gas zone 110. In some embodiments, the NO sensor is disposed in or near the outlet loop 124 of the reaction chamber 102. For example, the NO sensor may be disposed at an opening of the outlet loop 124, such as at an inlet or an outlet of the outlet loop 124. For example, the NO sensor may be disposed within the conduit of the outlet loop 124. In some embodiments, the NO sensor may be disposed downstream of the outlet circuit 124 or downstream of one or more filters or filtering devices downstream of the outlet circuit 124. For example, as shown in fig. 1 and 2, NO sensor 125 may be disposed downstream of filter 506 of filtration system 500, which is disposed downstream of outlet circuit 124.

In some embodiments, the plurality of electrodes of the NO generating device 100 includes a first electrode 116 and a second electrode 118. First electrode 116 and second electrode 118 are disposed in reaction medium 112. In some embodiments, the second electrode 118 is a counter electrode to the first electrode 116. For example, the first electrode 116 may be a cathode and the second electrode 118 may be an anode, or vice versa. As described herein, while some embodiments of the present disclosure are described with respect to the first electrode 116, similar embodiments with respect to the second electrode 118 will be apparent to those skilled in the art. In some embodiments, the plurality of electrodes includes a reference electrode. The reference electrode may be the first electrode 116, the second electrode 118, or a third electrode (not shown). The reference electrode may be disposed in reaction medium 112 or disposed externally thereto.

In some embodiments, as shown in fig. 2, the first electrode 116 and the second electrode 118 are electrically connected to the energy source 114. In some embodiments, the energy source 114 is configured to apply a voltage to the first electrode 116 or to generate a potential difference between the first electrode 116 and the second electrode 118. In some embodiments, the energy source 114 is configured to apply an electrical current to the first electrode 116 or to generate an electrical current that flows from the second electrode 118 to the first electrode 116, or vice versa. The voltage or current applied to the electrodes may be predetermined and/or adjusted based on one or more conditions, such as a desired concentration and/or flow rate of NO in the product gas.

In some embodiments, the voltage applied to the first electrode 116 may be measured as a potential difference between the first electrode 116 and the second electrode 118 or between the second electrode 118 and the first electrode 116. In some embodiments, the current applied to the first electrode 116 may be measured as the current through the first electrode 116. In some embodiments, the voltage applied to the first electrode 116 may be measured as a potential difference between the first electrode 116 and a reference electrode or between the reference electrode and the first electrode 116.

In some embodiments, reaction medium 112 is a liquid. For example, reaction medium 112 may comprise an aqueous or organic solution. In some embodiments, the reaction medium 112 includes a source of nitrite ions. In some embodiments, the NO generation device 100 generates NO by electrochemically reducing nitrite ions in the reaction medium 112 to NO adjacent and/or at a surface of an electrode (such as the first electrode 116). In some embodiments, electrochemical reduction of nitrite ions to NO is promoted or achieved by one or more catalysts. In some embodiments, one or more catalysts are dissolved or dispersed in the reaction medium 112. One or more catalysts may be adjacent to and/or in contact with a surface of an electrode (such as first electrode 116) to individually or collectively act as an electron transfer mediator between the surface of the electrode and nitrite ions in reaction medium 112.

In some embodiments, the catalyst may be immobilized on a surface of an electrode (such as the first electrode 116). In some embodiments, the catalyst comprises one or more compounds selected from the group consisting of cystine, cysteine, methionine, thiophene, and derivatives thereof. For example, the one or more catalysts may be covalently attached, adsorbed, doped, or covalently attached to a material deposited on the electrode, such as a polymer, film, or hydrogel. Some examples of materials that can be deposited on the electrodes can be found in PCT/US 2018/027081. As described herein, PCT/US2018/027081 is incorporated by reference for the related subject matter discussed in the present disclosure.

The catalyst may assist in electrochemically reducing nitrite ions in reaction medium 112 to NO at and/or near the surface of an electrode (e.g., first electrode 116). In some embodiments, the catalyst comprises a metal-containing compound, such as a metal-ligand complex. In some embodiments, the metal-containing compound may assist in electrochemically reducing nitrite ions in reaction medium 112 to NO according to the following reaction:

m (first valence) (l) + e ^- → M (second valence) (l) reaction 1

M (second valence) (l) + NO ₂ ^- +2H ⁺ → M (first valence) (l) + NO + H ₂ O reaction 2

Wherein M (l) represents a metal-ligand complex, M represents at least one metal ion, l represents at least one surrounding ligand or complexing agent, and NO ₂ ^- Represents a nitrite ion. NO can be generated by reducing at least one metal ion in the metal-ligand complex from a first valence to a second valence, the second valence being lower than the first valence. The reduced metal-ligand complex serves as an intermediate for reducing nitrite ions in reaction medium 112 to NO while being oxidized to the original metal-ligand complex.

The at least one metal ion may, for example, comprise one or more metal ions selected from copper, iron, titanium, chromium, manganese, cobalt and nickel ions. The at least one peripheral ligand or complexing agent may include, for example, one or more members selected from the group consisting of tris (2-pyridylmethyl) amine (TPA or TPMA), 1,4, 7-triazacyclononane, 1,4, 7-trimethyl-1, 4, 7-triazacyclononane (Me) ₃ TACN), tris (2-aminoethyl) amine, 3- ((2-aminoethyl) amino) propionic acid, and bis (2-aminopyridine) propionic acid. Some other examples of metal ions or surrounding ligands or complexing agents can be found in PCT/US 2018/027081.

In some embodiments, the use of a metal-ligand complex as a catalyst allows the use of cathodic voltage or cathodic current to generate NO and/or modulate the generation of NO. In some embodiments, controlling the magnitude of the voltage or current applied to the electrode (such as the first electrode 116) allows for control of the ratio of the reduced form of the metal-ligand complex to its oxidized form, e.g., at and/or near the electrode surface. This may allow for control of the amount and/or rate of NO generated at a given concentration of nitrite ion and metal-ligand complex in reaction medium 112.

In some embodiments, an electrode (such as first electrode 116) may have any suitable shape including one or more surfaces. For example, the first electrode 116 may comprise a plate, sheet, or mesh. In some embodiments, NO is electrochemically generated from one or more electrochemical reactions occurring at and/or near one or more surfaces of first electrode 116 when a cathode voltage is applied to first electrode 116, or when a cathode current is applied to first electrode 116. Some or all of the NO generated from the electrochemical reaction at and/or near the surface of the first electrode 116 in the reactive media 112 may be carried out of the reactive media 112 and into the gas region 110 of the reaction chamber 102. For example, carrier gas 122 may be used to sweep, purge, and/or entrain some or all of the NO generated from reaction medium 112.

The energy source 114 may include one or more suitable power devices or circuits that allow for the application of voltage or current to the electrodes, such as an electrical outlet, a power circuit, a direct current power source, an alternating current power source, a generator, or an energy storage device. The energy storage device may comprise, for example, one or more batteries or fuel cells. In some embodiments, energy source 114 includes one or more electrical circuits for controlling or adjusting the voltage or current applied to the electrodes. In some embodiments, one or more of the electrical circuits may include a potentiostat to control or adjust the voltage applied to the electrodes. In some embodiments, one or more electrical circuits may include a galvanostat to control or adjust the current through the electrodes.

In some embodiments, the polarity of the first electrode 116 and the second electrode 118 may be switched. For example, the polarity of the first and

second electrodes

116, 118 may be switched by reversing the polarity of the energy source 114, such as by reversing the polarity of the voltage or current from a DC power source using a reversing switching loop, or by using an AC power source. For example, the energy source 114 is an AC power source configured to apply a periodic alternating current or alternating voltage to the electrodes.

For example, the switching of the polarity of the electrodes may be automatically controlled by a control loop according to a software program. Additionally or alternatively, the switching of the polarity of the electrodes may be manually controlled by a user, for example by using a switch. The polarity of the electrodes can be switched during NO generation, between two operating cycles or between two phases. NO in the reaction medium 112 in contact with or adjacent to the electrode may cause degradation of the electrode and may negatively impact the NO generation efficiency. Switching the polarity of the electrodes may increase the effective surface area for NO generation and may increase the lifetime of the electrodes and/or the NO generating device 100.

The electrodes of the NO generating device 100, such as the first electrode 116, the second electrode 118 or the reference electrode, may be made of one or more materials. One or more electrodes of the NO generating device 100 may be made of the same material or different materials. In some embodiments, the electrodes of the NO generating device 100 comprise at least one conductive material. The at least one conductive material may be a metallic or non-metallic material. The at least one conductive material may be selected from, for example, a group of conductive materials including platinum, palladium, gold, copper, brass, silver, carbon, glassy carbon, boron Doped Diamond (BDD), graphite, stainless steel, titanium, iridium, ruthenium, and one or more alloys thereof, such as a ruthenium-iridium alloy.

In some embodiments, the electrode of the NO generation apparatus 100 comprises at least one substrate. The at least one substrate may be a metallic or non-metallic material. The at least one substrate may be selected from, for example, a group of materials including silicon dioxide, conductive glass, tin-doped indium oxide, fluorine-doped indium oxide, conductive plastic, platinum, gold, copper, brass, silver, carbon, glassy carbon, boron-doped diamond (BDD), graphite, stainless steel, titanium, iridium, ruthenium, and one or more alloys thereof, such as a ruthenium-iridium alloy. In some embodiments, the electrodes of the NO generation apparatus 100 comprise at least one conductive material coated on at least one substrate. The at least one conductive material may be coated on the at least one substrate using any suitable coating method, such as electroplating, physical Vapor Deposition (PVD), chemical Vapor Deposition (CVD), or Plasma Enhanced Chemical Vapor Deposition (PECVD).

The electrode (e.g., first electrode 116) of the NO generating device 100 may have any shape, configuration, and/or size. In some embodiments, the first electrode 116 provides a surface on and/or near which NO is electrochemically generated. For example, the shape of the first electrode 116 may be in the form of a plate, sheet, mesh, or rod. The surface of the first electrode 116 may have a surface area. The surface area may be positively correlated with the rate of NO generation at the surface. The first electrode 116 may have a structure that allows for a larger surface area, such as a porous structure.

Fig. 3A is a schematic illustration of the first electrode 116 and the second electrode 118 of the NO generation device 100, according to some embodiments of the present disclosure. The first electrode 116 and the second electrode 118 can be placed in the reaction chamber 102 using suitable means such that the surfaces of the first electrode and the second electrode are disposed in the reaction medium 112. For example, as shown in fig. 3A, a frame 126 may be used to place the first electrode 116 and the second electrode 118 in the reaction chamber 102. The frame 126 may have a top side that is connected to the first side 104 of the reaction chamber 102. The first electrode 116 and the second electrode 118 may be attached to the frame 126 in any suitable manner, such as by using screws, snaps, wires, clip fasteners, or any other suitable fastening means.

In some embodiments, as shown in fig. 3A, the first electrode 116 and the second electrode 118 comprise two rectangular plates having one or more surfaces 128. The first electrode 116 and the second electrode 118 may have the same size or similar sizes. In some embodiments, the first electrode 116 and/or the second electrode 118 have a length from about 3cm to about 15 cm. In some embodiments, the first electrode 116 and/or the second electrode 118 have a width from about 2cm to about 10cm. The first electrode 116 and the second electrode 118 can be disposed at any suitable distance apart, such as about 0.2cm to about 10cm apart. The first electrode 116 and the second electrode 118 may be arranged such that at least a portion of the surface 128 of the first electrode 116 extends along at least a portion of the surface 128 of the second electrode 118, such as extends parallel to at least a portion of the surface of the second electrode.

In some embodiments, as shown in fig. 1-2, the first electrode 116 and the second electrode 118 are vertically oriented. For example, the first electrode 116 and the second electrode can be disposed perpendicular to the second side 106 of the reaction chamber 102. In some embodiments, each electrode includes a top edge 130 and a bottom edge 132. The top edge 130 may extend along the first side 104 of the reaction chamber 102, such as parallel to the first side of the reaction chamber. The bottom edge 132 may extend along, such as parallel to, the second side of the reaction chamber 102.

Wires may be used to electrically connect the electrodes to the energy source 114. For example, as shown in fig. 3A, the wire 136 is connected at a first end to the energy source 114 (not shown) and at a second end to an electrode, such as the first electrode 116 or the second electrode 118. The wire 136 may be soldered or brazed to the electrodes (e.g., the first electrode 116 and the second electrode 118). The wires 136 may be made of one or more conductive materials (such as copper, aluminum, steel, or silver) and may be treated for corrosion protection purposes. In some embodiments, the wires 136 are secured to the frame 126.

In some embodiments, the voltage applied to the electrode (e.g., first electrode 116) is a DC voltage. In some embodiments, the voltage applied to the electrode (e.g., first electrode 116) ranges from about 1.0V to about 5.0V, such as from about 1.0V to about 2.0V, from about 2.0V to about 3.0V, from about 3.0V to about 4.0V, from about 4.0V to about 5.0V, or a combination thereof.

In some embodiments, energy source 114 is configured to apply an excitation voltage to an electrode (such as first electrode 116). In some embodiments, the excitation voltage is about 2 to about 8 times the predetermined voltage, such as about 2, about 3, about 4, about 5, about 6, about 7, or about 8 times.

In some embodiments, the current applied to the electrode (e.g., first electrode 116) is a DC current. In some embodiments, the current applied to an electrode (such as first electrode 116) ranges from about 0mA to about 600mA, such as from about 0mA to about 10mA, from about 10mA to about 50mA, from about 50mA to about 100mA, from about 100mA to about 200mA, from about 200mA to about 300mA, from about 300mA to about 400mA, from about 400mA to about 500mA, from about 500mA to about 600mA, or a combination thereof.

In some embodiments, the energy source 114 is configured to apply an excitation current to the first electrode 116. In some embodiments, the excitation current is about 2 to about 8 times the predetermined current, such as about 2 times, about 3 times, about 4 times, about 5 times, about 6 times, about 7 times, or about 8 times.

Those skilled in the art will recognize that the actuation voltage or actuation current need not be an integer multiple of the predetermined voltage or predetermined current. Any numerical value within this range may suffice for the purposes disclosed in this disclosure.

The polarity of the voltage or current may be switched manually or by software and/or hardware control to exchange the polarity of the first electrode 116 and the second electrode 118. In some embodiments, the polarity of the first electrode 116 and the second electrode 118 is periodically switched. For example, the polarity of the first electrode 116 and the second electrode 118 can be switched about every 10 minutes to about every 10 hours, such as about every 5 minutes to about every 10 minutes, about every 10 minutes to about every 30 minutes, about every 30 minutes to about every 1 hour, about every 1 hour to about every 2 hours, about every 2 hours to about every 3 hours, about every 3 hours to about every 4 hours, about every 4 hours to about every 5 hours, about every 5 hours to about every 6 hours, about every 6 hours to about every 7 hours, about every 7 hours to about every 8 hours, about every 8 hours to about every 9 hours, about every 9 hours to about every 10 hours, or a combination thereof.

In some embodiments, reaction medium 112 includes at least one buffer or buffer component to regulate or prevent a change in the pH of reaction medium 112. For example, the at least one buffer or buffer component may include one or more organic or inorganic buffers or buffer components selected from the group consisting of sodium hydroxide (NaOH), 4- (2-hydroxyethyl) -1-piperazineethanesulfonic acid (HEPES), 3- (N-morpholino) propanesulfonic acid (MOPS), citric acid, sodium citrate, tris (hydroxymethyl) aminomethane (Tris), phosphate Buffered Saline (PBS), boric acid, borax, and boric acid-borax buffers. Some other examples of buffers or buffer components that may be used in the reaction medium 112 may be found in PCT/US 2018/027081.

At least one buffer or buffer component in reaction medium 112 can have any suitable concentration. For example, the concentration of at least one buffer or buffer component in reaction medium 112 can range from about 0.01mol/L to about 0.5mol/L, from about 0.5mol/L to about 1.0mol/L, from about 1.0mol/L to about 1.5mol/L, from about 1.5mol/L to about 2.0mol/L, from about 2.0mol/L to about 2.5mol/L, from about 2.5mol/L to about 3.0mol/L, or combinations thereof.

The source of nitrite ions in reaction medium 112 may include one or more nitrites. The nitrite may be an organic nitrite or an inorganic nitrite. Examples of the organic nitrite include organic ammonium nitrite salts such as tetramethylammonium nitrite and tetraethylammonium nitrite. Examples of inorganic nitrites include metal nitrites such as nitrites of lithium, sodium, potassium, rubidium, calcium, magnesium, aluminum, and iron. Some other examples of nitrite ion sources can be found in PCT/US 2018/027081. The concentration of the one or more nitrites in reaction medium 112 can range from about 0.01mol/L to about 0.5mol/L, from about 0.5mol/L to about 1.0mol/L, from about 1.0mol/L to about 1.5mol/L, from about 1.5mol/L to about 2.0mol/L, from about 2.0mol/L to about 2.5mol/L, from about 2.5mol/L to about 3.0mol/L, from about 3.0mol/L to about 3.5mol/L, from about 3.5mol/L to about 4.0mol/L, from about 4.5mol/L to about 5.0mol/L, or a combination thereof.

When the catalyst is dissolved in reaction medium 112, the concentration of catalyst in reaction medium 112 can range from about 1mmol/L to about 5mmol/L, from about 1mmol/L to about 10mmol/L, from about 1mmol/L to about 15mmol/L, from about 5mmol/L to about 10mmol/L, from about 5mmol/L to about 15mmol/L, or from about 10mmol/L to about 15mmol/L.

Reaction medium 112 may include one or more other components. For example, reaction medium 112 may include one or more additives, such as ethylenediaminetetraacetic acid (EDTA), which may facilitate one or more electrochemical reactions for generating NO.

Embodiments of the NO generation apparatus 100 may include one or more features to improve the performance of the NO generation apparatus 100, such as increasing the reaction rate and/or faraday efficiency of the NO generation apparatus 100, increasing the concentration of NO in the product gas, or increasing the amount or concentration of NO generated using a given amount of the reaction medium 112. For example, the faradaic efficiency of the NO generating device 100 may be in the range of about 70% to about 80% or higher.

Temperature control of reaction medium

In some embodiments, reaction medium 112 is maintained at or near the reaction temperature or within a range of temperatures. The electrochemical reaction in the reaction chamber 102 may have the highest, desired, or optimized reaction rate and/or faradaic efficiency at or near the reaction temperature or within a temperature range. The reaction temperature or temperature range may be determined based on one or more conditions, such as the buffer and/or catalyst components and the concentration in reaction medium 112. In some embodiments, the reaction temperature or temperature range may range from about 5 ℃ to about 10 ℃, from about 10 ℃ to about 15 ℃, from about 15 ℃ to about 20 ℃, from about 20 ℃ to about 25 ℃, from about 25 ℃ to about 30 ℃, from about 20 ℃ to about 30 ℃, from about 30 ℃ to about 35 ℃, from about 35 ℃ to about 40 ℃, from about 40 ℃ to about 45 ℃, or combinations thereof.

In some embodiments, the NO generation apparatus 100 includes a temperature maintenance device 138 to control the temperature of the reaction medium 112. For example, as shown in fig. 1-2, the temperature maintenance device 138 can be disposed proximate the reaction chamber 102, such as below, beside, or around the reaction chamber 102. In some embodiments, temperature maintenance device 138 includes one or more temperature control devices, such as a temperature controlled water bath, a temperature controlled oil bath, an air agitation device (e.g., a fan), a heat radiator, a thermoelectric heating and/or cooling device (e.g., a p-n junction device).

In some embodiments, the NO generation apparatus 100 includes a temperature sensor 140 disposed in the reaction medium 112 and in communication with the temperature maintenance device 138. Temperature maintenance device 138 may monitor the temperature of reaction medium 112 based on a signal from temperature sensor 140. Temperature maintenance device 138 may heat or cool reaction medium 112 in response to the signal. In some embodiments, the voltage or current applied to an electrode (such as the first electrode 116) may be adjusted by the energy source 114 based on a signal from the temperature sensor 140. For example, a control loop of the energy source 114 may be in communication with the temperature sensor 140 and may adjust the magnitude and/or polarity of the voltage or current applied to the first electrode 116.

Transport of NO from a reaction medium

Some or all of the NO generated in reaction medium 112 may be carried from reaction medium 112. For example, NO generated in reaction medium 112 can be transported, such as by being swept, purged, and/or entrained from reaction medium 112 to gas zone 110 using carrier gas 122.

In some embodiments, as shown in FIG. 2, the carrier gas 122 is used to sweep a surface 128 of an electrode (such as the first electrode 116). Sweeping the surface of the electrode may increase the faradaic efficiency and/or reaction rate of the electrochemical reaction at and/or near the electrode surface and/or may increase the NO concentration of the product gas. For example, in some cases, one or more metal ions of the catalyst in reaction medium 112, such as M (monovalent) ions generated by electrochemical reaction 2, may precipitate into an insoluble form. For example, the metal ion of the catalyst may be Cu ²⁺ . In some cases, cu ²⁺ Can be precipitated from the following reaction:

Cu ²⁺ +2OH ^- →Cu(OH) ₂ ↓→CuO+H ₂ O

catalyst in reaction medium 112May reduce the concentration of catalyst in reaction medium 112 and may reduce the rate of the electrochemical reaction for the generation of NO. Precipitation of metal ions can result in insoluble forms of the metal ions, such as Cu (OH) ₂ To be deposited on the surface of the electrode. This may reduce the surface area for generating NO and may also reduce the lifetime of the electrode. Sweeping the surface of the electrode may increase the movement of species (such as metal ions) at and/or near the surface of the electrode. This may reduce or inhibit deposition of metal ions on the surface, and thus may increase the NO generation rate and/or NO concentration of the product gas.

The carrier gas 122 may be introduced into the reaction medium 112 by one or more flow control devices. For example, as shown in FIG. 2, the carrier gas source 200 can include a flow control device 204 that can measure and control the mass or volumetric flow of the carrier gas stream 122 introduced into the reaction medium 112. A valve 206 may be disposed downstream of the flow control device 204 to protect the flow control device 204. For example, valve 206 may be a one-way valve configured to prevent backflow of reaction medium 112 from inlet loop 120 to flow control device 204. An embodiment of supplying the carrier gas 122 from the carrier gas source 200 to the NO generation apparatus 100 will be further described below.

In some embodiments, the carrier gas 122 is introduced into the reaction medium 112 in the form of bubbles configured to propagate along a bubble path. The bubble path may extend along a surface of an electrode, such as surface 128 of first electrode 116, to sweep across the surface. As the carrier gas bubbles rise to the surface of reaction medium 112, the carrier gas bubbles may entrain, sweep, and/or purge NO generated near and/or at surface 128 of first electrode 116. The carrier gas bubbles can mix or disturb the reactive medium 112 near the surface 128 of the first electrode 116, and the carrier gas bubbles can increase the movement of species (such as metal ions) near the surface. The carrier gas bubbles can purge NO dissolved in the reaction medium 112 from the reaction medium 112 to the gas zone 110.

In some embodiments, the NO generation apparatus 100 includes one or more spargers to generate bubbles from the carrier gas 122. As used herein, a sparger can include a device or system configured to emit gas bubbles into a liquid. In some cases, the sprayer may be referred to as a bubbler. One or more spargers may be disposed at any suitable location in reaction medium 112 to emit bubbles of carrier gas 122 to transport (e.g., sweep, purge, and/or entrain) NO out of reaction medium 112. For example, one or more sprinklers can be disposed above or near the second side 106 of the reaction chamber 102.

In some embodiments, as shown in fig. 2, the NO generation apparatus 100 includes a first sprayer 134 disposed in the reaction medium 112 adjacent to the first electrode 116. In some embodiments, as shown in fig. 2, the NO generating apparatus 100 includes a second sprayer 134 disposed adjacent the second electrode 118. In some embodiments, the sparger 134 is configured to receive the carrier gas 122, and the sparger emits bubbles of the carrier gas to sweep across one or more surfaces 128 of the first electrode 116 or the second electrode 118. Fig. 3B is a perspective view of a sprinkler 134 according to some embodiments of the present disclosure. As shown in fig. 3B, the sprinkler 134 may have an elongated shape, such as an elongated cylindrical shape.

In some embodiments, as shown in fig. 3A, the sparger 134 can be disposed along the first or

second electrode

116, 118 such that gas bubbles emanating from the sparger 134 can rise and propagate along one or more surfaces 128 of the first or

second electrode

116, 118. For example, as shown in fig. 2 and 3A, the sparger 134 can be disposed between the bottom edge 132 of the first electrode 116 or the second electrode 118 and the second side 106 of the reaction chamber 102. Bubbles emitted from the sparger 134 can travel along a bubble path extending from the bottom edge 132 through the surface 128 to the top edge 130 of the first or

second electrode

116, 118. In some embodiments, the sprinklers 134 can extend along the length of the bottom edge 132 such that the gas bubbles can sweep across the entire surface 128 of the first electrode 116.

In some embodiments, the distance between the sprinkler 134 and the first or

second electrode

116, 118 may be selected to increase coverage and/or efficiency of the sweep of one or more surfaces of the electrode. The sprayer 134 may be disposed at a distance from the electrode, for example, less than about 1cm, less than about 5mm, less than about 2mm, less than about 1mm, or less than about 0.5mm.

The sparger 134 can have any suitable structure to receive the gas and emit bubbles of the gas. In some embodiments, the sparger 134 comprises a porous structure 141 that provides a plurality of pores for emitting gas bubbles. For example, as shown in fig. 3B, the sprinkler 134 can include an inner cavity 142 surrounded by a porous structure 141. Gas may flow through the lumen 142 and bubble through the pores in the porous structure 141. The lumen 142 may have a tubular shape extending from the first opening to the second opening. The internal cavity 142 may or may not extend along the centerline of the sprinkler 134. The lumen 142 may have a diameter selected based on one or more conditions, such as a flow rate of the received gas and a desired density and/or size of bubbles. For example, the lumen 142 may have a diameter ranging from about 1mm to about 9mm, such as from about 1mm to about 2mm, from about 2mm to about 3mm, from about 3mm to about 4mm, from about 4mm to about 5mm, from about 5mm to about 6mm, from about 6mm to about 7mm, from about 7mm to about 8mm, from about 8mm to about 9mm, or a combination thereof.

In some embodiments, as shown in fig. 2 and 3A, the outlet 144 of the inlet circuit 120 is fluidly connected to the sprinkler 134 (e.g., the internal cavity 142 of the sprinkler 134). Carrier gas 122 may flow from carrier gas source 200 through inlet circuit 120 to sparger 134 via outlet 144. In some embodiments, the sprinkler 134 is attached to the sprinkler seat 148. In some embodiments, the sprayer seat 148 is attached to the frame 126. The sprinkler seat 148 may allow the sprinkler 134 to be disposed in a desired position.

In some embodiments, the sprayer seat 148 may include one or more structures for directing the flow of air bubbles. For example, the sprinkler seat 148 may include a housing having one or more openings configured to direct gas bubbles emitted from the sprinkler 134 to one or more surfaces 128 of the electrode. For example, as shown in fig. 3A, the sprinkler seat 148 may include openings at a top portion and/or an upper portion of the sprinkler 134 such that gas bubbles may emanate from the upper portion of the sprinkler 134 and propagate along the surface 128 of the first electrode 116. The sprinkler seat 148 may include one or more blocking or sealing devices to prevent one or more portions of the sprinkler 134 from emitting gas or bubbles. For example, the sprinkler seat 148 may have a portion configured to prevent gas from flowing directly out of the interior chamber 142 without passing through the porous structure 141. For example, the sprayer seating 148 may have a portion that blocks or seals a first end of the interior chamber 142 opposite a second end connected to the outlet 144.

In some embodiments, sparger 134 comprises at least one porous material that provides porous structure 141. The density and/or size of the gas bubbles may depend on one or more conditions, such as gas pressure, flow rate of the gas, and density and/or size of the pores of the at least one porous material. Smaller orifices may allow the sparger 134 to generate smaller bubbles with a higher density for a given gas flow rate. The at least one porous material may comprise a metallic material, such as stainless steel. The at least one porous material may comprise a non-metallic material. The non-metallic material may be a polymeric material such as Polyethylene (PE), polycarbonate (PC), polyvinylidene fluoride (PVDF), ceramic, quartz or silicon carbide.

The size of the pores of the at least one porous material of the sparger 134 can be selected based on the desired density, size, and/or flow rate of the gas bubbles. For example, the pores may range in size from about 0.1 μm to about 0.5 μm, from about 0.1 μm to about 0.2 μm, from about 0.2 μm to about 0.5 μm, from about 0.5 μm to about 1 μm, from about 1.0 μm to about 10 μm, from about 10 μm to about 20 μm, from about 20 μm to about 50 μm, from about 50 μm to about 100 μm, from about 100 μm to about 150 μm, from about 150 μm to about 200 μm, from about 200 μm to about 300 μm, from about 300 μm to about 400 μm, from about 400 μm to about 500 μm, from about 500 μm to about 600 μm, from about 600 μm to about 700 μm, from about 700 μm to about 800 μm, from about 800 μm to about 900 μm, from about 900 μm to about 900 μm, from about 1mm, or combinations thereof.

The porous material of the sparger 134 can have a thickness through which the gas stream can pass to create gas bubbles. The thickness of the porous material may be measured from the inner surface to the outer surface of the porous material. Increasing the thickness of the porous material can increase gas flow resistance and reduce bubbling efficiency. Reducing the thickness of the porous material may reduce the density and/or velocity of the bubbles. The thickness of the porous material may be selected to obtain any suitable density and/or size of gas bubbles for sweeping the electrode surface. For example, the thickness of the porous material may range from about 0.5mm to about 1mm, from about 1mm to about 2mm, from about 2mm to about 3mm, from about 3mm to about 4mm, from about 4mm to about 5mm, from about 5mm to about 6mm, from about 6mm to about 7mm, from about 7mm to about 8mm, from about 8mm to about 9mm, from about 9mm to about 10mm, or combinations thereof.

Carrier gas generation

In some embodiments, the carrier gas 122 is generated or supplied by a carrier gas source 200. The carrier gas 122 may include any suitable gas, such as air, nitrogen, helium, argon, and oxygen. In some embodiments, the carrier gas 122 includes nitrogen. In some embodiments, the concentration of nitrogen in the carrier gas 122 is about 99.0% by volume or greater than 99.0% by volume. For example, the concentration of nitrogen in the carrier gas 122 may be about or greater than 99.10%, 99.20%, 99.30%, 99.40%, 99.50%, 99.60%, 99.70%, 99.80%, 99.90%, 99.95%, 99.98%, or 99.99% by volume. The carrier gas 122 may contain oxygen. For example, the concentration of oxygen in the carrier gas 122 may be less than approximately 1%, 0.5%, or 0.1%.

In some embodiments, as shown in FIG. 1, the carrier gas source 200 includes a nitrogen generating device 202 configured to generate the carrier gas 122 from compressed air. In some embodiments, compressed air is supplied to the carrier gas source 200 from an air compressor system or reservoir. In some embodiments, the compressed air is filtered prior to being supplied to the carrier gas source 200. For example, the carrier gas source 200 may include a filter device disposed upstream of and configured to be in fluid communication with the nitrogen generating device 202. The filtering device may comprise one or more filters, such as a dust filter and a moisture filter. In some embodiments, the carrier gas source 200 comprises a pressure sensor and a pressure controller, such as a pressure regulator or pressure control valve. The pressure controller may regulate the pressure and/or flow of compressed air into the nitrogen generating device 202 based on a response or signal from the pressure sensor.

The nitrogen generating apparatus 202 may include one or more suitable devices for generating nitrogen from compressed air. In some embodiments, nitrogen generation apparatus 202 includes at least one Carbon Molecular Sieve (CMS). The carbon molecular sieve may have a pore size distribution that allows separation of nitrogen from air. In some embodiments, the nitrogen generation apparatus 202 comprises at least one nitrogen separation membrane. Nitrogen separation membranes can separate nitrogen from air based on the permeation rate of nitrogen and oxygen through the membrane wall. The nitrogen separation membrane may have any suitable configuration. In some embodiments, the nitrogen separation membrane comprises at least one bundle of selectively permeable hollow fibers.

The nitrogen separation membrane may include one or more materials selected from the group consisting of poly (4-methyl-1-pentene), brominated polycarbonate, polypropylene, polyimide, and polydimethylsiloxane. In some embodiments, the nitrogen separation membrane has a plurality of pores having an average pore size ranging from about 0.005 μm to about 0.007 μm, from about 0.007 μm to about 0.01 μm, from about 0.01 μm to about 0.013 μm, from about 0.013 μm to about 0.015 μm, from about 0.015 μm to about 0.017 μm, from about 0.017 μm to about 0.019 μm, from about 0.019 μm to about 0.02 μm, or a combination thereof.

As described herein, the description of the nitrogen generation apparatus 202 is generally applicable to apparatuses that generate other carrier gases (such as helium, argon, and oxygen) and will be apparent to the skilled artisan.

In some embodiments, the nitrogen generating apparatus 202 is disposed upstream of and in fluid communication with the inlet loop 120. In some embodiments, as shown in fig. 1, the carrier gas source 200 further comprises a flow control device 204 disposed downstream of the nitrogen generating device 202 and upstream of the inlet loop 120. The flow control device 204 may be configured to control the flow of the carrier gas 122 into the NO generating apparatus 100. Increasing the flow of the carrier gas 122 may increase the rate of NO generation and/or the concentration of NO in the product gas. For example, increasing the flow rate of the carrier gas 122 may increase the sweep of the surface of the first electrode 116 and may increase the rate at which generated NO is transported from the reaction medium 112. In some embodiments, the flow rate of the product gas of the NO generating apparatus 100 output from the outlet loop 124 is proportional to the flow rate of the carrier gas 122.

Recirculation of product gas relative to reaction chamber

In some embodiments, as shown in fig. 2, the NO generation apparatus 100 includes a gas circulation loop 300. In some embodiments, the gas circulation loop 300 includes a circulation inlet 302 and a circulation outlet 304. In some embodiments, the circulation inlet 302 is in fluid communication with the gas region 110 of the reaction chamber 102. For example, circulation inlet 302 may include an opening disposed inside or on a wall of gas zone 110. In some embodiments, the recirculation outlet 304 is in fluid communication with the liquid region 108 of the reaction chamber 102. For example, the recycle outlet 304 may be in fluid communication with the inlet loop 120. For example, the recirculation outlet 304 may include an opening disposed inside or on a wall of the liquid region 108.

In some embodiments, the product gas in the gas zone 110 is recirculated from the recycle inlet 302 to the recycle outlet 304 relative to the reaction chamber 102. For example, recycled product gas 303 may flow from recycle inlet 302 to recycle outlet 304. In some embodiments, the gas circulation loop 300 includes a gas pump 306 configured to generate the recycled product gas stream 303. A gas pump 306 may be provided downstream of the recycle inlet 302 and upstream of the recycle outlet 304.

In some embodiments, as shown in fig. 2, the gas circulation loop 300 is in fluid communication with the outlet loop 124 of the NO generating device 100. For example, the recycle inlet 302 of the gas recycle loop 300 may be in fluid communication with the outlet loop 124. The gas circulation loop 300 and the outlet loop 124 may have a common inlet, such as a circulation inlet 302. The gas circulation loop 300 and the outlet loop 124 may have a common fluid path. In some embodiments, the gas circulation loop 300 includes a first filter device 508 disposed downstream of the circulation inlet 302. The common fluid path may extend from the common inlet to the first filter device 508.

In some embodiments, the first filter device 508 is disposed upstream of the gas pump 306. The filtering device 508 may reduce or remove liquid and/or solid matter from the recycled product gas 303. In some embodiments, the gas circulation loop 300 includes a second filtering device 307. The second filtering means 307 may comprise a capsule filter or a membrane filter. The second filtering device 307 may remove one or more impurities (such as liquid and solid matter) in the recycled product gas 303, thereby protecting the gas pump 306.

The recycled product gas 303 may be introduced to the surface of the electrode to sweep across the surface of the electrode. In some embodiments, the recirculation outlet 304 is in fluid communication with the sprayer 134. For example, the recirculation outlet 304 can be fluidly connected to the interior chamber 142 of the sprinkler 134. A gas pump 306 can be disposed downstream of the recycle inlet 302 and upstream of the sparger 134, and the recycled product gas 303 can flow from the recycle inlet 302 to the inner cavity 142 of the sparger 134.

In some embodiments, as shown in FIG. 2, recycled product gas 303 is combined with carrier gas 122 into gas stream 146. For example, the gas circulation loop 300 may include a three-way connector 308. A three-way connector 308 can be fluidly connected to the recycle outlet 304 and configured to receive the recycled product gas 303. The three-way connector 308 can be fluidly connected with the carrier gas source 200 and/or the inlet circuit 120 and configured to receive the carrier gas 122. Three-way connector 308 can combine the received recycled product gas 303 and carrier gas 122 into gas stream 146. The three-way connector 308 may comprise any suitable structure, such as a three-way fitting or a three-way valve. A gas stream 146 may be supplied to the sparger 134 to generate bubbles for sweeping over the surface of the electrode.

In some embodiments, the gas circulation loop 300 may include a valve 206. Valve 206 may be disposed upstream of recycle outlet 304. The valve 206 may be disposed downstream of the gas pump 306 and may be disposed downstream of the three-way connector 308. The valve 206 may prevent backflow of the gas stream 146 and/or backflow of the reaction medium 112 from the reaction chamber 102 to the gas pump 306. The gas stream 146 may flow through the valve 206 to the recycle outlet 304 and the outlet 144 and be supplied to the one or more spargers 134. One or more spargers 134 may also emit gas bubbles from gas flow 146 to transport (e.g., sweep, purge, and/or entrain) NO generated in reaction medium 112 to gas region 110. For example, in some embodiments, the sparger 134 emits bubbles from the gas stream 146 to sweep the surface of an electrode (such as the first electrode 116).

The product gas in gas zone 110 may include carrier gas 122 and generated NO. In some embodiments, recirculating the product gas in the gas zone 110 allows the carrier gas 122 in the product gas to be recirculated to the surface of the electrode. Recycling the carrier gas may reduce the amount of carrier gas needed to support NO generation, e.g., for sweeping across the first electrode 116 and/or transporting the generated NO. Recirculating the product gas may allow NO to accumulate in the product gas in the gas section 110 of the reaction chamber 102, allowing for a higher concentration of NO in the product gas in the gas section 110. This may allow for a higher and/or more stable concentration of NO in the product gas being transported from the gas zone 110 of the NO generating apparatus 100.

Fig. 4A is a graphical representation of the concentration of NO in the product gas versus the current applied to the first electrode 116, according to some embodiments of the present disclosure. In this example, the NO generation apparatus 100 may include a reaction chamber 102 having a gas region and a liquid region, a reaction medium 112 contained in the liquid region, first and

second electrodes

116, 118 disposed in the reaction medium 112, a sparger 134 for sweeping a surface of the first electrode 116, a gas circulation loop 300 for recirculating a product gas, and a gas circulation loop for circulating the product gas Swept across the sprinklers 134 of the first electrode 116. The electrodes may each be made of stainless steel and may each comprise a plate having a surface area of about 5cm by about 6 cm. Reaction medium 112 may include about 1.0mol/L NaNO ₂ About 7mmol/L of CuSO ₄ Approximately 7mmol/L Me ₃ TACN and HEPES buffer solution of about 0.5 mol/L. The HEPES buffer can be titrated using a suitable alkaline solution, such as NaOH solution, such that the reaction medium 112 can have a pH of about 6 to about 8, such as a pH of about 7.2. The sparger 134 may be cylindrical with a length of about 7cm, an inner diameter of about 5mm, and an outer diameter of about 10mm, and has an average pore size of about 20 μm. A carrier gas 122 containing N2 at a concentration of about 99.7% by volume may be introduced to sparger 134 at a flow rate of about 300 mL/min. The gas circulation loop 300 may recirculate the product gas at a flow rate of about 3L/min. As shown in fig. 4A, the concentration of NO in the product gas can be increased by increasing the current applied to the first electrode 116 from about 0mA to about 300 mA. In this example, fitting the data to a linear regression model indicates that the concentration of NO in the product gas can increase by approximately 36.1ppm for every 1mA of applied current, and that the NO generation device 100 can have a faraday efficiency of 70.7%. Reducing the sweep of the first electrode 116 may reduce the increase in NO concentration per unit of applied current and may reduce faraday efficiency.

Fig. 4B is a graphical representation of the concentration of NO in the product gas generated by the NO generation apparatus 100 as a function of time, according to some embodiments of the present disclosure. In this example, the NO generating device 100 may have the same reaction conditions as described in the example above with reference to fig. 4A, except that after the initial application of about 300mA of current over a ramp period of about 2 minutes, a 100mA of current may be applied to the first electrode 116 for about 60 hours. After the ramp period, the concentration of NO in the product gas of the NO generation plant 100 increases to about 3600ppm and is maintained at a steady state concentration of 3600ppm or about 3600ppm for about 60 hours. Generating such amounts of NO typically requires about 4 to 5 gas tanks to store about 8L of compressed NO having a NO concentration of about 800ppm at a pressure of about 13.8 MPa. The use of the sparger 134 to sweep the surface of the first electrode 116 and to recirculate the product gas through the gas circulation loop 300 allows the generation of NO at a steady concentration over a longer period of time. The amount of NO that can be generated by the NO generation apparatus 100, such as a product gas having a NO concentration of about 3600ppm in about 60 hours.

Separation of NO from reaction medium

The reaction medium 112 of the NO generating device 100 may be reused to generate NO before it is disposed of, replaced or replenished. For example, the reaction medium 112 of the NO generation apparatus 100 may be used to generate NO over multiple operating cycles in one stage or in multiple stages. Some of the NO generated may dissolve in reaction medium 112 after an operating cycle or phase. NO dissolved in the reaction medium 112 can reduce the concentration and/or amount of NO that can be generated by repeated use of the reaction medium 112 and can increase the latency between stages or operating cycles.

For example, NO dissolved in reaction medium 112 can interact with a metal-ligand complex catalyst, such as Cu (II) -1,4, 7-trimethyl-1, 4, 7-triazacyclononane (Cu (Me) ₃ TACN)). For example, during the waiting time between the two stages, NO dissolved in the reaction medium 112 may bind to Cu (Me) ₃ TACN) on the central copper ion. This may reduce the concentration of the metal-ligand complex in reaction medium 112 for catalyzing the electrochemical reaction for generating NO in the next stage, and may reduce the reaction rate and/or the concentration of NO in the product gas for the next stage. In some cases, the concentration of NO in the product gas of one stage may be lower than the concentration of NO in the product gas of the previous stage, such as about 10% to about 30% lower.

In some embodiments, one or more spargers 134 disposed in the reaction medium 112 can generate gas bubbles to sweep dissolved NO from the reaction medium 112 to the gas region 110 to reduce dissolved NO in the reaction medium 112. In some embodiments, sweeping the surface of the electrode may reduce NO dissolved in the reaction medium 112. For example, the sparger 134 can generate gas bubbles to propagate along and sweep across the surface 128 of the first electrode 116. The gas bubbles may entrain and/or sweep NO generated at and/or near the surface of the first electrode 116 out of the reaction medium 112, which may reduce or prevent the generated NO from dissolving in the reaction medium 112.

In some embodiments, as shown in fig. 1 and 2, the NO generation apparatus 100 includes a liquid-gas separation loop 400 to reduce or remove dissolved NO in the reaction medium 112. The liquid-gas separation loop 400 is configured to circulate a fluid stream (such as a liquid stream or a gas stream) relative to the reaction chamber 102. The liquid-gas separation loop 400 can be used before, during, and/or after reusing the reaction medium 112 to generate NO.

In some embodiments, as shown in fig. 2, the liquid-gas separation loop 400 includes a first port 402 and a second port 410. In some embodiments, first port 402 is in fluid communication with liquid region 108. The first port 402 may comprise an opening in the liquid region 108 of the reaction chamber 102 (e.g., below the level of the reaction medium 112). In some embodiments, second port 410 is in fluid communication with gas region 110. The second port 410 may have an opening in the gas region 110 of the reaction chamber 102 (e.g., above the level of the reaction medium 112). In some embodiments, liquid-gas separation circuit 400 is configured to circulate a flow of reaction medium 112 from first port 402 to second port 410 relative to reaction chamber 102. In some embodiments, the liquid-gas separation loop 400 is configured to circulate the product gas stream from the second port 410 to the first port 402 relative to the reaction chamber 102.

In some embodiments, liquid-gas separation loop 400 includes a pump 406. In some embodiments, the pump 406 is a dual liquid-gas pump. In some embodiments, the pump 406 is a reversible pump. The pump 406 may generate a fluid flow from the first port 402 to the second port 410 or from the second port 410 to the first port 402. In some embodiments, the fluid stream is a liquid stream. For example, the pump 406 may generate the flow 112 of the reactive medium from the first port 402 to the second port 410. In some embodiments, the fluid flow is a gas flow. For example, the pump 406 may generate a flow of product gas from the second port 410 to the first port 402.

The pump 406 may generate a fluid flow at any suitable flow rate. For example, the pump 406 may generate a fluid stream (e.g., a reactive media stream) at a flow rate ranging from about 0.25L/min to about 10L/min, such as from about 0.5L/min to about 1.0L/min, from about 1.0L/min to about 1.5L/min, from about 1.5L/min to about 2.0L/min, from about 2.0L/min to about 2.5L/min, from about 2.5L/min to about 3.0L/min, from about 3.0L/min to about 3.5L/min, from about 3.5L/min to about 4.0L/min, from about 4.0L/min to about 4.5L/min, from about 4.5L/min to about 5.0L/min, from about 5.0L/min to about 5.5L/min, from about 5.5L/min to about 6.0L/min, from about 6.0L/min to about 6.5L/min, from about 6.5L/min to about 7.5L/min, from about 5L/min to about 6.0L/min, from about 9.0L/min to about 8.5L/min, from about 9.5L/min to about 8.5L/min, from about 5L/min, or combinations thereof.

In some embodiments, as shown in fig. 1 and 2, the liquid-gas separation loop 400 includes a liquid-gas separation device 408. In some embodiments, a liquid-gas separation device 408 is disposed between the first port 402 and the second port 410. The liquid-gas separation device 408 may be disposed downstream or upstream of the pump 406. In some embodiments, the liquid-gas separation device 408 includes at least one first chamber 414 and at least one second chamber 416. The first chamber 414 and/or the second chamber 416 may have any suitable shape and size. For example, the first chamber 414 and/or the second chamber 416 may have a tubular structure. The first chamber 414 may be received in the second chamber 416, or vice versa. In some embodiments, the liquid-gas separation device 408 includes a housing or enclosure configured to enclose a first chamber 414 and a second chamber 416.

In some embodiments, the first chamber 414 and the second chamber 416 are separated by a separation membrane. The separation membrane may comprise a NO permeable material. For example, the separation membrane may include a material such as Polydimethylsiloxane (PDMS), silicone, or polypropylene. NO may diffuse from the liquid in the first chamber 414 through the separation membrane into the gas in the second chamber 416. The separation membrane may have any suitable configuration. For example, a plurality of hollow fibers having walls formed from a separation membrane.

The separation membrane may be selected to have any suitable area that allows for the reduction or removal of dissolved NO in the reaction medium 112 for a certain period and/or a certain amount of cycles. In some embodiments, the separation membrane of liquid-gas separation device 408 has a surface area ranging from about 500cm ² To about 50000cm ² E.g. from about 500cm ² To about 1000cm ² From about 1000cm ² To about 5000cm ² From about 5000cm ² To about 10000cm ² From about 10000cm ² To about 15000cm ² From about 15000cm ² To about 20000cm ² From about 20000cm ² To about 25000cm ² From about 25000cm ² To about 30000cm ² From about 30000cm ² To about 35000cm ² From about 35000cm ² To about 40000cm ² From about 40000cm ² To about 45000cm ² From about 45000cm ² To about 50000cm ² Or a combination thereof.

In some embodiments, the first chamber 414 includes an inlet 418 and an outlet 420. The pump 406 may drive the reaction medium 112 from the inlet 418 through the first chamber 414 to the outlet 420. As the reaction medium 112 flows through the first chamber 414, NO dissolved in the reaction medium 112 may diffuse through the separation membrane into the second chamber 416. In some embodiments, the second chamber 416 includes an inlet 422 and an outlet 426. The sweep gas may flow from the inlet 422 through the second chamber 416 to the outlet 426. The sweep gas may carry the NO diffused into the second chamber 416 out of the outlet 426 as a mixed gas. The mixed gas may be delivered to exhaust treatment device 700, as described further below.

The sweep gas may include any suitable gas, such as air, oxygen, and nitrogen, or a combination thereof. The sweep gas may be supplied to the inlet 422 from a gas source, such as the carrier gas source 200. In some embodiments, the carrier gas 122 is used as a sweep gas. For example, the fluid controller 424 may be used to control the flow of the carrier gas 122 from the carrier gas source 200 to the inlet 422. The fluid controller 424 may include a pressure controller, such as a pressure control valve or a pressure regulated controller.

In some embodiments, as shown in fig. 2, the NO generation apparatus 100 includes a filtering device 412. In some embodiments, the filtration device 412 is disposed upstream of the liquid-gas separation device 408. The filtering device 412 may include one or more filters configured to filter one or more impurities (such as solid matter) from the reaction media 112. The filter device 412 may protect the separation membranes of the liquid-gas separation device 112 from impurities in the reaction medium 112 as the reaction medium 112 flows through the liquid-gas separation device 408.

In some embodiments, the liquid-gas separation circuit 400 has an operating mode and a cleaning mode. In an operating mode, the liquid-gas separation loop 400 may reduce or remove dissolved NO in the reaction medium 112 by circulating the reaction medium 112 from the first port 402 through the liquid-gas separation device 408 to the second port 410. In the cleaning mode, gas in the gas zone 110 of the reaction chamber 102 may be circulated from the second port 410 to the first port 402 through the liquid-gas separation device 408. Circulating gas through the liquid-gas separation device 408 may transport the residual reaction medium 112 in the liquid-gas separation device 408 back to the reaction chamber 102 after the operational mode. For example, pump 406 can generate a fluid flow (e.g., a gas flow in gas region 110) at a flow rate ranging from about 0.25L/min to about 5L/min, such as from about 0.25L/min to about 0.5L/min, from about 0.5L/min to about 1.0L/min, from about 1.0L/min to about 1.5L/min, from about 1.5L/min to about 2.0L/min, from about 2.0L/min to about 2.5L/min, from about 2.5L/min to about 3.0L/min, from about 3.0L/min to about 3.5L/min, from about 3.5L/min to about 4.0L/min, from about 4.0L/min to about 4.5L/min, from about 4.5L/min to about 5.0L/min, or a combination thereof. The cleaning mode may reduce the loss of the reactive media 112 and may extend the life of the reactive media 112 and/or the NO generating device 100. The cleaning mode may dry the separation membrane and prepare it for the next operation mode.

In some embodiments, as shown in fig. 2, the liquid-gas separation circuit 400 includes a switching valve 404 for switching the liquid-gas separation circuit 400 between the operating mode and the cleaning mode. In some embodiments, switching valve 404 includes one or more valves configured to control a direction of fluid flow of liquid-gas separation loop 400. For example, switching valve 404 may include a set of normally closed valves, and may change the direction of fluid flow in liquid-gas separation loop 400 by opening different subsets of valves. In this case, the pump 406 may not necessarily be a reversible pump to operate in the working mode and the cleaning mode.

For example, as shown in FIG. 2, the switching valve 404 may include a set of four valves 404a-404d. In some cases, the valve 404a is disposed between the first port 402 and the pump 406; the valve 404b is disposed between the first port 402 and the fluid outlet 420 of the first chamber 414; valve 404c is disposed between second port 410 and pump 406; and valve 404d is disposed between the second port 410 and the fluid outlet 420 of the first chamber 414. For example, in the operating mode,

valves

404a and 404d are open, while

valves

404b and 404c are closed. The reaction medium 112 may flow from the first port 402 to the second port 410 through the valve 404a, the pump 406, the fluid inlet 418 and the fluid outlet 420 of the liquid-gas separation device 408, and the valve 404d. For example, in the cleaning mode,

valves

404a and 404d are closed, while

valves

404b and 404c are open. Gas in the gas region 110 of the reaction chamber 102 can flow from the second port 410 through the valve 404c, the pump 406, the fluid inlet 418 and the fluid outlet 420 of the liquid-gas separation device 408, and the valve 404b to the first port 402.

In some embodiments, liquid-gas separation circuit 400 includes a solenoid valve (not shown). The solenoid valve may be disposed upstream of the liquid-gas separation device 408. The solenoid valve may prevent reactive media 112 from entering liquid-gas separation device 408 due to pressure that may build up in reactive media 112 during the electrochemical generation of NO.

Fig. 4C is a graphical representation of the concentration of NO in the product gas generated by the NO generation apparatus 100 during multiple stages, according to some embodiments of the present disclosure. In this example, the NO generating device 100 may have the same reaction conditions as described in the example above with reference to fig. 4A, except that after an initial application of about 150mA of current over a ramp period of about 2 minutes in multiple stages, a current of 50mA may be applied to the first electrode 116. The NO generation apparatus 100 may also include a liquid-gas separation loop 400. After terminating the current applied to first electrode 116 in each stage, liquid-gas separation loop 400 may be operated in an operating mode and circulate reaction medium 112 through liquid-gas separation device 408 at a rate of approximately 0.5L/min for approximately 10 minutes to reduce or remove dissolved NO in a given reaction medium 112. The liquid-gas separation loop 400 may then be operated in a cleaning mode and circulate gas in the gas zone 110 through the liquid-gas separation device 408 at a flow rate of about 1L/min for about 0.5 minutes. As shown in FIG. 4C, the NO generation apparatus 100 using the reaction medium 112 can generate a product gas having an NO concentration of about 2000ppm in five consecutive stages.

Some examples of NO systems are provided below. In some examples, the NO system 10 may include a NO generation apparatus 100 and a carrier gas source 200. The NO generation apparatus 100 may include a reaction chamber 102 having a gas region and a liquid region, a reaction medium 112 contained in the liquid region, a cathode and an anode disposed in the reaction medium 112, two spargers 134, a gas circulation loop 300, and a liquid-gas separation loop 400. The sprinklers 134 may be disposed adjacent to the two electrodes, respectively, and configured to emit bubbles to propagate over the surfaces of the electrodes. The carrier gas source 200 may generate the carrier gas 122 from compressed air. The carrier gas source 200 may include a moisture filter and a dust filter to reduce or remove moisture and solid matter from the compressed air. The carrier gas source 200 may further comprise a nitrogen generation device 202 having a nitrogen separation membrane to separate N2 from compressed air. The cathode and anode may be electrically connected to a power source. The power supply may apply a current or voltage to the cathode, and NO may be generated at or near the surface of the cathode and swept or entrained to the gas region by the carrier gas 122 to generate the product gas. The gas circulation loop 300 can recirculate product gas from the gas zone to the sparger. The recycle gas may be combined with the carrier gas 122 to be introduced into the sparger. Liquid-gas separation loop 400 may include a liquid-gas separation device 408 to separate NO dissolved in the reaction medium after terminating the application of voltage or current to the cathode when current or voltage is applied to the cathode. Liquid-gas separation device 408 may include a separation membrane having a surface area. The liquid-gas separation circuit 400 can be operated in the working mode for a first period and can be operated in the cleaning mode for a second period after the first period.

For example, the cathode and anode may be made of platinum. The reaction medium may include about 0.01mol/L HEPES buffer, about 0.01mol/L sodium nitrite, and about 1mmol/L copper-tris (2-pyridylmethyl) amine (CuTPMA). The HEPES buffer can be titrated with a suitable alkaline solution, such as NaOH solution, so that the reaction medium can have a pH of about 6 to about 8, such as a pH of about 7.2. An excitation current of about 20mA may be applied to the cathode for about 0.5 minutes before applying a current of about 10mA to the cathode. The nitrogen separation membrane of the nitrogen generating apparatus 202 may be made of poly (4-methyl-1-pentene) and may have an average pore diameter of about 0.01 μm. The nitrogen generating apparatus 202 may generate the carrier gas 122 from compressed air having a concentration of about 99.0% N2 by volume. The carrier gas 122 may be introduced to the sparger 134 at a flow rate of about 50 mL/min. The gas circulation loop 300 may recirculate the product gas at a flow rate of about 0.5L/min. After a ramp period of about 10 minutes of applying current to the cathode, the NO generation device 100 may output a product gas having an NO concentration of about 200 ppm. After terminating the application of current to the cathode, liquid-gas separation loop 400 may be operated in the operating mode for about 10 minutes and thereafter may be operated in the cleaning mode for about 1 minute. The separation membrane of the liquid-gas separation device 408 may have a large size About 25000cm ² Surface area of (a).

As another example, the cathode and anode may be made of gold. The reaction medium may include about 1mol/L MOPS buffer, about 1mol/L sodium nitrite, and about 3mmol/L Fe-1,4, 7-triazacyclononane. The MOPS buffer can be titrated with a suitable alkaline solution (such as NaOH solution) such that the reaction medium can have a pH of about 6 to about 8, such as a pH of about 7.2. An activation voltage of about 4.2V may be applied to the cathode for about 1 minute before a voltage of about 1.4V is applied to the cathode. The nitrogen separation membrane of the nitrogen generating apparatus 202 may be made of brominated polycarbonate and may have an average pore diameter of about 0.02 μm. The nitrogen generating apparatus 202 may generate the carrier gas 122 from compressed air having a concentration of about 99.6% N2 by volume. The carrier gas 122 may be introduced to the sparger 134 at a flow rate of about 100 mL/min. The gas circulation loop 300 may recirculate the product gas at a flow rate of about 1L/min. After a ramp period of about 9 minutes of applying voltage to the cathode, the NO generation apparatus 100 may output a product gas having an NO concentration of about 1200 ppm. After terminating the application of voltage to the cathode, the liquid-gas separation loop 400 may be operated in the operating mode for about 5 minutes and thereafter may be operated in the cleaning mode for about 0.5 minutes. The separation membrane of the liquid-gas separation device 408 may have about 1000cm ² Surface area of (a).

As another example, the cathode and anode may be made of carbon. The reaction medium may include about 1.5mol/L Tris buffer, about 2mol/L potassium nitrite, and about 4mmol/L Ti (Me) ₃ TACN). The Tris buffer may be titrated with a suitable alkaline solution, such as a NaOH solution, so that the reaction medium may have a pH of about 6 to about 8, such as a pH of about 7.2. An excitation current of about 500mA may be applied to the cathode for about 1.5 minutes before applying a current of about 100mA to the cathode. The nitrogen separation membrane of the nitrogen generating apparatus 202 may be made of polypropylene and may have an average pore diameter of about 0.012 μm. The nitrogen generation device 202 may generate the carrier gas 122 from compressed air having a concentration of about 99.7% N2 by volume. The carrier gas 122 may be supplied at a rate of about 200mL/minIs introduced to the sprayer 134. The gas circulation loop 300 may recirculate the product gas at a flow rate of about 1.5L/min. After a ramp period of about 6 minutes of applying current to the cathode, the NO generation apparatus 100 may output a product gas having an NO concentration of about 3000 ppm. After terminating the application of current to the cathode, liquid-gas separation loop 400 may be operated in the operating mode for about 12 minutes and thereafter may be operated in the cleaning mode for about 0.9 minutes. The separation membrane of the liquid-gas separation device 408 may have about 1000cm ² To about 50000cm ² E.g. about 50000cm ² 。

As another example, the cathode and anode may be formed of SiO coated with glassy carbon ₂ And (4) preparing. The reaction medium may include about 2mol/L MOPS buffer, about 3mol/L sodium nitrite, and about 5mmol/L chromium-tris (2-pyridylmethyl) amine (CrTPMA). The MOPS buffer can be titrated with a suitable alkaline solution (such as NaOH solution) such that the reaction medium can have a pH of about 6 to about 8, such as a pH of about 7.2. An activation voltage of about 12V may be applied to the cathode for about 2 minutes before a voltage of about 2V is applied to the cathode. The nitrogen separation membrane of the nitrogen generating apparatus 202 may be made of polyimide and may have an average pore diameter of about 0.005 μm. The nitrogen generating apparatus 202 may generate the carrier gas 122 from compressed air having a concentration of about 99.99% N2 by volume. The carrier gas 122 may be introduced to the sparger 134 at a flow rate of about 300 mL/min. The gas recycle loop 300 may recirculate the product gas at a flow rate of about 2L/min. After a ramp period of about 5 minutes of applying a voltage to the cathode, the NO generating device 100 may output a product gas with an NO concentration of about 4200 ppm. After terminating the application of voltage to the cathode, the liquid-gas separation loop 400 may be operated in the operating mode for about 5 minutes and thereafter may be operated in the cleaning mode for about 1.5 minutes. The separation membrane of the liquid-gas separation device 408 may have about 1000cm ² To about 5000cm ² E.g. about 37500cm ² 。

As another example, the cathode and anode may be made of conductive glass coated with stainless steel. The reaction medium may comprise about 2.5mol/L phosphate buffer, about 4mol/L sodium nitrite, and about 6mmol/L manganese-tris (2-pyridylmethyl) amine (MnTPMA). The phosphate buffer may be titrated with a suitable alkaline solution, such as a NaOH solution, so that the reaction medium may have a pH of about 6 to about 8, such as a pH of about 7.2. An excitation current of about 1.4A may be applied to the cathode for about 2.5 minutes before a current of about 200mA is applied to the cathode. The nitrogen separation membrane of the nitrogen generating apparatus 202 may be made of Polydimethylsiloxane (PDMS) and may have an average pore size of about 0.008 μm. The nitrogen generating apparatus 202 may generate the carrier gas 122 from compressed air having a concentration of about 99.8% N2 by volume. The carrier gas 122 may be introduced to the sparger 134 at a flow rate of about 400 mL/min. The gas recycle loop 300 may recirculate the product gas at a flow rate of about 2.5L/min. After a ramp period of about 4.6 minutes of applying current to the cathode, the NO generation device 100 may output a product gas having an NO concentration of about 6300 ppm. After terminating the application of current to the cathode, the liquid-gas separation loop 400 may be operated in the operating mode for about 20 minutes and thereafter may be operated in the cleaning mode for about 2 minutes. The separation membrane of the liquid-gas separation device 408 may have about 1000cm ² To about 5000cm ² E.g. about 12500cm ² 。

As another example, the cathode and anode may be made of stainless steel coated with an iridium-ruthenium alloy. The reaction medium may include about 3mol/L boric acid-borax buffer, about 5mol/L potassium nitrite, and about 7mmol/L cobalt- (bis (2-aminoethylendin-propylpyridine) propionic acid the boric acid-borax buffer may be titrated with a suitable alkaline solution, such as NaOH solution, such that the reaction medium may have a pH of about 6 to about 8, such as about 7.2, the cathode may be applied with an excitation voltage of about 24V for about 3 minutes prior to applying a voltage of about 3V to the cathode, the nitrogen separation membrane of nitrogen generation device 202 may be made of brominated polycarbonate and may have an average pore size of about 0.015 μm, nitrogen generation device 202 may generate a carrier gas 122 containing N2 at a concentration of about 99.9% by volume from compressed air, the carrier gas may be supplied at a flow rate of about 600mL/min122 to the sprayer 134. The gas circulation loop 300 may recirculate the product gas at a flow rate of about 3L/min. After a ramp period of about 5 minutes of applying voltage to the cathode, the NO generation device 100 can output a product gas with an NO concentration of about 10400 ppm. After terminating the application of current to the cathode, the liquid-gas separation loop 400 may be operated in the operating mode for about 18 minutes and thereafter may be operated in the cleaning mode for about 1.6 minutes. The separation membrane of the liquid-gas separation device 408 may have about 1000cm ² To about 5000cm ² E.g. about 5000cm ² 。

Product gas filtration

The system 10 may include one or more filtration systems or devices to reduce or remove one or more impurities in the product gas. In some embodiments, as shown in FIG. 1, the system 10 includes a filtration system 500 disposed downstream of the NO generation apparatus 100. For example, the filtration system 500 may be disposed downstream of and in fluid communication with the gas zone 110 and/or the outlet circuit 124 of the NO generation facility 100. The filtration system 500 may reduce or remove one or more impurities, such as moisture and/or solid matter, in the product gas from the NO generating device 100. As described herein, moisture may include any liquid, such as water vapor, water droplets, solvent vapor, and solvent droplets, in a gas phase or a liquid phase that may be present in the product gas.

The filtration system 500 may include one or more filtration devices or filters. In some embodiments, the filtration system 500 includes one or more solid matter filters 502. It is contemplated that the solid matter filter 502 may be configured to filter any type of solid matter by, for example, modifying or selecting a filter material and/or pore size. In one embodiment, the solids filter 502 may be a salt aerosol filter. In some embodiments, the solid matter filter 502 comprises a membrane filter. The membrane filter may comprise a polymeric material having a porous structure. For example, the polymeric material may include one or more materials selected from Polytetrafluoroethylene (PTEF), polyvinylidene fluoride, polyethersulfone, mixed cellulose esters, polyamides (nylon), nylon 6, and nylon 66. The average pore size of the porous structure may range from about 0.01 μm to about 2 μm, such as from about 0.1 μm to about 0.2 μm, from about 0.2 μm to about 0.4 μm, from about 0.4 μm to about 0.6 μm, from about 0.6 μm to about 0.8 μm, from about 0.8 μm to about 1.0 μm, from about 1.0 μm to about 1.2 μm, from about 1.2 μm to about 1.4 μm, from about 1.4 μm to about 1.6 μm, from about 1.6 μm to about 1.8 μm, from about 1.8 μm to about 2 μm, or combinations thereof.

In one example, the solid matter filter 502 can include a member filter made of PTEF having an average pore size of about 1.0 μm. In another example, the solid matter filter 502 may comprise a member filter made of polyvinylidene fluoride having an average pore size of about 0.1 μm. In another example, the solid matter filter 502 may comprise a member filter made of polyethersulfone having an average pore size of about 2.0 μm. In another example, the solid matter filter 502 may comprise a member filter made of nylon 6 having an average pore size of about 0.1 μm. In another example, the solid matter filter 502 may comprise a member filter made of nylon 66 having an average pore size of about 0.8 μm. In another example, the solid matter filter 502 may comprise a member filter made from mixed cellulose esters having an average pore size of about 1.6 μm.

In some embodiments, the filtration system 500 includes one or more moisture filters 504. The moisture filter 504 may reduce or remove liquid, such as water, in the gas phase and/or the liquid phase. In some embodiments, the moisture filter 504 comprises a membrane filter. In some embodiments, the membrane filter comprises a polymeric material. The polymeric material may have a porous structure. The polymeric material may absorb liquid vapor and/or liquid droplets. Additionally or alternatively, the polymeric material may be at least partially permeable to liquid vapour and/or liquid droplets. For example, the membrane filter may comprise a Nafion (TM) membrane.

In some embodiments, the filtration system 500 includes one or more additional filters 506. A filter 506 may be disposed downstream of the solid matter filter 502 and/or the moisture filter 504 to further remove or reduce impurities, such as moisture and/or solid matter, from the product gas. In some embodiments, filter 506 comprises a membrane filter. In some embodiments, the membrane filter comprises a polymeric material. In some embodiments, the membrane filter has a porous structure. For example, the polymeric material of the membrane filter may have a porous structure. The average pore size of the porous structure may range from about 0.01 μm to about 2 μm, such as from about 0.01 μm to about 0.1 μm, from about 0.1 μm to about 0.2 μm, from about 0.2 μm to about 0.3 μm, from about 0.3 μm to about 0.4 μm, from about 0.4 μm to about 0.5 μm, from about 0.5 μm to about 1.0 μm, from about 1.0 μm to about 2 μm, or combinations thereof. In some embodiments, the average pore size of the filter 506 is equal to or less than the average pore size of the solid matter filter 502.

As described herein, a membrane filter used in some embodiments of the present disclosure may include at least one membrane that may have any suitable configuration for filtering or separating gases, liquids, and/or solids. For example, the membranes of a membrane filter may be configured for dead-end filtration, wherein a fluid may pass through the membranes and components to be separated from the fluid may be blocked or captured by the membranes. Alternatively, the membranes of the membrane filter may be configured for cross-flow filtration, wherein the fluid may pass through the surface of the membrane at the feed side and the components to be separated from the fluid may remain at the feed side or permeate through the membrane to the permeate side. An example configuration of cross-flow filtration is one or more hollow fibers formed from a membrane.

For example, the product gas output from the gas section 110 of the NO generating device 100 may comprise a certain amount of liquid impurities and/or solid impurities, such as water and salt aerosols. Such amounts of impurities may damage and/or affect the life of downstream equipment, such as the pump 306 and one or more of the filters 502-506. In some embodiments, the system 500 includes a filtering device 508 disposed downstream of the NO generating apparatus 100. In some embodiments, a filtration device 508 is disposed upstream of the pump 306 to reduce or remove liquid impurities and/or solid impurities in the recycled product gas 303. For example, the product gas output from the gas section 110 of the NO generation apparatus 100 may include one or more impurities, such as water or droplets or vapors of the reaction medium 112. In some embodiments, the filtering device 508 is disposed upstream of the solid matter filter 502 and/or the moisture filter 504. The filtering device 508 may reduce or remove liquid and/or solid impurities from the product gas before the product gas flows through one or more of the filters 502-506.

Fig. 5A-5C illustrate a filtering device 508 according to some embodiments of the present disclosure. As shown in fig. 5A-5C, in some embodiments, the filter device 508 includes a housing 510, an inlet 518, and an outlet 520. In some embodiments, the filter device 508 includes at least one chamber disposed in a housing 510. The inlet 518 and/or the outlet 520 may be in fluid communication with at least one chamber in the housing 510. The housing 510 may have any suitable shape, such as a cylindrical shape. As shown in fig. 5C, an inlet 518 may be provided at a bottom portion of the housing 510 in fluid communication with the chamber. An outlet 520 may be provided at a top portion of the housing 510 in fluid communication with the chamber.

In some embodiments, as shown in fig. 5B, the filtration apparatus 508 includes one or more filtration chambers 512. The filter chamber 512 may have any suitable shape, such as a cylindrical shape. The filter chambers 512 may be arranged about a longitudinal axis of the housing 510 and may or may not be equally spaced. The filter apparatus 508 may include any suitable number of filter chambers 512, such as 2 to 5 filter chambers. For example, the three filter chambers 512 may be equally spaced about 120 degrees about the longitudinal axis of the housing 510.

Each filter chamber 512 may have an inlet 522 and an outlet 524. The inlet and outlet of the one or more filter chambers 512 may define a flow path. One or more of the filter chambers 512 (such as a first filter chamber 512) may have an inlet 522 in fluid communication with the inlet 518 of the housing 510. One or more of the filter chambers 512 (such as the last filter chamber 512) may have an outlet 524 in fluid communication with the outlet 520 of the housing 510. In some embodiments, filter chamber 512 comprises a filter material 516 configured to reduce or remove one or more impurities in a fluid flowing therethrough. The filter material 516 may fill at least a portion of the filter chamber 512, such as a middle portion of the filter chamber 512. The filter material 516 may include any suitable material, such as silicone, sponge, cotton, polypropylene (e.g., PP cotton filter), foam, and foamed resin.

In some embodiments, the filter device 508 includes a feed chamber 526. The feed chamber 526 may be in fluid communication with the inlet 518 for receiving a fluid to be filtered, such as a gas stream. The feed chamber 526 may be in fluid communication with one or more filter chambers 512. For example, the feeding chamber 526 may have an outlet in fluid communication with the inlet 522 of the filter chamber 512. In some embodiments, the intake chamber 526 extends through a middle portion of the housing 510 such that a cavity is formed between the intake chamber 526 and an inner surface of the housing 510.

For example, as shown in fig. 5A-5C, the housing 510 may have a cylindrical shape. The feed chamber 526 may have a cylindrical shape extending along at least a portion of the longitudinal axis of the housing 510. The annular space formed between the feed chamber 526 and the housing 510 may form a cavity. In some embodiments, one or more chambers (such as filter chamber 512) are disposed in the cavity between the feed chamber 526 and the housing 510.

The filtering device 508 may be configured to allow at least some of the liquid impurities and/or solid impurities in the gas (such as the product gas output from the gas region 110) to be separated from the gas based on, for example, gravity settling or separation. In some embodiments, the inlet 522 of the filter chamber 512 is disposed vertically below the outlet 524 such that liquid and/or solid particles suspended in the gas flowing from the inlet 522 to the outlet 524 may settle out of the gas and may settle to the bottom of the filter chamber 512.

For example, the filter chamber 512 may have an elongated shape (such as a cylindrical shape) and may be disposed in an upright position along its longitudinal axis. In such a configuration, the inlet 522 may be disposed at a bottom or lower portion of the filter chamber 512, while the outlet 524 may be disposed at a top or upper portion of the filter chamber 512. The flow of gas may enter filter chamber 512 from inlet 522, move or rise through at least a portion of filter chamber 512, to outlet 524. As the gas stream moves or rises within the filter chamber 512, the gas stream may pass through the filter material 516, and liquid and/or solid impurities suspended in the gas stream may settle out and be separated from the gas stream.

In some embodiments, the filter apparatus 508 includes a buffer chamber 514 in fluid communication with the filter chamber 512. For example, the buffer chamber 514 may be fluidly connected with the filter chamber 512 via an opening or port at a bottom portion of the filter chamber 512. Gas to be filtered (e.g., a flow of gas) may flow from the buffer chamber 514 to the filter chamber 512 via an opening or port, rise in the filter chamber 512, and exit through an outlet 524. Liquid and/or solid matter settling out of the gas in the filter chamber 512 can settle to the bottom portion of the filter chamber 512. Settled liquids and/or solids may flow to the buffer chamber 514 and accumulate in the buffer chamber.

The accumulated liquid and/or solid matter in the buffer chamber 514 may be conveyed away from the filter device 508 by any suitable means, such as by gravity or by a pump. The liquid and/or solid matter carried out of the filter device 508 may be disposed of or reused. For example, the reaction medium 112 that settles out of the product gas from the NO generation apparatus 100 can be transported from the buffer chamber 514 back to the liquid region 108 of the reaction chamber 102 and reused.

In some embodiments, as shown in fig. 5C, the buffer chamber 514 is in fluid communication with the feed chamber 526. Fluid may flow from the feed chamber 526 to the buffer chamber 514 and from the buffer chamber 514 to the filter chamber 512. For example, a fluid to be filtered (such as a gas stream) may flow from the inlet 518 through the feed chamber 526, the buffer chamber 514, and the filter chamber 512 and to the outlet 520.

In some embodiments, as shown in fig. 5A-5C, the filtration apparatus 508 includes two or more fluidly connected filtration chambers 512 to allow more than one settling process to be performed. For example, the outlet 524 of the first filtering chamber 512 may be fluidly connected with the inlet 522 of the second filtering chamber 512. Gas may flow through two or more filter chambers 512 to allow liquid and/or solid contaminants to settle out of the gas stream as the gas stream rises from the inlet 522 to the outlet 524 of each filter chamber.

In some embodiments, as shown in fig. 5A and 5B, a buffer chamber 514 fluidly connects two filter chambers 512. The buffer chamber 514 may have an opening or conduit configured to connect with both filter chambers 512 such that fluid may flow from an inlet 522 to an outlet 524 in each of the two filter chambers 512. For example, as shown in fig. 5B, the outlet 524 of the first filter chamber 512 may be an inlet to the buffer chamber 514, and the inlet 522 of the second filter chamber 512 may be an outlet to the buffer chamber 514. Fluid may flow from the outlet 524 of the first filter chamber 512 to the buffer chamber 514 and from the buffer chamber 514 to the inlet 522 of the second filter chamber 512. In this case, as shown in fig. 5B, the outlet 524 of the first filtering chamber 512 may be disposed at a top portion of the buffer chamber 514, and the inlet 522 of the second filtering chamber 512 may be disposed at a bottom portion of the buffer chamber 514.

The filter device 508 may include one or more other components, such as components for covering or sealing one or more inlets, outlets, and/or chambers in the housing 510. In some embodiments, as shown in fig. 5A, the filter apparatus 508 includes a seal configured to cover a top side of the buffer chamber 514 to allow gas in the buffer chamber 514 to flow from the buffer chamber 514 to the one or more filter chambers 512. In some embodiments, as shown in fig. 5A, the filter device 508 includes a cover 528. A cover 528 may cover a top side of the housing 510 and may cover a top side of the filter chamber 512 to allow gas in the filter chamber 512 to exit at the outlet 524. The cover 528 may be secured to the housing 510 via any suitable connection, such as by a press-fit or using suitable fastening means (e.g., screw fasteners). In some embodiments, as shown in fig. 5A, the filter device 508 includes a sealing ring configured to form a seal around the inlet 518.

Pressure vessel

The flow rate and/or NO concentration of the product gas generated by the NO generation device 100 may vary due to changes in one or more conditions, such as changes in temperature, current or voltage applied to the electrodes, side reactions, electrode degradation, or concentrations of nitrite source and catalyst in the reaction medium 112. The system 10 may include one or more devices or systems (such as a pressure vessel) to stabilize the flow rate and/or NO concentration of the product gas generated by the NO generating device 100. Such a device or system may allow the system 10 to provide a stable supply of NO.

In some embodiments, as shown in fig. 1, the system 10 includes a pressure vessel 600. The pressure vessel 600 may be disposed downstream of and fluidly connected to the NO generation apparatus 100. In some embodiments, the pressure vessel 600 receives the product gas from the outlet loop 124 of the NO generating device 100. One or more filters of the filtration system 500 may be disposed downstream of the NO generation apparatus 100 and upstream of the pressure vessel 600. The product gas from the NO generation apparatus 100 may flow from the outlet loop 124 through one or more filters of the filtration system 500 to the pressure vessel 600. The filtration system 500 can reduce or remove one or more impurities, such as moisture and/or solid matter (e.g., salt aerosols), in the product gas before the product gas enters the pressure vessel 600.

In some embodiments, as shown in fig. 6A, the pressure vessel 600 includes a body 602, a gas inlet 612, and a gas outlet 614. The body 602 may have any suitable shape configured to enclose an internal cavity, such as a cylindrical shape. A gas inlet 612 and a gas outlet 614 are fluidly connected to the interior cavity of the body 602. For example, as shown in fig. 6A, the gas inlet 612 and/or the gas outlet 614 may each have an opening or port disposed on the body 602.

The pressure vessel 600 may receive and store the product gas from the NO generating device 100 during the pressure holding period. At the end of the pressure holding period, the pressure in the pressure vessel 600 may be increased to a predetermined level or a predetermined range. Additionally or alternatively, the concentration of NO in the product gas contained in the pressure vessel 600 may be increased to a predetermined level or range at the end of the pressure holding period. The pressure holding period may be predetermined and/or adjusted. In some embodiments, the product gas may be released from the pressure vessel 600 after a pressure hold period. The NO concentration of the product gas released from the pressure vessel 600 may increase during the ramp period and may reach a steady state at or after the end of the ramp period.

In some embodiments, the pressure vessel 600 is configured to shorten the pressure hold period and the ramp period to allow for a more rapid or immediate provision of a steady NO supply. For example, the pressure vessel 600 may include one or more flow paths in the interior cavity of the body 602. The one or more flow paths may comprise a tortuous flow path, such as a serpentine flow path. The one or more flow paths may allow the pressure and/or NO concentration of the product gas in at least a portion of the internal cavity of the body 602 to quickly reach a steady state. For example, one or more flow paths may allow new gas (such as product gas) to enter the internal cavity to quickly purge or deplete old gas (such as air or nitrogen) previously present in at least a portion of the internal cavity. Additionally or alternatively, the one or more flow paths may reduce or eliminate uneven mixing of the new gas with the old gas.

As described herein, a tortuous flow path (such as a serpentine flow path) may refer to an indirect flow path that extends in any direction in three-dimensional space from a first point to a second point. For example, a tortuous flow path may refer to an indirect flow path that extends from a first point to a second point through a cross-sectional and/or longitudinal plane of the pressure vessel 600.

For example, the pressure vessel 600 may allow a pressure holding period of less than about 60min, such as less than about 1min, less than about 5min, less than about 10min, less than about 20min, less than about 30min, less than about 40min, or less than about 50min. For example, the pressure vessel 600 may allow a ramp period of less than about 20min, such as less than about 1min, less than about 2min, less than about 3min, less than about 4min, less than about 5min, less than about 8min, or less than about 10min.

Fig. 6A-6C are various views of a pressure vessel 600 according to some embodiments of the present disclosure. In some embodiments, the pressure vessel 600 includes one or more panels or partitions 604 that define a plurality of fluidly connected regions within the internal cavity. In various configurations, the fluidly connected regions may form a tortuous flow path, such as a serpentine flow path, through the pressure vessel 600. For example, the plurality of panels 604 may divide the interior cavity into a first region 606 and a second region 608. The first region 606 and the second region 608 may be fluidly connected via, for example, an opening, port, or conduit. Fluid (e.g., product gas) entering the pressure vessel 600 may enter the first region 606 and may flow from the first region 606 to the second region 608 through a tortuous flow path. Alternatively, fluid (e.g., product gas) entering the pressure vessel 600 may enter the first region 606 and may exit the pressure vessel without flowing into or through the second region 608, i.e., may bypass the second region 608. The tortuous flow path may allow new gas entering the pressure vessel 600 to effectively purge or deplete the pressure vessel of old gas that previously existed. The tortuous flow path may also allow the pressure in one or more regions of the pressure vessel 600 to reach steady state in a shorter period of time than is required to allow the pressure in the entire pressure vessel to reach steady state.

In some embodiments, first region 606 is fluidly connected to gas inlet 612 and gas outlet 614. For example, the gas inlet 612 may be fluidly connected to a first opening or port disposed in the first region 606. The gas outlet 614 may be fluidly connected to a second opening or port disposed in the first region 606. Gas may flow from gas inlet 612 to gas outlet 614 via at least a portion of first region 606.

The first region 606 may be configured to allow gas entering the gas inlet 612 to rapidly fill at least a portion of the first region 606. In some embodiments, the first region 606 is divided into a plurality of chambers defining the first flow path 618. For example, one or more panels 616 may be disposed in the first region 606 and divide the first region into a plurality of chambers. The first flow path 618 may be a tortuous flow path, such as a serpentine flow path. The tortuous flow path may allow new gas entering the first zone 606 to quickly purge or deplete old gas previously present in one or more chambers of the first zone 606. This may allow the pressure in one or more chambers of the first region 606 to reach steady state in a shorter period of time than is required to allow the pressure in one or more chambers of the first region 606 and the second region 608 to reach steady state. For example, it may take less than about 5 minutes for one or more chambers of the first region 606 to reach a steady state pressure, but it may take about 20 to about 30 minutes for the internal cavity of the body 602 of the pressure vessel 600 to reach a steady state pressure.

For example, as shown in fig. 6B and 6C, the gas inlet 612 and the gas outlet 614 may be fluidly connected with the first chamber 606 a. The product gas may flow from the gas inlet 612 to the gas outlet 614 via at least a portion of the first chamber 606 a. The product gas received by the gas inlet 612 can enter and rapidly fill the first chamber 606a of the first zone 606, thereby allowing the pressure in the first chamber 606a to reach a steady state in a short period of time. This may reduce the pressure hold time before releasing the product gas from the gas outlet 614.

The first chamber 606a may have any suitable shape and/or size that allows the pressure of the product gas in the chamber to reach a steady state within a short pressure hold time. For example, the first chamber 606a may have an elongated shape and a narrow cross-section extending along a longitudinal dimension of the body 602. The first chamber 606a may have any suitable size or volume. For example, the first chamber 606a may have a volume that is 50% or less of the internal cavity of the body 602. For example, the pressure vessel 600 may have an internal volume of about 800mL, and the first chamber 606a may have a volume of about 10mL to about 200 mL. In one example, after a pressure hold period of about 20 minutes to receive and hold the product gas, the pressure vessel 600 may release the product gas at the gas outlet 614 and the concentration of NO in the released product gas may reach a steady state within about 10 minutes.

In some embodiments, the second region 608 is fluidly connected to the first region 606 via a channel 610. The second region 608 may receive and store the gas flowing from the first region 606. The second region 608 may include a tortuous flow path, such as a serpentine flow path. For example, the second region 608 may be configured to allow gas from the first region 606 to fill at least a portion of the second region 608.

In some embodiments, the second region 608 is divided into a plurality of chambers defining the second flow path 620. For example, one or more panels 616 may be disposed in second region 616 and divide the second region into a plurality of chambers. The second flow path 620 may be in fluid communication with the first flow path 618, for example, via the channel 610. Second flow path 620 and first flow path 618 may form one continuous flow path. The second first flow path 620 may be a tortuous flow path, such as a serpentine flow path. The tortuous flow path may allow new gas entering the second region 608 from the first region 606 to purge or deplete old gas previously present in one or more chambers of the second region 608. This may also allow the pressure in one or more chambers of the second region 608 to reach a steady state before the pressure throughout the second region 608 reaches a steady state.

The chambers of the second region 608 may be referred to as gas storage units. One or more of the plurality of chambers of the second region 608 may be further divided into one or more sub-chambers to further reduce the volume in each gas storage unit. This may reduce or eliminate uneven mixing of the new gas with the old gas in the second region 608, and this may reduce the time required for the pressure in the second region 608 to reach steady state. For example, the chambers of the second region 608 may each be divided by one or more partitions 609 into two or more fluidly connected sub-chambers. The partition 609 may have any suitable structure for directing the flow of gas in the chamber, such as a panel or plate. For example, as shown in fig. 6B and 6C, two or more partitions 609 may each extend along at least a portion of the longitudinal axis of the pressure vessel 600 and may be radially spaced apart such that the sub-chambers are fluidly connected via spaces 611 between the partitions.

As described herein, the fluidly connected chambers in the first region 606 or the second region 608 may have any suitable configuration to define a flow path that allows new gas to purge or deplete the old gas previously present in one or more chambers of the region. For example, as shown in fig. 6C, the inlet and outlet of a chamber (such as the first chamber 606 a) may be separately disposed along at least one dimension (such as a horizontal and/or longitudinal dimension). Such a configuration may allow new gas entering the chamber to flow through the chamber from the inlet to the outlet along at least one dimension to purge or deplete the chamber of old gas previously present.

The second region 608 can serve as a reservoir for the stored product gas. For example, when the flow rate of the product gas received at the gas inlet 612 is higher than the flow rate of the product gas released at the gas outlet 614, additional product gas may flow from the first region 606 to the second region 608 to be stored. When the flow rate of the product gas received at the gas inlet 612 is lower than the flow rate of the product gas released at the gas outlet 614, the product gas stored in the second region 608 may flow from the second region 608 to the first region 606 to supplement the product gas flow. In this case, the pressure vessel 600 may reduce variations in pressure, flow rate, and/or NO concentration of the product gas released at the gas outlet 614. This may be advantageous to provide a stable NO supply, such as in situations where NO generation may vary due to various conditions. It may also be advantageous to provide a supply of NO at a desired pressure, flow rate and/or concentration as required. The second region 608 may also serve as a backup source of NO. For example, in response to an anomaly in the NO generation facility 100 generating NO and/or transporting NO in the system 10, the product gas stored in the second region 608 may be released to continue or supplement the supply of NO.

In some embodiments, the pressure vessel 600 includes a pressure relief valve 622. The pressure relief valve 622 is configured to control the pressure in the pressure vessel 600 not to exceed a threshold value. The threshold may be a predetermined safety threshold. Pressure relief valve 622 may be normally closed, such as by the force of a spring. When the pressure in one or more regions in the pressure vessel 600 exceeds a threshold, the pressure relief valve 622 may be opened. In some embodiments, pressure relief valve 622 is in fluid communication with second region 608. As shown in fig. 1, the product gas released from pressure relief valve 622 may be transported from pressure vessel 600 to exhaust treatment device 700.

In some embodiments, the system 10 includes one or more pressure sensors to measure the pressure in one or more regions or chambers in the pressure vessel 600. In some embodiments, the pressure sensor 624 may be configured to measure the pressure in the first zone 606, such as the pressure in the first chamber 606a of the first zone 606. The measurement of the pressure sensor 624 may be indicative of the pressure of the product gas released from the gas outlet 614 to a downstream system or device. In some embodiments, one or more pressure sensors (not shown) may be configured to measure the pressure in the second region 608. The measurements of such a pressure sensor may be indicative of the amount of product gas stored in the second region 608.

In some embodiments, the pressure vessel 600 includes a purge valve 626. The purge valve 626 may be used to purge or deplete a gas, such as a product gas, in one or more regions in the internal cavity of the pressure vessel 600. For example, the purge valve 626 may be in fluid communication with the first zone 606 or the second zone 608. As shown in fig. 1, the product gas released from the purge valve 626 may be transported from the pressure vessel 600 to the exhaust treatment device 700. In some embodiments, as shown in fig. 1, NO sensor 628 is disposed downstream of purge valve 626 and is configured to measure the NO concentration of the product gas released from purge valve 626. The measurement of the NO sensor 628 may indicate whether the product gas has been purged or depleted from one or more regions of the pressure vessel 600.

In some embodiments, as shown in fig. 1, the system 10 includes one or more flow control devices 630 to control the flow of product gas released from the pressure vessel 600. A flow control device 630 may be disposed downstream of and in fluid communication with the gas outlet 614. The flow control device 630 may include a flow meter and/or a flow controller, such as a flow control valve. In some embodiments, the system 10 includes a first flow control device 630 and a second flow control device 630. The first flow control device 630 may be selected to measure and/or adjust flow rates within a first range and the second flow control device 630 may be selected to measure and/or adjust flow rates within a second range that is lower than the first range. The flow control device 630 may be in communication with and/or controlled by one or more other components of the system 10, such as the vent circuit 900, as described below.

Exhaust gas treatment

The system 10 may generate exhaust gas before, during, and/or after NO production and/or delivery. For example, an exhaust gas may be generated during the separation of NO from reaction medium 112 by liquid-gas separation device 408. Further, for example, the release of product gas from the pressure relief valve 622 of the pressure vessel 600 may generate off-gas. The exhaust of system 10 may include one or more components such as NO, carrier gases, moisture, and other nitrogen oxides that may be generated during NO generation and/or transport. For example, during NO generation or transport in the system 10, NO may be oxidized to nitrogen dioxide (NO) ₂ )。

Nitrogen oxides (also known as NO) _x ) Such as NO and NO ₂ If released directly from the system 10 into the environment, may result in air pollution and/or pose health risks. In some embodiments, as shown in FIG. 1, the system 10 includes one or more exhaust treatment devices 700 to treat the exhaust before releasing the exhaust from the system 10. The exhaust treatment device 700 may reduce or remove one or more nitrogen oxides in the exhaust, thereby reducing or eliminating the risk of potential air pollution and/or exposure to nitrogen oxides.

In some embodiments, the exhaust treatment device 700 is disposed downstream of and in fluid communication with the liquid-gas separation device 408. The exhaust treatment device 700 may receive the mixed gas from the outlet 426 of the liquid-gas separation device 408. The mixed gas may include a sweep gas and one or more nitrogen oxides (such as NO and NO) ₂ ). In some embodiments, the exhaust treatment device 700 is disposed downstream of the pressure vessel 600 and is in fluid communication with the pressure relief valve 622. When the pressure in the pressure vessel 600 reaches or exceeds a threshold value, the exhaust treatment device 700 may receive the product gas released from the pressure relief valve 622. The product gas may include a carrier gas and one or more nitrogen oxides (such as NO and NO) ₂ )。

In some embodiments, the off-gas from the pressure vessel 600 and the liquid-gas separation device 408 may be treated by the same off-gas treatment device 700. For example, the system 10 may include a three-way connector 702 disposed upstream of the exhaust treatment device 700 and downstream of the pressure vessel 600 and the liquid-gas separation device 408. The off-gases from the pressure vessel 600 and the liquid-gas separation device 408 may be combined at the three-way connector 702 and flow to the same off-gas treatment device 700. The three-way connector 702 may include any suitable structure, such as a three-way fitting or a three-way valve.

In some embodiments, the exhaust treatment device 700 reduces or removes one or more nitrogen oxides from the exhaust as the exhaust passes through the exhaust treatment device 700. In some embodiments, the exhaust treatment device 700 includes a body, an inlet, and an outlet. The inlet and outlet are in fluid communication with a cavity defined by the body. In some embodiments, at least a portion of the cavity is filled with a filter material that can reduce or remove one or more nitrogen oxides as the exhaust gas passes through the filter material. For example, the filter material may comprise a material configured to absorb one or more nitrogen oxides, NO _x (such as NO and NO) ₂ ) One or more absorbent materials.

In some embodiments, the absorbent material comprises a substrate prepared with an absorbent that can react with one or more nitrogen oxides. For example, the substrate may be coated with an oxidizing agent. The substrate may have any suitable configuration to provide a surface area for the absorbent to react with the one or more nitrogen oxides. For example, the substrate may include one or more materials selected from molecular sieves, silica gel, alumina, sponge, cotton, foamed resin, silica, and activated carbon. For example, the absorber may include one or more materials selected from permanganate, persulfate, chromate, and dichromate.

In some embodiments, the exhaust treatment device 700 includes a plurality of baffles configured to define a fluid path. In some embodiments, at least a portion of the flow path is filled with a filter material. The flow path may be a tortuous flow path, such as a serpentine flow path. For example, a plurality of baffles may extend from the walls of the cavity in a staggered manner to define a serpentine flow path. The tortuous flow path may extend along one or more dimensions. The tortuous flow path may increase contact between the exhaust gas and the filter material to allow for the reduction or removal of more nitrogen oxides as the exhaust gas passes through the device.

Fig. 7A-7C are various views of an exhaust treatment device 700 according to some embodiments of the present disclosure. 7A-7C, in some embodiments, the exhaust treatment device 700 includes a body 703, an inlet 722, and an outlet 724. The inlet 722 and the outlet 724 are in fluid communication with the cavity 706 defined by the body 703. The body 703 may have any suitable shape, configuration, and/or size. For example, the body 703 may have a cylindrical shape.

In some embodiments, the body 703 has a first side 718 and a second side 720. The inlet 722 and the outlet 724 may be disposed on opposite sides or the same side of the body 703. For example, the inlet 722 may be disposed on the first side 718 and the outlet 724 may be disposed on the second side 720. Alternatively, both the inlet 722 and the outlet 724 may be disposed on the first side 718 or the second side 720. In some embodiments, the body 703 includes an inner shell 708 and an outer shell 710 that extend from a first side 718 to a second side 720. Inner housing 708 and outer housing 710 may define annular cavity 706. The inner shell 708 and the outer shell 710 may have any suitable dimensions. For example, the outer shell 710 may range from 120mm to 160mm in diameter, while the inner shell 708 may range from 80mm to 120mm in diameter.

In some embodiments, as shown in fig. 7C, the cavity 706 is separated by a wall 716 that extends between the inner shell 708 and the outer shell 710 and from the first side 718 to the second side 720. The inlet 722 and the outlet 724 may be disposed adjacent opposite sides of the wall 716. At least a portion of the cavity 706 may be filled with a filter material (not shown). Exhaust passing through exhaust treatment device 700 may flow from inlet 722 through cavity 706 to outlet 724.

In some embodiments, exhaust treatment device 700 includes a plurality of baffles. The plurality of baffles may have any configuration that defines a tortuous flow path 704 (such as a serpentine flow path) in the cavity 706. In some embodiments, as shown in fig. 7C, the first set of baffles 712 may extend between the first and

second sides

718, 720 and from the inner housing 708 toward the outer housing 710, while the second set of baffles 714 may extend between the first and

second sides

718, 720 and from the outer housing 710 toward the inner housing 708.

Baffles

712 and 714 may extend any suitable distance between inner housing 708 and outer housing 710 to direct the exhaust flow. For example, the distance between the baffle 712 and the outer housing 710 and/or the distance between the baffle 714 and the inner housing 708 may be in the range of 2mm to 8 mm.

In some embodiments, the first set of baffles 712 and the second set of baffles 714 may be arranged in a staggered manner. For example, as shown in fig. 7C, a first set of baffles 712 may be evenly distributed around the circumference of the inner shell 708, while a second set of baffles 714 may be evenly distributed around the circumference of the outer shell 710, the second set of baffles being offset from the first set of baffles 712. Exhaust treatment device 700 may include any suitable number of partitions, such as 2 to 16 partitions. For example, the number of first set of baffles 712 and/or second set of baffles 714 may be in the range of 2 to 8. The number of baffles in the first group 712 and the second group 714 may or may not be the same. It is contemplated that exhaust treatment device 700 may include any suitable number of baffles, with or without suitable filter material.

Exhaust gas may flow from the inlet 722 to the outlet 724 through the tortuous flow path 704. The tortuous flow path 704 may be filled with filter material. As the exhaust gas passes through the filter material in the flow path 704, one or more nitrogen oxides in the exhaust gas may be absorbed. Exhaust may exit exhaust treatment device 700 from outlet 724 and may be released to the environment with or without further treatment.

Reduction and/or removal of toxic nitrogen oxides

NO can be oxidized to one or more toxic nitrogen oxides (e.g., NO) ₂ ) These toxic nitrogen oxides may present a health risk if delivered to the patient with NO. In a 1In some embodiments, system 10 includes a gas converter 800. The gas converter 800 may convert some or all of the potentially toxic nitrogen oxides (e.g., NO) that may be present in the product gas as it passes through the gas converter ₂ ) Is converted to NO. The gas converter 800 may reduce the potential risk of exposure to toxic nitrogen oxides and may increase NO production by converting other nitrogen oxides in the product gas back to NO.

In some embodiments, the gas converter 800 is disposed downstream of and in fluid communication with the NO generation device 100. In some embodiments, the gas converter 800 is disposed downstream of and in fluid communication with the filtration system 500. In some embodiments, the gas converter 800 is disposed downstream of and in fluid communication with the pressure vessel 600. Fig. 8A is an exploded view of a gas converter according to some embodiments of the present disclosure. In some embodiments, as shown in fig. 8A, the gas converter 800 includes a body 808, an inlet 818, and an outlet 820. The inlet 818 and the outlet 820 are in fluid communication with the cavity defined by the body 808. The body 808 may have any suitable shape. In some embodiments, the body 808 has a cylindrical shape extending between a first side and a second side. Two end caps 806 may cover the first and second sides of the body 808. The inlet 818 and the outlet 820 may be disposed at the same end cap 806 or at different end caps 806.

In some embodiments, the gas converter 800 includes one or more membrane filters 810 and a filter holder 812. The filter holder 812 may be configured to position the membrane filter 810 between the end cap 806 and the body 808. The membrane filter 810 may reduce or remove one or more impurities, such as moisture and solid matter, in the product gas entering and/or exiting the gas converter 800.

In some embodiments, at least a portion of the cavity is filled with a filter material that can absorb one or more toxic nitrogen oxides, such as NO, as the product gas passes through the filter material ₂ . For example, the filter material may include soda lime particles. In some embodiments, at least a portion of the cavity is filled with a filter materialThe filter material may be configured to remove one or more toxic nitrogen oxides (e.g., NO) from the product gas as it passes through the filter material ₂ ) Is converted to NO. In some embodiments, the filter material comprises a substrate configured to carry a reducing agent. For example, the surface of the substrate may be prepared, such as applied, treated or coated, using a reducing agent. The reductant may react with one or more nitrogen oxides and reduce them to NO. The substrate can have any suitable configuration to provide a surface area for supporting the reducing agent. For example, the substrate may comprise one or more materials selected from molecular sieves, silica gel, alumina, sponge, cotton, foamed resin. For example, the reducing agent may include one or more antioxidants, such as vitamin a, vitamin E, and vitamin C. As used herein, vitamin C may also be referred to as ascorbic acid or ascorbate.

The filter material may be prepared using any suitable method or process. For example, an amount of one or more reducing agents may be prepared as a solution. The solution may be an aqueous or organic solution, and the solution may be a saturated solution of one or more reducing agents. A certain amount of the base material may be added to the solution and mixed homogeneously. The substrate may then be removed from the solution and dried at a drying temperature for a period of time to allow the solvent to evaporate. Any suitable amount of reducing agent and substrate may be selected based on one or more conditions, such as the type of material used and the desired reducing power. For example, an amount of reducing agent ranging from about 5g to about 50g can be used to prepare about 100g of substrate per serving.

In one example, an amount of about 25g of vitamin C may be used to coat about 100g of alumina particles per serving. In another example, an amount of about 5g vitamin a may be used to prepare about 100g of cotton per serving. In another example, an amount of vitamin E of about 5g may be used to prepare a foamed resin in an amount of about 100g per serving. In another example, an amount of about 30g of vitamin C may be used to prepare a molecular sieve in an amount of about 100g per serving. In another example, an amount of about 20g vitamin A may be used to prepare about 100g sponge material per serving. In another example, an amount of vitamin E of about 15g may be used to prepare about 100g of silica gel per serving.

The drying temperature may range from about 40 ℃ to about 150 ℃, such as from about 40 ℃ to about 50 ℃, from about 50 ℃ to about 60 ℃, from about 60 ℃ to about 70 ℃, from about 70 ℃ to about 80 ℃, from about 80 ℃ to about 90 ℃, from about 90 ℃ to about 100 ℃, from about 100 ℃ to about 110 ℃, from about 110 ℃ to about 120 ℃, from about 120 ℃ to about 130 ℃, from about 130 ℃ to about 140 ℃, from about 140 ℃ to about 150 ℃, or combinations thereof. The drying time may range from about 0.1h to about 10h, such as from about 0.1h to about 0.2h, from about 0.2h to about 0.5h, from about 0.5h to about 1h, from about 1h to about 2h, from about 2h to about 3h, from about 3h to about 4h, from about 4h to about 5h, from about 5h to about 6h, from about 6h to about 7h, from about 7h to about 8h, from about 8h to about 9h, from about 9h to about 10h, or a combination thereof.

In some embodiments, as shown in fig. 8A-8B, the cavity of the gas converter 800 is divided into a plurality of chambers 816, each having an inlet and an outlet. The inlet of the first chamber may be fluidly connected to the inlet 818 and the outlet of the last chamber may be fluidly connected to the outlet 820. The inlet and outlet of the chamber 816 may be fluidly connected to define the flow path 802. The filter material may fill at least a portion of each chamber, such as from an inlet to an outlet of the chamber. The inlet and outlet of each chamber may be provided at opposite ends such that gas passing through the chamber may flow from the inlet, through the chamber, through the filter material, to the outlet.

The flow path 802 may be a tortuous flow path, such as a serpentine flow path. The tortuous flow path in the cavity of the body 808 may increase contact between the product gas and the filter material to allow more nitrogen oxides to be reduced to NO as the product gas passes through the device at a given cavity volume.

The chambers in the cavity of the gas converter 800 may have any suitable configuration. For example, one or more panels 814 may be disposed in and extend between both sides of the body 808. The panels 814 may be disposed equidistantly or non-equidistantly about the longitudinal axis of the body 808. The panels 814 may each extend radially from the longitudinal axis to an inner wall of the body 808. For example, the panel 814 may evenly divide the cavity into a plurality of elongated chambers 816 extending between the two sides of the body 808 and arranged about the longitudinal axis of the body 808. Any suitable number of panels 814 may be used. For example, if the face plates 814 are arranged about the longitudinal axis of the body 808, an odd number of face plates 814 may divide the cavity into an odd number of chambers, and the inlet 818 and outlet 820 may be disposed at the opposing end caps 806. Alternatively, an even number of panels 814 may divide the cavity into an even number of chambers, and the inlet 818 and outlet 820 may be disposed at the same end cap 806.

In one example, the cavity of the gas converter 800 may be evenly divided into three elongated chambers, as shown in fig. 8A-8B. Each chamber may be filled with a filter material. For example, the filter material may be prepared with alumina silica gel particles having an average diameter of about 0.2mm and vitamin C. First, about 5 g of vitamin C may be dissolved in 100 g of water to prepare a saturated aqueous solution of vitamin C. An amount of 100 grams of the alumino-silica particles may be added to the solution and mixed homogeneously. The alumino-silica particles may be dried at about 100 c for about 0.5 hours. The gas converter 800 may be used to process a gas stream containing 100ppm NO at a flow rate of 1.0L/min ₂ For a duration of about 90 hours. About 100% of NO in the gas stream can be removed ₂ Is converted to NO.

Alternatively, the filter material may be prepared from silica gel particles having an average diameter of about 3mm and vitamin E. First, approximately 15 grams of vitamin E can be prepared as a saturated solution. Approximately 100 grams of silica gel particles may be added to the solution and mixed homogeneously. The silica gel particles may be dried at about 50 ℃ for about 5 hours. The gas converter 800 may be used to process a gas stream containing 500ppm NO at a flow rate of 4.0L/min ₂ For a period of about 5 hours. Can be mixed with gas flowAbout 100% NO ₂ To NO.

In another example, the cavity of the gas converter 800 may be evenly divided into four elongated chambers, similar to the embodiment shown in fig. 8A-8B. Each chamber may be filled with a filter material. The filter material may be prepared with molecular sieve particles having an average diameter of about 5mm and vitamin a. First, approximately 25 grams of vitamin a can be prepared as a saturated solution. Approximately 100 grams of molecular sieve particles may be added to the solution and mixed homogeneously. The molecular sieve particles may be dried at about 80 ℃ for about 2 hours. The gas converter 800 can be used to process a gas stream containing 200ppm NO at a flow rate of 2.0L/min ₂ For a duration of about 70 hours. About 100% of NO in the gas stream can be removed ₂ Is converted to NO. Alternatively, the filter material may be prepared from alumina particles having an average diameter of about 6mm and vitamin C. Approximately 35 grams of vitamin C can be prepared as a saturated solution. Alumina particles can be added to the solution and allowed to mix homogeneously. The alumina sieve particles may be dried at about 120 c for about 0.25 hours. The gas converter 800 can be used to process a gas stream containing 500ppm NO at a flow rate of 1.0L/min ₂ For a duration of about 125 hours. About 100% of NO in the gas stream can be removed ₂ Is converted to NO.

In another example, the cavity of the gas converter 800 may be evenly divided into five elongated chambers, similar to the embodiment shown in fig. 8A-8B. Each chamber may be filled with a filter material. The filter material can be made from sponge and vitamin E. Approximately 40 grams of vitamin E can be prepared as a saturated solution. Approximately 100 grams of sponge may be dipped into the solution. The sponge may be dried at about 150 c for about 0.2 hours. The gas converter 800 may be used to process a gas stream containing 800ppm NO at a flow rate of 3.0L/min ₂ For a duration of about 12 hours. About 100% of NO in the gas stream can be removed ₂ To NO. Alternatively, the filter material may be made of cotton and vitamin a. Approximately 50 grams of vitamin a can be prepared as a saturated solution. Approximately 100 grams of cotton may be soaked in the solution. The cotton may be dried at about 70 deg.CFor about 3 hours. The gas converter 800 can be used to process a gas stream containing 400ppm NO at a flow rate of 4.0L/min ₂ For a duration of 35 hours. About 100% of NO in the gas stream can be removed ₂ Is converted to NO.

In some embodiments, the product gas released from the gas converter 800 may be the output gas of the system 10. The quality and/or flow of the output gas of the system may be monitored. For example, NO can be monitored ₂ And the concentration of moisture. In some embodiments, a flow meter is utilized to monitor the flow of the output gas of the system 10.

NO delivery and/or monitoring

The NO generated by the system 10 may be used for various NO-based therapies. For example, NO generated by the system 10 may be used for NO inhalation therapy. The NO generated by the system 10 may be delivered to the patient with or without another gas, such as oxygen. For example, NO generated by system 10 may be delivered to a patient by a flow of air or oxygen provided by a ventilator.

In some embodiments, as shown in fig. 1, system 10 includes a ventilation circuit 900 for delivering inhaled NO to a patient. In some embodiments, the vent circuit 900 is disposed downstream of and in fluid communication with the pressure vessel 600. The venting circuit 900 may also be disposed downstream of and in fluid communication with the gas converter 800. The ventilation circuit 900 may be configured to connect the system 10 to a respiratory device or system to deliver NO in any suitable form. For example, the ventilation circuit 900 may connect the system 10 to a ventilator, a nebulizer, a positive airway pressure, an oxygen supply, and the like.

Fig. 9 is a schematic diagram of a ventilation circuit 900 of the system 10 according to some embodiments of the present disclosure. In some embodiments, the ventilation circuit 900 includes an inspiratory circuit 904 and an expiratory circuit 922. The inspiratory circuit 904 may be configured to fluidly connect to a ventilator 906 and deliver a flow of gas (such as a flow of air or oxygen) from the ventilator 906 to a patient 910 via a mask or tube. The expiratory circuit 922 may deliver expired gases from the patient 910 to the ventilator 906.

In some embodiments, as shown in fig. 9, the vent circuit 900 includes a port 902 configured to receive a NO supply. For example, the port 902 may be disposed along and in fluid communication with an inspiratory circuit 904. In some embodiments, the port 902 is disposed downstream of and in fluid communication with the pressure vessel 600 and/or the gas converter 800. The NO supplied from the pressure vessel 600 may be mixed with and/or entrained by the oxygen or air flowing through the inspiratory circuit 904 to form a gas mixture 907 for delivery to the patient 910. In some embodiments, a humidifier 908 is disposed downstream of port 902 and a gas mixture 907 may be humidified by humidifier 908 prior to delivery to patient 910.

In some embodiments, the vent circuit 900 includes a flow controller 916. A flow controller 916 may be provided upstream of the port 902 and configured to control the flow of a gas stream (such as the NO-containing product gas from the pressure vessel 600 or gas converter 800) entering the port 902. The flow controller 916 may include an inlet port, an outlet port, a flow sensor, and a control valve. In some embodiments, flow controller 916 is a mass flow controller.

In some embodiments, the ventilation circuit 900 includes a control 918. The control 918 may communicate with the flow controller 916 via a wired connection or a wireless connection. The control 918 may send a control signal to the flow controller 916 to adjust the flow of the gas stream entering the port 902. For example, the control 918 may receive a sensor signal from the flow controller 916 indicative of the flow of the product gas entering the port 902, and the control may generate a control signal in response to the received sensor signal. A control signal may be sent from the control 918 to the flow controller 916 to adjust the flow of the gas stream entering the port 902.

In some embodiments, ventilation circuit 900 includes a flow sensor 905 configured to measure the flow of air or oxygen output from ventilator 906. A flow sensor 905 may be disposed along the suction circuit 904, such as upstream of the port 902. The control 918 may communicate with the flow sensor 905 via a wired connection or a wireless connection. The control 918 may send a control signal to the flow controller 916 to adjust the flow of the gas stream entering the port 902 based on a sensor signal from the flow sensor 905. For example, the control 918 may receive a sensor signal from the flow sensor 905 indicative of the flow of oxygen output by the ventilator 906, and the control may generate a control signal in response to the received sensor signal. A control signal may be sent to the flow controller 916 to adjust the flow of the product gas entering the port 902 to mix with the oxygen flow, thereby allowing adjustment of the concentration of NO in the mixed gas delivered to the patient 910.

In some embodiments, the ventilation circuit 900 includes one or more gas sensors. The gas sensor may be any suitable sensor configured to detect one or more types of gases, and the gas sensor may measure one or more components (e.g., NO) in gas mixture 907 ₂ 、O ₂ And moisture). For example, the gas sensor may be an electrochemical gas sensor, an infrared gas sensor, or a thermal conductivity gas sensor.

In some embodiments, the vent circuit 900 includes a sampling port 912. A sampling port 912 may be disposed along the inspiratory circuit 904 (e.g., downstream of the humidifier 908) and in fluid communication therewith. The sampling port 912 may be disposed upstream of an applicator, such as a mask or endotracheal tube. The sampled gas or sampled gas stream from sampling port 912 may be used to measure the concentration of various components of gas mixture 907.

In some embodiments, one or more gas sensors may be disposed near the sampling port 912, and the one or more gas sensors may communicate with the control device 918 via a wired connection or a wireless connection. In some embodiments, one or more gas sensors are disposed in gas monitoring device 1100. The sample gas flow may flow from sampling port 912 through sampling loop 914 to gas monitoring device 1100. Gas monitoring apparatus 1100 may be provided with A wired or wireless connection communicates with the control 918. May indicate one or more components (e.g. NO, NO) ₂ And O ₂ ) Is sent from the gas sensor or from the gas monitoring device 1100 to the control device 918. Control 918 may generate control signals in response to received sensor signals, and the control may send the control signals to one or more components of the system to adjust the concentration of one or more components of gas mixture 907. For example, control 918 may send a control signal to energy source 114 to adjust the NO concentration or to flow controller 916 to adjust NO, NO in gas mixture 907 ₂ And O ₂ The concentration of (c).

Gas monitoring device 1100 may include various features. For example, gas monitoring device 1100 may include an alarm device configured to alarm when one or more measured gas concentrations of gas mixture 907 exceeds a predetermined threshold (e.g., NO is 25ppm ₂ 5 ppm) one or more alarms (such as an audible alarm or a visual alarm). Gas monitoring device 1100 may include a display to display alarm and/or measured concentration values. Because gas mixture 907 may pass through humidifier 908, the sample gas stream from port 912 may have a high humidity. Reducing or removing moisture in the sample gas flow of gas mixture 907 may improve the accuracy of one or more gas sensors of gas monitoring apparatus 1100.

In some embodiments, the gas monitoring apparatus 1100 includes a moisture collector 1000 configured to reduce or remove moisture in the sample gas flow of the gas mixture 907. Fig. 10A is a perspective view of a moisture trap 1000 according to some embodiments of the present disclosure. Fig. 10B is a partial perspective view of the moisture trap 1000. Fig. 10C is another partial perspective view of the moisture trap 1000. As shown in fig. 10A-10C, in some embodiments, the moisture trap 1000 includes one or more inlets (such as inlet 1008) and one or more outlets (such as first outlet 1010 and second outlet 1012). A gas flow 1009 (such as a sample gas flow from port 912) may enter the moisture collector 1000 via one or more inlets, and the gas flow may exit the moisture collector 1000 via one or more outlets. For example, as shown in fig. 10A, the gas flow 1009 may enter the moisture trap 1000 via the inlet 1008, and the gas flow may be split into a first gas flow 1014 and a second gas flow 1016 that exit the moisture trap 1000 via the first outlet 1010 and the second outlet 1012, respectively.

In some embodiments, moisture collector 1000 includes cup 1002, cover 1004, and moisture filter 1006. In some embodiments, moisture filter 1006 is disposed between cup 1002 and cover 1004. Gas flow 1009 may flow from inlet 1008 through moisture filter 1006 and out outlet 1010 and/or outlet 1012. The moisture filter 1006 is permeable to gas, but impermeable to moisture (e.g., water droplets or water vapor). For example, the moisture filter 1006 may include a material having pores configured to allow gas molecules to pass through but not larger particles (such as water molecules or solid particles). In some embodiments, the moisture filter 1006 comprises a porous membrane. In some embodiments, the porous membrane is a gas permeable membrane. In some embodiments, the porous membrane is a hydrophobic membrane.

In some embodiments, the moisture trap 1000 includes one or more flow paths configured to allow a flow of gas to flow from the inlet to the outlet. In some embodiments, the moisture trap 1000 includes a first chamber 1018 and a second chamber 1020 defining a flow path. A first chamber 1018 may be disposed downstream of and in fluid communication with the inlet 1008. The second chamber 1020 may be disposed downstream of and in fluid communication with the first chamber 1018, and disposed upstream of and in fluid communication with the outlet 1010. Moisture filter 1006 may be disposed between first chamber 1018 and second chamber 1020. The gas flow 1009 may flow from the first chamber 1018 through the moisture filter 1006 to the second chamber 1020 and the gas flow may become the first gas flow 1014 having a lower moisture level than the gas flow 1009.

For example, moisture blocked by moisture filter 1006 may accumulate in first chamber 1018 and on moisture filter 1006. The accumulated moisture may form liquid droplets. Liquid droplets may accumulate on the side of moisture filter 1006 facing gas flow 1009 or first chamber 1018, may be collected in first chamber 1018, and may flow through opening 1022 of first chamber 1018 to cup 1002. Liquid accumulated on moisture filter 1006 may reduce the throughput of gas flow 1009 through the moisture filter, such as liquid accumulated on the side of moisture filter 1006 facing first chamber 1018. This liquid volume can block the pores of the gas permeable membrane of moisture filter 1006 and reduce the gas throughput of moisture trap 1000. In some embodiments, the moisture filter 1006 is disposed at an oblique angle to facilitate the accumulation of liquid due to gravity toward the edges of the moisture filter 1006.

In some embodiments, the moisture trap 1000 includes one or more additional flow paths to increase the throughput of the gas flow through the moisture trap 1000. For example, the moisture filter 1006 may include a third chamber 1024 and a fourth chamber 1026. Third chamber 1024 may be disposed in fluid communication with cup 1002, such as via an opening. The fourth chamber 1026 can be disposed downstream of and in fluid communication with the third chamber 1024, and the fourth chamber is disposed upstream of and in fluid communication with the outlet 1012. Moisture filter 1006 may be disposed between third chamber 1024 and fourth chamber 1026. As shown in fig. 10A, second gas flow 1016 may be directed by moisture filter 1006 to cup 1002, and may flow from cup 1002 to third chamber 1024, through moisture filter 1006, to fourth chamber 1026. The second gas flow 1016 may exit the moisture trap 1000 via outlet 1012. The second gas flow 1016 may sweep away liquid (e.g., water) that accumulates on the moisture filter 1006, thereby increasing the throughput of gas flowing through the moisture filter 1006.

In some embodiments, as shown in fig. 11A-11D, one or more outlets of the moisture trap 1000 are in fluid communication with a gas sensing circuit of the gas monitoring device 1100. For example,

outlets

1010 and 1012 may be in fluid communication with a gas sensing circuit. One or more gas flows from the moisture trap 1000 may be used to measure gas concentration by a gas sensing circuit. In some embodiments, the first gas flow 1014 from the moisture trap 1000 is used by a gas sensing circuit to measure the gas concentration.

The gas sensing circuit of gas monitoring apparatus 1100 may include various components and features for measuring gas concentration and/or improving measurement accuracy. In some embodiments, the gas monitoring device 1100 includes a sensing module 1102. The sensing module 1102 may include one or more gas sensors, such as NO ₂ Sensor 1102a, NO sensor 1102b, and O ₂ And a sensor 1102c. The one or more gas sensors can be disposed in one or more chambers configured to receive at least a portion of a gas flow circulating in the gas sensing circuit, such as the first gas flow 1014. For example, as shown in fig. 11A-11D, a gas sensor may be disposed in one of the chambers to measure the gas concentration of the gas flowing therethrough. Gas monitoring device 1100 may include a computer readable storage device and/or a processor (not shown) in wired or wireless communication with the sensors to receive and process the sensing signals received from the sensors. Gas monitoring device 1100 may include a transmitter loop (not shown) in wired or wireless communication with a processor, computer readable storage device, and/or gas sensor to transmit the sensed signal or reading to a controller, such as control device 918 or an electronic device (e.g., a tablet, computer, or smartphone). The gas sensor readings may be obtained by the gas sensor or the processor based on the sensing signals.

In some embodiments, the gas sensing circuit of gas monitoring device 1100 includes a pump 1104. The pump 1104 is configured to generate or drive one or more gas flows in the gas sensing circuit. In some embodiments, the gas sensing circuit includes one or more valves configured to direct one or more gas flows in the gas sensing circuit. For example, the gas sensing circuit may include at least one-way valve 1106, such as a ball check valve. Check valve 1106 may be provided in any suitable location to prevent backflow. For example, the pump 1104 may be disposed at a location downstream of the gas sensing circuit such that the flow of gas from the pump outlet may be released into the environment. A one-way valve 1106 may be provided downstream of the pump 1104 to prevent backflow of ambient air into the gas sensing circuit.

In some embodiments, the gas monitoring apparatus 1100 includes one or more switching valves configured to change the direction or flow path of the gas flow in the gas sensing circuit. For example, gas monitoring apparatus 1100 may include a first switching valve 1110 and a second switching valve 1112. The switching valve may have one or more positions (such as a first position and a second position) for selecting a gas flow path or flow direction in the gas sensing circuit. The position of the switching valve may be selected manually or automatically using a user interface. The user interface may be, for example, a graphical user interface or a control panel, such as a switch or button.

In some embodiments, one or more switching valves may be provided in the control module 1114. As shown in FIGS. 11A-11D, the control module 1114 may include one or more connection ports, such as connection ports 1116A-1116G. The switching valve may be fluidly connected to one or more connection ports. Such a configuration may improve assemblability and/or maintainability of gas monitoring apparatus 1100. For example, the first switching valve 1110 may have a first position to fluidly connect the

connection ports

1116A and 1116C, and the first switching valve may have a second position to fluidly connect the

connection ports

1116A and 1116D. For example, the second switching valve 1112 may have a first position to fluidly connect

connection ports

1116E and 1116G, and the second switching valve may have a second position to fluidly connect

connection ports

1116F and 1116G. In some embodiments, selected connection ports may be fluidly connected to form one or more flow paths. For example,

connection ports

1116B and 1116C may be fluidly connected. Various uses of the switching valve during one or more operations of gas monitoring apparatus 1100 are described further below.

In some embodiments, gas monitoring device 1100 includes one or more pressure sensors. In some embodiments, gas monitoring device 1100 includes at least one absolute pressure sensor 1118. In some embodiments, gas monitoring apparatus 1100 includes at least one differential pressure sensor 1120. A differential pressure sensor may be used to measure the flow of the gas stream in the gas sensing circuit. For example, the flow rate of the gas flow may be calculated based on the differential pressure measured by the differential pressure sensor 1120 and the bernoulli equation.

In some embodiments, the gas sensing circuit of gas monitoring device 1100 includes one or more flow regulators, such as first flow regulator 1122 and second flow regulator 1124. The flow regulator may be a flow controller, a flow restrictor, or a flow restrictor. The flow regulator may be configured to control the flow of the gas stream therethrough. For example, the flow regulator may be configured to limit the flow of the gas flow of the flow path to a particular range or value. In some embodiments, the first flow regulator 1122 is configured to regulate the first flow of gas 1014 from the moisture trap 1000. In some embodiments, second flow regulator 1124 is configured to regulate second gas flow 1016 from moisture trap 1000. In some embodiments, differential pressure sensor 1120 is configured to measure a differential pressure across flow regulator 1122.

In some embodiments, gas monitoring device 1100 includes one or more filters. A filter may be disposed at any suitable location in the gas sensing circuit to reduce or remove one or more impurities, such as moisture and solid matter, in the gas stream. Such a filter may further reduce or remove moisture in the gas sensing module to improve the measurement accuracy of the gas sensor. Additionally or alternatively, such a filter may reduce or prevent solid matter from entering the valve, which may increase the life of the gas monitoring apparatus 1100.

In some embodiments, a filter 1128 is disposed upstream of the gas sensing module 1102. Filter 1128 may include a moisture filter configured to reduce or remove moisture, such as water, from the gas and/or liquid phase. The filter 1128 may comprise a membrane filter, such as a nafion (tm) membrane filter. The gas sensing circuit of the gas monitoring apparatus 1100 may include one or more gas inlets (such as a first gas inlet 1127a and a second gas inlet 1127 b) configured to receive a flow of air from the environment or a supply of gas (such as a supply of compressed air). A filter 1126 may be provided downstream of the gas inlet to reduce or remove moisture and/or dust from the gas stream received by the gas inlet.

In some embodiments, the gas sensing circuit includes one or more NO' s _x An absorber 1108.NO (nitric oxide) _x Absorber 1108 may be configured to absorb one or more oxides of nitrogen, such as NO ₂ And NO. In some embodiments, NO _x An absorber 1108 is disposed upstream of the gas inlet to remove or reduce one or more oxides of nitrogen, such as NO, in the air stream entering the gas sensing circuit via the gas inlet ₂ And NO. The gas sensing circuit can include one or more gas outlets (such as gas outlet 1129) configured to output a flow of gas (such as second gas flow 1016 or first gas flow 1014) into the environment. In some embodiments, NO _x An absorber 1108 is disposed downstream of the gas outlet to remove or reduce one or more nitrogen oxides, such as NO, prior to releasing the gas stream into the environment ₂ And NO.

NO _x The absorber 1108 may include a gas inlet configured to absorb one or more nitrogen oxides, NO _x (such as NO and NO) ₂ ) One or more absorbent materials. NO _x The absorbent material in the absorber 1108 may be similar to the absorbent material of the exhaust gas treatment device 700. NO (nitric oxide) _x The absorber 1108 may have a structure similar to that of the exhaust gas treatment device 700. For example, NO _x The absorber 1108 may include a tortuous flow path, at least a portion of which is filled with one or more absorbent materials.

The various components of the gas monitoring apparatus 1100 may be used for one or more operational processes, such as an initialization process, a calibration process, a sampling process, and a cleaning process. Such one or more operational processes may be controlled automatically by the processor and/or manually by a user via a user interface, such as a control panel or graphical user interface. Embodiments of various processes performed by gas monitoring apparatus 1100 are described below.

In some embodiments, gas monitoring device 1100 is configured to perform an initialization process. Fig. 11A is a schematic illustration of a gas monitoring apparatus 1000 process according to some embodiments of the present disclosure. An initialization process may be performed to reduce or remove moisture in the gas sensing circuit and/or to purge pre-existing gas from the gas sensing circuit. For example, during an initialization process, ambient air may be introduced into and passed through at least a portion of the gas sensing circuit to dry and/or purge one or more flow paths of the sensing module 1102 and/or the gas sensing circuit.

In some embodiments, as shown in fig. 11A, during an initialization process, one or more switching valves may be switched to appropriate positions to fluidly connect selected connection ports to direct one or more gas flows in the gas sensing circuit. For example, the first switching valve 1110 may be switched to a second position to fluidly connect the

connection ports

1116A and 1116D. Second switching valve 1112 may be switched to its second position to fluidly connect

connection ports

1116F and 1116G. As shown by the arrows in fig. 11A, during the initialization process, for example, pump 1104 may generate an air flow through the gas sensing circuit (i.e., from gas inlet 1127a, through

connection ports

1116D and 1116A, sensing module 1102, filter 1128,

connection ports

1116G and 1116F, to outlet 1010). During the initialization process, air flow may also flow through one or more of flow regulator 1122, filter 1126, flow regulator 1124, and check valve 1106. The air flow may flow through the NO before exiting the sensing circuit via gas outlet 1129 _x An absorber 1108.

During the initialization process, as shown in fig. 11A, the pump 1104 can drive air flow to the outlet 1010, through the cup 1002, the outlet 1012, the

connection ports

1116B and 1116C, and to the gas outlet 1129. The initialization process may be performed for any suitable duration, such as less than about 1 minute, less than about 30 seconds, less than about 10 seconds, or less than about 1 second.

During the initialization process, it may be determined whether various components of gas monitoring device 1100 may be operating under normal conditions. Additionally or alternatively, gas monitoring device 1100 may generate one or more alarms indicating one or more abnormal conditions of the gas sensing circuit. For example, the switching valve may be switched to a different position to determine whether the valve can operate under normal conditions. The pump 1104 may be set to a certain flow rate and the flow rate of the gas stream generated by the pump 1104 may be measured to determine whether the pump 1104 can operate under normal conditions. When there is no gas flow in the gas sensing loop, the normal reading of the absolute pressure sensor 1118 may not exceed a predetermined value, such as any value from about 600mbar to about 1250mbar, and the normal flow rate calculated based on the reading of the differential pressure sensor 1120 may not exceed a flow rate range predetermined by the pump settings, such as from about 50ml/min to about 1000ml/min.

In some embodiments, the gas monitoring apparatus 1100 is configured to perform a calibration procedure to calibrate one or more gas sensors in the sensing module 1102. The calibration procedure may be performed regularly, such as periodically, on demand, or prior to delivery of gas mixture 907 to the patient. The sensor may be calibrated using a standard gas of known concentration of air (such as ambient air or compressed air) or a gaseous component thereof. Fig. 11B is a schematic diagram of a calibration process of gas monitoring apparatus 1100 according to some embodiments of the present disclosure. In some embodiments, as shown in FIG. 11B, ambient air is used during the calibration process. For example, the first switching valve 1110 may be switched to its first position to fluidly connect the

connection ports

1116B and 1116C. Second switching valve 1112 may be switched to its first position to fluidly connect

connection ports

1116E and 1116G. The pump 1104 can generate a flow of air from the gas inlet 1127b through

connection ports

1116E and 1116G, filter 1128, sensing module 1102, connection port 1116A, and connection port 1116C to the gas outlet 1129. NO _x An absorber 1108 may be disposed downstream of the gas inlet 1127b to remove or reduce NO before the air flow passes through the sensing module 1102 ₂ And NO. The air flow may alsoThrough one or more of flow regulator 1122, filter 1126, and check valve 1106.

During the calibration process, pump 1114 can also drive gas flow 1016 from outlet 1012 through

connection ports

1116B and 1116C to gas outlet 1129. Gas flow 1016 may also pass through filter 1126, flow regulator 1124, check valve 1106, and NO _x One or more of the absorbers 1108.

In some embodiments, a calibration process is performed to adjust a calibration curve of at least one sensor of the sensing module 1102, such as adjusting the calibration curve with an offset value. The calibration process may include a zero calibration and/or a span calibration. For example, in zero point calibration, air flow from the environment is passing through the NO _x Absorber 1108 may then be predetermined to have approximately 21% O ₂ About 0% or 0ppm NO and about 0% or 0ppm NO ₂ . The sensors of the sensing module may assume that the readings of the air flow correspond to these predetermined concentrations and may adjust their calibration curves with offset values.

In some embodiments, in span calibration, O may be used in the calibration process ₂ NO and/or NO ₂ Is known in concentration, is used to measure the concentration of the one or more standard gases. As shown in fig. 11C, the first switching valve 1110 may be switched to its first position to fluidly connect the

connection ports

1116A and 1116C. The second switching valve 1112 may be switched to its second position to fluidly connect

connection ports

1116F and 1116G. Pump 1104 can drive standard gas from outlet 1010 through connection port 1116F, connection port 1116G, filter 1128, sensing module 1102, connection port 1116A, and connection port 1116C and to gas outlet 1129. The standard gas flow may also pass through flow regulator 1122, check valve 1106 and NO before being released via gas outlet 1129 _x One or more of the absorbers 1108. The sensors of the sensing module may assume that the readings of the standard gas flow correspond to known concentrations of the standard gas and may adjust their calibration curves with an offset value.

In some embodiments, the gas monitoring device 1100 is configured to perform a sampling process to measure the concentration of one or more gas components in the sample gas stream. Fig. 11C is a schematic illustration of a sampling process of the gas monitoring apparatus 1100 according to some embodiments of the present disclosure. The sampling process may be performed on an as-needed basis, or may be performed continuously or intermittently while delivering gas mixture 907 to patient 910. In some embodiments, during sampling, the gas sensing circuit may receive the first gas flow 1014 from the outlet 1010 of the moisture trap 1000 and/or may receive the second gas flow 1016 from the outlet 1012 of the moisture trap 1000. The first flow regulator 1122 may regulate the flow of the first gas flow 1014 to a first flow rate. Second flow regulator 1124 can regulate the flow of second gas stream 1016 to a second flow rate. The first and second flow rates may be predetermined and adjusted based on the settings of the pump 1104 and/or the settings of the

flow regulators

1122 and 1124. The first flow rate and the second flow rate may be added to the flow rate of the pump 1104. For example, the flow rate of the pump 1104 may be in the range of about 50mL/min to about 1000mL/min, the first flow rate of the first gas stream 1014 may be in the range of about 40mL/min to about 800mL/min, and the second flow rate of the second gas stream 1016 may be in the range of about 10mL/min to about 200 mL/min.

In some embodiments, the concentration in the first gas stream 1014 is measured during sampling. As shown in fig. 11C, the first switching valve 1110 may be switched to its first position to fluidly connect the

connection ports

1116A and 1116C. Second switching valve 1112 may be switched to its second position to fluidly connect

connection ports

1116F and 1116G. The pump 1104 can drive a first gas flow 1014 from the outlet 1010 through connection port 1116F, connection port 1116G, filter 1128, sensing module 1102, connection port 1116A, and connection port 1116C and to a gas outlet 1129. The first gas flow 1014 may also pass through the flow regulator 1122, the one-way valve 1106, and NO before being released via the gas outlet 1129 _x One or more of the absorbers 1108. The pump 1104 can also drive the second gas flow 1016 from the outlet 1012 through the connection port 1116B and the connection port 1116C to the gas outlet 1129. The second gas flow 1016 may also be released via the gas outlet 1129 before the second gas flow 1016Through flow regulator 1124, check valve 1106 and NO _x One or more of the absorbers 1108.

In some embodiments, the one or more gas sensors of the sensing module 1102 are configured to identify and measure one or more gas components (such as NO) in the first gas flow 1014 as it passes through the gas sensing module 1102 ₂ NO and O ₂ ) The concentration of (c). Readings from these sensors may be transmitted via wired or wireless communication to a processor and/or computer readable storage medium (not shown) of gas monitoring device 1100 for further processing and/or transmission to one or more other devices.

The accuracy of one or more sensors in the sensing module 1102 may be improved when the first flow of gas 1014 passes the sensors at a predetermined flow rate or within a predetermined flow rate range. In some embodiments, the flow of the first gas flow 1014 is regulated by a flow regulator 1122, and a differential pressure sensor 1120 is used to measure the flow of the first gas flow 1014 through the flow regulator 1122. The predetermined flow rate or flow rate range may be any suitable value or range based on the type of sensor. For example, the one or more sensors may be electrochemical sensors, and the predetermined flow rate may range from about 50ml/min to about 450ml/min, such as from about 220ml/min to about 240ml/min. The pump 1104 may be used to adjust the flow of the first gas flow 1014 through the sensing module to a predetermined value or range.

In some embodiments, the gas monitoring device 1100 is configured to perform a cleaning process to reduce or remove liquid that accumulates on the moisture filter 1006 and/or in the gas sensing circuit of the moisture trap 1000. Fig. 11D is a schematic illustration of a cleaning process of the gas monitoring apparatus 1100 according to some embodiments of the present disclosure. As shown in fig. 11D, the first switching valve 1110 can be switched to its second position to disconnect the

connection ports

1116A and 1116C, thereby disconnecting the first gas flow 1014. Second switching valve 1112 may be switched to its first position to fluidly connect

connection ports

1116E and 1116G. Pump 1104 can drive second gas flow 1016 from outlet 1012 through connection port 1116B and connection port 1116C and To gas outlet 1129. Prior to releasing the second gas flow 1016 via gas outlet 1129, the second gas flow may also pass through filter 1126, flow regulator 1124, check valve 1106, and NO _x One or more of the absorbers 1108.

During the cleaning process, turning off the first gas flow 1014 allows the flow of the second gas flow 1016 to increase. As shown in fig. 10A, before exiting outlet 1012, second gas flow 1016 may flow from first chamber 1018 to cup 1002 and back to moisture filter 1006, such as the side of moisture filter 1006 facing gas flow 1009 or the side facing first chamber 1018 where liquid may accumulate. Increasing the flow of second gas stream 1016 may increase drying or sweeping of liquid accumulated on moisture filter 1006.

The gas monitoring device 1100 may perform a cleaning process based on demand and/or upon the occurrence of one or more abnormal conditions. The cleaning process may be performed for any suitable duration, such as less than about 2 minutes, less than about 1 minute, less than about 30 seconds, or less than about 10 seconds. The cleaning process may be started automatically or manually. For example, when liquid blocks at least a portion of the moisture filter 1006 and/or a flow path in the gas sensing circuit, the processor of the gas monitoring device 1100 may begin the cleaning process in response to one or more abnormal readings of the absolute pressure sensor 1118 and/or the differential pressure sensor 1120. For example, the normal absolute pressure measured by pressure sensor 1118 may be in the range of about 0.5bar to about 1.25bar during the sampling process. Absolute pressures outside this range may indicate that the moisture filter 1006 and/or the gas sensing circuit are plugged with liquid. The normal flow rate calculated based on the differential pressure measured by the pressure sensor 1120 may range from about 20ml/min to about 275ml/min, such as from about 20ml/min to about 50ml/min, from about 50ml/min to about 100ml/min, from about 100ml/min to about 150ml/min, from about 150ml/min to about 200ml/min, from about 200ml/min to about 250ml/min, or from about 250ml/min to about 275ml/min. Flow rates below this range may indicate that the moisture filter 1006 and/or the gas sensing circuit are plugged with liquid.

As described herein, the system 10 can be modular such that one or more components thereof, such as the reaction chamber 102, the reaction medium 112, one or more electrodes (e.g., the first electrode 116, the second electrode 118), the filtration system 500 or a filter thereof, the pressure vessel 600, the exhaust treatment device 700, the gas converter 800, and the flow control device, can be conveniently replaced, maintained, or serviced without substantially disassembling the system 10. Accordingly, maintenance costs of the system 10 may be reduced and the operational life of the system 10 may be extended.

In some embodiments, the system 10 may include a user interface in communication with the control loop. The user interface may include one or more controllers for receiving instructions from a user to adjust system parameters, such as the number of stages, the number of operating cycles in each stage, the concentration and/or flow rate of NO in a stage or operating cycle. The control loop may send control signals to various components to adjust these system parameters, such as the energy source 114, the carrier gas source 200, and the flow controllers or controls.

The system 10 or one or more components thereof, such as the NO generation apparatus 100 described herein, may be used in various methods for generating and/or delivering NO. For example, the system 10 or NO generation device 100 may be used to generate NO on demand. In some embodiments, the system 10 or NO generation apparatus 100 may be used to provide a steady supply of NO at a predetermined concentration over a ramp period. The ramp period may refer to a transition period during which the NO concentration of the product gas may change from an initial concentration to a predetermined steady-state concentration. For example, during the ramp period, the NO concentration of the product gas increases from an initial concentration (such as zero) to a predetermined steady-state concentration. The system 10 or NO generation apparatus 100 may be used to provide a steady supply of NO during one or more phases or during one or more operational cycles. The system 10 may be used to reduce or minimize potential air pollution and/or exposure to toxic gases (such as nitrogen dioxide) during the generation or delivery of NO. The system 10 may be used to deliver NO using another process gas (such as oxygen or air) supplied by a respiratory device (such as a ventilator). The system 10 may be used to monitor the concentration of one or more components of a gas mixture to be delivered to or inhaled by a patient.

As described herein, the steps of the disclosed methods may be modified in any manner, including by reordering steps, inserting steps, and/or deleting steps. Unless otherwise specified, one or more steps of the disclosed methods may be performed simultaneously or in any suitable temporal sequence.

Fig. 12 is a flow chart illustrating a NO generation method 1200 according to some embodiments of the present disclosure. In some embodiments, as shown in FIG. 12, method 1200 includes steps 1202-1210. In some embodiments, step 1202 includes applying a voltage or current to one or more of a plurality of electrodes disposed in a reaction medium via an energy source to generate NO. The plurality of electrodes may include a cathode. In some embodiments, NO is generated at or near one or more surfaces of the plurality of electrodes. The reaction medium may be contained in a reaction chamber of the NO generating device. In some embodiments, the reaction chamber comprises a gas region and a liquid region, and the reaction medium is disposed in the liquid region.

In some embodiments, the voltages or currents applied to the plurality of electrodes may be predetermined and/or adjusted in step 1202 based on one or more conditions, such as a desired concentration of NO in the output product gas. In some embodiments, the predetermined voltage ranges from about 1.4V to about 5.0V. In some embodiments, the predetermined current ranges from about 0mA to about 300mA. The rate of NO generation may increase with increasing voltage or current applied to the plurality of electrodes. In some cases, NO may be generated when a current of about 0mA is applied to the plurality of electrodes. In some embodiments, step 1202 includes terminating the voltage or current applied to the plurality of electrodes.

In some embodiments, step 1202 includes applying an excitation voltage or an excitation current to the plurality of electrodes for an excitation period prior to applying the predetermined voltage or the predetermined current. The excitation period may range from about 0.5 minutes to about 5 minutes, such as from about 0.5 minutes to about 1 minute, from about 1 minute to about 2 minutes, from about 2 minutes to about 3 minutes, from about 3 minutes to about 4 minutes, from about 4 minutes to about 5 minutes, or a combination thereof. In some embodiments, the excitation voltage is about 2 times to about 8 times the predetermined voltage. In some embodiments, the excitation current is about 2 to about 8 times the predetermined current.

In some embodiments, step 1202 includes switching the polarity of two electrodes (e.g., a cathode and an anode). For example, step 1202 may include reversing the polarity of the energy source, such as reversing the polarity of a DC power source or by using an AC power source. The polarity of the two electrodes may be switched on demand or according to a predetermined schedule. For example, the polarity of the two electrodes may be switched periodically, such as from about every 10 minutes to about every 10 hours.

In some embodiments, method 1200 includes step 1204. In some embodiments, step 1204 comprises receiving, by the NO generation apparatus, the carrier gas through an inlet loop of the NO generation apparatus. The inlet loop may be in fluid communication with at least one sparger disposed in the reaction medium. The at least one sprayer may be located proximate to one or more of the plurality of electrodes. In some embodiments, the carrier gas is received from a carrier gas source. In some embodiments, the carrier gas comprises nitrogen. In some embodiments, step 1204 includes generating a carrier gas from the compressed air by a carrier gas source. For example, a nitrogen generating device may be used to generate the carrier gas from compressed air.

In some embodiments, step 1204 includes controlling, by a flow control device, a flow rate of the carrier gas received through the inlet loop. In some embodiments, step 1204 includes receiving a carrier gas at a flow rate ranging from about 50mL/min to about 12L/min, such as from about 0.5L/min to about 1L/min, from about 1L/min to about 3L/min, from about 3L/min to about 5L/min, from about 5L/min to about 8L/min, from about 8L/min to about 10L/min, from about 10L/min to about 12L/min, or a combination thereof.

In some embodiments, step 1204 includes purging the system 10 with a carrier gas. For example, the carrier gas may pass through some or all of the gas flow regions of the systemOr paths such as the gas regions of the reaction chamber, inlet and outlet loops, circulation loops, and pressure vessels. The use of the carrier gas purge system 10 reduces the oxidation of NO generated in the product gas to toxic nitrous oxides (e.g., NO) ₂ ). Purging the system 10 may increase the life of a gas converter configured to reduce or remove NO ₂ 。

In some embodiments, method 1200 includes step 1206. In some embodiments, step 1206 includes sweeping a surface of one or more of the plurality of electrodes with a carrier gas. Sweeping the surface of the electrode may sweep, purge, and/or entrain NO generated at or near the surface of the electrode out of the reaction medium. This may generate a product gas, which may include the generated NO and carrier gas. In some embodiments, at least a portion of the product gas is received and/or accumulated in a gas region of a reaction chamber of the NO generating device.

In some embodiments, step 1206 includes generating bubbles of a carrier gas to sweep a surface of one or more of the plurality of electrodes. For example, step 1206 can include receiving the carrier gas through a sparger, and this step can include emitting bubbles of the carrier gas through the sparger in the reaction medium to sweep a surface of one or more of the plurality of electrodes. A sparger can be in fluid communication with the inlet circuit and disposed in the reaction medium adjacent to one or more of the plurality of electrodes. The gas bubbles emitted by the sparger can travel along a bubble path, which can extend along a surface of the at least one electrode.

In some embodiments, method 1200 includes step 1208. In some embodiments, step 1208 includes circulating the first fluid stream with respect to the reaction chamber using a first circulation loop. In some embodiments, step 1208 includes generating, by the gas pump, a first fluid flow from an inlet to an outlet of the first circulation loop. In some embodiments, the first fluid stream comprises the product gas stream generated in step 1206. In some embodiments, step 1208 includes filtering the recirculated fluid flow using one or more filters disposed upstream of the gas pump. The one or more filters may reduce or remove liquid and/or solid matter from the recirculated fluid flow prior to the recirculated fluid flow entering the gas pump.

In some embodiments, step 1208 can include circulating the first fluid stream at a flow rate ranging from about 0.5L/min to about 5.0L/min, such as from about 0.5L/min to about 1.0L/min, from about 1.0L/min to about 1.5L/min, from about 1.5L/min to about 2.0L/min, from about 2.0L/min to about 2.5L/min, from about 2.5L/min to about 3.0L/min, from about 3.0L/min to about 3.5L/min, from about 3.5L/min to about 4.0L/min, from about 4.0L/min to about 4.5L/min, from about 4.5L/min to about 5.0L/min, or a combination thereof.

In some embodiments, method 1200 includes step 1210. In some embodiments, step 1210 includes conveying the NO-containing product gas from the reaction chamber through an outlet loop. In some embodiments, the outlet loop is in fluid communication with a gas region of the reaction chamber. In some embodiments, the NO concentration of the product gas delivered from the reaction chamber may reach a steady state during the ramp period. For example, the ramp period may range from about 2 minutes to about 10 minutes.

In some embodiments, method 1200 may include one or more steps selected from steps 1212-1222 described below.

In some embodiments, method 1200 includes step 1212. In some embodiments, step 1212 includes measuring the concentration of NO in the product gas using a NO concentration sensor. In some embodiments, an NO concentration sensor may be disposed in contact with the product gas in the gas zone to measure the NO concentration in the gas zone. In some embodiments, an NO concentration sensor may be disposed in, near, or downstream of the outlet loop of the reaction chamber to detect the NO concentration of the product gas exiting the reaction chamber. For example, the NO sensor may be disposed at an opening of the outlet circuit, within a conduit of the outlet circuit, or downstream of a filter disposed downstream of the outlet circuit.

In some embodiments, method 1200 includes step 1214. Step 1214 may reduce or remove NO dissolved in the reaction medium after NO is generated in a phase or operating cycle. Step 1214 may include separating at least some of the dissolved NO from the reaction medium. Step 1214 may further include treating the separated NO, such as with an exhaust treatment device.

In some embodiments, step 1214 includes circulating the second fluid flow relative to the reaction chamber using a second circulation loop. In some embodiments, the second fluid stream in the second circulation loop comprises a liquid stream. In some embodiments, the second fluid flow in the second circulation loop comprises a gas flow. In some embodiments, step 1214 is performed before, during, and/or after the reaction medium is used to generate NO in step 1202. For example, step 1214 may be performed after terminating the voltage or current applied to the electrodes after NO is generated in a phase or operating cycle. Step 1214 may be performed before starting the application of voltage or current to the electrodes to generate NO for the next phase or operating cycle.

In some embodiments, step 1214 includes configuring and/or operating the second recirculation loop to operate in the operational mode. In the operating mode, the second fluid flow may comprise a reactive medium flow. In some embodiments, operating the second circulation loop in the operational mode includes circulating a second fluid stream from the first port of the second circulation loop, through the liquid-gas separation device, and out of the second port of the second circulation loop using the pump. The first port may be in fluid communication with a liquid region of the reaction chamber and the second port may be in fluid communication with a gas region of the reaction chamber.

In the operating mode, the second fluid stream may be circulated at any suitable flow rate, such as a flow rate ranging from about 0.1L/min to about 0.5L/min, from about 0.5L/min to about 1.0L/min, from about 1.0L/min to about 3.0L/min, from about 3.0L/min to about 5.0L/min, from about 5.0L/min to about 8.0L/min, or a combination thereof. The second recirculation loop may be operated in the operating mode for any suitable time, such as less than about 0.5 minutes, less than about 1 minute, less than about 2 minutes, less than about 5 minutes, less than about 10 minutes, or less than about 20 minutes.

In some embodiments, operating the second circulation loop in the operating mode includes separating NO from the reaction medium as the second fluid stream passes through the liquid-gas separation device. In some embodiments, operating the second circulation loop in the operating mode includes passing a sweep gas through the liquid-gas separation device to entrain NO separated from the second fluid stream as a mixed gas out of the liquid-gas separation device. In some embodiments, operating the second recirculation loop in the operating mode includes transporting the mixed gas to an exhaust treatment device prior to releasing the mixed gas into the environment.

In some embodiments, step 1214 includes configuring and/or operating the second circulation loop in the cleaning mode. The cleaning mode may be run after the working mode. In the cleaning mode, the second fluid flow may comprise a gas flow. In some embodiments, operating the second circulation loop in the cleaning mode includes circulating a second fluid flow from the second port of the second circulation loop through the liquid-gas separation device and out of the first port of the second circulation loop using the pump. In some embodiments, operating the second circulation loop in the cleaning mode comprises transporting residual reaction medium in the liquid-gas separation device back to the reaction chamber. The cleaning mode may prepare the liquid-gas separation device for the next operation mode, such as by drying a separation membrane of the liquid-gas separation device.

In the cleaning mode, the second fluid stream can be circulated at any suitable flow rate, such as a flow rate ranging from about 0.25L/min to about 0.5L/min, from about 0.5L/min to about 1.0L/min, from about 1.0L/min to about 3.0L/min, from about 3.0L/min to about 5.0L/min, or a combination thereof. The second circulation loop may be operated in the cleaning mode for any suitable time, such as less than about 0.5 minutes, less than about 1 minute, less than about 2 minutes, or less than about 5 minutes.

In some embodiments, step 1214 can include configuring the switching valve to a first position to allow the second circulation loop to operate in the working mode, and this step can include configuring the switching valve to a second position to allow the second circulation loop to operate in the cleaning mode.

In some embodiments, step 1214 includes purging the reaction chamber (e.g., a gas region of the reaction chamber) with the carrier gas. A carrier gas may accumulate in the gas region of the reaction chamber and this carrier gas may be circulated in the second circulation loop in the cleaning mode.

In some embodiments, method 1200 includes step 1216. In some embodiments, step 1216 includes passing the product gas from the reaction chamber through a filtration system. Step 1216 may include reducing or removing one or more impurities, such as solid matter (e.g., salt aerosols) and moisture, in the product gas by a filtration system. The filtration system may include one or more filtration devices or filters.

In some embodiments, method 1200 includes step 1218. In some embodiments, step 1218 includes delivering the product gas to a pressure vessel. In some embodiments, step 1218 includes receiving and storing the product gas in a pressure vessel for a pressure hold time. At the end of the pressure holding period, the pressure in the pressure vessel and/or the NO concentration may be increased to a predetermined level or a predetermined range. In some embodiments, the pressure vessel includes a first region and a second region. Step 1218 may include receiving the product gas through an inlet in fluid communication with the first zone of the pressure vessel. Step 1218 may include storing the product gas in a first region of the pressure vessel. Step 1218 may include releasing the product gas from the pressure vessel, such as through an outlet in fluid communication with the first zone. The concentration of NO in the product gas released from the pressure vessel may reach a steady state during the ramp period. The ramp period may refer to a transition period during which the NO concentration of the product gas may change from an initial concentration to a predetermined steady-state concentration. In some embodiments, step 1218 includes measuring and/or adjusting a flow rate of the product gas released from the pressure vessel using a flow control device. The flow control device may adjust the flow of the product gas in accordance with instructions received from the control device.

In some embodiments, step 1218 includes receiving and storing the product gas in a second zone in fluid communication with the first zone. Step 1218 may include storing the product gas in the second zone at a pressure less than or equal to a predetermined threshold. Step 1218 can include releasing the product gas stored in the second zone from the second zone to the first zone, and the step can further include releasing the product gas from the first zone out of the pressure vessel. In some embodiments, step 1218 includes releasing gas from the pressure vessel (such as from a second region of the pressure vessel) through the pressure relief valve when the pressure in one or more regions of the pressure vessel exceeds a predetermined threshold. In some embodiments, step 1218 includes treating the gas released through the pressure relief valve, such as by an exhaust treatment device.

In some embodiments, method 1200 includes step 1220. In some embodiments, step 1220 may include passing the product gas through a gas converter to reduce or remove one or more toxic nitrogen oxides, such as NO, in the product gas ₂ . In some embodiments, step 1220 includes absorbing or converting some or all of the toxic nitrogen oxides, such as NO, by the gas converter as the product gas passes therethrough ₂ . Toxic nitrogen oxides can be converted to NO. Step 1220 may include passing the product gas from the inlet through the tortuous flow path to the outlet of the gas converter, and this step may include passing the product gas through a filter material in the tortuous flow path. Step 1220 may include using a filter material to absorb some or all of the toxic nitrogen oxides in the product gas. Additionally or alternatively, step 1220 may include converting some or all of the toxic nitrogen oxides in the product gas to NO using a filter material.

In some embodiments, method 1200 includes step 1222. In some embodiments, step 1222 includes delivering NO or a gas mixture including NO to the patient using the ventilation circuit. The gas mixture may include one or more gas components, such as air, oxygen, moisture. In some embodiments, step 1222 includes delivering NO or a gas mixture to the patient through an inspiratory circuit of the ventilation circuit. In some embodiments, step 1222 includes receiving exhaled gas from the patient through an exhalation circuit of the ventilation circuit.

In some embodiments, step 1222 includes delivering NO through a flow of gas (e.g., air or oxygen) supplied by a breathing apparatus (e.g., a ventilator) connected to the ventilation circuit. For example, step 1222 may include combining a flow of gas (such as a flow of air or a flow of oxygen) supplied by a respiratory device (such as a ventilator) with a flow of product gas received from a NO system to generate a gas mixture. In some embodiments, step 1222 includes adding the water split mixture prior to delivering the gas mixture to the patient.

In some embodiments, step 1222 includes measuring a flow of gas (such as a flow of air or a flow of oxygen) supplied from a breathing apparatus (such as a ventilator) using a flow sensor. The flow sensor may communicate with the control device via a wired connection or a wireless connection. Step 1222 may further include sending a sensing signal or reading from the flow sensor to the control device.

In some embodiments, step 1222 includes measuring, by one or more gas sensors or a gas monitoring device including one or more gas sensors, a concentration of one or more components of a gas mixture to be delivered to a patient. For example, step 1222 may include obtaining a sample gas flow of a gas mixture to be delivered to a patient and measuring a concentration of one or more components of the sample gas flow. One or more gas sensors or gas monitoring devices may communicate with the control device via a wired or wireless connection. Step 1222 may include sending a sensing signal or reading from one or more gas sensors or gas monitoring devices to a control device. In some embodiments, step 1222 includes providing an alert when one or more readings of one or more gas sensors are above or below a threshold. The alarm may be in any suitable form, such as an audible or visual alarm, for any suitable duration.

In some embodiments, step 1222 includes controlling the flow of product gas to mix or combine with a flow of gas (such as a flow of air or oxygen) supplied by a breathing apparatus (such as a ventilator). For example, the control device may be in communication with a flow control device configured to control the flow of the product gas from the NO system. The control device may send instructions to the flow control device to adjust the flow rate of the product gas. The control device may generate instructions based on one or more sensed signals or readings of one or more flow sensors and/or one or more gas sensors.

In some embodiments, step 1222 includes controlling a flow of air or oxygen supplied by the ventilator. For example, the control device may be in wired or wireless communication with the ventilator. The control device may send instructions to the ventilator to adjust the flow of air or oxygen.

In some embodiments, step 1222 includes operating a gas monitoring device to measure a concentration of one or more components of a gas mixture to be delivered to a patient during one or more operations. For example, step 1222 may include performing one or more of an initialization process, a cleaning process, a sampling process, and a calibration process.

The foregoing description has been presented for purposes of illustration. They are not intended to be exhaustive or to be limited to the precise forms or embodiments disclosed. Modifications and adaptations to the embodiments will be apparent from consideration of the specification and practice of the disclosed embodiments. For example, the described embodiments include hardware, but systems and methods consistent with the present disclosure may be implemented in hardware and software. Further, while certain components have been described as being connected to one another, the components may be integrated with one another or distributed in any suitable manner.

Moreover, although illustrative embodiments have been described herein, the scope includes any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., of aspects across various embodiments), adaptations and/or alterations based on the present disclosure. Further, the steps of the disclosed methods may be modified in any manner, including by reordering steps or inserting steps or deleting steps.

The features and advantages of the present disclosure are apparent from the detailed description. Further, since numerous modifications and variations will readily occur to those skilled in the art upon studying this disclosure, it is not desired to limit the disclosure to the exact configuration and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the disclosure.

It should be understood that the above-described embodiments may be implemented by hardware, software (program code), or a combination of hardware and software. If implemented in software, it may be stored on the computer-readable medium described above. When executed by a processor, software may perform at least some of the steps of the disclosed methods.

In the foregoing specification, embodiments have been described with reference to numerous specific details that may vary from implementation to implementation. Certain adaptations and modifications of the described embodiments can be made. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims. The order of steps shown in the figures is also for illustrative purposes only and does not imply that all of the steps must be performed for any given method of operation nor that all of the steps be limited to any particular order of steps. Thus, those skilled in the art will appreciate that the steps may be performed in a different order while performing the same method. Further, the devices shown in the figures are merely illustrative, and a given device or system may include different combinations of components or modules of these devices.

Claims

1. An apparatus for generating Nitric Oxide (NO), the apparatus comprising:

a reaction chamber having a liquid region configured to contain a reaction medium and a gas region configured to contain a product gas comprising NO;

a plurality of electrodes disposed in the reaction medium, the plurality of electrodes including a cathode;

an energy source electrically connected to the plurality of electrodes and configured to apply a predetermined voltage or a predetermined current to the cathode to generate NO;

a sparger disposed in the reaction medium;

an inlet circuit in fluid communication with the sparger and configured to deliver a carrier gas to the sparger; and

an outlet loop in fluid communication with a gas region of the reaction chamber and configured to convey the product gas from the reaction chamber; and

a first circulation loop configured to circulate a first fluid flow relative to the reaction chamber, the first circulation loop comprising:

a first inlet in fluid communication with a gas region of the reaction chamber;

a first outlet in fluid communication with the sprinkler; and

A first pump configured to generate a first fluid flow from the first inlet to the first outlet.

2. The apparatus of claim 1, wherein the carrier gas comprises nitrogen.

3. The apparatus of claim 1, wherein the first fluid stream comprises a product gas stream.

4. The apparatus of claim 1, wherein the sparger is disposed adjacent to the cathode and is configured to emit gas bubbles in the reaction medium to propagate along a surface of the cathode.

5. The apparatus of claim 1, wherein the sparger comprises a porous structure comprising a plurality of pores having an average size of about 0.1 μ ι η to about 1 mm.

6. The apparatus of claim 1, wherein the reaction chamber includes a first side and a second side opposite the first side, and the cathode includes an electrode plate positioned substantially perpendicular to the second side of the reaction chamber.

7. The apparatus of claim 6, wherein the electrode plate comprises a surface, a first edge extending along a first side of the reaction chamber, and a second edge opposite the first edge extending along a second side of the reaction chamber.

8. The apparatus of claim 7, wherein the sparger is disposed between the second side of the reaction chamber and the second edge of the electrode plate, and the sparger is configured to emit gas bubbles along a gas bubble path extending from the second edge to the first edge of the electrode plate.

9. The apparatus of claim 1, further comprising a second circulation loop configured to circulate a second fluid flow relative to the reaction chamber, the second circulation loop comprising:

a first port in fluid communication with a liquid region of the reaction chamber;

a second port in fluid communication with a gas region of the reaction chamber;

a second pump configured to generate a second fluid flow from the first port to the second port or from the second port to the first port; and

a liquid-gas separation device disposed downstream of the second pump and configured to separate NO from the reaction medium as the reaction medium passes therethrough.

10. The apparatus of claim 9, wherein the liquid-gas separation device comprises an NO permeable separation membrane.

11. The apparatus of claim 10, wherein the separation membrane has a range from about 500cm ² To about 50000cm ² Surface area of (a).

12. The apparatus of claim 9, wherein the second circulation loop further comprises a switching valve and is configured to operate in a working mode and a cleaning mode, wherein

In the operating mode, the switching valve is in a first position, the second fluid stream comprises a reactive media stream, and the second pump is configured to circulate the second fluid stream from the first port through the liquid-gas separation device and to the second port; and

in the cleaning mode, the switching valve is in a second position, the second fluid flow comprises a gas flow, and the second pump is configured to circulate the second fluid flow from the second port through the liquid-gas separation device and to the first port.

13. The apparatus of claim 1, wherein the reaction medium comprises a buffer solution, a source of nitrite ions, and a catalyst.

14. The apparatus of claim 13, wherein the catalyst comprises a metal-ligand complex.

15. The apparatus of claim 13, the source of nitrite ions comprising one or more nitrites.

16. The apparatus of claim 1, wherein the predetermined voltage is about 1V to about 5.0V.

17. The apparatus of claim 1, wherein the predetermined current is about 0mA to about 600mA.

18. The apparatus of claim 1, further comprising an NO sensor configured to detect an NO concentration of the product gas.

19. A system for generating Nitric Oxide (NO), the system comprising:

apparatus for generating NO, the apparatus comprising:

a sparger disposed in the reaction medium;

a pressure vessel in fluid communication with the outlet circuit, the pressure vessel configured to receive product gas from the outlet circuit, store the received product gas at or below a predetermined pressure, and release the received product gas.

20. The system of claim 19, wherein the carrier gas comprises nitrogen.

21. The system of claim 19, further comprising a first circulation loop configured to circulate a first fluid flow relative to the reaction chamber, the first circulation loop comprising:

a first inlet in fluid communication with a gas region of the reaction chamber;

a first outlet in fluid communication with the sprayer; and

22. The system of claim 21, wherein the first fluid stream comprises a product gas stream.

23. The system of claim 19, wherein the sparger is disposed adjacent to the cathode and is configured to emit gas bubbles in the reaction medium to propagate along a surface of the cathode.

24. The system of claim 19, wherein the sparger comprises a porous structure comprising a plurality of pores having an average size of about 0.1 μ ι η to about 1 mm.

25. The system of claim 19, wherein the reaction chamber comprises a first side and a second side opposite the first side, and the cathode comprises an electrode plate positioned substantially perpendicular to the second side of the reaction chamber.

26. The system of claim 25, wherein the electrode plate comprises a surface, a first edge extending along a first side of the reaction chamber, and a second edge opposite the first edge extending along a second side of the reaction chamber.

27. The system of claim 26, wherein the sparger is disposed between the second side of the reaction chamber and the second edge of the electrode plate, and the sparger is configured to emit gas bubbles along a gas bubble path extending from the second edge to the first edge of the electrode plate.

28. The system of claim 19, further comprising a second circulation loop configured to circulate a second fluid flow relative to the reaction chamber, the second circulation loop comprising:

a second port in fluid communication with a gas region of the reaction chamber;

29. The system of claim 28, wherein the liquid-gas separation device comprises an NO permeable separation membrane.

30. The system of claim 28, wherein the separation membrane has a width of about 500cm ² To about 50000cm ² Surface area of (a).

31. The system of claim 28, wherein the second circulation loop further comprises a switching valve and is configured to operate in a working mode and a cleaning mode, wherein

In the operating mode, the switching valve is in a first position, the second fluid stream comprises a flow of a reactive medium, and the second pump is configured to circulate the second fluid stream from the first port through the liquid-gas separation device and to the second port; and is

32. The system of claim 19, wherein the reaction medium comprises a buffer solution, a source of nitrite ions, and a catalyst.

33. The system of claim 32, wherein the catalyst comprises a metal-ligand complex.

34. The system of claim 32, the source of nitrite ions comprising one or more nitrites.

35. The system of claim 19, wherein the predetermined voltage is about 1.4V to about 5.0V.

36. The system of claim 19, wherein the predetermined current is about 0mA to about 600mA.

37. The system of claim 19, further comprising an NO sensor configured to detect an NO concentration of the product gas.

38. The system of claim 19, wherein the pressure vessel comprises:

a body defining an internal cavity including a first region and a second region in fluid communication with and disposed downstream of the first region;

A gas inlet and a gas outlet in fluid communication with the first region; and

a plurality of baffles defining a tortuous flow path through the first region and the second region; and

a pressure relief valve disposed on the body and in fluid communication with the second region.

39. The system of claim 38, wherein

The first region includes a first plurality of chambers defining a first flow path; and is provided with

The second region includes a second plurality of chambers defining a second flow path in fluid communication with the first flow path.

40. The system of claim 38, wherein the pressure vessel further comprises a pressure sensor configured to detect a gas pressure in the first region.

41. The system of claim 19, further comprising a filtration system disposed downstream of and in fluid communication with the outlet loop, the filtration system configured to reduce one or more impurities in the product gas.

42. The system of claim 41, wherein the filtration system comprises a moisture filter and a solid matter filter.

43. The system of claim 42 wherein the solid matter filter comprises a polymeric material having a porous structure.

44. The system of claim 43, wherein the polymeric material comprises one or more materials selected from the group consisting of polytetrafluoroethylene, polyvinylidene fluoride, polyethersulfone, mixed cellulose esters, polyamide (nylon), nylon 6, and nylon 66.

45. The system of claim 43, wherein the porous structure has an average pore size of about 0.01 μm to about 2.0 μm.

46. The system of claim 42, wherein the moisture filter comprises at least one membrane filter.

47. The system of claim 21, further comprising a filtration device disposed downstream of the first inlet of the first circulation loop and upstream of the first pump, the filtration device configured to reduce or remove one or more liquid impurities and/or solid impurities in the first fluid stream.

48. The system of claim 47, wherein the filtration device is configured to allow the one or more liquid impurities and/or solid impurities to settle out of the first fluid stream based on gravity.

49. The system of claim 38, further comprising an exhaust treatment device disposed downstream of the pressure vessel and in fluid communication with the pressure relief valve, the exhaust treatment device configured to reduce or remove one or more oxides of nitrogen in the gas received from the pressure vessel via the pressure relief valve.

50. The system of claim 49, wherein the exhaust treatment device comprises a tortuous flow path at least partially filled with a filter material configured to react with the one or more nitrogen oxides.

51. The system of claim 50, wherein the filter material comprises a substrate prepared with an oxidizing agent.

52. The system of claim 51, wherein the substrate comprises at least one material selected from the group consisting of molecular sieves, silica gel, alumina, sponge, cotton, foam resins, silica, and activated carbon.

53. The system of claim 51, wherein the oxidizing agent comprises one or more salts selected from the group consisting of permanganates, persulfates, chromates, and dichromates.

54. The system of claim 19, further comprising a gas converter disposed downstream of and in fluid communication with the pressure vessel, the gas converter configured to absorb and/or convert one or more nitrogen oxides in the product gas to NO.

55. The system of claim 54, wherein the gas converter comprises:

a main body;

an inlet;

an outlet; and

a tortuous flow path extending from the inlet to the outlet, the tortuous flow path configured to be at least partially filled with a filter material.

56. The system of claim 55, wherein the filter material comprises a substrate prepared with a reducing agent.

57. The system of claim 56, wherein the substrate comprises at least one material selected from the group consisting of molecular sieves, silica gel, alumina, sponge, cotton, and foamed resin.

58. The system of claim 56, wherein the reducing agent comprises at least one selected from the group consisting of vitamin C, vitamin E, and vitamin A.

59. The system of claim 55, wherein the gas converter further comprises a plurality of baffles configured to divide the internal cavity of the body into a plurality of chambers defining the tortuous flow path.

60. The system of claim 19, further comprising a carrier gas source disposed upstream of and in fluid communication with the inlet circuit, the carrier gas source configured to generate the carrier gas or supply the carrier gas to the inlet circuit.

61. The system of claim 60, wherein the carrier gas source comprises a nitrogen generating device configured to generate the carrier gas from compressed air, the nitrogen generating device comprising a nitrogen separation membrane.

62. The system of claim 60, wherein the carrier gas comprises greater than about 99.0% nitrogen by volume.

63. The system of claim 60, wherein the carrier gas source comprises a flow control device configured to control a flow of carrier gas to the inlet circuit.

64. The system of claim 19, further comprising a ventilation circuit configured to connect with a respiratory device, the ventilation circuit comprising an inspiratory circuit disposed downstream of and in fluid communication with the respiratory device and the pressure vessel.

65. The system of claim 64, wherein the inspiratory circuit comprises:

an inlet configured to receive a flow of air or oxygen from the respiratory device;

a port disposed downstream of the inlet, the port configured to receive product gas from the pressure vessel;

A flow sensor disposed downstream of the inlet and configured to measure a flow rate of the air stream or the oxygen stream; and

an outlet configured to deliver a gas mixture comprising product gas from the pressure vessel and air or oxygen from the respiratory device.

66. The system of claim 65, wherein the inspiratory circuit further comprises a sampling port disposed upstream of the outlet and configured to output a sample gas flow of the gas mixture.

67. The system of claim 66, further comprising a gas monitoring device comprising one or more gas sensors configured to receive the sample gas stream and measure NO of the sample gas stream ₂ NO and O ₂ One or more concentrations of (a).

68. The system of claim 67, further comprising:

a flow control device configured to control the flow of product gas from the pressure vessel into the aspiration circuit;

a control device in communication with the flow sensor, the flow control device, and the gas monitoring device, wherein the control device is configured to

Receiving one or more sensing signals or readings from the gas monitoring device and/or the flow sensor;

generating instructions based on the one or more sensed signals or readings; and

sending the instruction to the flow control device to adjust the flow of product gas into the aspiration circuit.

69. A system for generating Nitric Oxide (NO), the system comprising:

an apparatus for generating NO, the apparatus comprising:

a reaction chamber having a liquid region configured to contain a reaction medium and a gas region configured to contain a product gas, the product gas comprising NO;

a plurality of electrodes disposed in the reaction medium, the plurality of electrodes comprising a cathode;

an energy source electrically connected to the plurality of electrodes and configured to apply a predetermined voltage or a predetermined current to the cathode to generate NO; and

a sparger disposed in the reaction medium;

an inlet circuit in fluid communication with the sparger and configured to deliver a carrier gas to the sparger;

a first inlet in fluid communication with a gas region of the reaction chamber;

a first outlet in fluid communication with the sprinkler; and

a first pump configured to generate a first fluid flow from the first inlet to the first outlet; and

a second circulation loop configured to circulate a second fluid flow relative to the reaction chamber, the second circulation loop comprising:

a second port in fluid communication with a gas region of the reaction chamber;

a liquid-gas separation device disposed downstream of the second pump and configured to separate NO from the reaction medium as the reaction medium passes therethrough;

a filtration system disposed downstream of and in fluid communication with the outlet circuit, the filtration system configured to reduce one or more impurities in the product gas;

A pressure vessel disposed downstream of and in fluid communication with the filtration system, the pressure vessel configured to receive product gas from the outlet circuit, store the received product gas at or below a predetermined pressure, and release the received product gas; and

a ventilation circuit disposed downstream of and in fluid communication with the pressure vessel, the ventilation circuit configured to deliver NO in the product gas to a patient.

70. A method for generating Nitric Oxide (NO), the method comprising:

applying a predetermined voltage or a predetermined current to one or more of a plurality of electrodes disposed in a reaction medium contained in a reaction chamber to generate NO by an energy source, the plurality of electrodes including a cathode, the reaction chamber including a gas region and a liquid region, the liquid region configured to contain the reaction medium, the gas region configured to contain a product gas including NO;

receiving a carrier gas through an inlet loop, the inlet loop in fluid communication with a sparger disposed in the reaction medium;

Emitting bubbles of the carrier gas in the reaction medium through the sparger to sweep across a surface of one or more of the plurality of electrodes;

circulating a first fluid stream in the first circulation loop relative to the reaction chamber, the first fluid stream comprising a product gas stream; and

the product gas is conveyed from the reaction chamber through an outlet loop that is in fluid communication with a gas region of the reaction chamber.

71. The method of claim 70, wherein circulating the first fluid stream relative to the reaction chamber comprises generating a first fluid stream by a first pump from a first inlet of the first circulation loop in fluid communication with a gas region of the reaction chamber to a first outlet of the first circulation loop in fluid communication with the sparger.

72. The method of claim 71, further comprising circulating the first fluid stream at a rate of about 0.5L/min to about 5.0L/min.

73. The method of claim 71, further comprising combining the first fluid flow with the carrier gas upstream of the sparger.

74. The method of claim 70, wherein said sparger comprises a porous structure comprising a plurality of pores having an average size of about 0.1 μm to about 1 mm.

75. The method of claim 70, wherein the reaction chamber comprises a first side and a second side opposite the first side, and the cathode comprises an electrode plate positioned substantially perpendicular to the second side of the reaction chamber.

76. The method of claim 75, wherein the electrode plate comprises a surface, a first edge extending along a first side of the reaction chamber, and a second edge opposite the first edge extending along a second side of the reaction chamber.

77. The method of claim 76, the sparger disposed between the second side of the reaction chamber and the second edge of the electrode plate, the method further comprising emitting the gas bubbles through the sparger along a path of the gas bubbles extending from the second edge to the first edge of the electrode plate.

78. The method of claim 70, further comprising:

terminating the application of the predetermined voltage or the predetermined current; and

A second fluid flow is generated in a second circulation loop relative to the reaction chamber.

79. The method of claim 78, wherein the second circulation loop further includes a switching valve and is configured to operate in a working mode and a cleaning mode, the method further comprising:

configuring the switching valve at a first position; and

operating the second circulation loop in the operating mode, comprising:

circulating the second fluid stream from a first port through a liquid-gas separation device and to a second port by a second pump, the first port in fluid communication with a liquid region of the reaction chamber, the second port in fluid communication with a gas region of the reaction chamber, the second fluid stream comprising a stream of a reaction medium; and

separating NO from the reaction medium by the liquid-gas separation device as the reaction medium passes therethrough.

80. The method of claim 79, wherein the liquid-gas separation device comprises a NO permeable separation membrane.

81. The method of claim 80, wherein said liquid-gas separation device comprises a membrane having a thickness of from 500cm ² To 50000cm ² The surface area of (a).

82. The method of claim 79, further comprising circulating the second fluid stream at a flow rate of about 0.25L/min to about 10.0L/min.

83. The method of claim 79, further comprising operating the second circulation loop in the work mode for less than about 20 minutes.

84. The method of claim 79, further comprising:

configuring the switching valve in a second position; and

operating the second circulation loop in the cleaning mode, comprising:

circulating, by the second pump, the second fluid stream from the second port to the first port through the liquid-gas separation device, the second fluid stream comprising a gas stream.

85. The method of claim 84, further comprising circulating said second fluid stream through said liquid-gas separation device at a flow rate of 0.25L/min to 5.0L/min.

86. The method of claim 84, further comprising operating the second circulation loop in the cleaning mode for a time of about 0.5 minutes to about 5 minutes.

87. The method as in claim 70, wherein the reaction medium comprises a buffer solution, a source of nitrite ions, and a catalyst.

88. The method of claim 87, wherein the catalyst comprises a metal-ligand complex.

89. The method of claim 87, the source of nitrite ions comprising one or more nitrites.

90. The method of claim 70, wherein the predetermined voltage is about 1.4V to about 5.0V.

91. The method of claim 70, wherein the predetermined current is about 0mA to about 600mA.

92. The method of claim 70, further comprising measuring the NO concentration of the product gas by a NO sensor.

93. The method of claim 70, further comprising applying an excitation voltage or an excitation current to at least one of said plurality of electrodes for an excitation period prior to applying said predetermined voltage or said predetermined current.

94. The method of claim 93, wherein the excitation period is about 0.5 minutes to about 5 minutes.

95. The method of claim 93, wherein the excitation voltage is about 2 times to about 8 times the predetermined voltage.

96. The method of claim 93 wherein the excitation current is about 2 to about 8 times the predetermined current.

97. The method of claim 70, further comprising passing a product gas having a steady state NO concentration through the outlet loop during a ramp period.

98. The method of claim 97, wherein the ramp period is from about 2 minutes to about 10 minutes.

99. The method of claim 70, further comprising receiving the carrier gas at a flow rate of about 50mL/min to about 12 mL/min.

100. The method of claim 70, further comprising delivering the product gas to a pressure vessel in fluid communication with the outlet loop, wherein the pressure vessel comprises:

a gas inlet and a gas outlet in fluid communication with the first region;

a plurality of baffles defining a tortuous flow path through the first and second regions; and

101. The method of claim 100, further comprising delivering the product gas from the pressure vessel via the gas outlet after a pressure hold period.

102. The method of claim 101, further comprising detecting a gas pressure in the first region by a pressure sensor.

103. The method of claim 70, further comprising:

passing the product gas from the outlet loop to a filtration system disposed downstream of and in fluid communication with the outlet loop; and

reducing one or more impurities in the product gas by the filtration system.

104. The method of claim 103, wherein the filtration system comprises a moisture filter and a solid matter filter.

105. The method of claim 104 wherein the solid matter filter comprises a polymeric material having a porous structure.

106. The method of claim 105, wherein the polymeric material is selected from the group consisting of polytetrafluoroethylene, polyvinylidene fluoride, polyethersulfone, mixed cellulose esters, polyamide (nylon), nylon 6, and nylon 66.

107. The method of claim 105, wherein the porous structure has an average pore size of 0.1 μ ι η to 2.0 μ ι η.

108. The method of claim 104, wherein said moisture filter comprises at least one membrane filter.

109. The method of claim 70, further comprising reducing or removing one or more liquid impurities and/or solid impurities in the first fluid stream based on gravity via a filtration device.

110. The method of claim 100, further comprising:

delivering gas released from the pressure vessel through the pressure relief valve to an exhaust treatment device; and

reducing one or more nitrogen oxides in the gas by the exhaust gas treatment device.

111. The method of claim 110, further comprising passing the product gas through a tortuous flow path of the exhaust treatment device at least partially filled with a filter material configured to react with the one or more nitrogen oxides.

112. The method of claim 111, wherein the filter material comprises a substrate prepared with an oxidizing agent.

113. The method of claim 112, wherein said substrate comprises at least one material selected from the group consisting of molecular sieves, silica gel, alumina, sponge, cotton, foam resins, silica, and activated carbon.

114. The method of claim 112, wherein the oxidizing agent comprises one or more salts selected from the group consisting of permanganates, persulfates, chromates, and dichromates.

115. The method of claim 100, further comprising:

passing the product gas from the pressure vessel to and through a gas converter comprising a tortuous flow path extending from an inlet to an outlet, the tortuous flow path configured to be at least partially filled with a filter material; and

absorbing one or more nitrogen dioxide species in the product gas, and/or converting one or more nitrogen dioxide species in the product gas to NO.

116. The method of claim 115, wherein the filter material comprises a substrate prepared by treatment with a reducing agent.

117. The method of claim 116, wherein the substrate comprises at least one material selected from the group consisting of molecular sieves, silica gel, alumina, sponge, cotton, and foamed resin.

118. The method of claim 116, wherein the reducing agent comprises at least one selected from the group of vitamin C, vitamin E, and vitamin a.

119. The method of claim 70, further comprising generating the carrier gas from compressed air by a nitrogen generating device comprising a nitrogen separation membrane.

120. The method of claim 119, wherein the carrier gas comprises greater than about 99.0% nitrogen by volume.

121. The method of claim 119, wherein the nitrogen separation membrane comprises a plurality of pores having an average pore size of about 0.005 μ ι η to about 0.02 μ ι η.

122. The method of claim 121, wherein said nitrogen separation membrane comprises at least one material selected from the group consisting of poly (4-methyl-1-pentene), brominated polycarbonate, polypropylene, polyimide, and polydimethylsiloxane.

123. The method of claim 119, further comprising controlling a flow of carrier gas to the inlet loop via a flow control device.

124. The method of claim 100, further comprising delivering the product gas through a ventilation circuit disposed downstream of and in fluid communication with the pressure vessel, the ventilation circuit configured to connect with a respiratory device.

125. The method of claim 124, further comprising:

receiving a flow of air or oxygen from the respiratory device via an inlet of an inspiratory circuit of the ventilation circuit;

Receiving product gas from the pressure vessel via a port disposed downstream of an inlet of the aspiration circuit; and

delivering a gas mixture comprising product gas from the pressure vessel and air or oxygen from the respiratory device via an outlet of the inspiratory circuit.

126. The method of claim 125, further comprising receiving a sample gas flow of the gas mixture from a sampling port of the inspiratory circuit through a gas monitoring device comprising one or more gas sensors.

127. The method of claim 126, further comprising measuring NO of the sample gas stream by the gas monitoring device ₂ NO and O ₂ One or more concentrations of (a).

128. The method of claim 126, further comprising:

receiving, by a control apparatus, one or more sensing signals or readings from the gas monitoring device;

generating, by the control device, instructions based on the one or more sensing signals; and

sending, by the control device, instructions to a flow control device disposed downstream of the pressure vessel to adjust a flow rate of product gas into the aspiration circuit.

129. The method of claim 126, further comprising:

receiving, by a control device, one or more sensing signals or readings from a flow sensor disposed downstream of the inlet and configured to measure a flow rate of the air stream or the oxygen stream;

generating, by the control device, instructions based on the one or more sensed signals or readings; and