HK1237756B - Hydrogen generation assemblies and hydrogen purification devices - Google Patents

Description

Hydrogen production equipment and hydrogen purification equipment

This application is a divisional application of the Chinese invention patent application with application date of March 3, 2014, application number 201480015413.5, and invention name “Hydrogen production device and hydrogen purification equipment”.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Patent Application Serial No. 13/829,766, entitled “Hydrogen Generation Apparatus and Hydrogen Purification Device,” filed on March 14, 2013. The entire disclosure of the above application is hereby incorporated by reference for all purposes.

Technical Field

The invention relates to a hydrogen production device and hydrogen purification equipment.

Background Art

The hydrogen production device is a device that converts one or more raw materials into a product stream containing hydrogen as a main component. The raw material may include a carbonaceous raw material and, in some embodiments, may also include water. The raw material is delivered from a raw material delivery system to the hydrogen production zone of the hydrogen production device, and the raw material is usually delivered under pressure and at an elevated temperature. The hydrogen production zone is usually associated with a temperature regulating device such as a heating device or a cooling device, which consumes one or more fuel streams to keep the hydrogen production zone within a suitable temperature range for effectively producing hydrogen. The hydrogen production device can generate hydrogen via a suitable mechanism (such as steam reforming, autothermal reforming, pyrolysis and/or catalytic partial oxidation).

However, the hydrogen generated or produced may have impurities. The gas may be referred to as a mixed gas stream containing hydrogen and other gases. Before the mixed gas stream is used, it must be purified, such as to remove at least a portion of the other gases. Therefore, the hydrogen production device may include a hydrogen purification device for improving the hydrogen purity of the mixed gas stream. The hydrogen purification device may include at least one hydrogen selective membrane that separates the mixed gas stream into a product stream and a by-product stream. The product stream contains a higher concentration of hydrogen and/or a lower concentration of one or more other gases from the mixed gas stream. Hydrogen purification using one or more hydrogen selective membranes is a pressure-driven separation method in which one or more hydrogen selective membranes are housed in a pressure vessel. The mixed gas stream contacts the mixed gas surface of the membrane, and the product stream is formed by at least a portion of the mixed gas stream that permeates through the membrane. The pressure vessel is typically sealed to prevent gas from entering or leaving the pressure vessel except through defined input and output port portions or conduits.

Product streams can be used in a variety of applications. One such application is energy production, such as in electrochemical fuel cells. Electrochemical fuel cells are devices that convert fuel and oxidant into electricity, reaction products, and heat. For example, fuel cells can convert hydrogen and oxygen into water and electricity. In these fuel cells, hydrogen is the fuel, oxygen is the oxidant, and water is the reaction product. A fuel cell stack contains multiple fuel cells and can be used in conjunction with a hydrogen production unit to provide an energy production device.

Examples of hydrogen production devices and/or components of those devices are described in the following documents: U.S. Patent Nos. 5,861,137; 6,319,306; 6,494,937; 6,562,111; 7,063,047; 7,306,868; 7,470,293; 7,601,302; 7,632,322; U.S. Patent Application Publication Nos. 2006/0090397; 2006/0272212; 2007/0266631; 2007/0274904; 2008/0085434; 2008/0138678; 2008/0230039; 2010/0064887; and 2013/0011301. The entire disclosures of the above-identified patents and patent application publications are hereby incorporated by reference for all purposes.

Summary of the Invention

Some embodiments may provide a hydrogen purification device. In some embodiments, the hydrogen purification device may include first and second end frames. The first and second end frames may include an input port configured to receive a mixed gas stream comprising hydrogen and other gases and an output port configured to receive a permeate stream comprising a higher concentration of hydrogen and a lower concentration of at least one of the other gases compared to the mixed gas stream. The first and second end frames may additionally include a byproduct port configured to receive a byproduct stream comprising at least a majority of the other gases. The hydrogen purification device may additionally include at least one hydrogen-selective membrane arranged between the first and second end frames and fixed thereto. The at least one hydrogen-selective membrane may have a feed side and a permeate side, at least a portion of the permeate stream being formed by a portion of the mixed gas stream passing from the feed side to the permeate side, and the remainder of the mixed gas stream remaining on the feed side forming at least a portion of the byproduct stream.

The hydrogen purification apparatus may further include a plurality of frames disposed between the first and second end frames and the at least one hydrogen-selective membrane and secured to the first and second end frames. The plurality of frames may include at least one permeate frame disposed between the at least one hydrogen-selective membrane and the second end frame. The at least one permeate frame may include a periphery shell and an output conduit formed on the periphery shell and configured to receive at least a portion of the permeate stream from the at least one hydrogen-selective membrane. The at least one permeate frame may additionally include an open area surrounded by the periphery shell and at least one membrane support structure spanning at least a majority of the open area and configured to support the at least one hydrogen-selective membrane. The at least one membrane support structure may include first and second membrane support plates. Each of the first and second membrane support plates may be free of perforations. Each of the first and second membrane support plates may include a first surface having a plurality of microgrooves configured to provide flow paths for the at least a portion of the permeate stream and a second surface opposite the first surface. The first and second membrane support plates may be stacked in the at least one membrane support structure such that the second surface of the first membrane support plate faces the second surface of the second membrane support plate.

Some embodiments may provide a hydrogen production device. In some embodiments, the hydrogen production device may include a fuel processing device configured to receive a feed stream and to operate in multiple modes. The multiple modes may include: an operating mode in which the fuel processing device generates a product hydrogen stream from the feed stream, and a standby mode in which the fuel processing device does not generate a product hydrogen stream from the feed stream. The fuel processing device may include: a hydrogen production zone containing a reforming catalyst and configured to receive a feed stream and generate a reformed product stream, and one or more hydrogen-selective membranes configured to receive a reformed product stream and generate at least a portion of a product hydrogen stream and a by-product stream from the reformed product stream. The fuel processing device may also include a reformed product conduit fluidically connecting the hydrogen production zone and the one or more hydrogen-selective membranes.

The hydrogen generation assembly may further include: a buffer tank configured to contain a product hydrogen stream, and a product conduit fluidically connecting the fuel processing assembly and the buffer tank. The hydrogen generation assembly may further include: a return conduit fluidically connecting the buffer tank and the reformate conduit, and a tank sensor assembly configured to detect a pressure in the buffer tank. The hydrogen generation assembly may further include: a control assembly configured to operate the fuel processing assembly between an operating mode and a standby mode based at least in part on the detected pressure in the buffer tank, and a return valve assembly configured to control flow in the return conduit, the control assembly configured to direct the return valve assembly to allow the product hydrogen stream to flow from the buffer tank to the reformate conduit when the fuel processing assembly is in the standby mode.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of an example of a hydrogen production apparatus.

FIG2 is a schematic diagram of another example of a hydrogen production apparatus.

FIG3 is a schematic diagram of a hydrogen purification device of the hydrogen production apparatus of FIG1 .

4 is an exploded isometric view of the example hydrogen purification apparatus of FIG. 3 .

5 is a top view of an example of a permeation frame and microporous screen structure of the hydrogen purification apparatus of FIG. 4 .

6 is a partial cross-sectional view of the hydrogen purification apparatus of FIG. 4 , showing the outer peripheral shell of the feed frame, the hydrogen selective membrane, the microporous screen structure, the outer peripheral shell of the permeate frame, and the membrane support structure of the permeate frame.

FIG. 7 is a partial cross-sectional view of another example of the outer peripheral shell of the permeation frame of the hydrogen purification apparatus of FIG. 4 .

8 is an isometric view of an example of a membrane support plate of the membrane support structure of the permeation frame of the hydrogen purification apparatus of FIG. 4 .

FIG. 9 is a cross-sectional view of another example of the membrane support structure of the hydrogen purification apparatus of FIG. 4 .

FIG. 10 is a partial schematic diagram of another example of the hydrogen production apparatus of FIG. 1 .

FIG. 11 is a partial schematic diagram of another example of the hydrogen production apparatus of FIG. 1 .

FIG. 12 is a partial schematic diagram of another example of the hydrogen production apparatus of FIG. 1 .

DETAILED DESCRIPTION

FIG1 shows an example of a hydrogen generation assembly 20. Unless specifically excluded, the hydrogen generation assembly may include one or more components of other hydrogen generation assemblies described herein. The hydrogen generation assembly may include any suitable structure configured to generate a product hydrogen stream 21. For example, the hydrogen generation assembly may include a feedstock delivery system 22 and a fuel processing assembly 24. The feedstock delivery system may include any suitable structure configured to selectively deliver at least one feed stream 26 to the fuel processing assembly.

In some embodiments, the feedstock delivery system 22 may additionally include any suitable structure configured to selectively deliver at least one fuel stream 28 to a burner or other heating device of the fuel processing assembly 24. In some embodiments, the feed stream 26 and the fuel stream 28 may be the same stream delivered to different components of the fuel processing assembly. The feedstock delivery system may include any suitable delivery mechanism, such as a volumetric or other pump or mechanism suitable for propelling fluid streams. In some embodiments, the feedstock delivery system may be configured to deliver the feed stream 26 and/or the fuel stream 28 without the use of a pump and/or other electric fluid-delivery mechanism. Examples of suitable feedstock delivery systems that can be used with the hydrogen production assembly 20 include the feedstock delivery systems described in the following documents: U.S. Patent Nos. 7,470,293 and 7,601,302, and U.S. Patent Application Publication No. 2006/0090397. The entire disclosures of the above patents and patent applications are hereby incorporated by reference for all purposes.

The feed stream 26 may include at least one hydrogen-producing fluid 30, which may include one or more fluids that can be used as reactants to produce the product hydrogen stream 21. For example, the hydrogen-producing fluid may include a carbon-containing feedstock, such as at least one hydrocarbon and/or alcohol. Examples of suitable hydrocarbons include methane, propane, natural gas, diesel, kerosene, gasoline, and the like. Examples of suitable alcohols include methanol, ethanol, polyols (such as ethylene glycol and propylene glycol), and the like. In addition, the hydrogen-producing fluid 30 may include water, such as when the fuel processing unit generates the product hydrogen stream via steam reforming and/or autothermal reforming. When the fuel processing unit 24 generates the product hydrogen stream via pyrolysis or catalytic partial oxidation, the feed stream 26 does not contain water.

In some embodiments, the feedstock delivery system 22 may be configured to deliver a mixture comprising water and a water-miscible carbonaceous feedstock (such as methanol and/or another water-soluble alcohol). The ratio of water to carbonaceous feedstock in such a fluid stream may vary depending on one or more factors, such as the specific carbonaceous feedstock used, user preferences, the design of the fuel processing device, the mechanism of the fuel processing device for generating a product hydrogen stream, etc. For example, the water to carbon ratio may be about 1:1 to 3:1. In addition, a mixture of water and methanol may be delivered at a molar ratio of 1:1 or near 1:1 (37 wt% water, 63 wt% methanol), while hydrocarbons or other alcohols may be delivered at a water-to-carbon molar ratio greater than 1:1.

When the fuel processing unit 24 generates the product hydrogen stream 21 via reforming, the feed stream 26 may include, for example, about 25-75 vol% methanol or ethanol (or another suitable carbonaceous feedstock miscible with water) and about 25-75 vol% water. For feed streams that at least substantially comprise methanol and water, those streams may include about 50-75 vol% methanol and about 25-50 vol% water. Streams containing ethanol or other water-miscible alcohols may include about 25-60 vol% alcohol and about 40-75 vol% water. An example of a feed stream for a hydrogen generation unit 20 utilizing steam reforming or autothermal reforming comprises 69 vol% methanol and 31 vol% water.

Although the feedstock delivery system 22 is shown as being configured to deliver a single feed stream 26, the feedstock delivery system may be configured to deliver two or more feed streams 26. Those streams may contain the same or different feedstocks and may have different compositions, have at least one common component, no common components, or have the same composition. For example, the first feed stream may include a first component such as a carbonaceous feedstock, and the second feed stream may include a second component such as water. Additionally, although the feedstock delivery system 22 may be configured to deliver a single fuel stream 28 in some embodiments, the feedstock delivery system may be configured to deliver two or more fuel streams. The fuel streams may have different compositions, have at least one common component, no common components, or have the same composition. Furthermore, the feed and fuel streams may be discharged from the feedstock delivery system in different phases. For example, one of the streams may be a liquid stream and the other a gaseous stream. In some embodiments, both streams may be liquid streams, while in other embodiments both streams may be gaseous streams. Additionally, although the hydrogen production assembly 20 is shown as including a single feedstock delivery system 22, the hydrogen production assembly may include two or more feedstock delivery systems 22.

Fuel processing assembly 24 may include a hydrogen-producing region 32 configured to generate an output stream 34 comprising hydrogen gas via any suitable hydrogen-producing mechanism. The output stream may include hydrogen gas as at least a majority component and may include other gaseous components. Output stream 34 may therefore be referred to as a "mixed gas stream," comprising hydrogen gas as a primary component but also comprising other gases.

The hydrogen-producing region 32 may include any suitable catalyst-containing bed or zone. When the hydrogen production mechanism is steam reforming, the hydrogen-producing region may include a suitable steam reforming catalyst 36 to facilitate production of an output stream 34 from a feed stream 26 comprising a carbonaceous feedstock and water. In such an embodiment, the fuel processing unit 24 may be referred to as a "steam reformer," the hydrogen-producing region 32 may be referred to as a "reforming region," and the output stream 34 may be referred to as a "reformed product stream." Other gases that may be present in the reformed product stream may include carbon monoxide, carbon dioxide, methane, steam, and/or unreacted carbonaceous feedstock.

When the hydrogen production mechanism is autothermal reforming, hydrogen-producing region 32 may include a suitable autothermal reforming catalyst to facilitate production of output stream 34 from feed stream 26 comprising water and a carbonaceous feedstock in the presence of air. Additionally, fuel processing assembly 24 may include air delivery assembly 38 configured to deliver an air stream to the hydrogen-producing region.

In some embodiments, the fuel processing device 24 may include a purification (or separation) zone 40, which may include any suitable structure configured to produce at least one hydrogen-rich stream 42 from the output (or mixed gas) stream 34. The hydrogen-rich stream 42 may include a greater concentration of hydrogen than the output stream 34 and/or a lower concentration of one or more other gases (or impurities) than those present in the output stream. The product hydrogen stream 21 includes at least a portion of the hydrogen-rich stream 42. Therefore, the product hydrogen stream 21 and the hydrogen-rich stream 42 may be the same stream and have the same composition and flow rate. Alternatively, some of the purified hydrogen in the hydrogen-rich stream 42 may be stored in a suitable hydrogen storage device for later use, and/or consumed by the fuel processing device. The purification zone 40 may also be referred to as a "hydrogen purification device" or a "hydrogen processing device."

In some embodiments, the purification region 40 may produce at least one byproduct stream 44, which may be free of hydrogen or contain some hydrogen. The byproduct stream may be discharged, sent to a burner device and/or other combustion source, used as a heating fluid stream, stored for later use, and/or otherwise utilized, stored, and/or disposed of. In addition, the purification region 40 may discharge the byproduct stream as a continuous stream in response to delivery of the output stream 34, or may discharge the stream intermittently, such as in a batch manner, or when the byproduct portion of the output stream is at least temporarily retained in the purification region.

The fuel processing assembly 24 may include one or more purification zones configured to produce one or more byproduct streams comprising hydrogen in an amount sufficient to be suitable for use as a fuel stream (or feed stream) for a heating assembly of the fuel processing assembly. In some embodiments, the byproduct stream may have a sufficient fuel value or hydrogen content to enable the heating assembly to maintain the hydrogen-producing region at a desired operating temperature or within a selected temperature range. For example, the byproduct stream may include hydrogen, such as 10-30 vol% hydrogen, 15-25 vol% hydrogen, 20-30 vol% hydrogen, at least 10 or 15 vol% hydrogen, at least 20 vol% hydrogen, etc.

The purification region 40 may comprise any suitable structure configured to enrich (and/or increase) the concentration of at least one component of the output stream 21. In most applications, the hydrogen-rich stream 42 will have a greater hydrogen concentration than the output stream (or mixed gas stream) 34. The hydrogen-rich stream may also have a lower concentration of one or more non-hydrogen components than those present in the output stream 34, and the hydrogen concentration of the hydrogen-rich stream may be higher, equal to, or lower than that of the output stream. For example, in a conventional fuel cell system, carbon monoxide may damage the fuel cell stack if present at even a few ppm, while other non-hydrogen components (such as water) that may be present in the output stream 34 will not damage the stack even at much higher concentrations. Thus, in such applications, the purification region may not increase the overall hydrogen concentration, but rather reduce the concentration of one or more non-hydrogen components that are harmful or potentially harmful to the desired use of the product hydrogen stream.

Examples of equipment suitable for use in purification region 40 include one or more hydrogen-selective membranes 46, a carbon monoxide chemical removal unit 48, and/or a pressure swing adsorption (PSA) system 50. Purification region 40 may include more than one type of purification equipment, and the equipment may have the same or different structures and/or operate by the same or different mechanisms. Fuel processing assembly 24 may include at least one restricted orifice and/or other flow restrictor downstream of the purification region, such as associated with one or more product hydrogen streams, hydrogen-rich streams, and/or by-product streams.

The hydrogen-selective membrane 46 is permeable to hydrogen gas but substantially, if not completely, impermeable to other components of the output stream 34. The membrane 46 may be formed of any material suitable for hydrogen permeability within the operating environment and parameters used to operate the purification zone 40. Examples of suitable materials for the membrane 46 include palladium and palladium alloys, particularly thin films of such metals and metal alloys. Palladium alloys have proven particularly effective, particularly alloys of palladium with 35 to 45 wt% copper. Palladium-copper alloys containing approximately 40 wt% copper have proven particularly effective, although other relative concentrations and compositions may also be used. Two other particularly effective alloys are palladium with 2 to 10 wt% gold, particularly palladium with 5 wt% gold; and palladium with 3 to 10 wt% indium and 0 to 10 wt% ruthenium, particularly palladium with 6 wt% indium and 0.5 wt% ruthenium. When palladium and palladium alloys are used, the hydrogen-selective membrane 46 may sometimes be referred to as "foil."

Chemical carbon monoxide removal assemblies 48 are devices that chemically react carbon monoxide and/or other undesirable components of the output stream 34 to form other compositions that are not potentially harmful. Examples of chemical carbon monoxide removal assemblies include water-gas shift reactors configured to produce hydrogen and carbon dioxide from water and carbon monoxide, partial oxidation reactors configured to convert carbon monoxide and oxygen (typically from air) into carbon dioxide, and methanation reactors configured to convert carbon monoxide and hydrogen into methane and water. Fuel processing assembly 24 may include more than one type and/or number of chemical removal assemblies 48.

Pressure swing adsorption (PSA) is a chemical process for removing gaseous impurities from the output stream 34 based on the principle that, under appropriate temperature and pressure conditions, certain gases will adsorb more strongly onto an adsorbent material than other gases. Typically, non-hydrogen impurities are adsorbed and removed from the output stream 34. Adsorption of the impurity gas occurs at a relatively high pressure. When the pressure is reduced, the impurities desorb from the adsorbent material, thereby regenerating the adsorbent material. Typically, PSA is a cyclic process and requires at least two beds operated continuously (as opposed to batchwise). Examples of suitable adsorbent materials that can be used in the adsorption beds are activated carbon and zeolites. The PSA system 50 also provides an example of an apparatus used in the purification zone 40 in which byproducts or components to be removed are not discharged directly from the purification zone as a gaseous stream concurrently with the purification of the output stream. Instead, these byproduct components are removed during regeneration of the adsorbent material or are otherwise removed from the purification zone.

In Figure 1, purification region 40 is shown within fuel processing assembly 24. Alternatively, purification region 40 may be located separately downstream of the fuel processing assembly, as schematically illustrated by dotted lines in Figure 1. Purification region 40 may also include portions within or outside of the fuel processing assembly.

The fuel processing assembly 24 may also include a temperature regulating device in the form of a heating assembly 52. The heating assembly may be configured to produce at least one heated fuel stream 28 from at least one heated exhaust stream (or combustion stream) 54, typically by combustion in the presence of air. The heated exhaust stream 54 is schematically illustrated in FIG1 as heating the hydrogen production region 32. The heating assembly 52 may include any suitable structure configured to produce a heated exhaust stream, such as a burner or combustion catalyst in which a fuel is combusted with air to produce the heated exhaust stream. The heating assembly may include an igniter or ignition source 58 configured to initiate combustion of the fuel. Examples of suitable ignition sources include one or more spark plugs, glow plugs, combustion catalysts, pilot lights, piezoelectric igniters, spark igniters, hot surface igniters, and the like.

In some embodiments, the heating assembly 52 may include a burner assembly 60 and may be referred to as a combustion-based or combustion-driven heating assembly. In a combustion-based heating assembly, the heating assembly 52 may be configured to receive at least one fuel stream 28 and burn the fuel stream in the presence of air to provide a hot combustion stream 54 that can be used to heat at least the hydrogen-producing region of the fuel processing assembly. Air can be delivered to the heating assembly via a variety of mechanisms. For example, an air stream 62 can be delivered to the heating assembly as a separate stream, as shown in FIG1 . Alternatively, or in addition, an air stream 62 can be delivered to the heating assembly together with at least one fuel stream 28 for the heating assembly 52 and/or extracted from the environment in which the heating assembly is used.

The combustion stream 54 may additionally, or alternatively, be used to heat other portions of the fuel processing assembly and/or a fuel cell system used with the heating assembly. In addition, other configurations or types of heating assembly 52 may also be used. For example, the heating assembly 52 may be an electrically powered heating assembly configured to heat at least the hydrogen-producing region 32 of the fuel processing assembly 24 by generating heat using at least one heating element, such as a resistive heating element. In those embodiments, the heating assembly 52 may not receive and burn a combustible fuel stream to heat the hydrogen-producing region to a suitable hydrogen-producing temperature. Examples of heating assemblies are disclosed in U.S. Patent No. 7,632,322, the entire disclosure of which is incorporated herein by reference for all purposes.

The heating device 52 may be housed in a common shell or housing along with the hydrogen-producing region and/or the separation region (as discussed further below). The heating device may be independently disposed relative to the hydrogen-producing region 32, but in thermal and/or fluid communication therewith to provide the desired heating of at least the hydrogen-producing region. The heating device 52 may be partially or entirely located within the common housing and/or at least a portion (or all) of the heating device may be located external to the housing. When the heating device is located external to the housing, the hot combustion gases from the burner assembly 60 may be delivered to one or more components within the housing via any suitable heat transfer conduit.

The heating device can also be configured to heat the feedstock delivery system 22, the feedstock supply stream, the hydrogen production zone 32, the purification (or separation) zone 40, or any suitable combination of those systems, streams, and zones. The heating of the feedstock supply stream can include evaporating components of the liquid reactant stream or the hydrogen production stream for producing hydrogen in the hydrogen production zone. In this embodiment, the fuel processing device 24 can be described as including an evaporation zone 64. The heating device can be additionally configured to heat other components of the hydrogen production device. For example, the heated exhaust stream can be configured to heat a pressure vessel and/or other pressure tank containing a heating fuel and/or hydrogen production fluid that forms at least a portion of the feed stream 26 and the fuel stream 28.

The heating device 52 can achieve and/or maintain any suitable temperature in the hydrogen production zone 32. The steam reformer is typically operated at a temperature in the range of 200°C to 900°C. However, temperatures outside this range are also within the scope of the present disclosure. When the carbonaceous feedstock is methanol, the steam reforming reaction will typically operate in a temperature range of about 200-500°C. Examples of subsets of this range include 350-450°C, 375-425°C, and 375-400°C. When the carbonaceous feedstock is a hydrocarbon, ethanol, or other alcohol, a temperature range of about 400-900°C will typically be used for the steam reforming reaction. Examples of this range itself include 750-850°C, 725-825°C, 650-750°C, 700-800°C, 700-900°C, 500-800°C, 400-600°C, and 600-800°C. The hydrogen-producing region 32 may include two or more zones or portions, each of which may operate at the same or different temperatures. For example, when the hydrogen-producing fluid comprises hydrocarbons, the hydrogen-producing region 32 may include two distinct hydrogen-producing portions or zones, one of which operates at a lower temperature than the other to provide a pre-reforming zone. In those embodiments, the fuel processing assembly may also be referred to as including two or more hydrogen-producing zones.

Fuel stream 28 may include any flammable liquid and/or gas suitable for being consumed by heating device 52 to provide the required heat output. Some fuel streams are gases when delivered and burned by heating device 52, while others can be delivered to the heating device as liquid streams. Examples of heating fuels suitable for fuel stream 28 include carbonaceous raw materials, such as methanol, methane, ethane, ethanol, ethylene, propane, propylene, butane, etc. Other examples include low molecular weight condensable fuels, such as liquefied petroleum gas, ammonia, light amines, dimethyl ether and low molecular weight hydrocarbons. Still other examples include hydrogen and carbon monoxide. In an embodiment of the hydrogen production device 20 comprising a temperature regulating device in the form of a cooling device rather than a heating device (such as can be used when utilizing an exothermic hydrogen generation process (e.g., partial oxidation) rather than an endothermic process (such as steam reforming)), the feedstock delivery system can be configured to deliver fuel or coolant streams to the device. Any suitable fuel or coolant fluid can be used.

The fuel processing assembly 24 may additionally include a shell or housing 66 in which at least the hydrogen-producing region 32 is housed, as shown in FIG1 . In some embodiments, the evaporation region 64 and/or the purification region 40 may be additionally contained in the shell. The shell 66 allows the components of the steam reformer or other fuel processing mechanism to be moved as a unit. The shell may also protect the components of the fuel processing assembly from damage by providing a protective enclosure and/or may reduce the heating requirements of the fuel processing assembly because the components can be heated as a unit. The shell 66 may include insulating material 68, such as solid insulating material, blanket insulating material, and/or an air-filled cavity. The insulating material may be inside the shell and/or outside the shell. When the insulating material is outside the shell, the fuel processing assembly 24 may also include an outer cover or jacket 70 outside the insulation, as schematically illustrated in FIG1 . The fuel processing assembly may include a different shell that includes other components of the fuel processing assembly, such as the feedstock delivery system 22 and/or other components.

One or more components of fuel processing assembly 24 may extend outside of the housing or be located external to the housing. For example, purification region 40 may be located external to housing 66, such as being separate from the housing but in fluid communication with the housing via a suitable fluid transfer conduit. As another example, a portion of hydrogen-producing region 32 (such as a portion of one or more reforming catalyst beds) may extend outside the housing, such as is schematically indicated in FIG1 by dashed lines to represent another housing configuration. Examples of suitable hydrogen-generating assemblies and components thereof are disclosed in U.S. Patent Nos. 5,861,137, 5,997,594, and 6,221,117, the entire disclosures of which are incorporated herein by reference for all purposes.

Another example of a hydrogen generation assembly 20 is shown in FIG2 and generally at 72. Unless specifically excluded, hydrogen generation assembly 72 may include one or more components of hydrogen generation assembly 20. Hydrogen generation assembly 72 may include a feedstock delivery system 74, a vaporization region 76, a hydrogen production region 78, and a heating assembly 80, as shown in FIG2. In some embodiments, hydrogen generation assembly 20 may also include a purification region 82.

The feedstock delivery system may include any suitable structure configured to deliver one or more feeds and/or fuel streams to one or more other components of the hydrogen generation device. For example, the feedstock delivery system may include a feedstock tank (or container) 84 and a pump 86. The feedstock tank may include any suitable hydrogen production fluid 88, such as water and a carbonaceous raw material (e.g., a methanol/water mixture). The pump 86 may have any suitable structure configured to deliver a hydrogen production fluid to the evaporation zone 76 and/or hydrogen production zone 78, and the hydrogen production fluid may be in the form of at least one feed stream 90 (which includes water and a carbonaceous raw material) comprising a liquid.

The evaporation zone 76 may include any suitable structure configured to receive and evaporate at least a portion of a feed stream comprising a liquid, such as a feed stream comprising a liquid 90. For example, the evaporation zone 76 may include an evaporator 92 configured to convert at least a portion of the feed stream comprising a liquid 90 into one or more vapor feed streams 94. In some embodiments, the vapor feed stream may comprise a liquid. An example of a suitable evaporator is a coil evaporator, such as a stainless steel coil.

The hydrogen production region 78 may include any suitable structure configured to receive one of a plurality of feed streams (such as a steam feed stream 94) from the evaporation region to produce one or more output streams 96 comprising hydrogen as a primary component and other gases. The hydrogen production region may generate the output stream via any suitable mechanism. For example, the hydrogen production region 78 may be generated via a steam reforming reaction. In this example, the hydrogen production region 78 may include a steam reforming region 97 having a reforming catalyst 98 that is configured to assist and/or promote the steam reforming reaction. When the hydrogen production region 78 generates the output stream 96 via a steam reforming reaction, the hydrogen production device 72 may be referred to as a "steam reforming hydrogen production device," and the output stream 96 may be referred to as a "reformed product stream."

The heating device 80 may include any suitable structure configured to generate at least one heated exhaust stream 99 for heating one or more other components of the hydrogen generation device 72. For example, the heating device may heat the evaporation region to any suitable temperature, such as at least a minimum evaporation temperature or a temperature at which at least a portion of a feed stream comprising a liquid is evaporated to form a steam feed stream. Additionally or alternatively, the heating device 80 may heat the hydrogen production region to any suitable temperature, such as at least a minimum hydrogen production temperature or a temperature at which at least a portion of a steam feed stream is reacted to produce hydrogen to form an output stream. The heating device is thermally connected to one or more components of the hydrogen generation device (such as the evaporation region and/or the hydrogen production region).

The heating apparatus may include a burner assembly 100, at least one blower 102, and an igniter assembly 104, as shown in FIG2 . The burner assembly may include any suitable structure configured to receive at least one air stream 106 and at least one fuel stream 108 and combust the at least one fuel stream in a combustion zone 110 to produce a heated exhaust stream 99. The fuel stream may be provided by the feedstock delivery system 74 and/or the purification zone 82. The combustion zone may be contained within the housing of the hydrogen generation assembly. The blower 102 may include any suitable structure configured to generate the air stream 106. The igniter assembly 104 may include any suitable structure configured to ignite the fuel stream 108.

The purification region 82 may include any suitable structure configured to produce at least one hydrogen-rich stream 112, which may include a higher concentration of hydrogen than the output stream 96 and/or a lower concentration of one or more other gases (or impurities) than those present in the output stream. The purification region may produce at least one byproduct stream or fuel stream 108, which may be sent to the burner assembly 100 and used as a fuel stream for the assembly, as shown in FIG2 . The purification region 82 may include a flow restriction orifice 111, a filter assembly 114, an alpha membrane assembly 116, and a methanation reactor assembly 118. The filter assembly (such as one or more hot gas filters) may be configured to remove impurities from the output stream 96 prior to the hydrogen purification membrane assembly.

The membrane device 116 may include any suitable structure configured to receive the output or mixed gas stream 96 comprising hydrogen and other gases and generate a permeate or hydrogen-rich stream 112 comprising a higher concentration of hydrogen and/or a lower concentration of other gases than the mixed gas stream. The membrane device 116 may incorporate a flat or tubular hydrogen permeable (or hydrogen selective) membrane, and more than one hydrogen permeable membrane may be incorporated into the membrane device 116. The permeate stream may be used for any suitable application, such as for one or more fuel cells. In some embodiments, the membrane device may generate a byproduct or fuel stream 108 comprising at least a majority of the other gases. The methanation reactor device 118 may include any suitable structure configured to convert carbon monoxide and hydrogen into methane and water. Although the purification region 82 is shown to include a flow restriction 111, a filter device 114, a membrane device 116, and a methanation reactor device 118, the purification region may have less than all of those devices and/or may, alternatively, or additionally, include one or more other components configured to purify the output stream 96. For example, purification region 82 may include only membrane device 116 .

In some embodiments, hydrogen generation assembly 72 may include a housing or shell 120 that may at least partially contain one or more other components of the assembly. For example, housing 120 may at least partially contain evaporation region 76, hydrogen production region 78, heating assembly 80, and/or purification region 82, as shown in FIG2 . Housing 120 may include one or more exhaust ports 122 configured to exhaust at least one combustion exhaust stream 124 generated by heating assembly 80.

In some embodiments, the hydrogen production assembly 72 may include a control system 126, which may include any suitable structure configured to control the operation of the hydrogen production assembly 72. For example, the control assembly 126 may include a control assembly 128, at least one valve 130, at least one pressure relief valve 132, and one or more temperature measuring devices 134. The control assembly 128 may detect the temperature in the hydrogen production region and/or the purification region via a temperature measuring device 134, which may include one or more thermocouples and/or other suitable devices. Based on the detected temperature, the operator of the control assembly and/or the control system may adjust the delivery of the feed stream 90 to the evaporation region 76 and/or the hydrogen production region 78 via the valve 130 and the pump 86. The valve 130 may include a solenoid valve and/or any suitable valve. The pressure relief valve 132 may be configured to ensure that excess pressure in the system can be released.

In some embodiments, hydrogen generation assembly 72 may include a heat exchange assembly 136, which may include one or more heat exchangers 138 configured to transfer heat from one portion of the hydrogen generation assembly to another portion. For example, heat exchange assembly 136 may transfer heat from hydrogen-rich stream 112 to feed stream 90 to increase the temperature of the feed stream prior to entering vaporization zone 76, as well as to cool hydrogen-rich stream 112.

An example of a purification region 40 (or hydrogen purification device) of the hydrogen generation assembly 20 of FIG. 1 is generally shown at 144 in FIG. 3. Unless specifically excluded, the hydrogen purification device may include one or more components of other purification regions described in the present disclosure. The hydrogen purification device 40 may include a hydrogen-separation region 146 and an outer cover 148. The outer cover may define an internal volume 150 having an inner perimeter 152. The outer cover 148 may include at least a first portion 154 and a second portion 156 that are combined to form a body 149 in the form of a sealed pressure vessel that may include defined input and output ports. Those ports may define fluid paths for delivering gases and other fluids into and out of the internal volume of the outer cover.

The first and second portions 154 and 156 may be secured using any suitable fixing means.

Mechanism or mechanism 158 is combined together. Examples of suitable fixing mechanisms include welding and/or bolts. Examples of seals that can be used to provide a fluid-tight interface between the first and second parts may include gaskets and/or welding. Additionally or alternatively, the first and second parts 154 and 156 can be fastened together so that at least a predetermined amount of pressure (compression) is applied to multiple components defining the hydrogen-separation zone within the outer cover and/or other components that can be added to the hydrogen production device. The applied pressure ensures that the multiple components are maintained in the appropriate position within the outer cover. Additionally or alternatively, the pressure applied to the multiple components defining the hydrogen-separation zone within the outer cover and/or other components can provide a fluid-tight interface between the multiple components defining the hydrogen-separation zone, between multiple other components and/or between the multiple components defining the hydrogen-separation zone and other components.

The housing 148 may include a mixed gas zone 160 and a permeate zone 162, as shown in FIG3 . The mixed gas zone and the permeate zone may be separated by a hydrogen-separation zone 146. At least one input port 164 may be provided through which a fluid stream 166 may be delivered to the housing. The fluid stream 166 may be a mixed gas stream 168 comprising hydrogen 170 and other gases delivered to the mixed gas zone 160. Hydrogen may be the primary component of the mixed gas stream. The hydrogen-separation zone 146 may extend between the mixed gas zone 160 and the permeate zone 162, so that the gas in the mixed gas zone must pass through the hydrogen-separation zone to enter the permeate zone. The gas may, for example, need to pass through at least one hydrogen-selective membrane as discussed further below. The permeate zone and the mixed gas zone may have any relative size suitable for use in the housing.

The housing 148 may also include at least one product outlet 174 through which a permeate stream 176 may be received by the permeate zone 162 and removed therefrom. The permeate stream may contain at least one of a higher concentration of hydrogen and a lower concentration of other gases than the mixed gas stream. In some embodiments, the permeate stream 176 may initially include at least a carrier or tail gas (sweep) gas component, such as those that may be delivered as tail gas stream 178 through tail gas outlet 180 in fluid communication with the permeate zone. The housing may also include at least one byproduct outlet 182 through which a byproduct stream 184 comprising at least one of a majority of the other gases 172 and a lower concentration of hydrogen 170 (relative to the mixed gas stream) may be removed from the mixed gas zone.

The hydrogen-separation zone 146 may include at least one hydrogen-selective membrane 186 having a first or mixed gas surface 188 oriented to contact the mixed gas stream 168, and a second or permeate surface 190 substantially opposite to the surface 100. The mixed gas stream 168 may be delivered to the mixed gas zone of the housing so as to contact the mixed gas surface of the one or more hydrogen-selective membranes. The permeate stream 176 may be formed by at least a portion of the mixed gas stream that passes through the hydrogen-separation zone and enters the permeate zone 162. The byproduct stream 184 may be formed by at least a portion of the mixed gas stream that does not pass through the hydrogen-separation zone. In some embodiments, the byproduct stream 184 may include a portion of the hydrogen present in the mixed gas stream. The hydrogen-separation zone may also be configured to capture or otherwise retain at least a portion of other gases that are subsequently removed as a byproduct stream when the separation zone is replaced, regenerated, or otherwise recharged.

3 , streams 166 , 176 , 178 , and/or 184 may include more than one actual stream flowing into or out of the hydrogen purification device 144 . For example, the hydrogen purification device may receive multiple mixed gas streams 168 , a single mixed gas stream 168 that is divided into two or more streams prior to contacting the hydrogen-separation region 146 , a single stream that is delivered to the internal volume 150 , etc. Thus, the housing 148 may include more than one input port 164 , product output port 174 , tail gas port 180 , and/or byproduct output port 182 .

The hydrogen selective membrane may be formed of any hydrogen-permeable material suitable for use in the operating environment and parameters of the operating hydrogen purification device. Examples of hydrogen purification devices are disclosed in U.S. Patent Nos. 5,997,594 and 6,537,352, the entire disclosures of which are hereby incorporated by reference for all purposes. In some embodiments, the hydrogen selective membrane may be formed of at least one of palladium and a palladium alloy. Examples of palladium alloys include alloys of palladium with copper, silver and/or gold. Examples of various membranes, membrane configurations, and methods for preparing membranes and membrane configurations are disclosed in U.S. Patent Nos. 6,152,995, 6,221,117, 6,319,306, and 6,537,352, the entire disclosures of which are hereby incorporated by reference for all purposes.

In some embodiments, a plurality of spaced-apart hydrogen-selective membranes 186 may be used in the hydrogen-separation region to form at least a portion of a hydrogen-separation device 192. When present, the plurality of membranes may collectively define one or more membrane devices 194. In such embodiments, the hydrogen-separation device may extend substantially from the first portion 154 to the second portion 156. Thus, the first and second portions may effectively compress the hydrogen-separation device. In some embodiments, the housing 148 may additionally, or alternatively, include end plates (or end frames) connected to opposite sides of the body portion. In such embodiments, the end plates may effectively compress the hydrogen-separation device (and other components that may be contained within the housing) located between a pair of opposing end plates.

Hydrogen purification using one or more hydrogen selective membranes is typically a pressure driven separation process in which a mixed gas stream is delivered to contact the mixed gas surface of the membrane at a pressure higher than that of the gas in the permeate zone of the hydrogen-separation zone. In some embodiments, when the hydrogen-separation zone is used to separate the mixed gas stream into a permeate stream and a by-product stream, the hydrogen-separation zone may be heated to an elevated temperature via any suitable mechanism. Examples of operating temperatures suitable for hydrogen purification using palladium and palladium alloy membranes include temperatures of at least 275°C, temperatures of at least 325°C, temperatures of at least 350°C, temperatures in the range of 275-500°C, temperatures in the range of 275-375°C, temperatures in the range of 300-450°C, temperatures in the range of 350-450°C, and the like.

An example of a hydrogen purification device 144 is generally shown at 196 in FIG. 4 . Unless specifically excluded, the hydrogen purification device 196 may include one or more components of other hydrogen purification devices and/or purification regions described herein. The hydrogen purification device 196 may include a housing or outer cover 198, which may include a first end plate or end frame 200 and a second end plate or end frame 202. The first and second end plates may be configured to be fastened and/or compressed together to define a sealed pressure vessel having an interior compartment 204 in which a hydrogen-separation region is supported. Similar to the hydrogen purification device 144, the first and second end plates may include input, output, tail gas, and byproduct ports (not shown).

The hydrogen purification device 196 may also include at least one hydrogen selective membrane 206 and at least one microporous mesh structure 208. The hydrogen selective membrane may be configured to receive at least a portion of the mixed gas stream from the input port and separate the mixed gas stream into at least a portion of a permeate stream and at least a portion of a by-product stream. The hydrogen selective membrane 206 may include a feed side 210 and a permeate side 212. At least a portion of the permeate stream is formed by a portion of the mixed gas stream that passes from the feed side to the permeate side, while the remainder of the mixed gas stream that remains on the feed side forms at least a portion of the by-product stream. In some embodiments, the hydrogen selective membrane 206 may be fastened to at least one membrane frame (not shown), which may then be fastened to the first and second end frames.

The micromesh structure 208 may comprise any suitable structure configured to support at least one hydrogen-selective membrane. For example, the micromesh structure may comprise generally opposing surfaces 214 and 216 configured to provide support for the permeate side 212 and a plurality of fluid passages 218 extending between the opposing surfaces and allowing the permeate stream to flow through the micromesh structure, as shown in FIG4 . The micromesh structure 208 may comprise any suitable material. For example, the micromesh structure may comprise stainless steel, such as stainless steel including an alumina layer configured to prevent diffusion between the stainless steel and the at least one hydrogen-selective membrane.

In some embodiments, the microscreen structure may comprise stainless steel 303 (aluminum modified), 17-7PH, 14-8PH, and/or 15-7PH. In some embodiments, the stainless steel may comprise from about 0.6 to about 1.5 wt% aluminum. The microscreen structure 208 may be sized such that it is contained (such as completely contained) within the open area of the permeate frame and/or supported by the membrane support structure within the open area, as shown in FIG5 . In other words, the microscreen structure may be sized such that it does not contact the peripheral housing of the permeate frame when the microscreen structure and the permeate frame are fastened or compressed to the first and second end frames.

Alternatively, the microporous screen structure can be supported and/or fastened to a non-porous peripheral wall portion or frame (not shown), such as supported or fastened to the peripheral shell of a permeable frame. When the microporous screen structure is fastened to a non-porous peripheral wall portion, the microporous screen structure can be referred to as a "porous central region portion." Examples of other microporous screen structures are disclosed in U.S. Patent Application Publication No. 2010/0064887, the entire disclosure of which is incorporated herein by reference for all purposes.

The hydrogen purification device 196 may also include a plurality of plates or frames 224 that are not known to be between or fastened to the first and/or second end frames. The frames may include any suitable structure and/or may be any suitable shape, such as square, rectangular, or circular. For example, the frame 224 may include an outer peripheral shell 226 and at least a first support member 228, as shown in FIG4. The outer peripheral shell may define an open area 230 and a frame plane 232. In addition, the outer peripheral shell 226 may include first and second opposing sides (opposing sides) 234 and 236, and third and fourth opposing sides 238 and 240, as shown in FIG4.

The first support member 228 may include any suitable structure configured to support the first portion 242 of the hydrogen-selective membrane 206, as shown in FIG4 . For example, the first support members of the plurality of frames may be coplanar with each other (or with other first support members of other frames in the plurality of frames) in a first support surface 244 to support the first portion 242 of the hydrogen-selective membrane, as shown in FIG4 . In other words, the first support member of each frame in the plurality of frames may be a mirror image of the first support members of other frames in the plurality of frames. The first support members may have any suitable orientation relative to the frame plane 232. For example, the first support plane 244 may be perpendicular to the frame plane, as shown in FIG4 . Alternatively, the first membrane support planes may intersect but not be perpendicular to the frame plane 232.

In some embodiments, the frame 224 may include a second support member 246 and/or a third support member 248, which may include any suitable structure configured to support the second portion 250 and/or the third portion 252 of the hydrogen-selective membrane 206, as shown in FIG4 . For example, the second support members of multiple frames may be coplanar with each other (or with other second support members of the multiple frames) in a second support plane 254 to support the second portion 250 of the hydrogen-selective membrane. Additionally, the third support members of the multiple frames may be coplanar with each other (or with other third support members of the multiple frames) in a third support plane 256 to support the third portion 252 of the hydrogen-selective membrane. In other words, the second support member of each frame in the multiple frames may be a mirror image of the second support member of the other frames in the multiple frames, and the third support member of each frame in the multiple frames may be a mirror image of the third support member of the other frames in the multiple frames. The second and/or third support planes may have any suitable orientation relative to the frame plane 232. For example, the second support plane 254 and/or the third support plane 256 may be perpendicular to the frame plane, as shown in FIG4 . Alternatively, the second and/or third support planes may intersect but not be perpendicular to the frame plane 232 .

The second support member 246 and/or the third support member 248 can have any suitable orientation relative to the first support member 228. For example, the first support member 228 can extend into the open area 230 from the third side 238 of the peripheral shell 226; the second support member 246 can extend into the open area from a fourth side of the peripheral shell (opposite to the third side); and the third support member 248 can extend into the open area from the third side. Alternatively, the first, second, and/or third support members can extend into the open area from the same side, such as from the first, second, third, or fourth side of the peripheral shell. In some embodiments, the first, second, and/or third support members can extend into the open area from the first side and/or the second side of the peripheral shell (opposite to the first side).

The first, second and/or third support members may, for example, be in the form of one or more projections or fingers 258 connected to and/or formed with the peripheral shell. The projections may extend from the peripheral shell in any suitable direction. The projections may be the full thickness of the peripheral shell or may be less than the full thickness of the shell. The projections of each frame of the frame 224 may compress the hydrogen-selective membrane so as to lock the membrane in place and reduce the effects of expansion of the hydrogen-selective membrane due to hydrogen dissolution. In other words, the projections of the frame 224 may support the hydrogen-selective membrane by stacked extensions of the end frame within the first and/or second membrane support plane. In some embodiments, the projections 258 may include one or more receptacles or holes (not shown) configured to receive at least one fastener (not shown) to fasten the frame 224 to the first and/or second end frame.

The frame 224 may include at least one feed frame 260, at least one permeate frame 262, and a plurality of liners or liners frames 264, as shown in FIG4. The feed frame 260 may be disposed between one of the first and second end frames and at least one hydrogen-selective membrane 206, or between two hydrogen-selective membranes 206. The feed frame may include a feed frame peripheral shell 266, a feed frame input conduit 268, a feed frame output conduit 270, a feed frame open area 272, and at least a first feed frame support member 274, as shown in FIG4. In some embodiments, the feed frame may include a second feed frame support member 276 and/or a third feed frame support member 278.

The peripheral housing 266 of the feed frame may include any suitable structure. For example, the peripheral housing of the feed frame may include a first section or first peripheral housing 280 and a second section or second peripheral housing 282, as shown in Figure 6. Please note that the components of Figure 6 have been exaggerated for illustrative purposes and do not reflect the relative sizes of those components. The first and second sections may be the first and second halves of the peripheral housing, or may be any suitable portion of the peripheral housing. In addition, the first and/or second sections may include channels or grooves (not shown) in any suitable relationship to each other, such as being offset from each other. The first section 280 and the second section 282 may be joined via any suitable method to form an airtight seal between those sections. For example, a feed frame gasket 284 may be used between those sections. Alternatively, the first and second sections may be brazed together or a layered metal may be used to join the first and second sections, as described in U.S. Patent Application Publication No. 2013/0011301. The entire disclosure thereof is hereby incorporated by reference for all purposes.

In addition, the peripheral shell 266 of the feed frame may include any suitable dimensions configured to support other components of the hydrogen purification device 196. For example, the peripheral shell of the feed frame may be sized so that it supports the peripheral shells of the permeate frames 262 and the membrane support structures 286 of those frames along multiple feed frame support planes 288. For example, the width of the peripheral shell 266 may be greater than the width 292 of the peripheral shell of the permeate frames 262 so that at least a portion 294 of the peripheral shell supports a portion 296 of the membrane support structure 286, as shown in Figure 6. In other words, the peripheral shell of the feed frame can lock the membrane support structure in place and serve as a stop for the support structure. The feed frame support planes can have any suitable orientation relative to the feed frame plane 300. For example, the feed frame support planes can be perpendicular to the feed frame plane, as shown in Figure 6. Or alternatively, the feed frame support planes can intersect but not be perpendicular to the feed frame plane 300.

The feed frame input conduit may be formed on the peripheral shell of the feed frame and/or configured to receive at least a portion of the mixed gas stream from the input port. The feed frame output conduit 270 may be formed on the peripheral shell of the feed frame and/or configured to receive the remainder of the mixed gas stream remaining on the feed side 210 of the hydrogen-selective membrane 206. The feed frame open area 272 may be arranged between the feed frame input and output conduits. The peripheral shell 266 of the feed frame may include a plurality of grooves or channels (not shown) that fluidly connect the input and output conduits to the feed frame open area. The channels may be formed on the peripheral shell via any suitable method and/or may have any suitable orientation, such as an angled orientation that can cause mixing in the feed frame open area 260.

The first, second and/or third feed frame support members may comprise any suitable structure configured to support the first, second and/or third portion of at least one hydrogen-selective membrane and/or may be mirrored with the first, second and/or third support members of the other frames. Additionally, the first, second and/or third feed frame support members may comprise any suitable structure configured to change the direction of flow of at least a portion of the mixed gas stream as it flows through the open area of the feed frame between the input and output conduits. The first and/or second feed frame support members may also be configured to promote turbulence or mixing within the open area of the feed frame. For example, in the absence of the first and/or second feed frame support members, the flow of at least a portion of the mixed gas stream flowing through the open area of the feed frame between the input and output conduits may move in at least a first direction (not shown). The first and/or second feed frame membrane support structure may be configured to change the flow of at least a portion of the mixed gas stream from at least a first direction to at least a second direction (not shown) that is different from the first direction.

The first, second and/or third feed frame support members may, for example, be in the form of at least one feed frame protrusion or finger 302 connected to and/or formed with the peripheral shell of the feed frame. The feed frame protrusion may extend from the peripheral shell in any direction. For example, the feed frame protrusion may extend from the peripheral shell of the feed frame in a direction that is generally perpendicular (and/or generally parallel) to the direction of flow of at least a portion of the mixed gas stream from the input conduit to the feed frame open area. For example, if the flow of the mixed gas stream from the input conduit to the feed frame open area is generally horizontal, the feed frame protrusion may extend from the peripheral shell of the feed frame in a substantially vertical and/or horizontal direction.

The permeate frame 262 can be configured such that at least one hydrogen-selective membrane is disposed between one of the first and second end frames and the permeate frame, or between two hydrogen-selective membranes. The permeate frame can include a permeate frame outer casing 304, a permeate frame output conduit 306, a permeate frame open area 308, and a membrane support structure 286, as shown in FIG5 .

The outer periphery shell of permeation frame can comprise any suitable structure.For example, the outer periphery shell of permeation frame can comprise first section or first periphery shell 310 and second section or second periphery shell 312, as shown in Figure 6.The first and second sections can be the first and second half of periphery shell, or can be any suitable part of periphery shell.In addition, the first and/or second section can comprise the passage or groove (not shown) that is any suitable relation to each other, such as offset each other.The first section 310 and the second section 312 can be engaged to form airtight seal between those sections via any suitable method.For example, permeation frame gasket 314 can be used between those sections.The permeation frame gasket can be configured to make when permeation frame 262 is fastened to first and second end frames, the thickness 316 of the outer periphery shell of permeation frame matches or substantially matches the thickness 318 of (equal to or substantially equal to) membrane support structure, as shown in Figure 6 and hereinafter further discussed.

Alternatively, the first and second segments may be brazed together, or a laminated metal may be used to join the first and second segments, as described in US Patent Application Publication No. 2013/0011301, the entire disclosure of which is incorporated herein by reference for all purposes.

In some embodiments, the peripheral shell 304 of the permeation frame can include a first section 320, a second section 322, and a third section 324 disposed between the first and second sections, as shown in FIG7 . Those sections can be the first, second, and third thirds of the peripheral shell, or any suitable portion of the peripheral shell. Additionally, the first, second, and/or third sections can include channels or grooves (not shown) in any suitable relationship to one another, such as being offset from one another. Please note that the components of FIG7 have been exaggerated for illustrative purposes and do not reflect the relative sizes of those components.

The first section 320, the second section 322, and the third section 324 can be joined via any suitable method to form an airtight seal between those sections. For example, a permeation frame gasket 326 can be used between those sections. The permeation frame gasket can be configured so that when the permeation frame 262 is fastened to the first and second end frames, the thickness 316 of the peripheral shell of the permeation frame matches or substantially matches (equal to or substantially equal to) the thickness 318 of the membrane support structure, as shown in Figure 6. Alternatively, the first, second, and/or third sections can be brazed together or laminated metal can be used to join the first, second, and/or third sections, as described in U.S. Patent Application Publication No. 2013/0011301. The entire disclosure of which is hereby incorporated by reference for all purposes.

The output conduit 306 can be formed on the peripheral shell 282 of the permeate frame and/or configured to receive the permeate flow from the membrane support structure 286, the permeate frame open area 308, and/or the hydrogen-selective membrane. The peripheral shell 282 can include a plurality of grooves or channels (not shown) that fluidly connect the output conduit to the permeate frame open area and/or the membrane support structure. The channels can be formed on the peripheral shell 282 by any suitable method and/or can have any suitable orientation, such as an angled orientation.

The membrane support structure 286 may include any suitable structure configured to support at least one hydrogen-selective membrane (such as the first, second, third, and/or other portions of the hydrogen-selective membrane). In some embodiments, similar to one or more other frames, the membrane support structure may include first, second, and/or third support members (not shown). Alternatively, the membrane support structure 288 may include a plurality of membrane support plates 328, as shown in FIG6 . The membrane support plates may span any suitable portion of the open area, such as at least a majority of the open area. Additionally, the membrane support plates may be solid, flat or planar, free of perforations or holes (or free of perforations or holes), free of protrusions and/or projections (or free of protrusions and/or projections), and/or may be incompressible (or substantially incompressible). Additionally, the membrane support plates may not be connected to the peripheral housing of the permeate frame (or may not have a connector). In other words, when the feed frame is secured to the first and second end plates, only the feed frame can lock the membrane support structure into place in the open area of the peripheral housing of the permeate frame. Additionally, the membrane support plates may be made of any suitable material, such as stainless steel.

The membrane support plate 328 may include a first face (or surface) 330 and a second, opposing face (or opposing surface) 332, as shown in FIG6 . The membrane support plate may include a plurality of microgrooves 334, as shown in FIG8 , which may include any suitable structure that provides one or more paths for permeate flow. When the membrane support plate 328 includes surface microgrooves, those plates may be referred to as "surface-grooved plates." The microgrooves may have any suitable orientation, such as being parallel to one another. Additionally, the microgrooves 334 may extend from a first edge 336 of the membrane support plate to a second, opposing edge 338, as shown in FIG8 (or from a third edge to a fourth opposing edge). Alternatively, one or more of the microgrooves may extend from the first edge to before the second edge, from the second edge to before the first edge, between the first and second edges but not including the first and second edges, etc. Furthermore, the microgrooves 334 may be located only on the first face, only on the second face, or on both the first and second faces. Furthermore, the microgrooves may be included along the entire length or width of the membrane support plate (as shown in FIG8 ), or may be located along any portion of that length or width, such as 25%, 50%, or 75% of the length or width.

Microgrooves 334 can have any suitable size.For example, microgrooves can have a width of 0.005 inch to 0.020 inch (or preferably 0.010 to 0.012 inch) and a degree of depth of 0.003 to 0.020 inch (or preferably 0.008 to 0.012 inch).Microgrooves can be spaced apart by any suitable distance, such as 0.003 to 0.020 inch (or preferably 0.003 to 0.007 inch).Microgrooves can be manufactured by any suitable method, such as chemical etching, machining and/or similar methods.

In some embodiments, the membrane support structure 286 may include a first membrane support plate 340 and a second membrane support plate 342, as shown in Figure 6. The first membrane support plate may include a first surface 344 and a second opposing surface 346. The second membrane support plate 342 may include a first surface 348 and a second opposing surface 349. The first surface of the first and/or second membrane support plates may include microgrooves 334. In addition, the second surfaces of the first and second membrane support plates may face each other. In other words, the first and second membrane support plates may be stacked in the membrane support structure such that the second surface of the first membrane support plate faces the second surface of the second membrane support plate, and/or vice versa. In some embodiments, the second surface of the first membrane support plate may contact the second surface of the second membrane support plate.

In some embodiments, the membrane support structure may include a third membrane support plate 350, which may be positioned between the first and second membrane support plates, as shown in Figure 9. Please note that the components of Figure 9 have been enlarged for illustrative purposes and may not reflect the relative sizes of those components. The membrane support structure may include first, second and third membrane support plates, which are stacked so that the third membrane support plate contacts the second side of the first and/or second membrane support plates. When the third membrane support plate is arranged between the first and second membrane support plates, the third membrane support plate may sometimes be referred to as a "center plate". The third membrane support plate may not have microgrooves on one or both sides thereof. The first, second and third membrane support plates may have any suitable size. For example, the first and second membrane support plates may be 0.060 inches, while the third membrane support plate may be 0.105 inches.

As discussed above, the permeate frame gaskets 314 and/or 326 can be configured such that when the permeate frame is fastened and/or compressed against the first and second end frames, the thickness of the permeate frame matches the thickness of the membrane support structure. The thickness of these gaskets prior to compression is greater than the thickness of the membrane support structure. When an elastomeric graphite gasket is used with a permeate frame gasket having a compression limit of 15 to 50%, the thickness of the permeate frame gasket prior to compression can result in a desired final thickness that falls within those compression limits. When a permeate frame includes such a gasket, the permeate frame may sometimes be referred to as a "self-regulating permeate frame." When the self-regulating permeate frame is compressed during assembly by feed frame compression (e.g., at a pressure of 1000 to 2000 psi) to form a hermetic seal between the feed frame and the hydrogen-selective membrane, pressure from the feed frame against the permeate frame can be prevented when the feed frame contacts the hydrogen-selective membrane, the microporous screen structure, and the membrane support structure (which may together form a substantially incompressible assembly or stack).

As an example, if the membrane support structure has a thickness of 0.257 inches, then the permeate frame ideally has a thickness of exactly or approximately 0.257 inches. When the peripheral shell of the permeate frame includes two sections that are each, for example, 0.120 inches thick, then the permeate frame liner should be constructed to be 0.017 inches thick after compaction. For example, a permeate frame liner that is 0.030 inches thick before compression can be compressed within its compression limit to 0.017 inches after compression, which will produce a permeate frame thickness that matches the thickness of the membrane support structure. Although the membrane support structure 286 is shown as including a membrane support plate 328, the membrane support structure may include a wire mesh and/or a perforated metal sheet (not shown).

The frame 224 may also include a gasket or gasket frame 264, as shown in FIG4 . The gasket frame may include any suitable structure configured to provide a fluid-tight interface between other frames, such as between the first and second end plates 200 and 202 and the feed frame 260, between the feed frame 260 and the hydrogen-selective membrane 206, and between the hydrogen-selective membrane (and microporous screen structure) and the permeate frame 262. An example of a gasket suitable for the gasket frame 264 is an elastomeric graphite gasket. Another example of a suitable gasket material is 866, sold by Flexitallic LP (Deer Park, Texas). Although the frame 224 is shown as including two feed frames 260 and a single permeate frame 262, the frame may include any suitable number of feed frames and permeate frames. Additionally, although the hydrogen purification device 196 is shown as including two hydrogen-selective membranes 206, the device may include any suitable number of those membranes.

Although one or more of the frames 224 are shown as including protrusions extending only in the vertical direction or only in the horizontal direction, the frame may additionally, or alternatively, include protrusions extending in the horizontal, vertical, and/or other suitable directions (e.g., diagonal, etc.). In addition, although one or more frames 224 are shown as including three protrusions, the frame may include one, two, four, five, or more protrusions. Furthermore, although one or more frames 224 are shown as including protrusions that are coplanar within the first, second, and/or third support planes, the frame may additionally, or alternatively, include protrusions that are coplanar within the fourth, fifth, or more support planes.

Another example of a hydrogen generation assembly 20 is generally shown at 354 in FIG. 10 . Unless specifically excluded, hydrogen generation assembly 354 may include one or more components of one or more other hydrogen generation assemblies described herein. The hydrogen generation assembly may provide or supply hydrogen to one or more hydrogen consuming devices 356 (such as fuel cells, hydrogen furnaces, etc.). Hydrogen generation assembly 354 may, for example, include a fuel processing assembly 358 and a product hydrogen management system 360.

The fuel processing assembly 358 may include any suitable structure configured to generate one or more product hydrogen streams 362 (such as one or more hydrogen gas streams) from one or more feed streams 364 via one or more suitable mechanisms (such as steam reforming, autothermal reforming, electrolysis, pyrolysis, partial oxidation, plasma reforming, photocatalytic water splitting, sulfur-iodine cycle, etc.). For example, the fuel processing assembly 358 may include one or more hydrogen generator reactors 366, such as reformers, electrolyzers, etc. The feed streams 364 may be delivered to the fuel processing assembly via one or more feed conduits 368 from one or more feedstock delivery systems (not shown).

The fuel processing assembly 358 can be configured to operate in multiple modes, such as an operating mode and a standby mode. In the operating mode, the fuel processing assembly can generate or produce a product hydrogen stream from a feed stream. For example, in the operating mode, a feedstock delivery system can deliver a feed stream to the fuel processing assembly and/or can perform other operations. Additionally, in the operating mode, the fuel processing assembly can receive a feed stream, can combust the fuel stream via a heating assembly, can vaporize the feed stream via a vaporization region, can generate an output stream via a hydrogen production region, can generate a product hydrogen stream and a by-product stream via a purification region, and/or can perform other operations.

In standby mode, the fuel processing assembly 358 is unable to generate a product hydrogen stream from a feed stream. For example, in standby mode, the feedstock delivery system is unable to deliver the feed stream to the fuel processing assembly and/or is unable to perform other operations. Additionally, in standby mode, the fuel processing assembly is unable to receive a feed stream, burn the fuel stream via the heating assembly, vaporize the feed stream via the vaporization region, generate an output stream via the hydrogen production region, generate a product hydrogen stream and a by-product stream via the purification region, and/or is unable to perform other operations. Standby mode may include when power to the fuel processing assembly is turned off or when the fuel processing assembly has no power.

In some embodiments, the plurality of modes may include one or more reduced output modes. For example, fuel processing assembly 358 may produce or generate product hydrogen stream 362 at a first output rate (such as a maximum output rate or a normal output rate) in the operating mode, and may produce or generate the product hydrogen stream at a second, third, fourth, or more rates less than the first rate (such as a minimum output rate) in the reduced output mode.

Product hydrogen management system 360 may include any suitable structure configured to manage product hydrogen generated by fuel processing assembly 358. Additionally, product hydrogen management system may include any suitable structure configured to interact with fuel processing assembly 358 to maintain any suitable amount of product hydrogen available to hydrogen consumers 356. For example, product hydrogen management system 360 may include product conduit 370, buffer tank 372, buffer tank conduit 374, sensor assembly 376, and control assembly 378.

The product conduit 370 can be configured to fluidically connect the fuel processing assembly 358 and the buffer tank 372. The buffer tank 372 can be configured to receive the product hydrogen stream 362 via the product conduit 370 to maintain a predetermined amount or volume of the product hydrogen stream and/or to provide the product hydrogen stream to one or more hydrogen consuming devices 356. In some embodiments, the buffer tank can be a low-pressure buffer tank. The buffer tank can be of any suitable size based on one or more factors, such as the expected or actual hydrogen consumption of the hydrogen consuming device, the cycle characteristics of the hydrogen generator reactor, the fuel processing assembly, etc.

In some embodiments, the buffer tank 372 can be sized to provide sufficient hydrogen for a minimum amount of time to operate a hydrogen-consuming device and/or a minimum amount of time to operate a fuel processing device, such as a minimum amount of time to operate a vaporization region, a hydrogen-producing region, and/or a purification region. For example, the buffer tank can be sized to allow operation of the fuel processing device for 2, 5, 10, or more minutes. A buffer tank conduit 374 can be configured to fluidically connect the buffer tank 372 and the hydrogen-consuming device 356.

Sensor device 376 may include any suitable structure configured to detect and/or measure one or more suitable operating variables and/or parameters in the buffer tank and/or generate one or more signals based on the detected and/or measured operating variables and/or parameters. For example, the sensor device may detect mass, volume, flow rate, temperature, current, pressure, refractive index, thermal conductivity, density, viscosity, absorbance, electrical conductivity, and/or other suitable variables and/or parameters. In some embodiments, the sensor device may detect one or more trigger events.

For example, the sensor assembly 376 may include one or more sensors 380 configured to detect pressure, temperature, flow rate, volume, and/or other parameters. The sensors 380 may, for example, include at least one buffer tank sensor 382 configured to detect one or more suitable operating variables, parameters, and/or triggering events in the buffer tank. The buffer tank sensor may be configured to detect, for example, the pressure in the buffer tank and/or generate one or more signals based on the detected pressure. For example, unless product hydrogen is withdrawn from the buffer tank at a flow rate equal to or greater than the incoming flow rate into the buffer tank, the pressure in the buffer tank may increase and the tank sensor may detect the increase in pressure in the buffer tank.

Control assembly 378 may include any configuration configured to control fuel processing assembly 358 based at least in part on input from sensor 376 (e.g., based at least in part on operational variables and/or parameters detected and/or measured by the sensor). Control assembly 378 may only receive input from sensor 376, or it may receive input from other sensor devices of the hydrogen generation assembly.

In some embodiments, the fuel processing assembly 358 may include a hydrogen generator reactor 366 (such as a hydrogen-producing region 385) and a hydrogen-selective membrane 387 adjacent to the fuel processing assembly 358 and/or a plurality of heaters 383 in thermal communication therewith. The heaters may be internal or external to the fuel processing assembly housing. In those embodiments, when the fuel processing assembly is in standby mode, the control assembly may communicate with the heaters and/or operate the heaters to maintain the hydrogen-producing region and/or the hydrogen-selective membrane at a predetermined temperature or temperature range. For example, the heaters may maintain the hydrogen-producing region and the hydrogen-selective membrane at a temperature between 300° C. and 450° C.

When heaters are used to maintain the hydrogen-producing region and the hydrogen-selective membrane at an elevated temperature, the standby mode may sometimes be referred to as a "hot standby mode" or a "hot standby state." The fuel processing unit can switch from hot standby mode to producing a product hydrogen stream in an operational mode in a shorter time than when the fuel processing unit is activated from a shutdown mode or a shutdown state. For example, when switching from hot standby mode to operational mode, the fuel processing unit can produce a product hydrogen stream in approximately 5 minutes.

The control device 378 may control only the fuel processing device, or the control device may control one or more other components of the hydrogen generation device. The control device may communicate with the sensor device, the fuel processing device, the product valve device (further described below), and/or the return valve device (further described below) via communication linkages 384. The communication linkages 384 may be any suitable single-channel or dual-channel wired and/or wireless mechanism for communication between corresponding devices, such as input signals, command signals, measured parameters, etc.

Control assembly 378 may, for example, be configured to operate fuel processing assembly 358 between an operational mode and a standby mode based at least in part on the detected pressure in buffer tank 372. For example, control assembly 378 may be configured to operate the fuel processing assembly in the standby mode when the detected pressure in the buffer tank is above a predetermined maximum pressure and/or to operate the fuel processing assembly in the operational mode when the detected pressure in the buffer tank is below a predetermined minimum pressure.

The predetermined maximum and minimum pressures may be any suitable maximum and minimum pressures. Those predetermined pressures may be set independently or without regard to other predetermined pressures and/or other predetermined variables. For example, the predetermined maximum pressure may be set according to the operating pressure range of the fuel processing device, such as an overpressure in the fuel processing device due to the back pressure of the product hydrogen management system. In addition, the predetermined minimum pressure may be set according to the pressure required by the hydrogen consuming device. Alternatively, the control device 378 may operate the fuel processing device so that it operates in an operating mode within a predetermined pressure differential (such as between the fuel processing device and the buffer tank and/or between the buffer tank and the hydrogen consuming device) and operates in a standby mode outside the predetermined pressure differential range.

In some embodiments, the product hydrogen management system 360 may include a product valve assembly 386, which may include any suitable structure configured to manage and/or direct the flow in the product conduit 370. For example, the product valve assembly may allow the product hydrogen stream to flow from the fuel processing assembly to the buffer tank, as shown at 388. Additionally, the product valve assembly 386 may be configured to vent the product hydrogen stream 362 from the fuel processing assembly 358, as shown at 390. The vented product hydrogen stream may be discharged to the atmosphere and/or vented to the product hydrogen management system (not shown).

The product valve assembly 386 may, for example, include one or more valves 392 configured to operate between a flow position, in which the product hydrogen stream from the fuel processing assembly flows through the product conduit and into the buffer tank, and a vent position, in which the product hydrogen stream from the fuel processing assembly is vented. The valves 392 may be disposed at any suitable portion of the product conduit prior to the buffer tank.

Control assembly 378 can be configured to operate the product valve assembly based on input from, for example, the sensor assembly. For example, when the fuel processing assembly is in standby mode, the control assembly can instruct or control the product valve assembly (and/or valve 392) to discharge the product hydrogen stream from the fuel processing assembly. Additionally, when fuel processing assembly 358 is in operating mode and/or reduced output mode, control assembly 378 can instruct or control product valve assembly 386 (and/or valve 392) to direct the product hydrogen stream from the fuel processing assembly to the buffer tank.

In some embodiments, the product hydrogen management system 360 may include a return conduit 394 that is fluidly connected to the buffer tank 372 and the fuel processing assembly 358, as shown in Figure 10. For example, the return conduit may be fluidly connected to the product conduit (such as an adjacent buffer tank) and the fuel processing assembly, which allows the product hydrogen flow to return to the fuel processing assembly. The return conduit may be fluidly connected to any suitable portion of the fuel processing assembly. For example, when the fuel processing assembly includes a hydrogen production region 78, one or more hydrogen purification (or hydrogen selective) membranes 116 and a reformate conduit 396 that is fluidly connected to the hydrogen production region and the hydrogen selective membrane, the return conduit 394 may be fluidly connected to the buffer tank and the reformate conduit, as shown in Figure 2. Although the return conduit is shown connected downstream of the hot gas filter 114, the return conduit may also be connected upstream of the hot gas filter and/or other suitable portions of the fuel processing assembly.

In embodiments including a return conduit 394, product hydrogen management system 360 may also include a return valve assembly 398, which may include any suitable structure configured to manage and/or direct flow in return conduit 394. For example, the return valve assembly may allow a product hydrogen stream to flow from the buffer tank to the fuel processing assembly, as shown at 400.

The return valve assembly 398 may, for example, include one or more valves 402 configured to operate between an open position, in which the product hydrogen stream from the buffer tank flows through the return conduit and into the fuel processing assembly, and a closed position, in which the product hydrogen stream from the buffer tank does not flow through the return conduit and into the fuel processing assembly. The valves 402 may be disposed at any suitable portion of the return conduit prior to the fuel processing assembly.

The control device 378 may be configured to operate the return valve device based on input from, for example, a sensor device. For example, when the fuel processing device 358 is in standby mode, the control device may instruct or control the return valve device (and/or valve 402) to allow the product hydrogen stream to flow from the buffer tank to the fuel processing device. In some embodiments, when the fuel processing device is in standby mode, the control device may instruct or control the return valve device and/or valve 402 to allow the product hydrogen stream to flow from the buffer tank to the fuel processing device for one or more predetermined durations and/or at one or more predetermined time intervals. The predetermined time and/or time interval may be based on preventing or minimizing the flow of the product hydrogen stream to the components of the non-hydrogen selective membrane of the fuel processing device and/or preventing the flow of the product hydrogen stream to those components. For example, the predetermined time (predetermined duration) may be 0.1 to 10 seconds with the valve in the open position, and the predetermined time interval (predetermined time interval) may be 1 to 12 hours. Introducing the product hydrogen stream into the fuel processing device (such as upstream of the hydrogen-selective membrane) when the predetermined time is between 0.1 and 10 seconds may sometimes be referred to as a "hydrogen burp."

Another example of a hydrogen production assembly 20 is generally shown at 404 in FIG. 11 . Unless specifically excluded, the hydrogen production assembly 404 may include one or more components of one or more other hydrogen production assemblies described herein. The hydrogen production assembly may provide or supply hydrogen to one or more hydrogen consuming devices 406 (such as fuel cells, hydrogen furnaces, etc.). The hydrogen production assembly 404 may, for example, include a fuel processing assembly 408 and a product hydrogen management system 410. The fuel processing assembly 408 may include any suitable structure configured to generate one or more product hydrogen streams 416 (such as one or more hydrogen gas streams) from one or more feed streams 418 via one or more suitable mechanisms.

Product hydrogen management system 410 may include any suitable structure configured to manage product hydrogen generated by fuel processing assembly 408. Additionally, product hydrogen management system may include any suitable structure configured to interact with fuel processing assembly 408 to maintain any suitable amount of product hydrogen available to hydrogen consumers 406. For example, product hydrogen management system 410 may include a product conduit 420, a buffer tank 422, a buffer tank conduit 424, a buffer tank sensor assembly 426, a product valve assembly 428, a return conduit 430, a return valve assembly 432, and a control assembly 434.

Product conduit 420 can be configured to fluidically connect fuel processing assembly 408 to buffer tank 422. Product conduit can include any suitable number of valves, such as check valves (such as check valve 436), control valves, and/or other suitable valves. Check valve 436 can prevent backflow from the buffer tank to the fuel processing assembly. The check valve can open at any suitable pressure, such as 1 psi or less. Buffer tank 422 can be configured to receive product hydrogen stream 416 via product conduit 420, retain a predetermined volume or volume of the product hydrogen stream, and/or provide the product hydrogen stream to one or more hydrogen consuming devices 406.

Buffer tank conduit 424 can be configured to fluidically connect buffer tank 422 and hydrogen-consuming device 406. The buffer tank conduit can include any suitable number of valves, such as check valves, control valves, and/or other suitable valves. For example, the buffer tank conduit can include one or more control valves 438. Control valves 438 can allow for isolation of the buffer tank and/or other components of the hydrogen generation assembly. The control valves can be controlled, for example, by control device 434 and/or other control devices.

The tank sensor assembly 426 may include any suitable structure configured to detect and/or measure one or more suitable operating variables and/or parameters within the buffer tank and/or generate one or more signals based on the detected and/or measured operating variables and/or parameters. For example, the buffer tank sensor assembly may detect mass, volume, flow rate, temperature, current, pressure, refractive index, thermal conductivity, density, viscosity, absorbance, electrical conductivity, and/or other suitable variables and/or parameters. In some embodiments, the buffer tank sensor assembly may detect one or more triggering events. For example, the buffer tank sensor assembly 426 may include one or more tank sensors 440 configured to detect pressure, temperature, flow rate, volume, and/or other parameters. The buffer tank sensors 440 may, for example, be configured to detect pressure within the buffer tank and/or generate one or more signals based on the detected pressure.

Product valve assembly 428 may include any suitable structure configured to manage and/or direct flow in product conduit 420. For example, product valve assembly may allow a product hydrogen stream to flow from the fuel processing assembly to a buffer tank, as indicated at 442. Additionally, product valve assembly 428 may be configured to vent product hydrogen stream 416 from fuel processing assembly 408, as indicated at 444. The vented product hydrogen stream may be vented to the atmosphere and/or to a vented product hydrogen management system (not shown), including venting the vented product hydrogen back to the fuel processing assembly in addition to (or in lieu of) a reflux valve assembly.

The product valve assembly 428 may, for example, include a three-way solenoid valve 446. The three-way solenoid valve may include a solenoid valve 448 and a three-way valve 450. The three-way valve may be configured to move between a plurality of positions. For example, the three-way valve 450 may be configured to move between a flow position and a discharge position. In the flow position, the product hydrogen stream is allowed to flow from the fuel processing assembly to the buffer tank, as shown at 442. In the discharge position, the product hydrogen stream from the fuel processing assembly is discharged, as shown at 444. In addition, the three-way valve may be configured to isolate the buffer tank from the product hydrogen stream when the valve is in the discharge position. The solenoid valve 448 may be configured to move the valve 450 between the flow and discharge positions based on input received from the control assembly 434 and/or other control assembly.

The return conduit 430 can be configured to fluidically connect the surge tank 422 and the fuel processing assembly 408 (such as a reformate conduit of the fuel processing assembly). The return conduit can include any suitable number of valves, such as check valves (such as check valve 454), control valves, and/or other suitable valves. The check valve 454 can prevent backflow from the fuel processing assembly to the surge tank. The check valve can open at any suitable pressure. In some embodiments, the return conduit 430 can include a flow restriction orifice 456 configured to restrict flow through the return conduit. The flow restriction orifice can be upstream or downstream of the solenoid valve of the return valve assembly. In addition, the flow restriction orifice 456 can be any suitable size, such as 0.005 inches to 0.035 inches, preferably 0.010 inches.

The return valve assembly 432 may include any suitable structure configured to manage and/or indicate flow in the return conduit 430. For example, the return valve assembly may allow the product hydrogen stream to flow from the buffer tank to the fuel processing assembly, as shown at 458. The return valve assembly 432 may, for example, include a solenoid valve 460. The solenoid valve may include a solenoid valve 462 and a valve 464. The valve may be configured to move between multiple positions. For example, valve 464 may be configured to move between an open position and a closed position. When in the open position, the product hydrogen stream is allowed to flow from the buffer tank to the fuel processing assembly, as shown at 458. When in the closed position, the product hydrogen stream is not allowed (or is restricted) from flowing from the buffer tank to the fuel processing assembly. In addition, the valve may be configured to isolate the buffer tank when the valve is in the closed position. The solenoid valve 462 may be configured to move the valve 464 between an open and closed position based on input from the control assembly 434 and/or other control assembly.

Control assembly 434 may include any suitable structure configured to control fuel processing assembly 408, product valve assembly 428, and/or return valve assembly 432 based at least in part on input from buffer tank sensor assembly 426 (e.g., based at least in part on operational variables and/or parameters detected and/or measured by the buffer tank sensor assembly). Control assembly 434 may receive input only from buffer tank sensor assembly 426 and/or may receive input from other sensor assemblies of the hydrogen generation assembly. Additionally, control assembly 434 may control only the fuel processing assembly, only the product valve assembly, only the return valve assembly, only the fuel processing assembly and the product valve assembly, only the fuel processing assembly and the return valve assembly, only the product valve assembly and the return valve assembly, or one or more other components of the fuel processing assembly, product valve assembly, and/or the hydrogen generation assembly. Control assembly 434 may communicate with the fuel processing assembly, buffer tank sensor assembly, product valve assembly, and/or return valve assembly via communication link 466. The communication link 466 may be any suitable wired and/or wireless mechanism for single or dual channel communication between the respective devices, such as input signals, command signals, measured parameters, etc.

Control device 434 may, for example, be configured to operate the fuel processing assembly between or between an operational and standby mode (and/or a reduced output mode) based at least in part on the detected pressure in buffer tank 438. For example, control device 434 may be configured to operate the fuel processing assembly in the standby mode when the detected pressure in the buffer tank is greater than a predetermined maximum pressure, in the reduced output mode when the detected pressure in the buffer tank is less than a predetermined maximum pressure and/or greater than a predetermined operating pressure, and/or in the operational mode when the detected pressure in the buffer tank is less than a predetermined operating pressure and/or a predetermined minimum pressure. The predetermined maximum and minimum pressures and/or the predetermined operating pressure may be any suitable pressure. For example, one or more of these pressures may be independently set based on the desired pressure range of the fuel processing assembly, the product hydrogen in the buffer tank, and/or the pressure requirements of hydrogen-consuming equipment. Alternatively, control device 434 may operate the fuel processing assembly so that it operates in the operational mode within a predetermined pressure differential range (such as between the fuel processing assembly and the buffer tank) and in the reduced output and/or standby mode outside the predetermined pressure differential range.

Additionally, control assembly 434 may be configured to operate the product valve assembly based on input, such as from sensor 426. For example, when fuel processing assembly 408 is in a standby mode, control assembly 434 may instruct or control solenoid valve 448 to move three-way valve 450 to a drain position. Additionally, when fuel processing assembly 408 is in a run mode, control assembly 434 may instruct or control solenoid valve 448 to move three-way valve 450 to a flow position.

Furthermore, control device 434 may be configured to operate the return valve assembly based on input, for example, from sensor 426. For example, when the fuel processing assembly is in a standby mode, control device 434 may instruct or control solenoid valve 462 to move valve 464 to an open position. Control device 434 may move valve 464 to the open position for a predetermined time and/or at predetermined time intervals. Additionally, control device 434 may instruct or control solenoid valve 462 to move valve 464 to the closed position outside of the predetermined time and/or predetermined time interval and/or when the fuel processing assembly is in an operating mode.

The control assembly 434 may include a first control mechanism 468 and a second control mechanism 470. The first control mechanism may communicate with, for example, the fuel processing assembly, the buffer tank sensor assembly, and the product valve assembly, and/or may be configured to control the product valve assembly. The second control mechanism 470 may communicate with, for example, the fuel processing assembly and the return valve assembly, and/or may be configured to control the return valve assembly. Although the control assembly 434 is shown as including first and second control mechanisms 468 and 470, the control assembly may include a single control mechanism configured to provide most or all of the functionality of the first and second control mechanisms.

The first control mechanism 468 may, for example, include a first controller 472, a first switching device 474, and a first energy supply 476. The first controller 472 may have any suitable form, such as a computerized device, software executed on a computer, an embedded processor, an analog device, and/or a functionally equivalent device. Additionally, the first processor may include any suitable software, hardware, and/or firmware.

The first switching device 474 may include any suitable structure configured to allow the first controller 472 to control the solenoid valve 448. For example, the switching device may include a first solid-state relay or first SSR 478. The first solid-state relay may allow the first controller 472 to control the solenoid valve 448 via the first energy supply 476. For example, when the solenoid valve 448 is controlled by 24 volts, the solid-state relay may allow the first controller 472 to control the solenoid valve 448 using a voltage signal other than 24 volts (e.g., 5 volts, 12 volts, 48 volts, etc.). The first energy supply 476 may include any suitable structure configured to provide energy sufficient to control the solenoid valve 448. For example, the first energy supply 476 may include one or more batteries, one or more solar panels, etc. In some embodiments, the energy supply may include one or more electrical outlet connectors and one or more rectifiers (not shown). Although the first solenoid valve and the first controller are described as operating at certain voltages, the first solenoid valve and the first controller may operate at any suitable voltage.

Second control mechanism 470 may, for example, include a second controller 480, a second switching device 482, and a second energy supply 484. Second controller 480 may have any suitable form, such as a computerized device, software executed on a computer, an embedded processor, an analog device, and/or a functionally equivalent device. Furthermore, the processor may include any suitable software, hardware, and/or firmware. For example, second controller 480 may include a time delay relay that provides a signal to solenoid valve 462 to move valve 464 to an open position for a predetermined time and/or at predetermined time intervals. The time delay relay may be energized, for example, only when the fuel processing assembly is in standby mode.

The second switching device 482 may include any suitable structure configured to allow the second controller 480 to control the solenoid valve 462. For example, the second switching device may include a second solid-state relay or a second SSR 486. The second solid-state relay may allow the second controller 480 to control the solenoid valve 462 via a second energy supply 484. For example, when the solenoid valve 462 is controlled by 24 volts, the solid-state relay may allow the second controller 480 to control the second solenoid valve 462 using a non-24 volt signal (such as 5 volts, 12 volts, 48 volts, etc.). The second energy supply 484 may include any suitable structure configured to provide sufficient energy to control the solenoid valve 462. For example, the second energy supply 484 may include one or more batteries, one or more solar panels, etc. In some embodiments, the second energy supply may include one or more receptacle connectors and one or more rectifiers (not shown). Although the second solenoid valve and the second controller are described as operating at certain voltages, the second solenoid valve and the second controller may operate at any suitable voltage.

In some embodiments, the first and/or second control mechanisms (or components of those mechanisms) may be configured to control other components of the hydrogen generation assembly and/or may be combined with other control mechanisms and/or control devices. For example, the first and second control mechanisms may share a power supply. Additionally, the second control mechanism may be configured to control the operation of heaters in thermal communication with the hydrogen-producing region and the hydrogen-selective membrane and/or may be connected to a control device that controls those heaters.

Another example of hydrogen generation assembly 20 is generally shown at 488 in FIG. 12 . Unless specifically excluded, hydrogen generation assembly 488 may include one or more components of one or more other hydrogen generation assemblies described herein. Components of hydrogen generation assembly 488 that are similar or identical to components of hydrogen generation assembly 404 in FIG. 11 are provided with the same reference numerals as components of hydrogen generation assembly 404. Because those components have been discussed previously, this section of the present disclosure focuses on components that are different from hydrogen generation assembly 404.

Product conduit 420 may include a flow portion or leg 489 and a bleed portion or leg 491. Hydrogen generation assembly 488 may include a product valve assembly 490, which may include any suitable structure configured to manage and/or direct flow in product conduit 420. For example, the product valve assembly may allow product hydrogen stream 416 to flow from the fuel processing assembly to a buffer tank (as shown at 442) and/or bleed product hydrogen stream 416 from fuel processing assembly 408 (as shown at 444). The bleed product hydrogen stream may be vented to the atmosphere and/or to a bleed product hydrogen management system (not shown).

Product valve assembly 490 may, for example, include a first solenoid valve 492 and a second solenoid valve 494. The first solenoid valve may include a first solenoid valve 496 and a first valve 498, while the second solenoid valve may include a second solenoid valve 500 and a second valve 502. The first valve may be configured to move between a plurality of positions, including a first open position and a first closed position. Additionally, the second valve may be configured to move between a plurality of positions, including a second open position and a second closed position.

When the first valve is in the open position, the product hydrogen stream is allowed to flow from the fuel processing unit to the buffer tank. Conversely, when the first valve is in the closed position, the buffer tank is isolated from the product hydrogen stream from the fuel processing unit (or the product hydrogen stream from the fuel processing unit is not allowed to flow to the buffer tank). When the second valve is in the open position, the product hydrogen stream from the fuel processing unit is discharged. Conversely, when the second valve is in the closed position, the product hydrogen stream from the fuel processing unit is not discharged.

The first solenoid valve 496 may be configured to move the first valve 498 between open and closed positions based on input received from the control device 434. Additionally, the second solenoid valve 500 may be configured to move the second valve 502 between open and closed positions based on input received from the control device.

Control device 434 may be configured to operate the product valve assembly based on, for example, input from the sensor assembly. For example, when the fuel processing assembly is in a standby mode, the control device may instruct or control the first and/or second solenoid valves to move the first valve to a closed position and/or the second valve to an open position. Furthermore, when fuel processing assembly 408 is in an operating mode and/or a reduced output mode, control device 434 may instruct or control the first and/or second solenoid valves to move the first valve to an open position and/or the second valve to a closed position.

The hydrogen production apparatus of the present disclosure may include one or more of the following:

o First and second end frames comprising input ports configured to receive a mixed gas stream comprising hydrogen and other gases.

o First and second end frames comprising output ports configured to receive a permeate stream comprising a higher concentration of hydrogen and a lower concentration of at least one of the other gases than the mixed gas stream.

o First and second end frames comprising a byproduct port configured to receive a byproduct stream comprising at least a majority of the other gas.

o At least one hydrogen-selective membrane disposed between and secured to the first and second end frames.

o at least one hydrogen-selective membrane having a feed side and a permeate side, at least a portion of the permeate stream being formed from a portion of the mixed gas stream passing from the feed side to the permeate side, and the remainder of the mixed gas stream remaining on the feed side forming at least a portion of the byproduct stream.

o a plurality of frames disposed between the first and second end frames and the at least one hydrogen-selective membrane and secured to the first and second end frames.

o a plurality of frames including at least one permeate frame disposed between the at least one hydrogen-selective membrane and the second end frame.

o At least one permeable frame comprising a peripheral shell.

o At least one permeate frame comprising an output conduit formed on the peripheral shell and configured to receive at least a portion of the permeate stream from the at least one hydrogen-selective membrane.

o At least one permeable frame comprising an open area surrounded by a peripheral shell.

o At least one permeate frame comprising at least one membrane support structure.

o At least one membrane support structure spanning at least a majority of the open area.

o At least one membrane support structure configured to support at least one hydrogen-selective membrane.

o At least one membrane support structure comprising first and second membrane support plates.

o First and second membrane support plates, which contain no perforations.

o First and second membrane support plates having a first side with a plurality of microgrooves configured to provide flow paths for at least a portion of the permeate stream.

o First and second membrane support plates having a second face opposite the first face.

o First and second membrane support plates stacked in at least one membrane support structure.

o First and second membrane support plates stacked in at least one membrane support structure such that the second face of the first membrane support plate faces the second face of the second membrane support plate.

o Incompressible first and second membrane support plates.

ο Flat first and second membrane support plates.

o At least one feed frame disposed between the first end frame and the at least one hydrogen-selective membrane.

o At least one feed frame comprising a peripheral shell.

o At least one feed frame comprising an input conduit formed on an outer peripheral shell of the at least one feed frame.

o At least one feed frame comprising an input conduit configured to receive at least a portion of the mixed gas stream from the input port.

o At least one feed frame comprising an output conduit formed on an outer peripheral shell of the at least one feed frame.

o At least one feed frame comprising an output conduit configured to receive a remainder of at least a portion of the mixed gas stream exiting the feed side of the at least one hydrogen-selective membrane.

o At least one feed frame comprising the feed frame disposed between the input and output conduits surrounded by a feed frame peripheral housing.

o A peripheral shell of at least one feed frame, the peripheral shell of the at least one feed frame being sized such that the peripheral shell of the at least one feed frame supports a portion of the peripheral shell of at least one permeate frame and at least one membrane support structure.

o A peripheral shell of at least one feed frame having dimensions such that the peripheral shell of the at least one feed frame supports a portion of the peripheral shell of at least one permeate frame and at least one membrane support structure along a plurality of support planes perpendicular to a frame plane of each frame of the plurality of frames.

o At least one microporous mesh structure disposed between the at least one hydrogen-selective membrane and the at least one permeate frame.

o At least one microporous mesh structure configured to support at least one hydrogen-selective membrane.

o At least one microscreen structure comprising generally opposed surfaces configured to provide support to the permeate side.

o At least one microporous screen structure comprising a plurality of fluid passages extending between opposing surfaces.

o At least one microporous screen structure sized not to contact the peripheral housing of the at least one permeable frame.

o At least one microscreen structure having dimensions so as not to contact the outer peripheral housing when the at least one microscreen structure and the at least one permeate frame are secured to the first and second end frames.

o At least one membrane support structure comprising a third membrane support plate.

o a third membrane support plate arranged between the first and second membrane support plates.

o Incompressible third membrane support plate.

ο Flat third membrane support plate.

o A third membrane support plate, which does not contain perforations.

o A third membrane support plate having no microgrooves.

o A peripheral shell of the permeation frame, comprising a first and a second peripheral shell.

o A peripheral shell of the permeate frame comprising a gasket disposed between first and second peripheral shells.

o A gasket configured such that the thickness of the peripheral shell of the permeate frame matches the thickness of the membrane support structure.

o A gasket configured such that when the permeate frame is fastened to the first and second end frames, the thickness of the peripheral shell of the permeate frame matches the thickness of the membrane support structure.

o A peripheral shell of the permeation frame, comprising a first, a second and a third peripheral shell.

o A peripheral shell of the permeate frame comprising a first liner disposed between first and second peripheral shells.

o A peripheral shell of the permeate frame comprising a second liner disposed between the second and third peripheral shells.

o First and second liners configured such that the thickness of the peripheral shell of the permeate frame matches the thickness of the membrane support structure.

o First and second liners configured such that the thickness of the peripheral shell of the permeate frame matches the thickness of the membrane support structure when the permeate frame is fastened to the first and second end frames.

o First and second membrane support plates, each having first and second opposing edges.

o A plurality of microgrooves extending from the first edge to the second edge.

o Multiple parallel microgrooves.

o A fuel processing unit configured to receive a feed stream.

o A fuel processing assembly configured to operate in multiple modes.

o A fuel processing assembly configured to operate in a plurality of modes, including an operating mode in which the fuel processing assembly produces a product hydrogen stream from a feed stream and a standby mode in which the fuel processing assembly does not produce a product hydrogen stream from the feed stream.

o A hydrogen-producing zone comprising a reforming catalyst.

o A hydrogen-producing region configured to receive a feed stream and produce a reformate stream.

o One or more hydrogen-selective membranes configured to receive a reformate stream.

o One or more hydrogen-selective membranes configured to generate at least a portion of a product hydrogen stream and a by-product stream from the reformate stream.

o A reformate conduit fluidly connecting the hydrogen-producing region and the one or more hydrogen-selective membranes.

o A buffer tank configured to contain the product hydrogen stream.

o A product conduit fluidly connecting the fuel processing unit and the surge tank.

o A reflux conduit fluidly connecting the buffer tank and the reformate conduit.

o A tank sensor device configured to detect pressure in the buffer tank.

o A reflux valve device configured to manage flow in the reflux conduit.

o A reflux valve arrangement comprising at least one valve.

o At least one valve configured to operate between an open position in which the product hydrogen stream from the buffer tank flows through the return conduit and into the reformate conduit, and a closed position in which the product hydrogen stream from the buffer tank does not flow through the return conduit and into the reformate conduit.

o A plurality of heaters in thermal communication with the hydrogen-producing region and the one or more hydrogen-selective membranes.

o A control device configured to operate the fuel processing device between an operating mode and a standby mode.

o A control assembly configured to operate the fuel processing assembly between an operating mode and a standby mode based at least in part on the sensed pressure in the buffer tank.

o A control device configured to instruct the return valve device to allow the product hydrogen stream to flow from the buffer tank to the reformate conduit.

o A control assembly configured to instruct the return valve assembly to allow the product hydrogen stream to flow from the buffer tank to the reformate conduit when the fuel processing assembly is in the standby mode.

o A control device configured to instruct the reflux device to allow the product hydrogen stream to flow from the buffer tank to the reformate product conduit at one or more predetermined time intervals.

o A control assembly configured to instruct the reflux assembly to allow the product hydrogen stream to flow from the buffer tank to the reformate conduit at one or more predetermined time intervals when the fuel processing assembly is in the standby mode.

o A control device configured to instruct the reflux device to allow the product hydrogen stream to flow from the buffer tank to the reformate conduit for a predetermined period of time at one or more predetermined time intervals.

o A control assembly configured to instruct the reflux assembly to allow the product hydrogen stream to flow from the buffer tank to the reformate conduit for a predetermined period of time at one or more predetermined time intervals when the fuel processing assembly is in the standby mode.

o A control device configured to move at least one valve to an open position for a predetermined period of time at predetermined time intervals.

o A control assembly configured to move the at least one valve to an open position for a predetermined period of time at predetermined time intervals when the fuel processing assembly is in a standby mode.

o A control device configured to operate the plurality of heaters to maintain the hydrogen-producing region and the one or more hydrogen-selective membranes within a predetermined temperature range.

o A control assembly configured to operate the plurality of heaters to maintain the hydrogen-producing region and the one or more hydrogen-selective membranes within a predetermined temperature range when the fuel processing assembly is in the standby mode.

Industrial Applicability

The present disclosure includes hydrogen generation assemblies, hydrogen purification equipment, and assemblies of those assemblies and equipment that may be used in fuel-processing and other industries in which hydrogen is purified, generated, and/or utilized.

The disclosure described above covers a plurality of different inventions with independent uses. Although each of these inventions has been disclosed in its preferred form, the specific embodiments thereof disclosed and explained herein should not be considered as limiting, as there may be countless variations. The subject matter of the present invention includes all novel and non-obvious combinations and sub-combinations of the various elements, features, functions and/or properties disclosed herein. Similarly, when any claim refers to "one/an/a" or "first" element or its equivalent, the claim should be understood to include a combination of one or more such elements, neither requiring nor excluding two or more such elements.

Inventions embodied in various combinations and subcombinations of features, functions, elements, and/or properties may be claimed through the expression of new claims in related applications. Such new claims, whether directed to different inventions or the same invention, and whether different from, broader than, narrower than, or equal to the scope of the original claims, are also deemed to be included in the subject matter of the inventions disclosed herein.

Claims (26)

1. Hydrogen purification equipment, including: First and second end frames, comprising: The inlet is designed to receive a mixed gas stream containing hydrogen and other gases. An output port configured to receive a permeate stream containing a higher concentration of hydrogen and a lower concentration of at least one of the other gases compared to the mixed gas stream; and The by-product port is configured to receive a by-product stream containing at least a majority of the other gases. At least one hydrogen-selective membrane is disposed between and fixed thereto the first and second end frames, the at least one hydrogen-selective membrane having a feed side and a permeate side, at least a portion of the permeate stream being formed by the portion of the mixed gas stream passing from the feed side to the permeate side, and the remaining portion of the mixed gas stream remaining on the feed side forming at least a portion of the byproduct stream; and A plurality of frames are disposed between the first and second end frames and the at least one hydrogen-selective membrane, and are fixed to the first and second end frames. The plurality of frames includes at least one permeation frame disposed between the at least one hydrogen-selective membrane and the second end frame. The at least one permeation frame includes: outer shell, An output conduit formed on the outer peripheral shell and configured to receive at least a portion of the permeate stream from the at least one hydrogen-selective membrane. An open area, which is surrounded by the outer shell, and At least one membrane support structure spanning at least a majority of the open region and configured to support the at least one hydrogen-selective membrane, the at least one membrane support structure comprising first and second membrane support plates, each of the first and second membrane support plates being perforated and having: The first surface has a plurality of microgrooves configured to provide flow channels for at least a portion of the permeate stream, and The second side is opposite to the first side. The first and second membrane support plates are stacked in the at least one membrane support structure such that the second surface of the first membrane support plate faces the second surface of the second membrane support plate. 2. The device of claim 1, wherein the first and second membrane support plates are incompressible and flat. 3. The apparatus of claim 1, wherein the plurality of frames includes at least one feed frame disposed between the first end frame and the at least one hydrogen-selective membrane, the at least one feed frame further comprising: outer shell, An inlet conduit, formed on the outer peripheral housing of the at least one feed frame and configured to receive at least a portion of the mixed gas stream from the inlet port, An output conduit, formed on the outer peripheral housing of the at least one feed frame and configured to receive the remainder of the at least a portion of the mixed gas stream remaining on the feed side of the at least one hydrogen-selective membrane, and An open area of the feed frame, which is surrounded by the outer peripheral shell of the feed frame and arranged between the inlet conduit and the outlet conduit, wherein the outer peripheral shell of the at least one feed frame is sized such that the outer peripheral shell of the at least one feed frame supports a portion of the outer peripheral shell of the at least one permeation frame and the at least one membrane support structure along a plurality of support planes perpendicular to the frame plane of each of the plurality of frames. 4. The device of claim 1, wherein the plurality of frames further comprises at least one microporous screen structure disposed between the at least one hydrogen-selective membrane and the at least one permeation frame and configured to support the at least one hydrogen-selective membrane, wherein the at least one microporous screen structure includes generally opposing surfaces configured to provide support for the permeation side and a plurality of fluid passages extending between the opposing surfaces, the at least one microporous screen structure being sized such that the at least one microporous screen structure does not contact the outer peripheral housing of the at least one permeation frame when the at least one microporous screen structure and the at least one permeation frame are fastened to the first and second end frames. 5. The device of claim 1, wherein the at least one membrane support structure further comprises a third membrane support plate disposed between the first and second membrane support plates. 6. The device of claim 5, wherein the third membrane support plate is incompressible, flat, and free of perforations and microgrooves. 7. The device of claim 1, wherein the outer peripheral housing of the permeation frame comprises first and second outer peripheral housings and a gasket disposed between the first and second outer peripheral housings. 8. The device of claim 7, wherein the liner is configured such that when the permeation frame is fastened to the first and second end frames, the thickness of the outer peripheral shell of the permeation frame matches the thickness of the membrane support structure. 9. The device of claim 1, wherein the outer peripheral housing of the permeation frame comprises a first, a second, and a third outer peripheral housing, a first gasket disposed between the first and second outer peripheral housings, and a second gasket disposed between the second and third outer peripheral housings. 10. The device of claim 9, wherein the first and second gaskets are configured such that when the permeation frame is fastened to the first and second end frames, the thickness of the outer peripheral shell of the permeation frame matches the thickness of the membrane support structure. 11. The device of claim 1, wherein the first and second membrane support plates each have opposing first and second edges, wherein the plurality of microgrooves extend from the first edge to the second edge. 12. The device of claim 11, wherein the plurality of microgrooves are parallel to each other. 13. A hydrogen production unit, comprising: A fuel processing device configured to receive a feed stream and capable of operating in multiple modes, including an operating mode in which the fuel processing device generates a product hydrogen stream from the feed stream and a standby mode in which the fuel processing device does not generate a product hydrogen stream from the feed stream, the fuel processing device comprising: The hydrogen production zone includes a reforming catalyst and is configured to receive the feed stream and produce a reforming product stream. One or more hydrogen-selective membranes configured to receive the reformate stream and generate at least a portion of the product hydrogen stream and byproduct stream from the reformate stream, and A reforming product conduit that is in fluid communication with the hydrogen production zone and the one or more hydrogen-selective membranes; A buffer tank configured to contain the hydrogen stream of the product; The product conduit is in fluid communication with the fuel processing unit and the buffer tank; A reflux conduit, which is in fluid communication with the buffer tank and the reforming product conduit; A tank sensor device configured to detect the pressure in the buffer tank; A control device configured to operate the fuel processing device between the operating mode and the standby mode based at least in part on the detected pressure in the buffer tank; and A reflux valve device configured to manage flow in the reflux conduit, and a control device configured to instruct the reflux valve device to allow the product hydrogen stream to flow from the buffer tank to the reformate conduit when the fuel processing unit is in standby mode. 14. The apparatus of claim 13, wherein the control device is configured to instruct the reflux device at one or more predetermined time intervals to allow the product hydrogen stream to flow from the buffer tank to the reformate conduit when the fuel processing device is in standby mode. 15. The apparatus of claim 14, wherein the control device is configured to instruct the reflux device at one or more predetermined time intervals, when the fuel processing device is in standby mode, to allow the product hydrogen stream to flow from the buffer tank to the reformate conduit for a predetermined time. 16. The apparatus of claim 13, wherein the reflux valve device includes at least one valve configured to operate between an open position and a closed position, wherein in the open position a stream of product hydrogen from the buffer tank flows through the reflux conduit and into the reforming product conduit, and in the closed position a stream of product hydrogen from the buffer tank does not flow through the reflux conduit and into the reforming product conduit. 17. The apparatus of claim 16, wherein the control device is configured to move the at least one valve to the open position for a predetermined time when the fuel processing device is in a standby mode. 18. The apparatus of claim 17, wherein the control device is configured to move the at least one valve to the open position for a predetermined time at one or more predetermined time intervals when the fuel processing device is in a standby mode. 19. The apparatus of claim 16, wherein the control device is configured to move the at least one valve to the open position at one or more predetermined time intervals when the fuel processing device is in a standby mode. 20. The apparatus of claim 13, further comprising a plurality of heaters in thermal communication with the hydrogen production zone and the one or more hydrogen selective membranes, wherein the control device is configured to operate the plurality of heaters to maintain the hydrogen production zone and the one or more hydrogen selective membranes within a predetermined temperature range when the fuel processing apparatus is in a standby mode. 21. A hydrogen purification apparatus, comprising: First and second end frames, comprising: The inlet is designed to receive a mixed gas stream containing hydrogen and other gases. An output port configured to receive a permeate stream containing a higher concentration of hydrogen and a lower concentration of at least one of the other gases compared to the mixed gas stream; and The by-product port is configured to receive a by-product stream containing at least a majority of the other gases. At least one hydrogen-selective membrane is disposed between and fixed thereto the first and second end frames, the at least one hydrogen-selective membrane having a feed side and a permeate side, at least a portion of the permeate stream being formed by the portion of the mixed gas stream passing from the feed side to the permeate side, and the remaining portion of the mixed gas stream remaining on the feed side forming at least a portion of the byproduct stream; and A plurality of frames are disposed between the first and second end frames and the at least one hydrogen-selective membrane, and are fixed to the first and second end frames. The plurality of frames includes at least one permeation frame disposed between the at least one hydrogen-selective membrane and the second end frame. The at least one permeation frame includes: outer shell, An output conduit formed on the outer peripheral shell and configured to receive at least a portion of the permeate stream from the at least one hydrogen-selective membrane. An open area, which is surrounded by the outer shell, and At least one membrane support structure spanning at least a majority of the open region and configured to support the at least one hydrogen-selective membrane, the at least one membrane support structure being free of perforations. The plurality of frames further include at least one microporous screen structure configured to support the at least one hydrogen-selective membrane, wherein the at least one microporous screen structure is disposed between the at least one hydrogen-selective membrane and the at least one permeation frame, and wherein the at least one microporous screen structure includes generally opposing surfaces configured to provide support for the permeation side and a plurality of fluid passages extending between the opposing surfaces. 22. The device of claim 21, wherein the at least one membrane support structure comprises first and second membrane support plates stacked in the at least one membrane support structure. 23. The apparatus of claim 22, wherein each of the first and second membrane support plates is free of perforations and comprises: The first surface has a plurality of microgrooves configured to provide flow channels for at least a portion of the permeate stream, and The second side is opposite to the first side. The first and second membrane support plates are stacked in the at least one membrane support structure such that the second surface of the first membrane support plate faces the second surface of the second membrane support plate. 24. The device of claim 21, wherein the at least one microporous screen structure comprises stainless steel. 25. The device of claim 24, wherein the at least one microporous screen structure comprises aluminum-modified stainless steel 303. 26. The device of claim 24, wherein the stainless steel comprises an aluminum oxide layer configured to prevent intermetallic diffusion between the stainless steel and the at least one hydrogen-selective membrane.