WO2007043247A1 - Fuel reformer - Google Patents

Fuel reformer Download PDF

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Publication number
WO2007043247A1
WO2007043247A1 PCT/JP2006/316803 JP2006316803W WO2007043247A1 WO 2007043247 A1 WO2007043247 A1 WO 2007043247A1 JP 2006316803 W JP2006316803 W JP 2006316803W WO 2007043247 A1 WO2007043247 A1 WO 2007043247A1
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WO
WIPO (PCT)
Prior art keywords
gas
fuel
combustion
hydrogen
passage
Prior art date
Application number
PCT/JP2006/316803
Other languages
French (fr)
Other versions
WO2007043247A9 (en
Inventor
Yasunori Iwakiri
Luc Rouveyre
Original Assignee
Nissan Motor Co., Ltd.
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Publication date
Application filed by Nissan Motor Co., Ltd. filed Critical Nissan Motor Co., Ltd.
Publication of WO2007043247A1 publication Critical patent/WO2007043247A1/en
Publication of WO2007043247A9 publication Critical patent/WO2007043247A9/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J19/24—Stationary reactors without moving elements inside
    • B01J19/248—Reactors comprising multiple separated flow channels
    • B01J19/249—Plate-type reactors
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
    • C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
    • C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
    • C01B3/323—Catalytic reaction of gaseous or liquid organic compounds other than hydrocarbons with gasifying agents
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
    • C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
    • C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
    • C01B3/34—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents
    • C01B3/38—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents using catalysts
    • C01B3/384—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents using catalysts the catalyst being continuously externally heated
    • C—CHEMISTRY; METALLURGY
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    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
    • C01B3/50—Separation of hydrogen or hydrogen containing gases from gaseous mixtures, e.g. purification
    • C01B3/501—Separation of hydrogen or hydrogen containing gases from gaseous mixtures, e.g. purification by diffusion
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    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
    • C01B3/50—Separation of hydrogen or hydrogen containing gases from gaseous mixtures, e.g. purification
    • C01B3/501—Separation of hydrogen or hydrogen containing gases from gaseous mixtures, e.g. purification by diffusion
    • C01B3/503—Separation of hydrogen or hydrogen containing gases from gaseous mixtures, e.g. purification by diffusion characterised by the membrane
    • C01B3/505—Membranes containing palladium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/24—Stationary reactors without moving elements inside
    • B01J2219/2401—Reactors comprising multiple separate flow channels
    • B01J2219/245—Plate-type reactors
    • B01J2219/2451—Geometry of the reactor
    • B01J2219/2453—Plates arranged in parallel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/24—Stationary reactors without moving elements inside
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    • B01J2219/2451—Geometry of the reactor
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    • B01J2219/2458—Flat plates, i.e. plates which are not corrugated or otherwise structured, e.g. plates with cylindrical shape
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/24—Stationary reactors without moving elements inside
    • B01J2219/2401—Reactors comprising multiple separate flow channels
    • B01J2219/245—Plate-type reactors
    • B01J2219/2461—Heat exchange aspects
    • B01J2219/2465—Two reactions in indirect heat exchange with each other
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
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    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/24—Stationary reactors without moving elements inside
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    • B01J2219/245—Plate-type reactors
    • B01J2219/2461—Heat exchange aspects
    • B01J2219/2466—The same reactant stream undergoing different reactions, endothermic or exothermic
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/24—Stationary reactors without moving elements inside
    • B01J2219/2401—Reactors comprising multiple separate flow channels
    • B01J2219/245—Plate-type reactors
    • B01J2219/2469—Feeding means
    • B01J2219/247—Feeding means for the reactants
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
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    • B01J2219/2475—Separation means, e.g. membranes inside the reactor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/24—Stationary reactors without moving elements inside
    • B01J2219/2401—Reactors comprising multiple separate flow channels
    • B01J2219/245—Plate-type reactors
    • B01J2219/2476—Construction materials
    • B01J2219/2477—Construction materials of the catalysts
    • B01J2219/2479—Catalysts coated on the surface of plates or inserts
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/02—Processes for making hydrogen or synthesis gas
    • C01B2203/0205—Processes for making hydrogen or synthesis gas containing a reforming step
    • C01B2203/0227—Processes for making hydrogen or synthesis gas containing a reforming step containing a catalytic reforming step
    • C01B2203/0233—Processes for making hydrogen or synthesis gas containing a reforming step containing a catalytic reforming step the reforming step being a steam reforming step
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/04—Integrated processes for the production of hydrogen or synthesis gas containing a purification step for the hydrogen or the synthesis gas
    • C01B2203/0405—Purification by membrane separation
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/04—Integrated processes for the production of hydrogen or synthesis gas containing a purification step for the hydrogen or the synthesis gas
    • C01B2203/0405—Purification by membrane separation
    • C01B2203/041—In-situ membrane purification during hydrogen production
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
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    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/04—Integrated processes for the production of hydrogen or synthesis gas containing a purification step for the hydrogen or the synthesis gas
    • C01B2203/0465—Composition of the impurity
    • C01B2203/047—Composition of the impurity the impurity being carbon monoxide
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
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    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/04—Integrated processes for the production of hydrogen or synthesis gas containing a purification step for the hydrogen or the synthesis gas
    • C01B2203/0465—Composition of the impurity
    • C01B2203/048—Composition of the impurity the impurity being an organic compound
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/06—Integration with other chemical processes
    • C01B2203/066—Integration with other chemical processes with fuel cells
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/08—Methods of heating or cooling
    • C01B2203/0805—Methods of heating the process for making hydrogen or synthesis gas
    • C01B2203/0811—Methods of heating the process for making hydrogen or synthesis gas by combustion of fuel
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    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/08—Methods of heating or cooling
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    • C01B2203/0822—Methods of heating the process for making hydrogen or synthesis gas by combustion of fuel the fuel containing hydrogen
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/08—Methods of heating or cooling
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    • C01B2203/0811—Methods of heating the process for making hydrogen or synthesis gas by combustion of fuel
    • C01B2203/0827—Methods of heating the process for making hydrogen or synthesis gas by combustion of fuel at least part of the fuel being a recycle stream
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/10—Catalysts for performing the hydrogen forming reactions
    • C01B2203/1005—Arrangement or shape of catalyst
    • C01B2203/1035—Catalyst coated on equipment surfaces, e.g. reactor walls
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/12—Feeding the process for making hydrogen or synthesis gas
    • C01B2203/1205—Composition of the feed
    • C01B2203/1211—Organic compounds or organic mixtures used in the process for making hydrogen or synthesis gas
    • C01B2203/1217—Alcohols
    • C01B2203/1223—Methanol
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/12—Feeding the process for making hydrogen or synthesis gas
    • C01B2203/1205—Composition of the feed
    • C01B2203/1211—Organic compounds or organic mixtures used in the process for making hydrogen or synthesis gas
    • C01B2203/1235—Hydrocarbons
    • C01B2203/1247—Higher hydrocarbons
    • C—CHEMISTRY; METALLURGY
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    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
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    • C01B2203/1288—Evaporation of one or more of the different feed components
    • C—CHEMISTRY; METALLURGY
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    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/16—Controlling the process
    • C01B2203/1604—Starting up the process
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    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
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    • C01B2203/1614—Controlling the temperature
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    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/16—Controlling the process
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    • C01B2203/1619—Measuring the temperature
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    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/16—Controlling the process
    • C01B2203/1614—Controlling the temperature
    • C01B2203/1623—Adjusting the temperature
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/10—Process efficiency

Definitions

  • This invention relates to a fuel reformer for generating hydrogen gas to be supplied for a fuel cell power plant, and more specifically, to a heating structure
  • JP2002-295811A published by Japan Patent Office m 2002 proposes a multi-stage combustion device which supplies fuel to a lean burn mixer in a
  • the temperature of the high-temperature gas may decrease before the gas reaches the heating object. Further, a great temperature difference occurs between Hie high-temperature gas inlet and the high-temperature gas outlet formed in the heating object, and hence a temperature deviation is apt to occur m the heating object.
  • the heating object is a fuel reforming element which catalytically reforms hydrocarbon fuel into hydrogen rich reformate gas
  • it is difficult to obtain favorable transfer efficiency between the combustion device ard the fuel reforming element. It is also difficult to control temperature distribution in the fuel reforming element.
  • this invention provides a fuel reformer which reforms hydrocarbon material into hydrogen gas, comprising a combustion space which generates a combustion heat by burning a fuel in an oxidant gas supplied from outside, and a catalytic reforming passage comprising a reforming catalyst which reforms the hydrocarbon material into a reformate gas containing hydrogen.
  • the catalyst is activated by being heated by the combustion heat generated by the combustion space, and the catalytic reforming passage is disposed in parallel with the combustion space.
  • the fuel reformer further comprises a hydrogen permeable membrane which faces the catalytic reforming passage and extracts hydrogen in the reformate gas, a hydrogen collecting space which collects the hydrogen extracted by the hydrogen permeable membrane, and a reformate gas supply passage which supplies the combustion space with the reformate gas from which the hydrogen has been extracted.
  • FIG. 1 is a perspective view including a partial cutaway view of a fuel
  • FIG. 2 is a perspective view of the fuel reformer in a state where various
  • FIG. 3 is a cross -sectional view of the fuel reformer taken along a line
  • FIG. 4 is a cross -sectional view of the fuel reformer taken along a line
  • FIG. 5 is a plan view of a combustion element according to this invention.
  • FIG. 6 is a plan view of a reforming element according to this invention.
  • FIG. 7 is a plan view of a hydrogen gas permeable element according to
  • FIG 8 is a plan view of a hydrogen gas collecting element according to
  • FIG. 9 is similar to FIG. 5, but shows a variation of the combustion
  • FIG. 10 is a plan view of a reforming element provided in a fuel reformer accordmg to a second embodiment of this invention.
  • FIGs. 1 IA and HB are a plan view of a combustion element according to the second embodiment of this invention and a front view of a side wall provided in the combustion element.
  • FIG. 12 is similar to FIG. 2, but shows a third embodiment of this invention
  • FIG. 13 is a cross -sectional view of the fuel reformer according to the
  • FIGs. 14A and 14B are a plan view of a combustion element provided in the fuel reformer according to the third embodiment of this invention and a front view of a side wall provided in the combustion element.
  • FIG. 15 is a plan view of a reforming element provided m the fuel reformer according to the third embodiment
  • FIG 16 is a plan view of a partition plate provided in the. fuel reformer according to the third embodiment.
  • a fuel reformer comprises a stack of plural fuel reforming units 3 stacked between a lower end plate 2 and an upper end plate 4 and secured together by stack bolts in the direction of stacking.
  • the fuel reformer comprises plural hydrogen gas outlets 13 and plural oxidant gas inlets 42 on its lateral surfaces and fuel passages 62 on its top surface.
  • the hydrogen gas outlets 13 are configured such that they can open and close.
  • a hydrogen rich gas passage 7 is, connected to the hydrogen gas outlets 13, an oxidant gas supply passage 5 is connected to the oxidant gas inlets 42, and a fuel supply passage 6 is connected to the fuel passages 62.
  • the fuel supply passage 6 provides the fuel passages 62 with a mixture of water and hydrocarbon material, e.g., gasoline or methanol, as fuel from outside.
  • a mixture of water and hydrocarbon material e.g., gasoline or methanol
  • the fuel reforming unit 3 comprises a plate-shaped hydrogen gas collecting element 10 which collects hydrogen, a plate-shaped hydrogen permeable element 20 which extracts hydrogen from a reformate gas, a plate-shaped reforming element 30 which reforms a mixture of the fuel and steam mto the reformate gas, and a plate-shaped combustion element 40 which heats the reforming element 30.
  • the hydrogen permeable element 20, the reforming element 30 and the combustion element 40 are stacked on both sides of the hydrogen gas collecting element 10 With respect to the fuel reforming unit 3 located in the uppermost
  • the intermediate fuel reforming unit 3 may also be constructed in the same way as the uppermost or lowermost fuel reforming unit 3.
  • the combustion element 40 burns a combustible gas with oxygen in the air and heats the reforming element 30 by combustion heat.
  • the combustion element 40 composes a plate 41 and partition plates 50 disposed on the both sides thereof.
  • a combustion space 44 is formed in the central part of the plate 41, and an oxidant gas inlet 42 and a combustion gas outlet 43 are formed on the respective ends of the combustion space 44.
  • the plate 41 is substantially divided into two pieces by the combustion space 44, the oxidant gas inlet 42 and the combustion gas outlet 43. Accordingly, the plate 41 may be constructed by manufacturing two pieces, each of which corresponds to the upper portion of the plate 41 in the figure, and disposing one of the two pieces upside down so as to face the other of the two pieces.
  • the oxidant gas inlet 42 and the combustion gas outlet 43 need not necessarily penetrate the plate 41 and may be formed in the shape of a groove m the plate 41.
  • a partition plate 50 is stacked on both sides of the plate 41 and the space constituted by the combustion space 44, the oxidant gas inlet 42 and the combustion gas outlet 43 is delimited by these partition plates 50 with respect to the stacking direction of the elements 10-40.
  • a pair of purge gas passages 61 penetrates the plate 41 and the partition plates 50 on the two sides of the oxidant gas inlet 42.
  • a pair of fuel passages 62 penetrates the plate 41 and the partition plates 50 on the two sides of the combustion gas outlet 43.
  • a porous body 45 which supports an oxidation catalyst is accommodated in the combustion space 44 and sandwiched between the partition plates 50.
  • the end faces of the porous body 45 respectively face the oxidant gas mlet 42 and the combustion gas outlet 43.
  • a pair of reformate gas supply spaces 46 is formed on the two sides of the porous body 45. Each of the reformate gas supply spaces 46 is delimited by the plate 41, the porous body 45 and the partition plates 50. A part of the reformate gas generated in the reforming element 30 is supplied to the reformate gas supply spaces 46 via through-holes 51 formed in the partition plates 50.
  • the oxidation catalyst may be supported on the surface of the partition
  • the catalyst support area of the partition plates 50 may be increased by
  • the porous body 45 comprises a central region porous body 45A disposed in a central region and linearly connecting the oxidant gas mlet 42 and the combustion gas outlet 43.
  • the oxidation catalyst is supported, on the walls between the pores of the porous body 45A.
  • the porous body 45 comprises boundary region porous bodies 45B which have smaller pore diameters and a higher density than the central region porous
  • the central region porous body 45A has a smaller flow resistance than the boundary region porous bodies 45B, and hence the porous body 45 forms an oxidant gas flow passage which extends from the oxidant gas inlet 42 toward the combustion gas outlet 43.
  • the porous bodies 45B in the boundary regions function to distribute the reformate gas in the reformate gas supply spaces 46 to the entire central region porous body 45A uniformly.
  • the oxidant gas herein denotes air which contains oxygen.
  • the air supplied from the oxidant gas supply passage 5 is led to the central region porous body 45A via the oxidant gas inlet 42, and the reformate gas in the pair of reformate gas supply spaces 46 is transmitted through the boundary region porous bodies 45B towards the central region porous body 45A.
  • the combustion element 40 burns combustible components such as hydrogen (H 2 ), carbon monoxide (CO) and methane (CH 4 ) contained in the reformate gas that has reached the central region porous body 45A together with oxygen m the air Since the reformate gas is supplied uniformly throughout the entire central region porous body 45A as described above, this combustion also occurs uniformly in the entire central region porous body 45A.
  • the combustion heat generated by combustion of the reformate gas in the central region porous body 45A is transferred to the reforming element 30 adjacent to the central region porous body 45A via the partition plate 50.
  • the combustion temperature of the reformate gas should be kept lower than the heat resisting limit of the reforming catalyst provided in the reforming element 30, but higher than a catalytic reaction minimum temperature of the reforming catalyst which is determined from the reaction speed of the reforming catalyst. This is accomplished by settmg the density or thickness of the boundary region porous body 45b appropriately, or setting the operation pressure of the combustion element 40 appropriately, or setting the operation pressure of the reforming element 30 appropriately.
  • the reforming element 30 comprises a plate 31 which is penetrated by the purge gas passages 61 and the fuel passages 62 in the same positions as the plate 41
  • One surface of the plate 31 is m contact with the partition plate 50 and the other surface of the plate 31 is in contact with the hydrogen permeable element 20.
  • a plurality of fuel supply holes 32 which penetrate the plate 31, a fuel vapor passage 33 in the form of. parallel slits formed in the plate 31 so as to be connected with the fuel supply holes 32, a catalytic reforming passage 34 in the form of parallel slits formed in the plate 31 as a downstream extension of the fuel vapor passage 33, an outlet 35 of the catalytic reforming passage 34, and a pair of connection passages 36 in the form of a pair of slits formed m the plate 31 and connected with the outlet 35 are provided.
  • the fuel supply holes 32 supply a mixture of water and hydrocarbon material to the fuel vapor passage 33.
  • the fuel vapor passage 33 vaporizes the mixture to generate fuel vapor.
  • the catalytic reforming passage 34 performs steam reforming of the fuel vapor that is supplied from the fuel vapor passage 33 and generates the reformate gas.
  • the pair of connection passages 36 are disposed on the two sides of the catalytic reforming passage 34 in positions corresponding to the pair of reformate gas supply spaces 46 in the combustion element 40.
  • the pair of connection passages 36 supply the reformate gas that has reached the outlet 35 to the pair of reformate gas supply spaces 46 via the through-holes 51 formed in the partition plates 50.
  • the fuel vapor passage 33 and the catalytic reforming passage 34 is closed by the partition plate 50.
  • the other side of the parallel slits is closed by a surface of the hydrogen permeable element 20.
  • the fuel vapor passage 33 is disposed so as to overlap the downstream part of the central region porous body 45A.
  • the mixture of water and hydrocarbon material flowing in the fuel vapor passage 33 is vaporized by the heat transferred from the combustion element 40 via the partition plate 50.
  • the fuel vapor generated in the fuel vapor passage 33 is supplied to the catalytic reforming passage 34 located downstream.
  • the catalytic reforming passage 34 is disposed in a position overlapping the upstream part of the central region porous body 45A of the combustion element 40.
  • a reforming catalyst is supported on the surface of the slit walls and the partition plate 50 facing the slits.
  • the reforming catalyst is a known steam reforming catalyst which reforms a mixture of water and hydrocarbon material in the form of vapor.
  • the vapor of the mixture that flows out from the fuel vapor passage 33 undergoes steam reforming while passing through the slits of the catalytic reforming passage 34 and is reformed into the reformate gas.
  • Hydrogen contained in the reformate gas generated in the catalytic reforming passage 34 is extracted into the hydrogen gas collecting element 10 through the hydrogen permeable element 20 which is disposed adjacent to the reforming element 30.
  • the residual components of the reformate gas flows out from the outlet 35 of the catalytic reforming passage 34 into the pair of the connection passages 36, and are then supplied to the pair of reformate gas supply spaces
  • Steam reforming is an endothermal reaction consuming the combustion heat transmitted from the combustion element 40 via the partition plate 50.
  • the reforming reaction that the catalytic reforming passage 34 performs should however not limited to steam reforming. It can also perform autothermal reforming (ATR) which is a combination of a preferential oxidation reaction of fuel vapor and a steam reforming reaction of the same. Under ATR, heat generated by the preferential oxidation reaction which is an exothermal reaction is consumed in the steam reforming reaction which is a endothermal reaction, thereby enabling reforming of fuel vapor without providing heat from outside.
  • ATR autothermal reforming
  • One side of the slits constituting the pair of connection passages 36 is closed by a surface of the hydrogen permeable element 20.
  • the other side of the slits communicates with the through-holes 51 formed in the partition plate 50.
  • the reformate gas is supplied from the outlet 35 to the central region porous body 45A via the connection passages 36, through- holes 51, reformate gas supply spaces 46 and boundary region porous bodies 45B.
  • the temperature of the reforming element 30 rises efficiently and the catalytic reaction speed in the reforming element 30 is maintained at a high level. Since there is no extreme temperature increase in a specific part of the central region porous body 45A, the peak combustion temperature of the central region porous body 45A is suppressed which is preferable in view of the heat resistance characteristics of the reforming catalyst. Further, the emission of nitrogen oxides (NOx) is also suppressed.
  • NOx nitrogen oxides
  • the hydrogen permeable element 20 comprises a plate 21 which is penetrated by the purge gas passages 61 and the fuel passages 62 in the same positions as the plate 41. Further, a fuel manifold 63 and a hole 23 are formed in the plate 21 to pass therethrough. The hole 23 is formed m a position which overlaps the catalytic reforming passage 34 of the reforming element 30. Referring again to FIG 3, a supporting body 24 of a hydrogen permeable membrane 25 is fitted m the hole 23. The hydrogen permeable membrane 25 is supported on a surface of the supporting body 24 so as to face the catalytic reforming passage 34.
  • the hydrogen permeable membrane 25 comprises a palladium foil coated or the surface of the supporting body 24.
  • the palladium foil is formed by applying palladium slurry which is a mixture of palladium (Pd) , water, and a binder, to the surface of the supporting body 24 and drying it.
  • a typical application thickness of the palladium slurry is 1 to 10 micrometers ( ⁇ m).
  • the operation pressure in each passage of the reforming element 30 such as the catalytic reforming passage 34 is set to be higher than passages in the other elements.
  • the supporting structure of the supporting body 24 is determined such that a surface pressure exerted on the hydrogen permeable membrane 25 can be supported by the plate 21 via the supporting body 24.
  • the supporting body 24 is constituted by a hydrogen permeable material.
  • the hydrogen gas collecting element 10 comprises a plate 11 which is penetrated by the purge gas passages 61 , the fuel manifold 63, and one of the fuel passages 62 in the same positions as the plate 21. Further, in this plate 11, a boundary between the one of the fuel passages 62 and the fuel manifold 63 is removed so that they communicate with each other
  • a cut-out is further formed m the plate 11 to function as a hydrogen gas collecting space 12.
  • the hydrogen gas collecting space 12 covers a region facmg the supporting body 24 of the hydrogen permeable element 20, communicates with the one of the purge gas passage 61, and has the hydrogen gas outlet 13 opening on the side face of the fuel reforming unit 3.
  • hydrogen contained in the reformate gas generated in the catalytic reforming passage 34 of the reforming element 30 flows into the hydrogen gas collecting space 12 of the hydrogen gas collecting element 10 by passing through the hydrogen permeable membrane 25 of the hydrogen permeable element 20, and is discharged into the hydrogen rich gas passage 7 from the hydrogen gas outlet 13.
  • the fuel supplied to the fuel passage 62 which is a
  • mixture of water and hydrocarbon material flows into the fuel manifold 63 of the hydrogen gas collecting element 10 and supplied to the fuel vapor passage 33 of the reforming element 30 via the fuel supply holes 32 of the reforming element 30 opening onto the fuel manifold 63.
  • the warm-up operation during operation start-up is performed in the following manner.
  • air is supplied from the oxidant gas inlet 42 while the hydrogen gas outlets 13 are closed, and a combustible gas such as vaporized hydrocarbon material is supplied to the oxidant gas supply passage 5 and /or the fuel supply
  • the combustible gas supplied to the oxidant gas supply passage 5 is distributed to the respective oxidant gas inlets 42 of the fuel reforming units 3 communicating with the oxidant gas supply passage 5.
  • the combustible gas flows into the central region porous body 45A disposed in the combustion space 44 of the combustion element 40.
  • the combustible gas supplied to the fuel supply passage 6 is distributed to the respective fuel manifolds 63 of the fuel reforming units 3 via the fuel passage 62.
  • the combustible gas flows into the reformate gas supply spaces 46 from the fuel manifold 63 via the fuel supply holes 32, the fuel vapor passage 33, the catalytic reforming passage 34, the outlet35 and the pair of connection passages 36, and is transmitted to the central region porous body 45A by passing through the boundary region porous bodies 46B.
  • the combustible gas which is supplied from the reformate gas supply spaces 46 to the central region porous body 45A through the boundary region porous bodies 46B is distributed evenly over the entire .length of the central region porous body 45A and burns in the entire region of the central region porous body 45A, thereby heating the entire region of the central region porous body 45A.
  • the reforming element 30 is also heated evenly over the entire region.
  • the combustible gas generated by catalytic combustion is then discharged from the combustion gas outlet 43 as post-reaction gas under the oxidation catalyst.
  • the supply of combustible gas to the oxidant gas supply passage 5 and/or the fuel supply passage 6 is terminated.
  • hydrogen contained in the reformate gas that is generated in the catalytic reforming passage 34 passes through the hydrogen permeable membrane 25 of the hydrogen permeable element 20, and is then collected in the hydrogen gas collecting space 12 and discharged into the hydrogen rich gas passage 7 from the hydrogen gas outlet 13 as hydrogen rich gas .
  • the hydrogen rich gas thus produced is supplied to a fuel cell stack or accumulated in a accumulation device
  • the residual reformate gas in the catalytic reforming passage 34 flows out from the outlet 35 to the pair of the connection passages 36, and is transmitted to the central region porous body 45A via the through-holes 51, the pair of reformate gas supply spaces 46, and the pair of boundary region porous bodies 45B. Having reached the central region porous body 45A, the residual reformate gas undergoes catalytic combustion.
  • the combustion gas generated by the catalytic combustion is discharged from the combustion gas outlet 43 to the outside of the fuel reforming unit 3. It is preferable to cause the combustion gas discharged from the combustion gas outlet 43 to pass through a radiator in order to collect moisture and heat before being released mto the atmosphere.
  • heat transfer from the combustion gas in the combustion element 40 to the reformate gas in the reforming element 30 is performed via the partition plate 50 in the form of heat transfer between parallel flows or reverse flows which are formed on the both sides of the partition plate 50.
  • This type of heat transfer helps to maintain a high temperature in the entire region of the reforming element 30 and the reaction speed of the reforming catalyst is thereby maintained at a high level. Smce the combustion element 40 and the reforming element 30 are stacked together via the partition plate 50, the size of the fuel reformer can be reduced.
  • the thickness of the downstream part of the porous bodies 45B is set to be greater than the thickness of the upstream part of the same
  • the density of the downstream part of the porous bodies 45B is set to be greater than the density of the upstream part of the same.
  • the flow resistance through the upstream part of the porous body 45B is smaller than that through the downstream part of the same, and a greater amount of the reformate gas is provided in the upstream part of the porous body 45A than in the downstream part of the same.
  • the temperature of the upstream part of the central region porous body 45A becomes higher than the temperature of the downstream part of the same.
  • the boundary region porous bodies 45B are arranged to have a steadily greater thickness towards the downstream.
  • the temperature of any specific region with respect to the oxidant gas flow direction in the central region porous body 45A can be raised or lowered.
  • the temperature distribution in the reforming element 30 is thus controlled, it is not necessary to increase the air mixing ratio of the gas in the cornbustion space 44 in order to suppress the peak combustion temperature, and the peak combustion temperature can be suppressed under a small air supply amount. As a result, the heat radiation amount of a radiator which collects moisture in the combustion gas discharged from the combustion gas outlet 43 is small, and hence the radiator can be made small. Further, since the combustible components such as carbon monoxide (CO) and methane (CH 4 ) of the reformate gas after separating hydrogen at the hydrogen permeable
  • membrane 25 are used for combustion m the combustion element 40, the energy of the hydrocarbon material is efficiently utilized.
  • the reforming element 30 has shortened connection passages 36 so as to correspond to the catalytic reforming passage 34 of the adjacent reforming element 30. Accordingly, the region of the partition plate 50 where the through-holes 51 are formed is also decreased.
  • a hole 64 which penetrates the plates 11-31 constituting the reforming element 30, hydrogen permeable element 20, and hydrogen gas collecting element 10 is provided in order to supply the reformate gas in the outlet 35 to the combustion space 44 m the combustion element 40.
  • the width of the combustion space 44 in the combustion element 40 is great in the vicinity of the oxidant gas inlet 42 and gradually narrows towards the combustion gas outlet 43.
  • an oxidation catalyst is supported on the walls of the combustion space 44.
  • a pair of reformate gas supply spaces 46 is partitioned by thin side walls 47 on both sides of the upstream part of the combustion space 44.
  • the reformate gas supply spaces 46 communicate with the connection passages 36 m the reforming element 30 via the through -holes 51 as in the case of the first embodiment.
  • a second reformate gas supply space 48 is provided in the central region of the upstream part of the combustion space 44.
  • the second reformate gas supply space 48 is formed by walls 49 similar to the side walls 47.
  • the second reformate gas supply space 48 communicates with the hole 64 at the oxidant gas inlet 42.
  • the walls 49 have communication holes 48A similar to the communication holes 47A.
  • the two sides of the walls 49 in the stacking direction of the elements 10-40 are in contact with the partition plates 50 so as to partition the second reformate gas supply space 48 from the combustion space 44
  • the reformate gas is supplied uniformly in the lateral direction, or in the vertical direction in FIG.
  • the intervals between the communication holes 47A and 48A are respectively set to decrease steadily upstream and increases steadily downstream with respect to the flow of oxidant gas in the combustion space 44.
  • the reformate gas supply amount is larger in the upstream part, and hence more combustion heat is generated in the upstream part
  • the upstream part corresponds to the downstream part of
  • the catalytic reforming passage 34 of the adjacent reforming element 30, and the reforming reaction in the catalytic reforming passage 34 is thereby enhanced further in the downstream part, which is preferred in view of accomplishing the reforming reaction of fuel vapor into hydrogen rich gas
  • the heat generated by combustion is uniform with respect to the lateral direction of the oxidant gas flow, but with respect to the longitudinal direction thereof, the generated heat in the upstream part is larger than the generated heat m the downstream part.
  • the components of the reforming unit 3 other than the reforming element 30 and the combustion element 40 are identical to those of the first embodiment.
  • the fuel reformer it is also preferable to construct the fuel reformer to be able to supply additional fuel to the hole 64.
  • the additional fuel is then supplied to the combustion space 44 from the second reformate gas supply space 48 as well as from the outlet 35 of the catalytic reforming passage 34 via the pair of the connection passages 36, the through- holes 51, and the reformate gas supply space 46.
  • both the reformate gas and the additional - 23 - between the reforming element 30 and the combustion element 40 communicates with a groove 53 which is formed on the partition plate 50 located on the opposite side of the combustion element 40 to the reforming
  • the groove 53 is formed on the partition plate 50 from the hole 65 in the lateral direction towards the center.
  • Another groove 54 communicating with the groove 53 is formed on the partition plate 50 in the
  • the intervals between the communication holes 55 are set to be smaller in the upstream part of the combustion space 44 with respect to the flow of oxidant gas and to increase steadily downstream.
  • the reformate gas supply amount is larger in the upstream part of the combustion space 44 such that the generation amount of combustion heat is smaller in this region
  • This region corresponds to the downstream part of the catalytic reforming passage 34 of the reforming element 30.
  • the reforming reaction in the catalytic reforming passage 34 is further promoted in the downstream part, which is preferred in view of accomplishing the reforming reaction of fuel vapor into hydrogen rich gas.
  • the other components of the reforming unit 3 are identical to those of the second embodiment. As shown in FIG. 12, the outer shape of the fuel reformer is identical to that of the first embodiment. - 24 -
  • the reformate gas supply to the combustion space 44 of the combustion element 40 is performed not only horizontally from the both sides of the combustion space 44 but also vertically from the communication holes 55 located on the opposite side of the combustion space 44 to the reforming element 30.
  • the distribution of reformate gas m the combustion space 44 in the lateral direction is thereby made more uniform than that of the second embodiment
  • the pair of connection passages 36, the pair of reformate gas supply spaces 46, the communication holes 47A, the second reformate gas supply space 48, the communication holes 48A, the through-holes 51, the grooves 53 and 54, the communication holes 55, and the holes 64 and 65 constitute the reformate gas supply passage m the claims.
  • the through -holes 51 are disposed at regular intervals in the partition plate 50, but the intervals and/or diameters of the through-holes 51 may be varied according to a distance from the oxidant gas inlet 42 in the oxidant gas flow direction,
  • this invention increases heat transfer efficiency from the combustion element to the fuel reforming element and enables control of temperature distribution in the fuel reforming element. Hence, a favorable effect is anticipated when this invention is applied to the fuel reformer for a fuel cell vehicle, which is subjected to wide temperature variation.

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Abstract

A fuel reformer which reforms hydrocarbon fuel into a hydrogen rich reformate gas comprises a combustion space (44) and a catalytic reforming passage (34) which are disposed in parallel and adjacent via a partition plate (50). The catalytic reforming passage (34) reforms hydrocarbon fuel into a hydrogen rich reformate gas through a catalytic reaction performed under combustion heat transmitted from the combustion space (44). A hydrogen permeable membrane(25) extracts hydrogen from the reformate gas into a hydrogen gas collecting space (12) while supplying the reformate gas after the separation of hydrogen to the combustion space (44), thereby realizing a high heat transfer efficiency from the combustion space (44) to the catalytic reforming passage (34) as well as a favorable temperature distribution in the catalytic reforming passage (34).

Description

DESCRIPTION FUEL REFORMER
FIELD OF THE INVENTION
This invention relates to a fuel reformer for generating hydrogen gas to be supplied for a fuel cell power plant, and more specifically, to a heating structure
of a reforming element.
BACKGROUND OF THE INVENTION
JP2002-295811A published by Japan Patent Office m 2002 proposes a multi-stage combustion device which supplies fuel to a lean burn mixer in a
multi-stage fashion along a direction of a fuel mixture gas flow in order to generate a high-temperature gas while suppressing generation of nitrogen oxides (NOx) and unburned fuel, and supplies the generated high-temperature gas to a heating object such as a heat exchanger disposed downstream of the multi-stage
combustion device.
SUMMARY OF THE INVENTION
In this prior art device, since the heating object is disposed downstream
of the combustion device, the temperature of the high-temperature gas may decrease before the gas reaches the heating object. Further, a great temperature difference occurs between Hie high-temperature gas inlet and the high-temperature gas outlet formed in the heating object, and hence a temperature deviation is apt to occur m the heating object.
For example, when the heating object is a fuel reforming element which catalytically reforms hydrocarbon fuel into hydrogen rich reformate gas, it is difficult to obtain favorable transfer efficiency between the combustion device ard the fuel reforming element. It is also difficult to control temperature distribution in the fuel reforming element.
It is therefore an object of this invention to increase the heat transfer efficiency from a combustion element to a fuel reforming element, as well as to enable temperature distribution control in the fuel reforming element.
In order to achieve the above object, this invention provides a fuel reformer which reforms hydrocarbon material into hydrogen gas, comprising a combustion space which generates a combustion heat by burning a fuel in an oxidant gas supplied from outside, and a catalytic reforming passage comprising a reforming catalyst which reforms the hydrocarbon material into a reformate gas containing hydrogen. The catalyst is activated by being heated by the combustion heat generated by the combustion space, and the catalytic reforming passage is disposed in parallel with the combustion space.
The fuel reformer further comprises a hydrogen permeable membrane which faces the catalytic reforming passage and extracts hydrogen in the reformate gas, a hydrogen collecting space which collects the hydrogen extracted by the hydrogen permeable membrane, and a reformate gas supply passage which supplies the combustion space with the reformate gas from which the hydrogen has been extracted.
The details as well as other features and advantages of this invention are
set forth in the remainder of the specification and are shown in the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view including a partial cutaway view of a fuel
reformer according to this invention.
FIG. 2 is a perspective view of the fuel reformer in a state where various
outer pipings have been removed.
FIG. 3 is a cross -sectional view of the fuel reformer taken along a line
III-III in FIG. 2
FIG. 4 is a cross -sectional view of the fuel reformer taken along a line
IV-IV in FIG. 2.
FIG. 5 is a plan view of a combustion element according to this invention.
FIG. 6 is a plan view of a reforming element according to this invention.
FIG. 7 is a plan view of a hydrogen gas permeable element according to
this invention.
FIG 8 is a plan view of a hydrogen gas collecting element according to
this invention.
FIG. 9 is similar to FIG. 5, but shows a variation of the combustion
element.
FIG. 10 is a plan view of a reforming element provided in a fuel reformer accordmg to a second embodiment of this invention.
FIGs. 1 IA and HB are a plan view of a combustion element according to the second embodiment of this invention and a front view of a side wall provided in the combustion element.
FIG. 12 is similar to FIG. 2, but shows a third embodiment of this invention
FIG. 13 is a cross -sectional view of the fuel reformer according to the
third embodiment of this invention taken along a line XIII-XIII in FIG. 12.
FIGs. 14A and 14B are a plan view of a combustion element provided in the fuel reformer according to the third embodiment of this invention and a front view of a side wall provided in the combustion element.
FIG. 15 is a plan view of a reforming element provided m the fuel reformer according to the third embodiment
FIG 16 is a plan view of a partition plate provided in the. fuel reformer according to the third embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 2 of the drawings, a fuel reformer comprises a stack of plural fuel reforming units 3 stacked between a lower end plate 2 and an upper end plate 4 and secured together by stack bolts in the direction of stacking.
The fuel reformer comprises plural hydrogen gas outlets 13 and plural oxidant gas inlets 42 on its lateral surfaces and fuel passages 62 on its top surface. The hydrogen gas outlets 13 are configured such that they can open and close.
Referπng to FIG. 1, a hydrogen rich gas passage 7 is, connected to the hydrogen gas outlets 13, an oxidant gas supply passage 5 is connected to the oxidant gas inlets 42, and a fuel supply passage 6 is connected to the fuel passages 62.
The fuel supply passage 6 provides the fuel passages 62 with a mixture of water and hydrocarbon material, e.g., gasoline or methanol, as fuel from outside.
Referπng to FIG. 3, the fuel reforming unit 3 comprises a plate-shaped hydrogen gas collecting element 10 which collects hydrogen, a plate-shaped hydrogen permeable element 20 which extracts hydrogen from a reformate gas, a plate-shaped reforming element 30 which reforms a mixture of the fuel and steam mto the reformate gas, and a plate-shaped combustion element 40 which heats the reforming element 30.
The hydrogen permeable element 20, the reforming element 30 and the combustion element 40 are stacked on both sides of the hydrogen gas collecting element 10 With respect to the fuel reforming unit 3 located in the uppermost
or lowermost position of the fuel reformer, they are stacked only on one side of the hydrogen gas collecting element 10, and the lower end plate 2 or the upper end plate 4 is stacked on the other side of the hydrogen gas collecting element
10.
The intermediate fuel reforming unit 3 may also be constructed in the same way as the uppermost or lowermost fuel reforming unit 3.
The combustion element 40 burns a combustible gas with oxygen in the air and heats the reforming element 30 by combustion heat. The combustion element 40 composes a plate 41 and partition plates 50 disposed on the both sides thereof.
Referring to FIG. 5, a combustion space 44 is formed in the central part of the plate 41, and an oxidant gas inlet 42 and a combustion gas outlet 43 are formed on the respective ends of the combustion space 44. The plate 41 is substantially divided into two pieces by the combustion space 44, the oxidant gas inlet 42 and the combustion gas outlet 43. Accordingly, the plate 41 may be constructed by manufacturing two pieces, each of which corresponds to the upper portion of the plate 41 in the figure, and disposing one of the two pieces upside down so as to face the other of the two pieces.
The oxidant gas inlet 42 and the combustion gas outlet 43 need not necessarily penetrate the plate 41 and may be formed in the shape of a groove m the plate 41.
A partition plate 50 is stacked on both sides of the plate 41 and the space constituted by the combustion space 44, the oxidant gas inlet 42 and the combustion gas outlet 43 is delimited by these partition plates 50 with respect to the stacking direction of the elements 10-40.
A pair of purge gas passages 61 penetrates the plate 41 and the partition plates 50 on the two sides of the oxidant gas inlet 42. Similarly, a pair of fuel passages 62 penetrates the plate 41 and the partition plates 50 on the two sides of the combustion gas outlet 43.
A porous body 45 which supports an oxidation catalyst is accommodated in the combustion space 44 and sandwiched between the partition plates 50. The end faces of the porous body 45 respectively face the oxidant gas mlet 42 and the combustion gas outlet 43.
A pair of reformate gas supply spaces 46 is formed on the two sides of the porous body 45. Each of the reformate gas supply spaces 46 is delimited by the plate 41, the porous body 45 and the partition plates 50. A part of the reformate gas generated in the reforming element 30 is supplied to the reformate gas supply spaces 46 via through-holes 51 formed in the partition plates 50.
The oxidation catalyst may be supported on the surface of the partition
plates 50 facing the porous body 45 instead of the porous body 45. In this case, the catalyst support area of the partition plates 50 may be increased by
surface treatment which adjusts undulations or asperity of the surface on the partition plates 50.
The porous body 45 comprises a central region porous body 45A disposed in a central region and linearly connecting the oxidant gas mlet 42 and the combustion gas outlet 43. The oxidation catalyst is supported, on the walls between the pores of the porous body 45A.
In boundary regions located on the two sides of the central region, the porous body 45 comprises boundary region porous bodies 45B which have smaller pore diameters and a higher density than the central region porous
body 45A.
According to the above arrangement, the central region porous body 45A has a smaller flow resistance than the boundary region porous bodies 45B, and hence the porous body 45 forms an oxidant gas flow passage which extends from the oxidant gas inlet 42 toward the combustion gas outlet 43.
The porous bodies 45B in the boundary regions function to distribute the reformate gas in the reformate gas supply spaces 46 to the entire central region porous body 45A uniformly. The oxidant gas herein denotes air which contains oxygen.
In the combustion element 40, therefore , the air supplied from the oxidant gas supply passage 5 is led to the central region porous body 45A via the oxidant gas inlet 42, and the reformate gas in the pair of reformate gas supply spaces 46 is transmitted through the boundary region porous bodies 45B towards the central region porous body 45A.
The combustion element 40 burns combustible components such as hydrogen (H2), carbon monoxide (CO) and methane (CH4) contained in the reformate gas that has reached the central region porous body 45A together with oxygen m the air Since the reformate gas is supplied uniformly throughout the entire central region porous body 45A as described above, this combustion also occurs uniformly in the entire central region porous body 45A. The combustion heat generated by combustion of the reformate gas in the central region porous body 45A is transferred to the reforming element 30 adjacent to the central region porous body 45A via the partition plate 50.
The flow rate of the oxidant gas supplied to the oxidant gas inlet 42
should be adjusted such that the excess air factor of the mixture of the oxidant gas and the reformate gas in the central region porous body 45A is greater than unity, or in other words the mixture is in a lean state. The combustion temperature of the reformate gas should be kept lower than the heat resisting limit of the reforming catalyst provided in the reforming element 30, but higher than a catalytic reaction minimum temperature of the reforming catalyst which is determined from the reaction speed of the reforming catalyst. This is accomplished by settmg the density or thickness of the boundary region porous body 45b appropriately, or setting the operation pressure of the combustion element 40 appropriately, or setting the operation pressure of the reforming element 30 appropriately.
It is also possible to share the combustion element 40 between two adjacent fuel reforming units 3.
Referring to FIG. 6, the reforming element 30 comprises a plate 31 which is penetrated by the purge gas passages 61 and the fuel passages 62 in the same positions as the plate 41 One surface of the plate 31 is m contact with the partition plate 50 and the other surface of the plate 31 is in contact with the hydrogen permeable element 20.
In the reforming element 30, a plurality of fuel supply holes 32 which penetrate the plate 31, a fuel vapor passage 33 in the form of. parallel slits formed in the plate 31 so as to be connected with the fuel supply holes 32, a catalytic reforming passage 34 in the form of parallel slits formed in the plate 31 as a downstream extension of the fuel vapor passage 33, an outlet 35 of the catalytic reforming passage 34, and a pair of connection passages 36 in the form of a pair of slits formed m the plate 31 and connected with the outlet 35 are provided.
The fuel supply holes 32 supply a mixture of water and hydrocarbon material to the fuel vapor passage 33. The fuel vapor passage 33 vaporizes the mixture to generate fuel vapor The catalytic reforming passage 34 performs steam reforming of the fuel vapor that is supplied from the fuel vapor passage 33 and generates the reformate gas. The pair of connection passages 36 are disposed on the two sides of the catalytic reforming passage 34 in positions corresponding to the pair of reformate gas supply spaces 46 in the combustion element 40. The pair of connection passages 36 supply the reformate gas that has reached the outlet 35 to the pair of reformate gas supply spaces 46 via the through-holes 51 formed in the partition plates 50.
As shown in FIG. 3, one side of the parallel slits forming the fuel vapor
passage 33 and the catalytic reforming passage 34 is closed by the partition plate 50. The other side of the parallel slits is closed by a surface of the hydrogen permeable element 20. The fuel vapor passage 33 is disposed so as to overlap the downstream part of the central region porous body 45A. The mixture of water and hydrocarbon material flowing in the fuel vapor passage 33 is vaporized by the heat transferred from the combustion element 40 via the partition plate 50. The fuel vapor generated in the fuel vapor passage 33 is supplied to the catalytic reforming passage 34 located downstream.
The catalytic reforming passage 34 is disposed in a position overlapping the upstream part of the central region porous body 45A of the combustion element 40.
A reforming catalyst is supported on the surface of the slit walls and the partition plate 50 facing the slits. The reforming catalyst is a known steam reforming catalyst which reforms a mixture of water and hydrocarbon material in the form of vapor.
The vapor of the mixture that flows out from the fuel vapor passage 33 undergoes steam reforming while passing through the slits of the catalytic reforming passage 34 and is reformed into the reformate gas.
Hydrogen contained in the reformate gas generated in the catalytic reforming passage 34 is extracted into the hydrogen gas collecting element 10 through the hydrogen permeable element 20 which is disposed adjacent to the reforming element 30. The residual components of the reformate gas flows out from the outlet 35 of the catalytic reforming passage 34 into the pair of the connection passages 36, and are then supplied to the pair of reformate gas supply spaces
46 of the combustion element 40 via the through-holes 51 formed in the partition plate 50.
Steam reforming is an endothermal reaction consuming the combustion heat transmitted from the combustion element 40 via the partition plate 50. The reforming reaction that the catalytic reforming passage 34 performs should however not limited to steam reforming. It can also perform autothermal reforming (ATR) which is a combination of a preferential oxidation reaction of fuel vapor and a steam reforming reaction of the same. Under ATR, heat generated by the preferential oxidation reaction which is an exothermal reaction is consumed in the steam reforming reaction which is a endothermal reaction, thereby enabling reforming of fuel vapor without providing heat from outside.
One side of the slits constituting the pair of connection passages 36 is closed by a surface of the hydrogen permeable element 20. The other side of the slits communicates with the through-holes 51 formed in the partition plate 50. In order to set the operation pressure of the combustion element 40 to be lower than that of the reforming element 30, the reformate gas is supplied from the outlet 35 to the central region porous body 45A via the connection passages 36, through- holes 51, reformate gas supply spaces 46 and boundary region porous bodies 45B.
The reformate gas supplied to the central region porous body 45A joins
the flow of oxidant gas, which is formed longitudinally in the central region porous body 45A, through the boundary region porous body 45B. Accordingly, combustion of the reformate gas in the central region porous body 45A is also uniform along the oxidant gas flow. Owing to this construction, the temperature distribution in the central region porous body 45A is also uniform, and the temperature rises uniformly over the entire region of the central region porous
body 45A without causing an extreme temperature increase in a specific part of the central region porous body 45A. As a result, the temperature of the reforming element 30 rises efficiently and the catalytic reaction speed in the reforming element 30 is maintained at a high level. Since there is no extreme temperature increase in a specific part of the central region porous body 45A, the peak combustion temperature of the central region porous body 45A is suppressed which is preferable in view of the heat resistance characteristics of the reforming catalyst. Further, the emission of nitrogen oxides (NOx) is also suppressed.
Referring to FIG. 7, the hydrogen permeable element 20 comprises a plate 21 which is penetrated by the purge gas passages 61 and the fuel passages 62 in the same positions as the plate 41. Further, a fuel manifold 63 and a hole 23 are formed in the plate 21 to pass therethrough. The hole 23 is formed m a position which overlaps the catalytic reforming passage 34 of the reforming element 30. Referring again to FIG 3, a supporting body 24 of a hydrogen permeable membrane 25 is fitted m the hole 23. The hydrogen permeable membrane 25 is supported on a surface of the supporting body 24 so as to face the catalytic reforming passage 34.
The hydrogen permeable membrane 25 comprises a palladium foil coated or the surface of the supporting body 24. The palladium foil is formed by applying palladium slurry which is a mixture of palladium (Pd) , water, and a binder, to the surface of the supporting body 24 and drying it. A typical application thickness of the palladium slurry is 1 to 10 micrometers (μm).
The operation pressure in each passage of the reforming element 30 such as the catalytic reforming passage 34 is set to be higher than passages in the other elements. The supporting structure of the supporting body 24 is determined such that a surface pressure exerted on the hydrogen permeable membrane 25 can be supported by the plate 21 via the supporting body 24. The supporting body 24 is constituted by a hydrogen permeable material.
Referring to FIG 8, the hydrogen gas collecting element 10 comprises a plate 11 which is penetrated by the purge gas passages 61 , the fuel manifold 63, and one of the fuel passages 62 in the same positions as the plate 21. Further, in this plate 11, a boundary between the one of the fuel passages 62 and the fuel manifold 63 is removed so that they communicate with each other
A cut-out is further formed m the plate 11 to function as a hydrogen gas collecting space 12. The hydrogen gas collecting space 12 covers a region facmg the supporting body 24 of the hydrogen permeable element 20, communicates with the one of the purge gas passage 61, and has the hydrogen gas outlet 13 opening on the side face of the fuel reforming unit 3. The hydrogen gas outlet
13 communicates with the hydrogen rich gas passage 7 shown in FIG 1.
Referring again to FIG. 3, hydrogen contained in the reformate gas generated in the catalytic reforming passage 34 of the reforming element 30 flows into the hydrogen gas collecting space 12 of the hydrogen gas collecting element 10 by passing through the hydrogen permeable membrane 25 of the hydrogen permeable element 20, and is discharged into the hydrogen rich gas passage 7 from the hydrogen gas outlet 13.
Referring to FIG. 4, the fuel supplied to the fuel passage 62 which is a
mixture of water and hydrocarbon material flows into the fuel manifold 63 of the hydrogen gas collecting element 10 and supplied to the fuel vapor passage 33 of the reforming element 30 via the fuel supply holes 32 of the reforming element 30 opening onto the fuel manifold 63.
In this fuel reformer, the warm-up operation during operation start-up is performed in the following manner.
First, air is supplied from the oxidant gas inlet 42 while the hydrogen gas outlets 13 are closed, and a combustible gas such as vaporized hydrocarbon material is supplied to the oxidant gas supply passage 5 and /or the fuel supply
passage 6.
The combustible gas supplied to the oxidant gas supply passage 5 is distributed to the respective oxidant gas inlets 42 of the fuel reforming units 3 communicating with the oxidant gas supply passage 5. In each fuel reforming
unit 3, the combustible gas flows into the central region porous body 45A disposed in the combustion space 44 of the combustion element 40. The combustible gas supplied to the fuel supply passage 6 is distributed to the respective fuel manifolds 63 of the fuel reforming units 3 via the fuel passage 62. In each fuel reforming unit 3, the combustible gas flows into the reformate gas supply spaces 46 from the fuel manifold 63 via the fuel supply holes 32, the fuel vapor passage 33, the catalytic reforming passage 34, the outlet35 and the pair of connection passages 36, and is transmitted to the central region porous body 45A by passing through the boundary region porous bodies 46B.
The combustible gas which is supplied from the oxidant gas inlet 42 to the central region porous body 45A undergoes catalytic combustion in the upstream part of the central region porous body 45A and heats the same.
In contrast, the combustible gas which is supplied from the reformate gas supply spaces 46 to the central region porous body 45A through the boundary region porous bodies 46B is distributed evenly over the entire .length of the central region porous body 45A and burns in the entire region of the central region porous body 45A, thereby heating the entire region of the central region porous body 45A. As a result of heat transfer from the entire region of the central region porous body 45A to the adjacent reforming element 30, the reforming element 30 is also heated evenly over the entire region. The combustible gas generated by catalytic combustion is then discharged from the combustion gas outlet 43 as post-reaction gas under the oxidation catalyst.
As the fuel reformer warms up, the supply of combustible gas to the oxidant gas supply passage 5 and/or the fuel supply passage 6 is terminated.
Next, air is supplied to the oxidant gas supply passage 5, and a liquid fuel constituted by a mixture of hydrocarbon material and water is supplied to the fuel supply passages 6 The fuel is vaporized in the fuel vapor passage 33 and reformed into the reformate gas by passing through the catalytic reforming passage 34. The reformate gas thus generated is led to the connection passages 36 via the outlet 35 of the reforming passage 34, transmitted to the central region porous body 45A via the through -holes 51, the pair of reformate gas supply spaces 46, and the pair of the boundary region porous bodies 45B, and is burned in the entire region of the central region porous body 45A to warm up the entire reforming element 30.
When the temperatures of all the elements have reached a warm up completion temperature, the supply amount of the liquid fuel to the fuel supply passage 6 is increased and the hydrogen gas outlet 13 is opened while maintaining
the operation pressure of the reforming element 30.
Thereafter, hydrogen contained in the reformate gas that is generated in the catalytic reforming passage 34 passes through the hydrogen permeable membrane 25 of the hydrogen permeable element 20, and is then collected in the hydrogen gas collecting space 12 and discharged into the hydrogen rich gas passage 7 from the hydrogen gas outlet 13 as hydrogen rich gas . The hydrogen rich gas thus produced is supplied to a fuel cell stack or accumulated in a accumulation device
After separating hydrogen by the hydrogen permeable membrane 25, the residual reformate gas in the catalytic reforming passage 34 flows out from the outlet 35 to the pair of the connection passages 36, and is transmitted to the central region porous body 45A via the through-holes 51, the pair of reformate gas supply spaces 46, and the pair of boundary region porous bodies 45B. Having reached the central region porous body 45A, the residual reformate gas undergoes catalytic combustion. The combustion gas generated by the catalytic combustion is discharged from the combustion gas outlet 43 to the outside of the fuel reforming unit 3. It is preferable to cause the combustion gas discharged from the combustion gas outlet 43 to pass through a radiator in order to collect moisture and heat before being released mto the atmosphere.
In this fuel reformer, heat transfer from the combustion gas in the combustion element 40 to the reformate gas in the reforming element 30 is performed via the partition plate 50 in the form of heat transfer between parallel flows or reverse flows which are formed on the both sides of the partition plate 50. This type of heat transfer helps to maintain a high temperature in the entire region of the reforming element 30 and the reaction speed of the reforming catalyst is thereby maintained at a high level. Smce the combustion element 40 and the reforming element 30 are stacked together via the partition plate 50, the size of the fuel reformer can be reduced.
Referring to FIG. 9, it is also possible to vary the density or thickness of the boundary region porous bodies 45B between the upstream part and the downstream part with respect to the flow of oxidant gas. Herem, the thickness of the downstream part of the porous bodies 45B is set to be greater than the thickness of the upstream part of the same Alternatively, the density of the downstream part of the porous bodies 45B is set to be greater than the density of the upstream part of the same. According to this arrangement, the flow resistance through the upstream part of the porous body 45B is smaller than that through the downstream part of the same, and a greater amount of the reformate gas is provided in the upstream part of the porous body 45A than in the downstream part of the same. When the reformate gas is burned in this configuration, the temperature of the upstream part of the central region porous body 45A becomes higher than the temperature of the downstream part of the same.
In FIG. 9, the boundary region porous bodies 45B are arranged to have a steadily greater thickness towards the downstream. By varying the density or thickness of the boundary region porous bodies 45B according to the distance from the oxidant gas mlet 42, the temperature of any specific region with respect to the oxidant gas flow direction in the central region porous body 45A can be raised or lowered.
Generally speaking, it is necessary to supply a greater amount of reformate gas to a part of the central region porous body 45A located nearby the catalytic reforming passage 34 of the reforming element 30 in order to cause this part of the central region porous body 45A to generate more heat. It is therefore preferable to decrease the density or thickness of the boundary region porous bodies 45B at a part nearby the catalytic reforming passage 34 of the reforming element 30.
By controlling the temperature distribution m the central region porous body 45A as descnbed above, it is possible to control the temperature distribution in the reforming element 30.
If the temperature distribution in the reforming element 30 is thus controlled, it is not necessary to increase the air mixing ratio of the gas in the cornbustion space 44 in order to suppress the peak combustion temperature, and the peak combustion temperature can be suppressed under a small air supply amount. As a result, the heat radiation amount of a radiator which collects moisture in the combustion gas discharged from the combustion gas outlet 43 is small, and hence the radiator can be made small. Further, since the combustible components such as carbon monoxide (CO) and methane (CH4) of the reformate gas after separating hydrogen at the hydrogen permeable
membrane 25 are used for combustion m the combustion element 40, the energy of the hydrocarbon material is efficiently utilized.
Next, referring to FIG. 10 and FIGs. HA and HB, a second embodiment of this invention will be described
Referring to FIG. 10, the reforming element 30 according to this embodiment has shortened connection passages 36 so as to correspond to the catalytic reforming passage 34 of the adjacent reforming element 30. Accordingly, the region of the partition plate 50 where the through-holes 51 are formed is also decreased.
In the outlet 35, a hole 64 which penetrates the plates 11-31 constituting the reforming element 30, hydrogen permeable element 20, and hydrogen gas collecting element 10 is provided in order to supply the reformate gas in the outlet 35 to the combustion space 44 m the combustion element 40.
Referring to FIGs. 1 IA and HB, the width of the combustion space 44 in the combustion element 40 is great in the vicinity of the oxidant gas inlet 42 and gradually narrows towards the combustion gas outlet 43.
Instead of providing the porous body 45 in the combustion space 44, an oxidation catalyst is supported on the walls of the combustion space 44. In order to promote a better catalytic combustion reaction, however, it is possible to accommodate the porous body 45 in the combustion space 44 as in the case of the first embodiment.
In this embodiment, a pair of reformate gas supply spaces 46 is partitioned by thin side walls 47 on both sides of the upstream part of the combustion space 44. The reformate gas supply spaces 46 communicate with the connection passages 36 m the reforming element 30 via the through -holes 51 as in the case of the first embodiment.
Plural communication holes 47A are formed on the respective side walls
47 in order to supply the reformate gas in the reformate gas supply spaces 46 to the combustion space 44.
A second reformate gas supply space 48 is provided in the central region of the upstream part of the combustion space 44. The second reformate gas supply space 48 is formed by walls 49 similar to the side walls 47. The second reformate gas supply space 48 communicates with the hole 64 at the oxidant gas inlet 42. The walls 49 have communication holes 48A similar to the communication holes 47A. The two sides of the walls 49 in the stacking direction of the elements 10-40 are in contact with the partition plates 50 so as to partition the second reformate gas supply space 48 from the combustion space 44 By providing the second reformate gas supply space 48 in the central region of the upstream part of the combustion space 44, the reformate gas is supplied uniformly in the lateral direction, or in the vertical direction in FIG.
HA, in the combustion space 44. As a result, heat application to the catalytic reforming passage 34 in the adjacent reforming element 30 is made uniform.
Referring to FIG 1 IA, the intervals between the communication holes 47A and 48A are respectively set to decrease steadily upstream and increases steadily downstream with respect to the flow of oxidant gas in the combustion space 44. According to this arrangement, the reformate gas supply amount is larger in the upstream part, and hence more combustion heat is generated in the upstream part The upstream part corresponds to the downstream part of
the catalytic reforming passage 34 of the adjacent reforming element 30, and the reforming reaction in the catalytic reforming passage 34 is thereby enhanced further in the downstream part, which is preferred in view of accomplishing the reforming reaction of fuel vapor into hydrogen rich gas
To summarize the above, the heat generated by combustion is uniform with respect to the lateral direction of the oxidant gas flow, but with respect to the longitudinal direction thereof, the generated heat in the upstream part is larger than the generated heat m the downstream part.
The components of the reforming unit 3 other than the reforming element 30 and the combustion element 40 are identical to those of the first embodiment.
In this embodiment, it is also preferable to construct the fuel reformer to be able to supply additional fuel to the hole 64. The additional fuel is then supplied to the combustion space 44 from the second reformate gas supply space 48 as well as from the outlet 35 of the catalytic reforming passage 34 via the pair of the connection passages 36, the through- holes 51, and the reformate gas supply space 46.
In the combustion space 44, both the reformate gas and the additional - 23 - between the reforming element 30 and the combustion element 40, and communicates with a groove 53 which is formed on the partition plate 50 located on the opposite side of the combustion element 40 to the reforming
element 30.
Referring to FIG 16, the groove 53 is formed on the partition plate 50 from the hole 65 in the lateral direction towards the center. Another groove 54 communicating with the groove 53 is formed on the partition plate 50 in the
longitudinal direction. At the bottom of the groove 54, communication holes 55 which communicates with the combustion space 44 of the combustion element 40 are provided.
Referring to FIG. 14A, the intervals between the communication holes 55 are set to be smaller in the upstream part of the combustion space 44 with respect to the flow of oxidant gas and to increase steadily downstream.
According to this arrangement of the communication holes 55, the reformate gas supply amount is larger in the upstream part of the combustion space 44 such that the generation amount of combustion heat is smaller in this region This region corresponds to the downstream part of the catalytic reforming passage 34 of the reforming element 30. As a result, the reforming reaction in the catalytic reforming passage 34 is further promoted in the downstream part, which is preferred in view of accomplishing the reforming reaction of fuel vapor into hydrogen rich gas.
The other components of the reforming unit 3 are identical to those of the second embodiment. As shown in FIG. 12, the outer shape of the fuel reformer is identical to that of the first embodiment. - 24 -
According to this embodiment, the reformate gas supply to the combustion space 44 of the combustion element 40 is performed not only horizontally from the both sides of the combustion space 44 but also vertically from the communication holes 55 located on the opposite side of the combustion space 44 to the reforming element 30. The distribution of reformate gas m the combustion space 44 in the lateral direction is thereby made more uniform than that of the second embodiment
In the embodiments described above, the pair of connection passages 36, the pair of reformate gas supply spaces 46, the communication holes 47A, the second reformate gas supply space 48, the communication holes 48A, the through-holes 51, the grooves 53 and 54, the communication holes 55, and the holes 64 and 65 constitute the reformate gas supply passage m the claims.
The contents of Tokugan 2005-286870, with a filing date of September
30, 2005 in Japan, are hereby incorporated by reference.
Although the invention has been described above with reference to certain embodiments of the invention, the invention is not limited to the embodiments described above. Modifications and variations of the embodiments described above will occur to those skilled in the art, within the scope of the claims.
For example, the through -holes 51 are disposed at regular intervals in the partition plate 50, but the intervals and/or diameters of the through-holes 51 may be varied according to a distance from the oxidant gas inlet 42 in the oxidant gas flow direction,
INDUSTRIAL FIELD OF APPLICATION - 25 -
As descnbed above, this invention increases heat transfer efficiency from the combustion element to the fuel reforming element and enables control of temperature distribution in the fuel reforming element. Hence, a favorable effect is anticipated when this invention is applied to the fuel reformer for a fuel cell vehicle, which is subjected to wide temperature variation.
The embodiments of this invention in which an exclusive property or
privilege is claimed are defined as follows:

Claims

- 26 -CLAIMS
1. A fuel reformer which reforms hydrocarbon material into hydrogen gas, comprising. a combustion space (44) which generates a combustion heat by burning a fuel in an oxidant gas supplied from outside;
a catalytic reforming passage (34) comprising a reforming catalyst which reforms the hydrocarbon material into a reformate gas containing hydrogen,
the catalyst being activated by being heated by the combustion heat generated by the combustion space (44), the catalytic reforming passage (34) being disposed in parallel with the combustion space (44); a hydrogen permeable membrane (25) which faces the catalytic reforming passage (34) and extracts hydrogen in the reformate gas; a hydrogen collecting space (12) which collects the hydrogen extracted by the hydrogen permeable membrane (25); and a reformate gas supply passage (36, 46, 47A, 48, 48A, 51, 53, 54, 55, 64, 65) which supplies the reformate gas from which the hydrogen has been extracted to the combustion space (44) .
2. The fuel reformer as defined in Claim 1, further comprising a fuel vapor passage (33) which generates a fuel vapor which is a mixture of the hydrocarbon material and water in a vaporized form, and supplies the fuel vapor to the catalytic reforming passage (34). - 27 -
3. The fuel reformer as defined in Claim 2, wherein the oxidant gas m the combustion space (44) and the fuel vapor in the catalytic reforming passage (34) have opposite flow directions to one another.
4. The fuel reformer as defined in Claim 1, further comprising a passage (5, 6) which can supply the fuel to the combustion space (44) from outside
5. The fuel reformer as defined in Claim 4, wherein the combustion space (44) composes an inlet (42) which introduces the oxidant gas and an outlet (43) which discharges a combustion gas, and the reformate gas supply passage (36, 46, 47A, 48, 48A, 51, 53, 54, 55, 64, 65) comprises openings (47A, 48A, 55) which respectively supply the reformate gas to plural regions of a flow of oxidant gas m the combustion space (44).
6. The fuel reformer as defined m Claim 5, wherem the openings (47A, 48A, 55) comprise horizontal openings (47A) which face the flow of oxidant gas in a lateral direction from outside of the flow.
7. The fuel reformer as defined in Claim 5, wherein the openings (47A, 48A, 55) comprise horizontal openings (48A) which face the flow of oxidant gas in a lateral direction from inside of the flow.
8. The fuel reformer as defined in Claim 6, wherein the openings (47A, 48A, 55) further comprise vertical openings (55) which face the flow of oxidant gas in a - 28 - lateral direction from an opposite side of the combustion space (44) to the catalytic reforming passage (34).
9. The fuel reformer as defined in Claim 5, wherein an upstream part of the combustion space (44) has a larger cross- sectional area than a downstream part thereof.
10. The fuel reformer as defined in Claim 9, wherein the openings facing an upstream portion of the oxidant gas flow are disposed at smaller intervals than the openings facing a downstream portion of the oxidant gas flow.
11. The fuel reformer as defined in Claim 4, wherein wall surfaces forming the combustion space (44) support an oxidation catalyst.
12. The fuel reformer as defined in Claim 4, wherein a porous body (45) is enclosed in the combustion space (44) .
13. The fuel reformer as defined m Claim 12, wherein the porous body (44) comprises a central region porous body (45A) supporting an oxidation catalyst and disposed in a central region of the combustion space (44), and a pair of boundary region porous bodies (45B) disposed on both sides of the central region porous body (45A) m the combustion space (44), wherein a flow of the oxidant gas is mainly formed through the central region porous body (45A) , and the pair of the boundary region porous bodies (45B) has a greater gas flow - 29 - resistance than the central region porous body (45A) .
14. The fuel reformer as defined in Claim 13, wherein the reformate gas supply
passage (36, 46, 47A, 48, 48A, 51, 53, 54, 55, 64, 65) comprises a pair of reformate gas supply spaces (46) respectively facing the pair of boundary region porous bodies (45B) from the opposite direction to the central region porous body (45A) m order to supply the reformate gas to the first porous body (45A) through the pair of boundary region porous bodies (45B) .
15. The fuel reformer as defined in Claim 14, wherein the reformate gas supply passage (36, 46, 47A, 48, 48A, 51, 53, 54, 55, 64, 65) further comprises a pair of connection passages (36) disposed in parallel with the pair of the reformate gas supply spaces (46) and connected to an outlet (35) υf the catalytic reforming passage (34), wherein each of the connection passages (36) communicates with a corresponding reformate gas supply space (46) via through- holes (51).
16. The fuel reformer as defined m Claim 15, wherein a gas flow resistance in an upstream part of the boundary region porous bodies (45B) is set to be greater than a gas flow resistance in a downstream part of the boundary region porous bodies (45B) with respect to the flow of the oxidant gas in the central region porous body (45A) .
17 The fuel reformer as defined in any one of Claim 1 through Claim 16, wherein an operation pressure in the combustion space (44) is set to be lower - 30 - than an operation pressure in the catalytic reforming passage (34).
18. The fuel reformer as defined in any one of Claim 1 through Claim 16, further comprising a stack of fuel reforming units (3), each of which comprises the combustion space (44), the catalytic reforming passage (34), the hydrogen permeable membrane (25), and the hydrogen gas collecting space (12).
19. The fuel reformer as defined in Claim 18, wherein each of the combustion space (44), the catalytic reforming passage (34), the hydrogen permeable membrane
(25), and the hydrogen gas collecting space (12) is formed in a plate-shaped
element (40, 30, 20, 10).
PCT/JP2006/316803 2005-09-30 2006-08-22 Fuel reformer WO2007043247A1 (en)

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CN112960647B (en) * 2021-03-16 2022-10-25 哈尔滨工业大学 Reforming hydrogen production and catalytic combustion integrated device with variable catalyst particle arrangement

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