JP2022513039A - Parallel gas absorption method and system with enhanced absorber - Google Patents

Abstract

The gas treatment system will be described. The gas treatment system is configured to contact a sour feed gas stream containing acid gas with a solvent stream to produce a partially sweetened gas stream and a rich parallel flow contact that has absorbed the acid gas. Equipped with a system. At least one of the parallel flow contact systems is configured to send a rich solvent flow to the regenerator. The regenerator is configured to remove the absorbed acid gas from the rich solvent stream to generate a lean solvent stream. The gas treatment system is a solvent treatment apparatus configured to treat at least a portion of the lean solvent stream to generate a fortified solvent stream, as well as a partial sweetening gas stream and a partially loaded solvent stream in contact with each other. It also comprises a final parallel flow contact system configured to generate a solvent flow and a final gas flow. [Selection diagram] Fig. 3

Description

Mutual reference to related applications This application is a US provisional patent application No. 62/769144 filed on November 19, 2018, entitled "ENHANCED ACID GAS REMOVAL WITHIN A GAS PROCESSING SYSTEM (enhancement of acid gas removal in gas treatment systems). ) ”Is the priority interest.

This technique uses a treatment solvent in a gas treatment system with a parallel flow scheme to enhance the removal of acid gas from the gas flow. More specifically, the art provides the use of solvent treatment equipment associated with the final stages of a gas treatment system to enhance the ability of the solvent to selectively remove acid gas from the gas stream.

This section is intended to introduce various aspects of the art that may be relevant to exemplary embodiments of the art. This description is believed to help provide a framework for a good understanding of certain aspects of the art. Therefore, it should be understood that this section should be read from this point of view and does not necessarily recognize the prior art.
When hydrocarbons are produced from storage tanks, non-hydrocarbon gases are often produced accidentally. Such gases include pollutants such as hydrogen sulfide (H _{2S) and carbon dioxide (CO 2 )} . When H _{2S or CO 2 is} generated as part of a hydrocarbon gas stream, the source gas stream is sometimes referred to as "sour gas". H ₂ S and CO ₂ are often collectively referred to as "acid gas".
In addition to the hydrocarbon production stream, the acid gas may accompany the syngas stream or the refinery gas stream. Acid gas may also be present in so-called flash gas streams in gas treatment equipment. In addition, acid gas may be produced by burning coal, natural gas, or other carbonaceous fuels.
Natural gas streams may contain other "acidic" impurities as well as H _{2S and CO 2 .} These impurities include mercaptans and other trace sulfur compounds (eg COS). The natural gas stream may also contain water. Such impurities are often removed before use in industry or at home. For example, the natural gas stream is typically purified prior to sale to a concentration of less than 4 parts per million (ppm) and CO ₂ to a concentration of less than _2-3 volume percent (vol%). .. The extent to which such impurities should be removed is stipulated by pipeline regulations that help ensure public safety and reduce corrosion to maintain pipeline integrity.
Acid gas removal is a costly and equipment intensive process. Removal of H ₂ S from natural gas streams is by safety, health and environmental considerations when dealing with toxic H ₂ S, as well as treatment of sulfur by-products into solid sulfur or acid gas infusion methods. It is particularly complicated due to the injection of H _2S rich gas.
Various methods have been devised to remove acid gas from the raw natural gas stream. For example, the raw material natural gas stream may be treated with a solvent. Examples of the solvent include chemical solvents such as amines. Examples of amines used for sour gas treatment include monoethanolamine (MEA), diethanolamine (DEA), and methyldiethanolamine (MDEA).
A physical solvent may be used instead of the chemical solvent. Examples thereof include SELEXOL (trademark) (manufactured by Dow Chemical Company) and RECTISOL (registered trademark) (manufactured by The Linde Group). However, chemical solvents are generally more effective than physical solvents, especially at supply gas pressures below about 2.07 MPa (about 300 psia). In some cases, a hybrid solvent which is a mixture of a physical solvent and a chemical solvent may be used. One example is Sulfinol®.

Chemical solvents such as amine-based solvents depend on the chemical reaction between the solvent in the natural gas stream and the acid gas. This reaction method is sometimes called "gas sweetening". As an example, the reaction between the acid gas and the tertiary amine (R ₁ R ₂ R ₃ -N) is shown in the following formulas 1 and 2.
R-NH ₂ + H ₂ S → R-NH ₂ H ⁺ + SH- ⁽ Very fast reaction) (Equation 1)
R-NH ₂ + CO ₂ + H ₂ O → R-NH ₂ H ⁺ + HCO _3- ⁽ Slow reaction) (Equation 2)
As shown in Equation 1, the reaction of H _2S with amines is inherently very fast and is often regarded as instantaneous with respect to diffusion and other kinetic limitations. However, as shown in Equation 2, the reaction of CO ₂ is a little slower. Utilizing these differences in reaction rates, it is possible to selectively remove one type of impurity from other impurities in the gas treatment system. The primary and secondary amines have a fast reaction pathway with CO ₂ forming carbamate. Therefore, these amines are usually not available for selective H _2S removal. An exception to this is the "steric hindrance" amine, which prevents CO ₂ from reacting with amino hydrogen to form carbamate.
With shale gas, it is often necessary to remove H ₂ S with little or no CO ₂ removed. Therefore, selective H _2S removal is becoming a central part of the treatment facility for natural gas assets. Solvents with high selectivity for H ₂ S may be used to achieve this selective H ₂ S removal. The "H _{2S selectivity" of the solvent is defined as the ratio of H 2 S} removal to CO ₂ removal, which is a function of each reaction rate. _High H 2S selectivity can be obtained by using a solvent having a slow reaction rate with CO ₂ . Similarly, by minimizing the contact time between the gas phase and the liquid phase, the uptake of H _2S can be enhanced more than CO ₂ .

An exemplary embodiment provides a gas treatment system. The gas treatment system comprises a number of parallel flow contact systems, which are contacted with a sour feed gas stream containing acid gas and a solvent stream to partially sweeten the gas stream and a rich solvent containing absorbed acid gas. It is configured to generate a flow. At least one of the parallel flow contact systems is configured to send a rich solvent flow to the regenerator. The regenerator is configured to remove the absorbed acid gas from the rich solvent stream and generate a lean solvent stream. Further, the gas treatment system is a solvent treatment apparatus configured to treat at least a part of the lean solvent flow to generate a strengthened solvent flow, and the partially sweetened gas flow and the strengthened solvent flow are brought into contact with each other. It also comprises a final parallel flow contact system configured to generate a partially loaded solvent flow and a final gas flow.
Another exemplary embodiment provides a method of enhancing acid gas removal within a gas treatment system. In this method, a sour feed gas stream containing acid gas is brought into contact with the solvent stream in a number of parallel flow contact systems to produce a partially sweetened gas stream and a rich solvent stream that has absorbed the acid gas. Steps to do are included. In this method, the absorbed acid gas is removed from the rich solvent flow in the regenerator to generate a lean solvent flow, and at least a part of the lean solvent flow is treated in the solvent treatment device to generate a strengthened solvent flow. The step of producing is also included. The method further comprises contacting the partially sweetened gas stream with the enhanced solvent stream in the final parallel flow contact system to generate a partially loaded solvent stream and final gas stream. Is done.

Another exemplary embodiment provides a gas treatment system. The gas treatment system comprises a number of parallel flow contact systems, which contact a sour feed gas stream containing an acid gas with a solvent stream to provide a partial sweetening gas stream, and a rich solvent containing a first portion of the acid gas. It is configured to generate a flow. The gas treatment system is equipped with a first regenerator, which removes the first portion of the acid gas from the rich solvent stream to regenerate the solvent stream and recirculates the solvent stream to at least one of the parallel flow contact systems. It is configured to let you. The gas treatment system also comprises a final parallel flow contact system, which contacts the partial sweetening gas flow with the enhanced solvent flow to produce the final gas flow and a partially loaded solvent flow containing a second portion of acid gas. It is configured to do. The gas treatment system further processes a second regenerator configured to remove a second portion of the acid gas from the partially loaded solvent stream to generate a lean solvent stream, and at least a portion of the lean solvent stream to finalize. It comprises a solvent treatment apparatus configured to generate a reinforced solvent stream that is contacted with a partial sweetening gas stream in a parallel flow contact system.
The advantages of this technique will be better understood by reference to the following detailed description and accompanying drawings.

It is a process flow diagram of a gas treatment system provided with a parallel flow scheme and configured to enhance acid gas removal. FIG. 3 is a process flow diagram of another gas treatment system with a parallel flow scheme configured to enhance acid gas removal. FIG. 5 is a process flow diagram of a separation system equipped with a large number of parallel flow contact systems and cooling devices to enhance acid gas removal. It is a process flow diagram of a separation system including a large number of parallel flow contact systems and an anion exchange bed for enhancing acid gas removal. FIG. 5 is a process flow diagram of a first separation system with a large number of parallel flow contact systems and a second separation with a final parallel flow contact system and corresponding solvent treatment equipment. It is a schematic diagram of a parallel flow contact system. It is a process flow diagram which shows the method for strengthening the acid gas removal in a gas treatment system.

The following detailed description sections describe specific embodiments of the present art. However, as long as the following description is specific to a particular embodiment or use of the art, this description is intended to be illustrative only and merely provides an exemplary embodiment. .. Accordingly, the art is not limited to the particular embodiments described below, but includes all alternatives, modifications, and equivalents within the true spirit and scope of the appended claims.
First, for ease of reference, specific terms used herein, and their meanings as used in this context, are described. If the term used herein is not defined below, those of ordinary skill in the art have given it as reflected in at least one printed publication or issued patent. It should be considered as the definition of the maximum range. Furthermore, the present art is not limited to the use of the terms shown below, and all equivalents, synonyms, terms or techniques that serve the same or similar purposes as new developments are within the scope of this claim. Is considered to be.

"Acid gas" refers to any gas that dissolves in water to produce an acidic solution. Non-limiting examples of acid gas include hydrogen sulfide (H _{2S), carbon dioxide (CO 2), sulfur dioxide (SO 2), carbon disulfide (CS 2 ) , carbonyl} sulfide (COS), mercaptan, or Examples of these are mixtures.
The "parallel flow contact device" generally refers to a container that receives a gas flow and a separation solvent flow in a manner in which the gas flow and the solvent flow come into contact with each other while flowing in the same direction in the contact device.
The term "parallel flow" refers to the internal arrangement of processing flows within a unit operation that can be divided into several subsections and flows in the same direction.
The term "dehydrated natural gas flow" refers to a natural gas flow that has undergone a dehydration process. Normally, dehydrated natural gas streams have a water content of less than 3.18 kg (7 lb) H ₂ O / million standard cubic feet for US pipeline applications or less than 0.1 ppm for LNG applications. Any suitable method can be used to dehydrate the natural gas stream. Typical examples of suitable dehydration methods include treatment of natural gas streams with molecular sieves (for LNG specifications) or dehydration with glycols or methanol (for US pipeline specifications). It is not limited to these. Alternatively, by forming methane hydrate; for example, by utilizing a dehydration step as described in WO 2004/070297, the natural gas stream can be dehydrated.
As used herein, the term "dehydration" is used to obtain a dehydrated natural gas stream by partially or completely removing water and optionally some heavy hydrocarbons from the feed gas stream. Refers to the pretreatment of the raw material supply gas flow. This dehydration can be achieved, for example, by a pre-cooling cycle for an external cooling loop or a cold internal treatment stream. Moisture can also be removed by pretreatment with molecular sieves such as zeolites, silica gel, alumina oxide, or other desiccants. Moisture can also be removed by washing with glycol, monoethylene glycol (MEG), diethylene glycol (DEG) or triethylene glycol (TEG), or glycerol. The water content in the gas supply stream is preferably less than 1 volume percent (vol%), preferably less than 0.1 vol%, more preferably less than 0.01 vol%.

As used herein, the term "fluid" refers to a gas, a liquid, a combination of a gas and a liquid, a combination of a gas and a solid, and a combination of a liquid and a solid.
The term "combustion exhaust gas" refers to all gas flows generated as a by-product of hydrocarbon combustion.
The term "gas" is used interchangeably with "vapor" and is defined as a substance or mixture of substances in a gaseous state that is distinct from a liquid or solid state. Similarly, the term "liquid" means a substance or mixture of substances in a liquid state that is distinct from a gaseous or solid state.
A "hydrocarbon" is an organic compound predominantly containing hydrogen and carbon elements, but may be present in small amounts of nitrogen, sulfur, oxygen, metals, or any number of other elements. As used herein, the term "hydrocarbon" generally refers to components found in natural gas, petroleum, or chemical processing equipment. Furthermore, the term "hydrocarbon" may also refer to components found in raw natural gas such as CH ₄ , C ₂ H ₆ , C ₃ isomers, C ₄ isomers, benzene and the like.
With respect to fluid processing equipment, the term "continuously" means that the fluid flow undergoing fluid separation moves from one building unit to the next, while maintaining a nearly constant downstream flow. It means that two or more devices are arranged along the flow line. Similarly, the term "in series" means that two or more components of a fluid mixing and separating device are sequentially connected or more preferably integrated into a single tubular device.
The term "industrial plant" refers to any plant that produces a gas stream containing at least one hydrocarbon or acid gas. One non-limiting example is a coal-powered power plant. Another example is a cement plant that emits CO ₂ at low pressure.
The term "liquid solvent" refers to a nearly liquid phase fluid that absorbs one component preferentially over another. For example, the liquid solvent may preferentially absorb the acid gas, which allows at least a portion of the acid gas component to be removed or "rubbed off" from the gas stream. Further, the liquid solvent can preferentially absorb one acid gas over another.

"Natural gas" refers to a multi-component gas obtained from a crude oil well or from an underground gas-containing formation. The composition and pressure of natural gas can vary significantly. Normal natural gas streams contain methane (CH ₄ ) as the main component, i.e., in excess of 50 mole percent (mol%) of natural gas streams. The natural gas stream also contains ethane (C ₂ H ₆ ), high molecular weight hydrocarbons (eg C3 _- C ₂₀ hydrocarbons), acid gases (eg carbon dioxide and hydrogen sulfide), or any combination thereof. Can be. Natural gas can also contain small amounts of contaminants such as water, nitrogen, iron sulfide, wax, crude oil, or any combination thereof. The natural gas stream may be sufficiently purified prior to use in the embodiments described herein to remove compounds that may act as toxicants.
"Non-absorbable gas" means a gas that is not well absorbed by the solvent during the gas treatment or conditioning process.
As used herein, "purification" includes a separation step that removes impurities that can cause problems downstream.

"Solvent" refers to a substance that is at least partially capable of dissolving or dispersing other substances so that a solution can be provided or formed. The solvent may be polar, non-polar, neutral, protic, aprotic or the like. The solvent may contain any suitable element, molecule, or compound such as methanol, ethanol, propanol, glycol, ether, ketone, other alcohols, amines, salts solutions and the like. The solvent may include a physical solvent, a chemical solvent and the like. The solvent can act by any suitable mechanism such as physical absorption, chemical absorption, chemical adsorption, physical adsorption, adsorption, pressure swing adsorption, temperature swing adsorption and the like. Specific solvents useful for acid gas absorption include monoethanolamine (MEA), 2- (2-aminoethoxy) ethanol [Digglycollamine® (DGA)], diethanolamine (DEA), and diisopropanolamine (DIPA). , Methyldiethanolamine (MDEA), triethyleneamine, FLEXSORB® SE, 2-amino-2-methyl-1-propanol (AMP), or FLEXSORB® SE PLUS, UCARSOL ™ family products, etc. Examples include, but are not limited to, compounded amines or compounded MDEA solutions.
When used with respect to a quantity or quantity of a material, or a particular feature thereof, "almost" refers to an amount sufficient to produce the effect intended to be provided by the material or feature. The exact degree of acceptable deviation may depend on the particular context.
The term "sweetening natural gas stream" refers to a natural gas stream from which at least a portion of the acid gas component has been removed.

Overview This technique enhances the removal of acid gas from a sour gas stream using a treatment solvent in a gas treatment system with a parallel flow scheme. In various embodiments, the technique is utilized to selectively remove H _2S from a sour natural gas stream. Specifically, the sour natural gas stream may be purified to an _H2S concentration of less than 4 ppm to meet pipeline regulations.
The parallel flow scheme may utilize any number of parallel flow contact systems continuously connected within the conduit. The natural gas stream and the liquid solvent stream move together, ie, in parallel, within the parallel flow contact system. In some embodiments, the natural gas stream and the liquid solvent stream generally move together along the long axis of the parallel flow contact system.
Each parallel flow contact system in the gas treatment system may be equipped with a parallel flow contact device that facilitates absorption of acid gas such as H _{2S and CO 2 into} the solvent flow. In addition, each parallel flow contact system may be equipped with a separation device capable of separating the natural gas flow from the solvent flow that has absorbed the acid gas and producing a sweetened liquid-free natural gas flow.
In some embodiments, the solvent stream is an amine-based solvent capable of absorbing acid gases such as H _{2S and CO 2 in} a natural gas stream. For example, the solvent includes monoethanolamine (MEA), 2 (2-aminoethoxy) ethanol [Dilycholamine® (DGA)], diethanolamine (DEA), diisopropanolamine (DIPA), methyldiethanolamine (MDEA), and tri. Formulated amines such as ethyleneamine, FLEXSORB® SE, 2-amino-2-methyl-1-propanol (AMP), or FLEXSORB® SE PLUS and UCARSOL ™ family products, or blended MDEA solutions. However, it is not limited to these.

According to current technology, as a solvent flows through a series of parallel flow contact systems, the solvent becomes loaded with contaminants such as H _{2S and CO 2 .} As a result, in rapidly reacting components such as H ₂ S, CO ₂ that is thermodynamically suitable for absorption begins to replace H ₂ S, so that the vicinity of the outlet of the parallel flow contact system is in a pinch state. May become. For normal shale gas applications where it is desirable to remove H 2S to 1,000 ppm, ₃ or 4 parallel current contact systems may be used. However, when the solvent flows through the apparatus, the solvent is loaded with H ₂ S and CO ₂ , and the ability of the solvent to further reduce the H ₂ S concentration of the natural gas stream is reduced, so that 4 ppm of H in the final stage. It is especially difficult to make _2S specifications.
Therefore, according to the embodiments described herein, the use of solvent treatment equipment upstream of the final parallel flow contact system enhances H _2S removal. As further described with reference to FIGS. 1A, 1B, 2, 3, 4, and 6, the solvent treatment apparatus is configured to modify the solvent flow to increase H _2S absorption in the final parallel flow contact system. are doing.

Gas Treatment System FIG. 1A is a process flow diagram of a gas treatment system 100 comprising a parallel flow scheme and configured to enhance acid gas removal. The gas treatment system 100 may be used to remove acid gas components such as H _{2S and CO 2 from} the supply gas stream 102. The gas treatment system 100 may also be used to remove water or other impurities from the supply gas stream 102. A large number of parallel flow contact systems 104A to F may be adopted for the gas treatment system 100. For example, as further described with reference to FIG. 5, each parallel flow contact system 104A-F may include a parallel flow contact device and a separation device.
Examples of the supply gas flow 102 include a natural gas flow from a hydrocarbon generation operation, a combustion exhaust gas flow from a power plant, and a synthetic gas (thin gas) flow. When the supply gas flow 102 is a syngas flow, the supply gas flow 102 may be cooled and filtered before being introduced into the gas treatment system 100. Further, the supply gas flow 102 may be a flash gas flow taken out from the flash drum in the gas treatment facility itself. Further, the supply gas flow 102 may be an exhaust gas flow from the Claus sulfur recovery method or an impurity flow from the solvent regeneration device. Further, the supply gas flow 102 may be an exhaust gas discharge flow from a cement plant or another industrial plant. In this example, CO ₂ may be absorbed from excess air or from nitrogen-containing combustion emissions.

The supply gas stream 102 may also contain a non-absorbable gas such as methane and one or more impurities such as CO ₂ and H ₂ S. In some embodiments, the supply gas stream 102 comprises a large amount of H ₂ S, for example about 1,000 ppm H ₂ S. The gas treatment system 100 may convert the supply gas flow 102 into a sweetening gas flow 106 by removing CO ₂ and H ₂ S. In various embodiments, the sweetening gas stream 106 contains H 2S with a concentration of less than 4 ppm and CO ₂ with a concentration of less than _2-3 vol%.
In operation, the supply gas flow 102 may also flow into the first parallel flow contact system 104A, where the supply gas flow 102 is mixed with the solvent flow 108. In various embodiments, the solvent stream 108 comprises an amine solution such as monoethanolamine (MEA), diethanolamine (DEA) or methyldiethanolamine (MDEA). The solvent flow 108 may contain a lean solvent that has undergone a desorption step to remove acid gas impurities. For example, in the gas treatment system 100 shown in FIG. 1A, the solvent flow 108 introduced into the first parallel flow contact system 104A contains a semi-lean solvent taken out from the central portion of the regeneration device 110. The lean solvent stream 112 taken out of the regenerator 110 may be directed towards the fifth and final parallel flow contact systems 104E and 104F.
In various embodiments, the gas treatment system 100 employs a series of parallel flow contact systems 104A-F. The parallel flow contact systems 104A to F remove a part of the acid gas component from the supply gas flow 102, whereby the sweetened gas flow is discharged in the downstream direction. The final parallel flow contact system 104F provides the final sweetening gas flow 106.
The supply gas stream 102 may pass through the inlet separator 114 before flowing into the first parallel flow contact system 104A. The supply gas flow 102 may be purified by filtering impurities such as salt water and excavation fluid using the inflow port separating device 114. Some particle filtration may be performed. Purification of the supply gas flow 102 can prevent the solvent from foaming during the acid gas treatment step.

In some embodiments, the supply gas stream 102 may be pretreated upstream of the inlet separator 114 or the first parallel flow contact system 104A. For example, the feed gas stream 102 may be washed with water to remove glycols or other chemical additives. This wash may be performed via a separate processing loop (not shown) that introduces water into the gas, such as through an additional parallel flow contact system. Water has an affinity for glycol and draws glycol from the supply gas stream 102. This sequentially promotes control of foaming in the parallel flow contact systems 104A-F. For flue gas applications, a corrosion inhibitor may be added to the solvent during the process to delay the reaction of O ₂ with the steel.
As shown in FIG. 1A, the solvent flow 108 flows into the first parallel flow contact system 104A. The transfer of the semi-lean solvent flow 108 to the first parallel flow contact system 104A may be assisted by pumps 116A and 116B and cooling device 117. The cooling device 117 may allow the solvent flow 108 to flow into the first parallel flow contact system 104A at a suitable temperature, while the pumps 116A and 116B allow the solvent flow 108 to flow from, for example, about 0.10 MPa (15 psia) to about. It may flow into the first parallel flow contact system 104A at a suitable pressure of 10.34 MPa (1,500 psig).
Once inside the first parallel flow contact system 104A, the supply gas flow 102 and the solvent flow 108 move along the major axis of the first parallel flow contact system 104A. As they move, the liquid amine (or other treatment solution) interacts with the H _2S and CO ₂ in the feed gas stream 102, and the H ₂ S and CO ₂ chemically attach or absorb to the amine molecule. Will be done. The partially loaded or "rich" first solvent flow 118A may flow out of the bottom of the first parallel flow contact system 104A. Further, the partial sweetening first gas flow 120A may flow out from the top of the first parallel flow contact system 104A and flow into the second parallel flow contact system 104B.

As shown in the example of FIG. 1A, a third parallel flow contact system 104C may be provided after the second parallel flow contact system 104B, and a fourth parallel flow contact system 104D may be provided after the third parallel flow contact system 104C. May be good. Further, the fifth parallel flow contact system 104E may be provided after the fourth parallel flow contact system 104D, and the final parallel flow contact system 104F may be provided after the fifth parallel flow contact system 104E. The second, third, fourth, and fifth parallel flow contact systems 104B, 104C, 104D, and 104E may generate partial sweetening gas flows 120B, 120C, 120D, and 120E, respectively. Also, the second, third, fourth, fifth, and final parallel flow contact systems 104B, 104C, 104D, 104E, and 104F each have partial load solvent flows 118B, 118C, 118D, 118E, and 118F, respectively. May be generated. When amines are used as the solvent flow 108, the partially loaded solvent flows 118A-F may contain a rich amine solution. In the gas treatment system 100, the second partial load solvent flow 118B merges with the first partial load solvent flow 118A and is regenerated by the regeneration device 110.
When the gas flows 120A to E with advanced sweetening are generated, the gas pressure in the gas treatment system 100 decreases. When this happens, the hydraulic pressures of the enriched solvent streams 118A-F may increase accordingly. This can be achieved by arranging one or more booster pumps (not shown) between each parallel flow contact system 104A-F to increase the hydraulic pressure in the gas treatment system 100.
In the gas treatment system 100, the solvent flow may be regenerated by flowing the partially loaded solvent flows 118A and 118B through the flash drum 122. The absorbed natural gas 124 may be flash evaporated from the partially loaded solvent streams 118A and 118B in the flash drum 122, or may be flushed out of the flash drum 122 via the tower top line 126.

The obtained rich solvent flow 128 may be flowed from the flash drum 122 to the regeneration device 110. The rich solvent flow 128 may be introduced into the regenerator 110 for desorption. The regenerator 110 may include a remover unit 130 with a tray or other internal structure (not shown). The removing device unit 130 may be arranged directly above the reheating device unit 132. A heat source 134 may be provided in the reheating device unit 132 in order to generate heat. The regenerator 110 produces a regenerated lean solvent stream 112, which is circulated for reuse in the fifth and final parallel flow contact systems 104E and 104F. The tower gas removed from the regeneration device 110 may contain concentrated H _{2S and CO 2 ,} and may be discharged from the regeneration device 110 as a column top impurity flow 136.
The column top impurity flow 136 may flow into the condenser 138 to cool the column top impurity flow 136. The obtained cooling impurity flow 140 may be flowed to the reflux storage device 142. The reflux storage device 142 may separate any residual liquid, such as condensed water, from the impurity stream 140. This produces a nearly pure acid gas stream 144, which may flow out of the reflux storage device 142 via the tower top line 146.

Then, in some embodiments, H ₂ S in the acid gas stream 144 is converted to elemental sulfur using a sulfur recovery unit (not shown). The sulfur recovery unit may be a so-called Claus unit. Those skilled in the art understand that the "Klaus method" is a method that may be used in the natural gas and essential oil industries to recover elemental sulfur from H 2S _- containing gas streams.
In fact, it is possible to react the "exhaust gas" obtained from the Klaus method, which can contain H ₂ S, SO ₂ , CO ₂ , N ₂ , and water vapor, to convert SO ₂ to H ₂ S via hydrogenation. be. The hydrogenated exhaust gas stream has a high partial pressure and contains a large amount of CO ₂ such as more than 50% and a small amount of H _2S such as a few% or less. This type of gas flow, which is normally close to atmospheric pressure, is capable of selective H _2S removal. _The recovered H 2S may be circulated in the front stage of the Claus unit or isolated downstream. Alternatively, various methods known in the field of gas separation may be used to directly oxidize H _2S converted to elemental sulfur.
Since the H _{2S reaction is more instantaneous than the CO 2 reaction} , shortening the residence time, that is, the contact time between the vapor phase and the liquid phase, reduces the amount of CO ₂ absorbed by the solvent. The design of the parallel flow contact systems 104A _- F enhances selective H 2S removal due to the short contact time inherent in the device design.
As shown in FIG. 1A, the residual liquid flow 148 may flow out from the bottom of the reflux storage device 142. The residual liquid flow 148 may flow through the recirculation pump 150. The recirculation pump 150 may increase the pressure of the residual liquid flow 148 and suck the residual liquid flow 148 into the regeneration device 110. The residual liquid stream 148 may flow out of the regenerator 110, for example, from the bottom of the reboiler section 132, as part of the lean solvent stream 112. Water may be added to the lean solvent stream 112 to balance the loss of water vapor to the sweetening gas stream 106 and the acid gas stream 144. This water may be added at the intake port or the suction port of the reflux pump 150.

The lean solvent flow 112 may be at low pressure. Therefore, the lean solvent flow 112 may be passed through the booster pump 152. A lean solvent stream 112 may be flowed from the booster pump 152 to the cooling device 154. The cooling device 154 may cool the lean solvent flow 112 after being heated by the regenerating device 110 and return it to the vicinity of the ambient temperature.
In some embodiments, the lean solvent stream 112 may then flow into the solvent tank 156. In another embodiment, the solvent tank 156 is off line to provide a storage tank for the lean solvent flow 112.
The movement of the lean solvent flow 112 towards the fifth and final parallel flow contact systems 104E and 104F may be assisted by pump 158. The lean solvent flow 112 may be flowed by the pump 158 at a suitable pressure of, for example, about 0.10 MPa (15 psia) to about 10.34 MPa (1,500 psig).
The first portion 160 of the lean solvent flow 112 may merge with the partially loaded solvent flow 118F and flow into the fifth parallel flow contact system 104E. The second portion 162 of the lean solvent stream 112 may flow into the solvent treatment apparatus 164 configured to treat the lean solvent stream 112 to produce the enhanced solvent stream 166. According to the embodiments described herein, the enhanced solvent stream 166 is a treated solvent stream capable of absorbing a higher concentration of acid gas than the lean solvent stream 112. The fortified solvent flow 166 may be a highly H _2S selective solvent flow capable of selectively absorbing high concentrations of H ₂ S in contrast to CO ₂ . In various embodiments, a fortified solvent stream 166 is used to bring the H 2S concentration to less than ₄ ppm in the final sweetening gas stream 106.

In various embodiments, the solvent treatment apparatus 164 places the lean solvent stream 112 at least near ambient temperature, eg, about 20 ° C to 25 ° C, or at least about 5 ° C below ambient temperature, or at least about 10 ° C below ambient temperature. Enhanced by cooling to a temperature, or at least about 20 ° C. below the ambient temperature, or a temperature equal to or slightly lower than the temperature of the partial sweetening gas stream 120E flowing into the final parallel flow contact system 104F. It is a cooling device configured to generate a solvent flow 166. For example, the solvent treatment device 164 may be an ammonia cooling device, a chilled water stream from a cooling water tower, or any other suitable type of cooling device.
In some embodiments, an analyzer (not shown) and a control device (not shown) may be connected to the solvent treatment device 164, as described in more detail with reference to FIG. The analyzer may be configured to determine the acid gas concentration of the final sweetening gas stream 106 flowing out of the final parallel flow contact system 104F. Next, the temperature of the solvent treatment device 164 may be adjusted by the control device based on the analysis of the sweetening gas flow 106.
In some embodiments, the solvent treatment apparatus 164 is an anion exchange bed that produces a fortified solvent stream 166 by removing residual HS ^- and HCO ₃ ^- from the lean solvent stream 112. In another embodiment, the solvent treatment apparatus 164 is an electrodialysis unit configured to generate an enhanced solvent flow 166 by reducing the lean load of the lean solvent flow 112. In these embodiments, the solvent treatment apparatus 164 may also be used to remove heat-stable salt contaminants from the lean solvent stream 112.
In another embodiment, the solvent treatment apparatus 164 produces a reinforced solvent stream 166 by injecting a reinforced fluid into the lean solvent stream 112 to enhance the ability of the solvent to selectively absorb the acid gas. For example, a liquid H _{2S scavenger may be added to the lean solvent stream 112 to enhance the solvent's ability to remove residual H 2 S} in the partial sweetening gas stream 120E. In some embodiments, a controlled bypass (not shown) ensures that the H _2S concentration in the final sweetening gas stream 106 is 3-4 ppm rather than 0 ppm, which wastes the scavenger. May be.

The process flow diagram of FIG. 1A is not intended to show that the gas treatment system 100 includes all of the components shown in FIG. 1A. In addition, any number of components may be added within the gas treatment system 100, depending on the details of the particular implementation. For example, the gas treatment system 100 may include any suitable type of heater, cooling device, condensing device, liquid pump, gas compressor, blower, bypass line, other type of separation and / or fractionation device, valve, switch. , A control device, a pressure measuring device, a temperature measuring device, a level measuring device, a flow rate measuring device, and the like may be provided. Further, an arbitrary number of parallel flow contact systems may be added to the gas treatment system 100.
In some embodiments, the lean solvent stream 112 removed from the regenerator 110 is directed only towards the final parallel flow contact system 104F, not the fifth parallel flow contact system 104E. In those embodiments, the entire lean solvent stream 112 is sent to the solvent treatment device 164 to generate a fortified solvent stream 166.
In some embodiments, a portion of the rich solvent stream 128 is acidified before the rich solvent stream 128 flows into the regenerator 110. This can be achieved by adding 1-2 weight percent (% by weight) of phosphoric acid to the rich solvent stream 128. Acidifying the rich solvent stream 128 causes the rich solvent stream 128 to release more acid gas during the regeneration step.

FIG. 1B is a process flow diagram of another gas treatment system 168 with a parallel flow scheme configured to enhance acid gas removal. The structural units having the same numbers as those in FIG. 1A are as described with reference to FIG. 1A. The operation of the gas treatment system 168 of FIG. 1B is the same as the operation of the gas treatment system 100 of FIG. 1A. However, in the gas treatment system 168 of FIG. 1B, the first parallel flow contact system 104A receives a partial load solvent flow 118B from the second parallel flow contact system 104B. Therefore, the gas treatment system 168 does not include a semi-lean solvent stream 108.
Since the partial load solvent flow 118B received by the first parallel flow contact system 104A of FIG. 1B has already been processed in the second parallel flow contact system 104B, the partial load solvent flow 118B received by the first parallel flow contact system 104A Load solvent flow 118B can be very rich. Therefore, it may be desirable to perform the intermediate treatment of the partially loaded solvent flow 118B to some extent.
Alternatively, the semi-lean solvent stream can be removed from other sweetening operations within the gas treatment system 168 and used at least partially as an amine solution for the first or second parallel flow contact system 104A or 104B. In this respect, there is a situation where one kind of solvent is used for a plurality of facilities in the gas treatment system 168. This is called integrated gas treatment. For example, MDEA may also be used for high pressure and H 2S selective _acid gas removal and Klaus exhaust gas treatment (TGT) methods. The rich amine stream obtained from the TGT method is less loaded with H _{2S and CO 2 due} to the low pressure of the method. Therefore, in some embodiments, the rich amine stream obtained from the TGT method is used as a semi-lean stream for the first or second parallel flow contact system 104A or 104B. The semi-lean flow (not shown) is pumped to a suitable pressure and into the first or second parallel flow contact system 104A or 104B, optionally with a partial load solvent flow from the subsequent parallel flow contact system. It may be injected.
Further, in the gas treatment system 168 of FIG. 1B, the first partially loaded solvent solution 118A flows through the flash drum 122 and then through the heat exchanger 170. In the heat exchanger 170, the temperature of the first partially loaded solvent solution 118A rises through heat exchange with the lean solvent flow 112 taken out from the regeneration device 110. This heats the first partially loaded solvent solution 118A while cooling the lean solvent stream 112 before it is introduced into the regenerator 110.

The process flow diagram of FIG. 1B is not intended to show that the gas treatment system 168 comprises all of the components shown in FIG. 1B. In addition, any number of components may be added within the gas treatment system 168, depending on the details of the particular implementation. For example, the gas treatment system 168 may include any suitable type of heater, cooling device, condensing device, liquid pump, gas compressor, blower, bypass line, other type of separation and / or fractionation device, valve, switch. , A control device, a pressure measuring device, a temperature measuring device, a level measuring device, a flow rate measuring device, and the like may be provided. Further, an arbitrary number of parallel flow contact systems may be added to the gas treatment system 168.
According to the embodiments described in FIGS. 1A and 1B, the gas treatment systems 100 and 168 include a backflow arrangement of parallel flow contact devices. However, it should be understood that the embodiments described herein also apply to parallel configurations of parallel flow contact devices in which the freshly generated solvent flow is supplied to each stage. In addition, the individual parallel flow contact devices are configured to include both horizontal and vertical sections, with or without series separation at the stage immediately after contact, and dehydration, H _2S removal in the subsequent portion of the single series device. , And innumerable different configurations such as configurations in which CO ₂ removal occurs. Also, all parallel flow contact systems may be grouped together in a single pressure vessel oriented vertically or horizontally.

Separation system FIG. 2 is a process flow diagram of a separation system 200 including a number of parallel flow contact systems 202A-C and a cooling device 204 for enhancing acid gas removal. The separation system 200 may be implemented as part of a gas treatment system such as the gas treatment system 100 or 168 described with reference to FIGS. 1A or 1B. In the gas treatment system, a large number of continuously connected parallel flow contact systems 202A to C, such as the parallel flow contact systems 104A to F described with reference to FIGS. 1A and 1B, may be utilized. In the exemplary arrangement shown in FIG. 2, a first parallel flow contact system 202A, a second parallel flow contact system 202B, and a third parallel flow contact system 202C are provided.
The sour supply gas flow 206 may flow into the first parallel flow contact system 202A. The first parallel flow contact system 202A may generate a first partial sweetening gas flow 208A, and this gas flow may flow from the first parallel flow contact system 202A to the second parallel flow contact system 202B. The second parallel flow contact system 202B may then generate a second partial sweetening gas flow 208B, which may flow from the second parallel flow contact system 202B to the third parallel flow contact system 202C. good. In some embodiments, the third parallel flow contact system 202C produces a final sweetening gas flow 210.
Each of the first, second, and third parallel flow contact systems 202A-C also produces their respective rich solvent flows 212A-C. The third rich solvent flow 212C may be directed toward returning to the second parallel flow contact system 202B, and the second rich solvent flow 212B may be directed toward returning to the first parallel flow contact system 202A. Further, the first rich solvent flow 212A may be returned to the regeneration device 214. In some embodiments, the regenerator 214 is the same as or similar to the regenerator 110 described with reference to FIGS. 1A and 1B.

The regenerator 214 may remove the absorbed acid gas and other impurities from the first rich solvent stream 212A to generate a lean solvent stream 216. After that, the lean solvent flow 216 may be sent to the cooling device 204, which may lower the temperature of the lean solvent flow 216 to generate an enhanced solvent flow 218. In various embodiments, the cooling device 204 corresponds to the solvent treating device 164 described with reference to FIGS. 1A and 1B. Further, in various embodiments, the reinforced solvent stream 218 is a solvent stream capable of absorbing a higher concentration of acid gas from the second partial sweetening gas stream 208B. For example, the fortified solvent flow 218 may be a highly H _2S selective solvent flow capable of absorbing higher concentrations of H ₂ S in contrast to CO ₂ .
The cooling device 204 sets the temperature of the lean solvent stream 216 to at least -12 ° C. (10 ° F) lower than the ambient temperature, or to the temperature of the second partial sweetening gas stream 208B flowing into the third parallel flow contact system 202C. It may be any suitable type of cooling device capable of lowering the temperature to the same or slightly lower temperature. For example, the cooling device 204 may be an ammonia cooling device or a cold water stream from a water tower. Further, in some embodiments, the cooling device 204 comprises a small addition system for injecting the reinforcing fluid into the lean solvent stream 216.
The reinforced solvent flow 218 may flow from the cooling device 204 into the third parallel flow contact system 202C. Within the third parallel flow contact system 202C, the reinforced solvent flow 218 contacts the second partial sweetening gas flow 208B and releases an increased amount of acid gas such as H 2S from the _second partial sweetening gas flow 208B. Absorb. The obtained sweetening gas stream 210 may contain a low concentration _acid gas such as H 2S of less than 4 ppm.
The separation system 200 may also include an analyzer 220 and a control device 222. The analyzer 220 performs an external analysis of the final sweetening gas flow 210 flowing out of the third parallel flow contact system 202C to determine the acid gas concentration such as the _H2S and CO ₂ concentrations of the final sweetening gas flow 210. It may be configured as. The control device 222 may then adjust the temperature of the cooling device 204 based on the analysis of the sweetening gas flow 210. In some embodiments, the cooling device 204 may be operated at different temperatures depending on the acid gas concentration of the final sweetening gas stream 210, so that the analyzer 220 and the control device 222 may be used within the separation system 200. It leads to energy saving.

The process flow diagram of FIG. 2 is not intended to show that the separation system 200 includes all of the components shown in FIG. In addition, any number of components may be added within the isolation system 200, depending on the details of the particular implementation. For example, any number of parallel flow contact systems may be added within the separation system 200.
FIG. 3 is a process flow diagram of a separation system 300 including a large number of parallel flow contact systems 302A to C and an anion exchange bed 304 for enhancing acid gas removal. The separation system 300 may be implemented as part of a gas treatment system such as the gas treatment system 100 or 168 described with reference to FIGS. 1A or 1B. As the gas treatment system, a large number of continuously connected parallel flow contact systems 302A to C, such as the parallel flow contact systems 104A to F described with reference to FIGS. 1A and 1B, may be utilized. In the exemplary arrangement shown in FIG. 3, a first parallel flow contact system 302A, a second parallel flow contact system 302B, and a third parallel flow contact system 302C are provided.

The sour supply gas flow 306 may flow into the first parallel flow contact system 302A. The first parallel flow contact system 302A may generate a first partial sweetening gas flow 308A, which may flow from the first parallel flow contact system 302A to the second parallel flow contact system 302B. Next, the second parallel flow contact system 302B may generate a second partial sweetening gas flow 308B, which may flow from the second parallel flow contact system 302B to the third parallel flow contact system 302C. good. In some embodiments, the third parallel flow contact system 302C produces a final sweetening gas flow 310.
Each of the first, second, and third parallel flow contact systems 302A-C also produces the respective rich solvent flows 312A-C. The third rich solvent flow 312C may be directed toward returning to the second parallel flow contact system 302B, and the second rich solvent flow 312B may be directed toward returning to the first parallel flow contact system 302A. Further, the first rich solvent flow 312A may be returned to the regeneration device 314. In some embodiments, the regenerator 314 is the same as or similar to the regenerator 110 described with reference to FIGS. 1A and 1B.
The regenerator 314 may remove the absorbed acid gas and other impurities from the first rich solvent stream 312A to generate a lean solvent stream 316. After that, the lean solvent flow 316 may be sent to the anion exchange bed 304. In various embodiments, the anion exchange bed 304 corresponds to the solvent treatment apparatus 164 described with reference to FIGS. 1A and 1B.
By removing the residual acid gas from the lean solvent stream 316, the anion exchange bed 304 can generate a reinforced solvent stream 318. Also, the anion exchange bed 304 can remove heat-stable salt contaminants from the lean solvent stream 316.
According to the embodiments described herein, the enhanced solvent stream 318 is a solvent stream capable of absorbing a higher concentration of acid gas from the second partial sweetening gas stream 308B. For example, in some embodiments, the enhanced solvent flow 318 may be a highly H _2S selective solvent flow capable of absorbing H ₂ S faster than CO ₂ . In these embodiments, the anion exchange bed 304 produces a reinforced solvent stream 318 by removing residual HS ^{- and} HCO _3- from the lean solvent stream 316.

The process flow diagram of FIG. 3 is not intended to show that the separation system 300 includes all of the components shown in FIG. In addition, any number of components may be added within the isolation system 300, depending on the details of the particular implementation. For example, any number of parallel flow contact systems may be added within the separation system 300.
FIG. 4 is a process flow diagram of a first separation system 400 with a large number of parallel flow contact systems 402A-C and a second separation system 404 with a final parallel flow contact system 406 and a corresponding solvent treatment device 408. The first and second separation systems 400 and 404 may be implemented as part of a gas treatment system such as a gas treatment system similar to the gas treatment system 100 or 168 described with reference to FIGS. 1A or 1B. As the gas treatment system, a large number of continuously connected parallel current contact systems 402A to C and 406, such as the parallel flow contact systems 104A to F described with reference to FIGS. 1A and 1B, may be utilized. In the exemplary arrangement shown in FIG. 4, the first separation system 400 comprises a first parallel flow contact system 402A, a second parallel flow contact system 402B, and a third parallel flow contact system 402C, and the second separation system 404 is final. It is equipped with a parallel flow contact system 406.
Within the first separation system 400, the sour supply gas stream 410 may flow into the first parallel flow contact system 402A. The first parallel flow contact system 402A may generate a first partial sweetening gas flow 412A, and this gas flow may flow from the first parallel flow contact system 402A to the second parallel flow contact system 402B. The second parallel flow contact system 402B may then generate a second partial sweetening gas flow 412B, which may flow from the second parallel flow contact system 402B to the third parallel flow contact system 402C. good. The third parallel flow contact system 402C may then generate a third partial sweetening gas flow 412C, which is the final parallel flow contact from the second parallel flow contact system 402B within the second separation system 404. It may be sent to system 406.
Each of the first, second, and third parallel flow contact systems 402A-C also produces the respective rich solvent flows 414A-C. The third rich solvent flow 414C may be directed toward returning to the second parallel flow contact system 402B, and the second rich solvent flow 414B may be directed toward returning to the first parallel flow contact system 402A. Further, the first rich solvent flow 414A may be returned to the first regeneration device 416. In some embodiments, the first regenerator 416 is the same as or similar to the regenerator 110 described with reference to FIGS. 1A and 1B.

The first regenerator 416 may remove the absorbed acid gas and other impurities from the first rich solvent stream 414A to generate a first lean solvent stream 418. The first lean solvent stream 418 may then be recirculated to the third parallel flow contact system 402C.
Within the final parallel flow contact system 406, the third partial sweetening gas flow 412C is brought into contact with the reinforced solvent flow 420 to produce the final sweetening gas flow 422. According to the embodiments described herein, the enhanced solvent stream 420 is a treated solvent stream capable of absorbing a high concentration of acid gas. Therefore, the final sweetening gas stream 422 may contain low concentration acid gas such as H 2S less than ₄ ppm.
The final parallel flow contact system 406 also produces a partially loaded solvent flow 424. The partially loaded solvent flow 424 may be sent to the second regeneration device 426. In some embodiments, the second regenerator 426 is the same as or similar to the regenerator 110 described with reference to FIGS. 1A and 1B. The second regenerator 426 may remove the absorbed acid gas and other impurities from the partially loaded solvent stream 424 to generate a second lean solvent stream 428.
According to the embodiments described herein, the second lean solvent stream 428 is then sent to the solvent treatment apparatus 408. The solvent treatment apparatus 408 is configured to treat the second lean solvent flow 428 to generate a fortified solvent flow 420. In various embodiments, the solvent treatment device 408 is the same as or similar to the solvent treatment device 164 described with reference to FIGS. 1A and 1B. The enhanced solvent flow 420 may then be sent to the booster pump 430 before being directed back to the final parallel flow contact system 406.
The process flow diagram of FIG. 4 is not intended to show that the first and second separation systems 400 and 404 include all of the components shown in FIG. In addition, any number of components may be added within the first and second separation systems 400 and 404, depending on the details of the particular implementation. For example, any number of parallel flow contact systems may be added within the first separation system 400 or the second separation system 404.

Parallel Flow Contact System FIG. 5 is a schematic diagram of the parallel flow contact system 500. The components in the gas stream may be separated by the parallel flow contact system 500. The parallel flow contact system 500 may also support the implementation of various gas treatment systems such as the gas treatment systems 100 and 168 of FIGS. 1A and 1B that require rapid separation of components. In some embodiments, the parallel flow contact system 500 is a parallel flow contact system 104A-F, 202A-C, 302A-C, 402A-C described with reference to FIGS. 1A, 1B, 2, 3, and 4. , And one of 406.
The parallel flow contact system 500 may include a parallel flow contact device 502 arranged in series within the conduit 504. The parallel flow contact device 502 may include a number of components for efficient contact between the liquid solvent flow and the fluidized gas flow 506. The liquid solvent stream can be used to separate impurities such as H _{2S and CO 2 from} the gas stream 506.
In various embodiments, the parallel flow contact device 502 comprises a mixer 508 and a mass transfer unit 510. As shown in FIG. 5, the gas stream 506 may flow into the mixer 508 through the conduit 504. The liquid solvent flow 512 may flow into the mixer 508, for example, through a hollow space 514 connected to the flow path 516 in the mixer 508.
From the flow path 516, the liquid solvent flow 512 is discharged as minute droplets through the injection opening 518 into the gas flow 506 and then flows into the mass transfer unit 510. As a result, the processing gas flow 520 can be generated in the mass transfer unit 510. The processing gas stream 520 may also contain small droplets dispersed in the gas phase. The droplets may also contain impurities derived from the gas stream 506 absorbed or dissolved in the liquid solvent stream 512.
The processing gas flow 520 may be flowed from the mass transfer unit 510 to a separation device 522 such as a cyclone type separation device, a mesh screen, or a settling container. Separator 522 removes droplets from the gas phase. The droplet may contain the original liquid solvent stream that has absorbed the impurities 524, and the gas phase may contain the purified gas stream 526. In various embodiments, the purified gas stream 526 is a gas stream purified by removal of H _{2S and CO 2 .}

A Method for Enhancing Acid Gas Removal in a Gas Treatment System FIG. 6 is a process flow diagram illustrating a method 600 for enhancing acid gas removal in a gas treatment system. Method 600 is carried out by a gas treatment system such as the gas treatment systems 100 and 168 described with reference to FIGS. 1A and 1B. The gas treatment system may also include one or more separation systems such as the separation systems 200, 300, 400, and 404 described with reference to FIGS. 2, 3, and 4. In addition, the gas treatment system may include a number of parallel flow contact systems. In various embodiments, the parallel flow contact system corresponds to the parallel flow contact system 500 described with reference to FIG.
The method begins at block 602, where the sour supply gas stream containing acid gas and the solvent stream are brought into contact with each other in a number of parallel flow contact systems to provide partial sweetening gas flow and acid gas. Generates an absorbed rich solvent stream. At least one of the parallel flow contact systems is configured to send a rich solvent flow to the regenerator. Also, in some embodiments, each parallel flow contact system is configured to recirculate the corresponding solvent flow to the preceding one of the parallel flow contact systems.
In various embodiments, the sour feed gas stream is a sour natural gas stream. Moreover, in various embodiments, the sour feed gas stream comprises at _least 1,000 ppm H 2S. In these embodiments, the absorbed acid gas is predominantly H _{2S and the partial sweetening gas stream is a gas stream from which some of the H 2 S} has been removed.

At block 604, the absorbed acid gas is removed from the rich solvent stream in the regenerator to generate a lean solvent stream. In some embodiments, the regenerator may correspond to the regenerator 110 described with reference to FIGS. 1A and 1B.
At block 606, at least a portion of the lean solvent stream is treated in the solvent treatment apparatus to generate a strengthened solvent stream. The solvent treatment apparatus may correspond to the solvent treatment apparatus 164 described with reference to FIGS. 1A and 1B. In some embodiments, the solvent treatment device is a cooling device that produces an enhanced solvent stream by lowering the temperature of the lean solvent stream. In another embodiment, the solvent treatment apparatus is an anion exchange bed that produces a fortified solvent stream by removing residual HS- ^, HCO _3- ^, and thermostable salt contaminants from the lean solvent stream. In another embodiment, the solvent treatment apparatus is an electrodialysis unit that reduces the lean load of the lean solvent stream and produces an enhanced solvent stream by removing the heat-stable salt contaminant from the lean solvent stream. Furthermore, in another embodiment, the solvent treatment apparatus produces a fortified solvent stream by injecting the intensifying fluid into the lean solvent stream to increase the ability of the solvent to absorb the acid gas.
At block 608, the partial sweetening gas stream is contacted with the reinforced solvent stream in the final parallel flow contact system to produce a partially loaded solvent stream and a final gas stream. In various embodiments, the final gas stream comprises H 2S with a concentration of less than 4 ppm and CO ₂ with a concentration of less than _2-3 vol%.

The process flow diagram of FIG. 6 is not intended to show that the steps of method 600 are performed in any particular order, or that all steps of method 600 are included in all examples. In addition, any number of steps not shown in FIG. 6 may be added to method 600, depending on the details of the particular implementation. For example, in an embodiment where the solvent treatment apparatus is a cooling apparatus, in method 600, an analyzer is used to determine the acid gas concentration of the final gas stream, and then a control device is used to determine the acid gas concentration of the final gas stream. It may also include increasing or decreasing the temperature of the cooling device based on this.
In some embodiments, method 600 is performed using two separate separation systems, such as the first and second separation systems 400 and 404 described with reference to FIG. In these embodiments, the final parallel flow contact system may employ in-step circulation utilization of its own solvent flow using a separate regeneration device. Specifically, a partially loaded solvent stream leaving the final parallel flow contact system may be sent to the regenerator, which may generate a lean solvent stream. The lean solvent stream may then be sent to the solvent treatment device, which may generate an enhanced solvent stream. The enhanced solvent flow may then be circulated and utilized in the final parallel flow contact system to generate the final gas flow.
The present art is prone to various modifications and alternative formations, and the above embodiments are shown by way of illustration only. However, it should be reminded that the art is not intended to be limited to the particular embodiments disclosed herein. In fact, the art includes all alternatives, modifications, and equivalents that fall within the true spirit and scope of the appended claims.

The process flow diagram of FIG. 6 is not intended to show that the steps of method 600 are performed in any particular order, or that all steps of method 600 are included in all examples. In addition, any number of steps not shown in FIG. 6 may be added to method 600, depending on the details of the particular implementation. For example, in an embodiment where the solvent treatment apparatus is a cooling apparatus, in method 600, an analyzer is used to determine the acid gas concentration of the final gas stream, and then a control device is used to determine the acid gas concentration of the final gas stream. It may also include increasing or decreasing the temperature of the cooling device based on this.
In some embodiments, method 600 is performed using two separate separation systems, such as the first and second separation systems 400 and 404 described with reference to FIG. In these embodiments, the final parallel flow contact system may employ in-step circulation utilization of its own solvent flow using a separate regeneration device. Specifically, a partially loaded solvent stream leaving the final parallel flow contact system may be sent to the regenerator, which may generate a lean solvent stream. The lean solvent stream may then be sent to the solvent treatment device, which may generate an enhanced solvent stream. The enhanced solvent flow may then be circulated and utilized in the final parallel flow contact system to generate the final gas flow.
The present art is prone to various modifications and alternative formations, and the above embodiments are shown by way of illustration only. However, it should be reminded that the art is not intended to be limited to the particular embodiments disclosed herein. In fact, the art includes all alternatives, modifications, and equivalents that fall within the true spirit and scope of the appended claims.
(Additional note)
The present invention can be understood as follows.
(Appendix 1)
A gas treatment system:
A plurality of parallel flow contact systems configured to contact a sour supply gas stream containing an acid gas with a solvent stream to generate a partially sweetened gas stream and a rich solvent stream that has absorbed the acid gas. A plurality of parallel flow contact systems, wherein at least one of the plurality of parallel flow contact systems is configured to send the rich solvent flow to the regenerator;
The regenerating device configured to remove the absorbed acid gas from the rich solvent stream to generate a lean solvent stream;
A solvent treatment apparatus configured to treat at least a portion of the lean solvent stream to produce a strengthened solvent stream;
A final parallel flow contact system configured to contact the partially sweetening gas stream with the enhanced solvent stream to generate a partially loaded solvent stream and a final gas stream.
A gas treatment system characterized by being equipped with.
(Appendix 2)
The gas treatment system according to Appendix 1, wherein the sour supply gas stream includes a sour natural gas stream.
(Appendix 3)
The gas treatment system according to Appendix 1, wherein the absorbed acid gas contains hydrogen sulfide (H2S ₎ .
(Appendix 4)
The gas treatment system according to Appendix 3, wherein the final gas flow contains _H2S of 4 parts per million (ppm) or less .
(Appendix 5)
Each of the plurality of parallel flow contact systems is configured to recirculate the corresponding solvent flow to the preceding one of the plurality of parallel flow contact systems, the final parallel flow contact system being the partial. The gas treatment system according to Appendix 1, which is configured to recirculate the loaded solvent flow to the preceding one of the plurality of parallel flow contact systems.
(Appendix 6)
The gas treatment system according to Appendix 1, wherein the solvent treatment device includes a cooling device configured to lower the temperature of the lean solvent flow to generate the enhanced solvent flow.
(Appendix 7)
An analyzer configured to determine the acid gas concentration of the final gas stream;
A control device configured to raise or lower the temperature of the cooling device based on the acid gas concentration determined by the analyzer.
The gas treatment system according to Appendix 6.
(Appendix 8)
The gas treatment system according to Appendix 1, wherein the solvent treatment apparatus includes an anion exchange bed.
(Appendix 9)
The gas treatment system according to Appendix 1, wherein the solvent treatment device includes an electrodialysis unit.
(Appendix 10)
The gas treatment system according to Appendix 1, wherein the solvent treatment apparatus is configured to generate the strengthening solvent flow by injecting the strengthening fluid into the lean solvent flow.
(Appendix 11)
Each of the plurality of parallel flow contact systems:
A parallel flow contact device arranged in series in a conduit, wherein the parallel flow contact device is:
An annular support ring configured to maintain the parallel flow contact device within the conduit;
Numerous radial blades configured to allow the solvent flow to flow into the parallel flow contact device; and
A central gas introduction cone configured to allow the sour supply gas flow to flow into the hollow portion in the parallel flow contact device.
Equipped with
The parallel flow contact device; the parallel flow contact device;
Separator configured to remove the droplets from the sour supply gas stream
The gas treatment system according to Appendix 1.
(Appendix 12)
A method for enhancing acid gas removal within a gas treatment system, wherein:
A step of contacting a sour supply gas stream containing an acid gas with a solvent stream in a plurality of parallel flow contact systems to generate a partially sweetened gas stream and a rich solvent stream absorbing the acid gas;
A step of removing the absorbed acid gas from the rich solvent stream in the regenerator to generate a lean solvent stream;
A step of treating at least a part of the lean solvent stream in a solvent treatment apparatus to generate a fortified solvent stream;
A step of contacting the partially sweetening gas flow with the enhanced solvent flow in a final parallel flow contact system to generate a partially loaded solvent flow and final gas flow.
A method characterized by the inclusion of.
(Appendix 13)
The method according to Appendix 12, wherein the sour supply gas stream includes a sour natural gas stream.
(Appendix 14)
The method according to Appendix 12, wherein the absorbed acid gas contains hydrogen sulfide (H2S ₎ .
(Appendix 15)
The method according to Appendix 14, wherein the final gas stream comprises _H2S in parts per million (ppm) or less .
(Appendix 16)
The step of recirculating the corresponding solvent flow from each of the plurality of parallel flow contact systems to the preceding one of the plurality of parallel flow contact systems; and
The step of recirculating the partially loaded solvent flow from the final parallel flow contact system to the preceding one of the plurality of parallel flow contact systems.
The method according to Appendix 12, which comprises.
(Appendix 17)
The method according to Appendix 12, wherein the solvent treatment device includes a cooling device configured to lower the temperature of the lean solvent flow to generate the enhanced solvent flow.
(Appendix 18)
The step of analyzing the final gas flow to determine the acid gas concentration of the final gas flow; and
A step of raising or lowering the temperature of the cooling device based on the acid gas concentration of the final gas flow.
The method according to Appendix 17, which comprises.
(Appendix 19)
The method according to Appendix 12, wherein the solvent treatment apparatus comprises an anion exchange bed.
(Appendix 20)
The method according to Appendix 12, wherein the solvent treatment apparatus includes an electrodialysis unit.
(Appendix 21)
The step of treating at least a part of the lean solvent flow in the solvent treatment apparatus includes a step of generating the strengthened solvent flow by injecting the strengthening fluid into the lean solvent flow, according to Appendix 12. Method.
(Appendix 22)
In the step of contacting the sour supply gas flow and the solvent flow in the plurality of parallel flow contact systems:
A step of inflowing the solvent flow into the parallel flow contact device via the annular support ring and a plurality of radial blades extending from the annular support ring, wherein the annular support ring has the parallel flow contact device in a conduit. The process of securing in series with
In a step of flowing the sour supply gas flow to the parallel flow contact device through the central gas introduction cone supported by the plurality of radial blades, the first portion of the sour supply gas flow is the central gas introduction cone. The second portion of the sour supply gas flow flows around the central gas introduction cone between the plurality of radial blades;
A step of bringing the sour-supplied gas stream into contact with the solvent stream to incorporate droplets formed from the solvent stream into the sour-supplied gas stream;
A step of separating the droplet from the sour supply gas flow in the separation device.
12. The method according to Appendix 12.
(Appendix 23)
A gas treatment system:
Multiple parallel flow contact systems configured to contact a sour feed gas stream containing an acid gas with a solvent stream to generate a partial sweetening gas stream and a rich solvent stream containing the first portion of the acid gas. ;
A first portion of the acid gas is removed from the rich solvent stream to generate the solvent stream; a first configured to recirculate the solvent stream to at least one of the plurality of parallel flow contact systems. Playback device;
A final parallel flow contact system configured to contact the partial sweetening gas stream with the enhanced solvent stream to produce a final gas stream and a partially loaded solvent stream containing a second portion of the acid gas;
A second regeneration device configured to remove the second portion of the acid gas from the partially loaded solvent stream to generate a lean solvent stream;
A solvent treatment apparatus configured to treat at least a portion of the lean solvent stream and generate the enhanced solvent stream in contact with the partial sweetening gas stream in the final parallel flow contact system.
A gas treatment system characterized by being equipped with.
(Appendix 24)
23. The gas treatment system according to Appendix 23, wherein the sour supply gas stream includes a sour natural gas stream.
(Appendix 25)
23. The gas treatment system according to Appendix 23, wherein the acid gas contains hydrogen sulfide (H _2S ).
(Appendix 26)
25. The gas treatment system according to Appendix 25, wherein the final gas flow comprises _H2S of 4 million parts per (ppm) or less .
(Appendix 27)
23. The gas treatment system according to Appendix 23, wherein each of the plurality of parallel flow contact systems is configured to recirculate the corresponding solvent flow to the preceding one of the plurality of parallel flow contact systems. ..
(Appendix 28)
23. The gas treatment system according to Appendix 23, wherein the solvent treatment device includes a cooling device configured to lower the temperature of the lean solvent flow to generate the enhanced solvent flow.
(Appendix 29)
An analyzer configured to determine the acid gas concentration of the final gas stream;
A control device configured to raise or lower the temperature of the cooling device based on the acid gas concentration determined by the analyzer.
28. The gas treatment system according to Appendix 28.
(Appendix 30)
23. The gas treatment system according to Appendix 23, wherein the solvent treatment apparatus includes an anion exchange bed.
(Appendix 31)
23. The gas treatment system according to Appendix 23, wherein the solvent treatment apparatus includes an electrodialysis unit.
(Appendix 32)
23. The gas treatment system according to Appendix 23, wherein the solvent treatment apparatus is configured to generate the strengthening solvent flow by injecting the strengthening fluid into at least a part of the lean solvent flow.
(Appendix 33)
Each of the plurality of parallel flow contact systems:
A parallel flow contact device arranged in series in a conduit, wherein the parallel flow contact device is:
An annular support ring configured to maintain the parallel flow contact device within the conduit;
Numerous radial blades configured to allow the solvent flow to flow into the parallel flow contact device; and
A central gas introduction cone configured to allow the sour supply gas flow to flow into the hollow portion in the parallel flow contact device.
Equipped with
The parallel flow contact device; the parallel flow contact device;
Separator configured to remove the droplets from the sour supply gas stream
23. The gas treatment system according to Appendix 23.

Claims (33)

A gas treatment system:
A plurality of parallel flow contact systems configured to contact a sour supply gas stream containing acid gas with a solvent stream to generate a partially sweetened gas stream and a rich solvent stream that has absorbed the acid gas. A plurality of parallel flow contact systems, wherein at least one of the plurality of parallel flow contact systems is configured to send the rich solvent flow to the regenerator;
The regenerating device configured to remove the absorbed acid gas from the rich solvent stream to generate a lean solvent stream;
A solvent treatment apparatus configured to treat at least a portion of the lean solvent stream to generate a fortified solvent stream; as well as contacting the partial sweetening gas stream with the fortified solvent stream and partially loading it. A gas treatment system comprising a final parallel flow contact system configured to generate a solvent flow and a final gas flow. The gas treatment system according to claim 1, wherein the sour supply gas stream includes a sour natural gas stream. The gas treatment system according to claim 1, wherein the absorbed acid gas contains hydrogen sulfide ₍ H 2S). The gas treatment system of claim 3, wherein the final gas stream _comprises H 2S of 4 million parts per (ppm) or less. Each of the plurality of parallel flow contact systems is configured to recirculate the corresponding solvent flow to the preceding one of the plurality of parallel flow contact systems, the final parallel flow contact system being the partial. The gas treatment system according to claim 1, wherein the loaded solvent flow is configured to recirculate to the preceding one of the plurality of parallel flow contact systems. The gas treatment system according to claim 1, wherein the solvent treatment device includes a cooling device configured to lower the temperature of the lean solvent flow to generate the enhanced solvent flow. A claim comprising an analyzer configured to determine the acid gas concentration of the final gas flow; and a control device configured to raise or lower the temperature of the cooling device based on the acid gas concentration determined by the analyzer. 6. The gas treatment system according to 6. The gas treatment system according to claim 1, wherein the solvent treatment apparatus includes an anion exchange bed. The gas treatment system according to claim 1, wherein the solvent treatment device includes an electrodialysis unit. The gas treatment system according to claim 1, wherein the solvent treatment apparatus is configured to generate the strengthening solvent flow by injecting the strengthening fluid into the lean solvent flow. Each of the plurality of parallel flow contact systems:
A parallel flow contact device arranged in series in a conduit, wherein the parallel flow contact device is:
An annular support ring configured to maintain the parallel flow contact device within the conduit;
It comprises a number of radial blades configured to allow the solvent flow to flow into the parallel flow contact device; and a central gas introduction cone configured to allow the sour supply gas flow to flow into the hollow portion within the parallel flow contact device.
The parallel flow contact device is configured to streamline the uptake of droplets formed from the solvent flow into the sour supply gas stream; as well as to remove the droplets from the sour supply gas stream. The gas treatment system according to claim 1, further comprising a separation device. A method for enhancing acid gas removal within a gas treatment system, wherein:
A step of contacting a sour supply gas stream containing an acid gas with a solvent stream in a plurality of parallel flow contact systems to generate a partially sweetened gas stream and a rich solvent stream absorbing the acid gas;
A step of removing the absorbed acid gas from the rich solvent stream in the regenerator to generate a lean solvent stream;
The step of treating at least a portion of the lean solvent stream in a solvent treatment apparatus to generate a fortified solvent stream; and in the final parallel flow contact system, the partial sweetening gas stream and the fortified solvent stream are brought into contact with each other. The method comprises the steps of generating a partially loaded solvent flow and a final gas flow. 12. The method of claim 12, wherein the sour supply gas stream comprises a sour natural gas stream. The method according to claim 12, wherein the absorbed acid gas contains hydrogen sulfide ₍ H 2S). 15. The method of claim 14, wherein the final gas stream _comprises H 2S in parts per million (ppm) or less. The step of recirculating the corresponding solvent flow from each of the plurality of parallel flow contact systems to the preceding one of the plurality of parallel flow contact systems; and the partial loading solvent flow of the final parallel flow. 12. The method of claim 12, comprising recirculating the contact system to the preceding one of the plurality of parallel flow contact systems. 12. The method of claim 12, wherein the solvent treatment device comprises a cooling device configured to lower the temperature of the lean solvent stream to generate the enhanced solvent stream. Claims include a step of analyzing the final gas flow to determine the acid gas concentration of the final gas flow; and a step of raising or lowering the temperature of the cooling device based on the acid gas concentration of the final gas flow. 17. The method according to 17. 12. The method of claim 12, wherein the solvent treatment apparatus comprises an anion exchange bed. 12. The method of claim 12, wherein the solvent treatment apparatus comprises an electrodialysis unit. 12. The step according to claim 12, wherein the step of treating at least a part of the lean solvent flow in the solvent treatment apparatus includes a step of generating the strengthened solvent flow by injecting the strengthening fluid into the lean solvent flow. the method of. In the step of contacting the sour supply gas flow and the solvent flow in the plurality of parallel flow contact systems:
A step of allowing the solvent flow to flow into the parallel flow contact device via the annular support ring and a plurality of radial blades extending from the annular support ring, wherein the annular support ring has the parallel flow contact device in a conduit. The process of securing in series with
A step of flowing the sour supply gas flow through the parallel flow contact device via a central gas introduction cone supported by the plurality of radial blades, wherein the first portion of the sour supply gas flow is the central gas introduction cone. The second portion of the sour supply gas flow flows around the central gas introduction cone between the plurality of radial blades;
A step of bringing the sour-supplied gas stream into contact with the solvent stream to incorporate the droplets formed from the solvent stream into the sour-supplied gas stream; and separating the droplets from the sour-supplied gas stream in a separator. 12. The method of claim 12, comprising the process. A gas treatment system:
Multiple parallel flow contact systems configured to contact a sour supply gas stream containing an acid gas with a solvent stream to produce a partial sweetening gas stream and a rich solvent stream containing the first portion of the acid gas. ;
A first portion of the acid gas is removed from the rich solvent stream to regenerate the solvent stream; a first configured to recirculate the solvent stream to at least one of the plurality of parallel flow contact systems. Playback device;
A final parallel flow contact system configured to contact the partial sweetening gas stream with the enhanced solvent stream to generate a final gas stream and a partially loaded solvent stream containing a second portion of the acid gas;
A second regeneration apparatus configured to remove the second portion of the acid gas from the partially loaded solvent stream to generate a lean solvent stream; as well as treating at least a portion of the lean solvent stream to the final average. A gas treatment system comprising a solvent treatment apparatus configured to generate the enhanced solvent flow in contact with the partial sweetening gas flow within the flow contact system. 23. The gas treatment system of claim 23, wherein the sour supply gas stream comprises a sour natural gas stream. 23. The gas treatment system according to claim 23, wherein the acid gas contains hydrogen sulfide ₍ H 2S). 25. The gas treatment system of claim 25, wherein the final gas stream _comprises H 2S in parts per million (ppm) or less. 23. The gas treatment of claim 23, wherein each of the plurality of parallel flow contact systems is configured to recirculate the corresponding solvent flow to the preceding one of the plurality of parallel flow contact systems. system. 23. The gas treatment system according to claim 23, wherein the solvent treatment device includes a cooling device configured to lower the temperature of the lean solvent flow to generate the enhanced solvent flow. A claim comprising an analyzer configured to determine the acid gas concentration of the final gas flow; and a control device configured to raise or lower the temperature of the cooling device based on the acid gas concentration determined by the analyzer. 28. The gas treatment system. 23. The gas treatment system of claim 23, wherein the solvent treatment apparatus comprises an anion exchange bed. 23. The gas treatment system according to claim 23, wherein the solvent treatment device includes an electrodialysis unit. 23. The gas treatment system according to claim 23, wherein the solvent treatment apparatus is configured to generate the strengthening solvent flow by injecting the strengthening fluid into at least a part of the lean solvent flow. Each of the plurality of parallel flow contact systems:
A parallel flow contact device arranged in series in a conduit, wherein the parallel flow contact device is:
An annular support ring configured to maintain the parallel flow contact device within the conduit;
It comprises a number of radial blades configured to allow the solvent flow to flow into the parallel flow contact device; and a central gas introduction cone configured to allow the sour supply gas flow to flow into the hollow portion within the parallel flow contact device.
The parallel flow contact device is configured to streamline the uptake of droplets formed from the solvent flow into the sour supply gas stream; as well as to remove the droplets from the sour supply gas stream. 23. The gas treatment system according to claim 23, comprising a separating device.

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