The invention provides a device for hydrogen production comprising a reaction chamber containing one or more catalysts disposed therein, a fuel gas inlet, and a hydrogen-rich gas outlet; a first reactant gas chamber having a first reactant gas inlet for conveying a first reactant gas and being in fluid communication with an exhaust; and a second reactant gas chamber having a second reactant gas inlet for conveying a second reactant gas; wherein the reaction chamber and the first reactant gas chamber share a first wall therebetween, the first wall comprising a thermally conductive substrate having a reaction chamber face and a first reactant gas chamber face, wherein the first reactant gas chamber face of the first wall has a reaction surface which is coated with a reactant gas decomposition catalyst; wherein the first reactant gas chamber further comprises a second wall opposite the first wall defining a volume therebetween, the second wall being shared between the first reactant gas chamber and the second reactant gas chamber; wherein the second wall comprises one or more apertures disposed in an aperture-containing area along a length and width of the second wall such that the second reactant gas chamber and the first reactant gas chamber are in fluid communication with one another, wherein the aperture-containing area has a first section, a second section, and a third section, the first section being a third of the aperture-containing area distal to the fuel gas inlet and the third section being a third of the aperture-containing area proximal to the fuel gas inlet, the second section being a third of the aperture containing area of the second wall between the first section and the third section, wherein the total cross-sectional area of the one or more apertures disposed in the first section is less than the total cross-sectional area of the one or more apertures disposed in the third section, wherein the total cross-sectional area of the one or more apertures disposed in the second section is greater than the total cross-sectional area of the one or more apertures disposed in the first section and less than the total cross-sectional area of the one or more apertures disposed in the third section, wherein the cross-sectional area of the second reactant gas chamber is greater than the total cross-sectional area of the one or more apertures.
B01J 4/00 - Feed devicesFeed or outlet control devices
B01J 15/00 - Chemical processes in general for reacting gaseous media with non-particulate solids, e.g. sheet materialApparatus specially adapted therefor
B01J 19/24 - Stationary reactors without moving elements inside
B01J 8/02 - Chemical or physical processes in general, conducted in the presence of fluids and solid particlesApparatus for such processes with stationary particles, e.g. in fixed beds
B01J 19/00 - Chemical, physical or physico-chemical processes in generalTheir relevant apparatus
The invention provides a device for producing hydrogen gas and a process therefor. It also provides a system for generating electrical energy from hydrogen gas. More particularly, the invention provides a device for producing hydrogen comprising an ammonia cracker having one or more raw cracked gas outlets in fluid communication with a common raw cracked gas flow conduit, one or more gas separators in fluid communication with the ammonia cracker via the common raw cracked gas flow conduit, and in fluid communication with a common partially purified cracked gas flow conduit; one or more filter assemblies, each having a first container having one or more walls, one or more partially purified cracked gas inlets and one or more purified cracked gas outlets, wherein the one or more partially purified cracked gas inlets are in fluid communication with the one or more gas separators via the common partially purified cracked gas flow conduit, the first container containing a single mass of adsorbent comprising silica gel, wherein the one or more partially purified cracked gas inlets and one or more purified cracked gas outlets are arranged such that a partially purified cracked gas flows through the single mass of adsorbent in use.
B01D 53/04 - Separation of gases or vapoursRecovering vapours of volatile solvents from gasesChemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases or aerosols by adsorption, e.g. preparative gas chromatography with stationary adsorbents
C01B 3/04 - Production of hydrogen or of gaseous mixtures containing hydrogen by decomposition of inorganic compounds, e.g. ammonia
C01B 3/50 - Separation of hydrogen or hydrogen containing gases from gaseous mixtures, e.g. purification
C01B 3/56 - Separation of hydrogen or hydrogen containing gases from gaseous mixtures, e.g. purification by contacting with solidsRegeneration of used solids
H01M 8/0662 - Treatment of gaseous reactants or gaseous residues, e.g. cleaning
A hydrogen production device for producing a hydrogen rich gas from ammonia comprising a first chamber comprising an inner wall and an outer wall defining an internal volume, wherein the first chamber contains an ammonia decomposition catalyst disposed between the inner wall and the outer wall, the first chamber having one or more ammonia gas inlets and one or more raw cracked gas outlets, wherein said one or more ammonia gas inlets and one or more raw cracked gas outlets are arranged such that the ammonia flows through the first chamber from the one or more ammonia gas inlets to the one or more raw cracked gas outlets and contacts the ammonia decomposition catalyst; and one or more heat sources for heating the ammonia decomposition catalyst; wherein the first chamber has one or more fins, said one or more fins disposed between the inner wall and the outer wall of the first chamber, wherein the first chamber has an internal surface area, wherein the internal volume is between 10 ml and 100 litres and wherein the ratio of the internal surface area in mm2 to the internal volume in mm3 is between approximately 1:2 and 1:6.
B01J 8/02 - Chemical or physical processes in general, conducted in the presence of fluids and solid particlesApparatus for such processes with stationary particles, e.g. in fixed beds
C01B 3/04 - Production of hydrogen or of gaseous mixtures containing hydrogen by decomposition of inorganic compounds, e.g. ammonia
4.
ALKALINE FUEL CELL STACK WITH RECIRCULATING ELECTROLYTE SYSTEM
An electrolyte chamber assembly (10) for an electrochemical cell 3, the assembly (10) comprising a forward electrolyte flow plate (8) and a rearward electrolyte flow plate 6 that are abutted with each other to form the assembly (10). The inward facing side of each flow plate (6, 8) is provided with an electrolyte inflow channel (15), an electrolyte outflow collector (34) and an electrolyte chamber aperture (14) that are mirror images of the electrolyte inflow channel (15), the electrolyte outflow collector (34) and the electrolyte chamber aperture (14) on the other flow plate (6, 8). The two electrolyte inflow channels (15) create together an electrolyte inflow pipe (16), the two electrolyte outflow collectors (34) create together an electrolyte outflow pipe 32 and the two electrolyte chamber apertures (14) create together an electrolyte chamber (19).
An air supply arrangement for air flow plates (5) of electrochemical cells (3) within a fuel cell stack (1). Each air flow plate (5) has a gas exchange volume (19). A common air supply pipe (11) supplies air to the air flow plates (5). There is an air supply region (35) and a separate air distribution conduit (15) for each air flow plate (5). Each air distribution conduit (15) provides an air header volume (43) and has an inlet and an outlet. The common air supply pipe (11) is connected to each air supply region (35) and each air supply region (35) is connected to the inlet of each air distribution conduit (15). The outlet of each air distribution conduit (15) is connected to a gas exchange volume (19) and each gas exchange volume (19) extends across the width of the associated air flow plate (5).
H01M 8/0265 - CollectorsSeparators, e.g. bipolar separatorsInterconnectors characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant the reactant or coolant channels having varying cross sections
H01M 8/0606 - Combination of fuel cells with means for production of reactants or for treatment of residues with means for production of gaseous reactants
An electrochemical cell (3) for use in a fuel cell stack (1) comprising a resilient electrical conduction member sub-assembly (10, 16) having a first flow plate (5, 9), a second flow plate (6, 8) and a bipolar plate (11, 22). A fluid chamber (17, 19) is created by the first flow plate (5, 9), the second flow plate (6, 8), the bipolar plate (11, 22) and an electrode (13, 18) and has an inflow duct (59, 63) and an outflow duct (61, 65). A resilient electrical conduction member (15, 20) is located within the fluid chamber (17, 19) so that in use, a fluid can flow between the inflow duct (59, 61) and the outflow duct (61, 65). The resilient electrical conduction member (15, 20) is in electrically conductive contact with the bipolar plate (11, 22) and with the electrode (13, 18) via a plurality of electrical contacts (51) and the resilient electrical conduction member (15, 20) is compressed between the bipolar plate (11, 22) and the electrode (13, 18).
B60L 53/57 - Charging stations without connection to power networks
H01M 4/86 - Inert electrodes with catalytic activity, e.g. for fuel cells
H01M 8/0228 - Composites in the form of layered or coated products
H01M 8/0258 - CollectorsSeparators, e.g. bipolar separatorsInterconnectors characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant
An electrochemical cell (3) for use in a fuel cell stack (1) comprising a resilient electrical conduction member sub-assembly (10, 16) having a first flow plate (5, 9), a second flow plate (6, 8) and a bipolar plate (11, 22). A fluid chamber (17, 19) is created by the first flow plate (5, 9), the second flow plate (6, 8), the bipolar plate (11, 22) and an electrode (13, 18) and has an inflow duct (59, 63) and an outflow duct (61, 65). A resilient electrical conduction member (15, 20) is located within the fluid chamber (17, 19) so that in use, a fluid can flow between the inflow duct (59, 61) and the outflow duct (61, 65). The resilient electrical conduction member (15, 20) is in electrically conductive contact with the bipolar plate (11, 22) and with the electrode (13, 18) via a plurality of electrical contacts (51) and the resilient electrical conduction member (15, 20) is compressed between the bipolar plate (11, 22) and the electrode (13, 18).
An electrolyte chamber assembly (10) for an electrochemical cell 3, the assembly (10) comprising a forward electrolyte flow plate (8) and a rearward electrolyte flow plate 6 that are abutted with each other to form the assembly (10). The inward facing side of each flow plate (6, 8) is provided with an electrolyte inflow channel (15), an electrolyte outflow collector (34) and an electrolyte chamber aperture (14) that are mirror images of the electrolyte inflow channel (15), the electrolyte outflow collector (34) and the electrolyte chamber aperture (14) on the other flow plate (6, 8). The two electrolyte inflow channels (15) create together an electrolyte inflow pipe (16), the two electrolyte outflow collectors (34) create together an electrolyte outflow pipe 32 and the two electrolyte chamber apertures (14) create together an electrolyte chamber (19).
An air supply arrangement for air flow plates (5) of electrochemical cells (3) within a fuel cell stack (1). Each air flow plate (5) has a gas exchange volume (19). A common air supply pipe (11) supplies air to the air flow plates (5). There is an air supply region (35) and a separate air distribution conduit (15) for each air flow plate (5). Each air distribution conduit (15) provides an air header volume (43) and has an inlet and an outlet. The common air supply pipe (11) is connected to each air supply region (35) and each air supply region (35) is connected to the inlet of each air distribution conduit (15). The outlet of each air distribution conduit (15) is connected to a gas exchange volume (19) and each gas exchange volume (19) extends across the width of the associated air flow plate (5).
H01M 8/2484 - Details of groupings of fuel cells characterised by external manifolds
H01M 8/0202 - CollectorsSeparators, e.g. bipolar separatorsInterconnectors
H01M 8/0606 - Combination of fuel cells with means for production of reactants or for treatment of residues with means for production of gaseous reactants
09 - Scientific and electric apparatus and instruments
11 - Environmental control apparatus
17 - Rubber and plastic; packing and insulating materials
35 - Advertising and business services
42 - Scientific, technological and industrial services, research and design
Goods & Services
Polymer membranes for use in fuel cells; polymer membranes
for use in hydrogen fuel cells; anion exchange membranes for
use in fuel cell technology; anion exchange membranes for
use in alkaline electrolysis; anion exchange membranes for
use in alkaline water electrolysis; anion exchange membranes
for reversible water electrolysis; anion exchange membranes
for use in fuel synthesis; anion exchange membranes for use
in electrodialysis; anion exchange membranes for use in
reverse electrodialysis; anion exchange membranes for use in
acid remediation; anion exchange membranes for use in
alkaline batteries; anion exchange membranes for use in salt
water batteries; anion exchange membranes for use in flow
batteries; anion exchange membranes for use in redox flow
batteries. Anion exchange membranes for use in desalination. Polymeric ion exchange membranes in roll, film or sheet
form; anion exchange membranes in roll, film or sheet form;
polymeric ion exchange membranes and polymeric membranes in
roll or sheet form. Development and promotional campaigns in relation to anion
exchange membrane technology; development and promotional
campaigns in relation to polymeric ion exchange membranes. Scientific research and development; consultancy relating to
anion exchange membrane technology; consultancy relating to
polymeric ion exchange membranes.
12.
REACTANT GAS PLATES, ELECTROCHEMICAL CELLS, CELL STACKS AND POWER SUPPLY SYSTEMS
A reactant gas plate (200, 300) for conveying a reactant gas in an electrochemical cell (100), comprises a reactant gas volume (210, 310) having an inflow array (224, 324) of spaced- apart inflow apertures (222, 322), to allow reactant gas to flow into the reactant gas volume (210, 310); and an outflow array (234, 334) of spaced-apart outflow apertures (232, 332), to allow reactant gas to flow out of the reactant gas volume (210, 310), the outflow array (234, 334) having a proximal end (227, 327) and a distal end (228, 328); a collector channel (240, 340) having a proximal end (215, 315) and a distal end (216, 316), extending adjacent the outflow array (234, 334) and in fluid communication with the reactant gas volume (210, 310) through the outflow apertures (232, 332); and an exhaust port (250, 350) in fluid communication with the collector channel (240, 340) at the distal end (216, 316), to allow reactant gas to flow out of the reactant gas plate (200, 300). The outflow array (234, 334) has a proximal half (221, 321) coterminous with the proximal end (227, 327), and a distal half (223, 323) coterminous with the distal end (228, 328). The outflow apertures (232, 332) are arranged to reduce the hydrodynamic resistance for reactant gas flowing through the proximal half (221, 321) of the outflow array (234, 334) relative to the hydrodynamic resistance for reactant gas flowing through the distal half (223, 323), operable to bias the flow of reactant gas towards the proximal end (215, 315) of the collector channel (240, 340).
H01M 8/0258 - CollectorsSeparators, e.g. bipolar separatorsInterconnectors characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant
H01M 8/026 - CollectorsSeparators, e.g. bipolar separatorsInterconnectors characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant characterised by grooves, e.g. their pitch or depth
H01M 8/04089 - Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants
H01M 8/0606 - Combination of fuel cells with means for production of reactants or for treatment of residues with means for production of gaseous reactants
H01M 8/1007 - Fuel cells with solid electrolytes with both reactants being gaseous or vaporised
09 - Scientific and electric apparatus and instruments
35 - Advertising and business services
37 - Construction and mining; installation and repair services
42 - Scientific, technological and industrial services, research and design
Goods & Services
Fuel cells; fuel cells for stationary applications; fuel
cells for temporary power applications; fuel cells for
transport applications; parts and fittings for fuel cells. Development and promotional campaigns in relation to
hydrogen energy; development and promotional campaigns in
relation to hydrogen fuel cell energy. Maintenance and refurbishment of fuel cells; maintenance and
refurbishment of parts and fittings for fuel cells;
recharging services for electric vehicles; charging station
services for electric vehicles; consultancy services in
relation to the aforementioned services. Scientific research and development; research and
development in the field of fuel cell technology;
technological consultancy relating to membrane technology;
engineering project management services in relation to fuel
cell energy projects; technological consultancy in relation
to integration of hydrogen power energy systems in off-grid
locations; consultancy services in relation to the
aforementioned services.
09 - Scientific and electric apparatus and instruments
35 - Advertising and business services
42 - Scientific, technological and industrial services, research and design
Goods & Services
Fuel cells; hydrogen fuel cells; alkaline fuel cells; high
current density alkaline fuel cell; fuel cells running on
direct hydrogen; fuel cells running on hydrogen from organic
hydrogen carriers; fuel cells running on cracked ammonia;
fuel cells running on reformed or cracked methane; fuel
cells running on hydrogen produced by electrolysis; parts
and fittings for fuel cells. Development and promotional campaigns in relation to fuel
cell technology; development and promotional campaigns in
relation to hydrogen fuel cell technology. Scientific research and development; consultancy relating to
fuel cell technology; consultancy relating to hydrogen fuel
cell technology.
09 - Scientific and electric apparatus and instruments
35 - Advertising and business services
42 - Scientific, technological and industrial services, research and design
Goods & Services
Fuel cells; hydrogen fuel cells; alkaline fuel cells; high current density alkaline fuel cell; fuel cells running on direct hydrogen; fuel cells running on hydrogen from organic hydrogen carriers; fuel cells running on cracked ammonia; fuel cells running on reformed or cracked methane; fuel cells running on hydrogen produced by electrolysis; parts and fittings for fuel cells Development of advertising, marketing, and promotional campaigns in relation to fuel cell technology; development of advertising, marketing, and promotional campaigns in relation to hydrogen fuel cell technology Scientific research and development; consultancy relating to fuel cell technology; consultancy relating to hydrogen fuel cell technology
09 - Scientific and electric apparatus and instruments
11 - Environmental control apparatus
17 - Rubber and plastic; packing and insulating materials
35 - Advertising and business services
42 - Scientific, technological and industrial services, research and design
Goods & Services
Integral parts for fuel cells, namely, polymer membranes; integral parts for hydrogen fuel cells, namely, polymer membranes; integral parts of fuel cells, namely, anion exchange membranes Integral components for desalination units, namely anion exchange membranes for use in desalination Polymer films for use in manufacture and assembly, namely, polymeric ion exchange membranes in roll, film or sheet form; Polymer films for use in manufacture and assembly, namely, anion exchange membranes in roll, film or sheet form; Polymer films for use in manufacture and assembly, namely, polymeric ion exchange membranes and polymeric membranes in roll or sheet form Development of promotional campaigns for business in relation to anion exchange membrane technology; development of promotional campaigns for business in relation to polymeric ion exchange membranes Scientific research and development; technological consultancy in the fields of engineering, chemistry, and technology relating to anion exchange membrane technology; technological consultancy in the fields of engineering, chemistry, and technology relating to polymeric ion exchange membranes
A membrane electrode assembly (8), suitable for use in a fuel cell or electrolyser, comprising: - an anion exchange membrane (4); - two catalyst containing layers (3, 5) each disposed either side of the anion exchange membrane (4), and; - two gas diffusion layers (2, 6), each in contact with one of said catalyst containing layers 3, 5), - wherein the anion exchange membrane (4) comprises a solid state electrolyte, - at least one catalyst containing layer (3, 5) comprises particulates of the solid state electrolyte material of the anion exchange membrane (4).
A fuel cell system (10) comprises at least one fuel cell stack (20), and a recirculation network (25, 32, 40, 46, 54) for circulating a liquid electrolyte (12) through each fuel cell stack (20). The recirculation network includes a fluid supply duct (40) and a decoupling module (44) in the recirculation network; the decoupling module (44) comprising an upper chamber and a lower chamber separated by a perforated plate (60), and the fluid supply duct (40) being arranged to supply the liquid electrolyte to the upper chamber (57). The perforated plate (60) has a surface area several times larger than the cross-sectional area of the inlet duct (40), and defines multiple perforations, each of which is a countersunk hole (64) for through flow of the liquid electrolyte into the lower chamber (58), where the liquid electrolyte falls into a collection tray (66). The collection tray (66) communicates with a fluid flow duct (46) of the recirculation network, and is sufficiently far below the plate (60) that the liquid electrolyte that has fallen through each countersunk hole (64) breaks up into droplets before it reaches the collection tray (66). The collection tray (66) may be provided with an overflow (70) so excess electrolyte may overflow into a secondary decoupling unit (75).
A fuel cell stack (10) comprises a plurality of fuel cells each with a chamber (K) for electrolyte with at least one inlet (114) and at least one outlet (116), and an inlet header (45) to supply electrolyte to all the cells in parallel. Each cell comprises a first plate (12) to define the electrolyte chamber (K), a second plate (13) to define an oxidizing gas chamber (0) and a third plate (14) to define a fuel gas chamber (H), each of these plates (12-14) also defining a side chamber (36) adjacent to but sealed from the corresponding chambers (K, 0, H), so the side chambers (36) defines an electrolyte outlet channel. An electrolyte flow channel (15) is also defined above the top portion of and in communication with the electrolyte chamber (K), so electrolyte is supplied from electrolyte supply (45) through openings (56) into the electrolyte chamber (K), flows upwards towards the top of the electrolyte chamber (K), exits said electrolyte chamber (K) via grooves (60), flows along the flow channel (15), breaks up into droplets at lip (68) and falls into the side chamber (36) prior to being expelled via electrolyte outlet (116). This arrangement reduces leakage currents.
An electrode (10) comprises a metal sheet (11) defining multiple through-holes (14), and a fluid-permeable layer (16) comprising fibrous and/or particulate electrically- conductive material and a polymer binder, which is to be bonded to a front surface of the metal sheet (11). In making the electrode (10), the front surface is subjected to an etching process to form multiple depressions (21) or blind recesses that do not extend through the metal sheet (11); placing the fluid-permeable layer onto the front surface to form an assembly; and subjecting the assembly to compression such that the fluid-permeable layer (16) bonds to the metal sheet (11) and protrudes into the through-holes (14) and into the depressions (21). No polymeric bonding layer on the metal surface is required, and the depressions (21) lead to satisfactory adhesion between the metal sheet (11) and the fluid permeable layer (16), and improved electrical properties of a fuel cell (25) that incorporates the electrode (10).
A fuel cell system (300) comprises multiple fuel cells (25) forming a fuel cell stack (200) with output terminals (302) to provide electric power to a load (305) in a load circuit. The fuel cells (25) at each end of the stack (200) are electrically connected to an end-cell circuit (312), whereas the remaining fuel cells of the stack are electrically connected to the output terminals (302). The end-cell circuit (312) may be arranged so that the current density is no more than 0.2 times the current density in the remaining fuel cells. This has been found to suppress deterioration of the fuel cells (25).
A catalytic material may be formed by taking carbon nanotubes, contacting the carbon nanotubes with a polyelectrolyte chain containing nitrogen atoms, so as to coat the carbon nanotubes with the polyelectrolyte chain, and then heat treating the coated carbon nanotubes to a temperature of at least 200°C. A suitable polyelectrolyte is poly- (diallyldimethylammonium chloride) (PDDAC). A preferred heat treatment temperature is between 400° and 440°C, and the catalytic activity appears to decrease with higher treatment temperatures. The resulting material is suitable for use as an oxygen reduction catalyst in a fuel cell electrode. It avoids the costs involved with use of platinum as catalyst.
A liquid electrolyte fuel cell system comprises at least one fuel cell (80) comprising a liquid electrolyte chamber (82) between an anode (83) and an opposed cathode (84). During operation of the fuel cell system, ageing of the cathode is counteracted by (a) increasing the flow rate of gas to the cathode (84) during the course of operation; and/or (b) decreasing the concentration of electrolyte supplied to the liquid electrolyte chamber (82) during the course of operation. The optimum effect is achieved by performing both changes.
A liquid electrolyte fuel cell (25) includes an electrolyte chamber (26), and two electrodes, one on either side of the electrolyte chamber, which are an anode (10a) and a cathode (10c). Each electrode comprises: a sheet (11) of metal through which are defined a multiplicity of through-holes (14), a first fluid-permeable layer (16) comprising fibrous and/or particulate electrically-conductive material which is bonded to the sheet of metal, in electrical contact with the sheet of metal, and is hydrophobic; and a second fluid-permeable layer (18) comprising electrically-conductive material and catalytic material, which is bonded to the outer surface of the first fluid-permeable layer, and which is at least partly hydrophobic. The cell (25) is structurally asymmetric, as a larger proportion of the area of the sheet in the cathode (10c) is holes than is the case in the anode (10a).
A liquid electrolyte fuel cell system (60) comprises at least two fuel cell stacks (20a, 20b), each comprising a plurality of fuel cells, each fuel cell comprising a liquid electrolyte chamber between opposed electrodes, the electrodes being an anode and a cathode. At least one fuel cell stack (20a) is arranged to operate at an elevated temperature such as 65°C, and at least one fuel cell stack (20b) is arranged to operate at a temperature below the elevated temperature, such as 35°C. The system (60) comprises a heat exchanger (62; 64) to transfer heat from at least one fuel cell stack (20a) at the elevated temperature to at least one fuel cell stack (20b) at the lower temperature. This may be achieved by heat exchange between the respective electrolytes.
A liquid electrolyte fuel cell with means (202) to define an electrolyte chamber (208), and comprising two electrodes (10): an anode (10a) on one side of the electrolyte chamber (208) and a cathode (10b) on the other side. The anode (10a) comprises a sheet (1 1 ) of metal through which are defined a multiplicity of through- holes (14), and a gas-permeable layer (16) comprising fibrous and/or particulate electrically-conductive material which is bonded to and in electrical contact with the sheet (1 1 ) of metal, and is hydrophobic, and a second fluid-permeable layer (18) comprising fibrous and/or particulate electrically-conductive material and catalytic material, which is bonded to the outer surface of the gas-permeable layer (16), and is less hydrophobic than the first gas-permeable layer (16). The fuel cell (200) also comprises means (26, 50, 44) to adjust the pressure difference between electrolyte (20) within the electrolyte chamber (208) and a gas exposed to the surface of the anode (10a) remote from the electrolyte chamber (208), so that an interface between the electrolyte (10) and the gas is at an intermediate position within the second fluid- permeable layer (18). Raising the anode gas pressure above the electrolyte pressure has been found to improve long-term performance of the cell.
A liquid electrolyte fuel cell comprises means to define an electrolyte chamber (208), and two electrodes (10), one on either side of the electrolyte chamber (208), each electrode comprising:—a sheet (11) of metal through which are defined a multiplicity of through-holes (14), and—a gas-permeable layer (16) of fibrous and/or particulate electrically-conductive material which is bonded to and in electrical contact with the sheet of metal (11), and which comprises catalytic material (18). The electrode (10) may be arranged such that the gas-permeable layer (16) faces the electrolyte chamber (208).
A fuel cell stack (10) comprises a plurality of fuel cells each with a chamber (K) for electrolyte with at least one inlet (114) and at least one outlet (116), and an inlet header (45) to supply electrolyte to all the cells in parallel. Each cell comprises a first plate (12) to define the electrolyte chamber (K), a second plate (13) to define an oxidising gas chamber (0) and a third plate (14) to define a fuel gas chamber (H), each of these plates (12-14) also defining a side chamber (36) adjacent to but sealed from the corresponding chambers (K, 0, H), so the side chambers (36) defines an electrolyte outlet channel. An electrolyte flow channel (15) is also defined above the top portion of and in communication with the electrolyte chamber (K), so electrolyte is supplied from electrolyte supply (45) through openings (56) into the electrolyte chamber (K), flows upwards towards the top of the electrolyte chamber (K), exits said electrolyte chamber (K) via grooves (60), flows along the flow channel (15), breaks up into droplets at lip (68) and falls into the side chamber (36) prior to being expelled via electrolyte outlet (116). This arrangement reduces leakage currents.
A liquid electrolyte fuel cell system (10) comprises at least one fuel cell with a liquid electrolyte chamber between opposed electrodes, the electrodes being an anode and a cathode, and means (30, 32) for supplying a gas stream to a gas chamber adjacent to the cathode and withdrawing a spent gas stream (38) from the gas chamber adjacent to the cathode, the system also comprising a liquid electrolyte storage tank (40), and means (42, 44, 47, 48) to circulate liquid electrolyte between the liquid electrolyte storage tank (40) and the fuel cells. In addition the system comprises a gas heater (50) and a humidification chamber (52) in the duct (36) leading to the said gas chamber, and means (53, 66, 68) to supply liquid electrolyte to the humidification chamber (52) so the gas is humidified by contact with the liquid electrolyte.
A fuel cell stack (10) comprises a plurality of fuel cells each with a chamber (K) for liquid electrolyte with at least one inlet (32) and at least one outlet (34), and at least one header (30) to supply electrolyte to all the cells in parallel. The fuel cell stack (10) comprises multiple elements (62, 63, 64, 70) stacked together, wherein at least some of the elements (62, 63, 64) comprise a plate having a surface that is intended to abut a surface of an adjacent element (70). The plate (62, 63, 64) defines a first surface portion that is to be sealed to the adjacent element, the first surface portion defining a groove with a sealing element of resilient polymeric material (72, 73, 74) moulded into the groove and projecting out of the groove. The plate also defines a second surface portion that is exposed, such that when stacked and compressed together the resilient polymeric material (72, 73, 74) is compressed entirely into the surface groove and seals onto the surface of the adjacent element (70) whereas the second surface portion is in direct contact with the surface of the adjacent element (70). When the stack (10) is compressed, the length of the stack is well-defined. The sealing takes place only where sealing is required, and is more reliable.
A liquid electrolyte fuel cell system (10) comprises at least one fuel cell with a liquid electrolyte chamber between opposed electrodes, the electrodes being an anode and a cathode, and means (30, 32) for supplying a gas stream to a gas chamber adjacent to the cathode and withdrawing a spent gas stream (38) from the gas chamber adjacent to the cathode, the system also comprising a liquid electrolyte storage tank (40), and means (42, 44, 47, 48) to circulate liquid electrolyte between the liquid electrolyte storage tank (40) and the fuel cells. In addition the system comprises a water storage tank (60) adjacent to the storage tank (40), and means (50, 51) for condensing water vapour from the spent gas stream (38), and for feeding (56) the condensed water vapour into the water storage tank (60). The water storage tank (60) has an overflow outlet (64); and a communication duct (68) linking the liquid electrolyte storage tank (40) and the water storage tank (60) below the level of the overflow outlet (60). This automatically replaces any water that evaporates from the electrolyte, without requiring any electronics.
A fuel cell stack (10) comprises a plurality of fuel cells each with a chamber (K) for electrolyte with at least one inlet and at least one outlet, and at least one header (30) to supply electrolyte to all the cells in parallel, and means (14) to collect electrolyte that has flowed through the cells. For each cell, the electrolyte outlets (34) feed into an electrolyte flow channel arranged such that in use there is a free surface of electrolyte within the electrolyte flow channel, the electrolyte flow channel being separate from the corresponding electrolyte flow channels for other cells, but such that the free surfaces of all the electrolyte flow channels are at a common pressure. Electrolyte is maintained at a constant depth in this open flow channel by a weir (38), and then flows over the weir to trickle or drip down the outside of the stack. This ensures uniform outlet electrolyte pressure throughout the stack (10) and across the individual cells, and avoids or reduces ionic leakage currents through the electrolyte outlets.
A system (10) for supplying a liquid electrolyte to cell stacks (32) arranged at a plurality of different heights comprises a plurality of constant head supply tanks (12) for containing liquid electrolyte, one for each of the different heights. Each such supply tank (12) is adapted to ensure that the surface of the liquid electrolyte is at atmospheric pressure, and to feed electrolyte to a cell stack, and incorporates an overflow duct (18) to keep the electrolyte at a constant level. For each supply tank (12) except the lowest, the overflow duct (18) supplies overflowing electrolyte to a supply tank at a lower height. The system also includes an electrolyte storage tank (20), and means (24, 26) to supply electrolyte from the storage tank (20) to the highest supply tank (12).
A system (10) for supplying and removing a plurality of fluids to and from a cell stack (11), wherein the cell stack comprises a plurality of fluid connection ports, includes a connection module (60) defining a plurality of connection ports (72) to mate with the connection ports (64) of the stack (11). The connection ports may have clearance to allow for misalignment, and may have a face seal (73). A fluid duct (12) communicates with each connection port (72) of the connection module (60), and there is a valve (32) in each fluid feed duct (12) to control fluid flow. The valves (32) may be controlled by a stack monitor (84).
A liquid electrolyte fuel cell comprises means to define an electrolyte chamber, and electrodes on opposite sides of the electrolyte chamber. The electrode comprises an electrically conductive sheet (10) through which are defined a multiplicity of through-pores or holes (14). These may be formed by laser drilling through the sheet. The electrode would normally also include a layer (16) of catalytic material. The margin (15) of the sheet is not perforated or porous, to simplify sealing.
A liquid electrolyte fuel cell comprises means to define an electrolyte chamber (208), and two electrodes (10), one on either side of the electrolyte chamber (208), each electrode comprising: - a sheet (11) of metal through which are defined a multiplicity of through-holes (14), and - a gas-permeable layer (16) of fibrous and/or particulate electrically-conductive material which is bonded to and in electrical contact with the sheet of metal (11), and which comprises catalytic material (18). The electrode (10) may be arranged such that the gas-permeable layer (16) faces the electrolyte chamber (208).
A fuel cell stack (10) comprises a plurality of fuel cells each with a chamber (K) for electrolyte with at least one inlet and at least one outlet, and at least one header (30) to supply electrolyte to all the cells in parallel, and means (14) to collect electrolyte that has flowed through the cells. For each cell, the electrolyte outlets (34) feed into an electrolyte flow channel arranged such that in use there is a free surface of electrolyte within the electrolyte flow channel, the electrolyte flow channel being separate from the corresponding electrolyte flow channels for other cells, but such that the free surfaces of all the electrolyte flow channels are at a common pressure. Electrolyte is maintained at a constant depth in this open flow channel by a weir (38), and then flows over the weir to trickle or drip down the outside of the stack. This ensures uniform outlet electrolyte pressure throughout the stack (10) and across the individual cells, and avoids or reduces ionic leakage currents through the electrolyte outlets.
A system (10) for supplying a liquid electrolyte to cell stacks (32) arranged at a plurality of different heights comprises a plurality of constant head supply tanks (12) for containing liquid electrolyte, one for each of the different heights. Each such supply tank (12) is adapted to ensure that the surface of the liquid electrolyte is at atmospheric pressure, and to feed electrolyte to a cell stack, and incorporates an overflow duct (18) to keep the electrolyte at a constant level. For each supply tank (12) except the lowest, the overflow duct (18) supplies overflowing electrolyte to a supply tank at a lower height. The system also includes an electrolyte storage tank (20), and means (24, 26) to supply electrolyte from the storage tank (20) to the highest supply tank (12).
A cell stack (20) including a plurality of cells arranged electrically in series, wherein each cell comprises electrodes of opposite polarity constituting an anode (18) and a cathode (19), wherein pairs of electrodes of opposite polarity are integral with each other, being defined by spaced-apart portions of a sheet- like conductive element (10). The conductive element (10) may be folded around a non-conducting separator plate (24) that defines gas flow chambers on opposite faces, for different gases. The cell stack (20) may be used for a liquid electrolyte fuel cell.
A liquid electrolyte fuel cell comprises means to define an electrolyte chamber, and electrodes on opposite sides of the electrolyte chamber. The electrode comprises an electrically conductive sheet (10) through which are defined a multiplicity of through-pores or holes (14). These may be formed by laser drilling through the sheet. The electrode would normally also include a layer (16) of catalytic material. The margin (15) of the sheet is not perforated or porous, to simplify sealing.
A system block (10) for mounting one or more cell stacks consists of two opposed half-blocks (12, 14) between which is sandwiched at least one separation plate (16). Each half-block (12, 14) comprises a flat plate and a multiplicity of protruding ribs. The ribs may be formed by injection moulding. The protruding ribs on an inner surface, that is a surface that faces the separation plate, define flow channels for fluids, while protruding ribs (20) on an opposite, outer surface of a half-block (12) define locating recesses or sockets for connection to cell stacks or to fluid flow ducts. At least some of the flow channels communicate with apertures in the flat plate of the half-block or apertures in the separation plate (16), and the cell stacks communicate with some of these apertures. The system block (10) enables fluids such as liquid electrolyte, hydrogen and air, to be supplied to and removed from one or more fuel cell stacks, while only requiring a single external connection for each fluid to or from the system block.
An electrode for use in a fuel cell consists of a porous plastic substrate, a conductive layer and a catalyst layer, in which the substrate is hydrophilic. Preferably the substrate has a water wicking rate no less than 40 mm per 600 s. Such an electrode may be used in a fuel cell, with an electrolyte chamber (8) defined between two opposed electrodes (11, 12), the electrodes having the catalyst layers (5) facing away from the electrolyte in contact with respective gas chambers (7, 9). Preferably the electrolyte is maintained at a negative pressure during operation.
A fuel-cell system A fuel-cell stack control network comprises a network controller (130); and a plurality of fuel-cell stacks (110a-n) each with a controller (5). Each controller (5) includes a microprocessor (10) and interfaces (50, 70) for input and output of signals to and from the fuel cell stack (110), and a network interface (90) for communication with the network controller. The network controller (130) can hence control and monitor the fuel-cell stacks.
An electrode for use in a fuel cell consists of a porous plastic substrate, a conductive layer and a catalyst layer, in which the substrate is hydrophilic. Preferably the substrate has a water wicking rate no less than 40 mm per 600 s. Such an electrode may be used in a fuel cell, with an electrolyte chamber (8) defined between two opposed electrodes (11, 12), the electrodes having the catalyst layers (5) facing away from the electrolyte in contact with respective gas chambers (7, 9). Preferably the electrolyte is maintained at a negative pressure during operation.
A fuel cell assembly comprises a fuel cell stack (200) comprising a plurality of fuel cells, a releasable clamp (235) to retain the components of the fuel cell stack; and a casing (240) into which the stack is insertable. The casing (240) provides means (250, 252) to compress the fuel cell stack components together. Each fuel cell in the stack (200) comprises two electrodes (11, 12) that are mutually spaced so as to form an electrolyte chamber therebetween, and each electrode incorporates a catalyst; the fuel cell stack is made up of plates (202) to define electrolyte chambers and plates (206) to define the gas chambers, the electrodes being sealingly secured between plates in the stack. At least one end plate (230) defines ports (232) to supply or withdraw fluids from the fuel cells.
A fuel cell assembly comprises a fuel cell stack (160) with at least one fuel cell (10), and a pump (50). Each fuel cell (10) includes a first gas chamber, an electrolyte chamber, and a second gas chamber, and two electrodes separating the electrolyte chamber from the gas chambers. The pump (50) is arranged to reduce the pressure of an electrolyte (40) in the electrolyte chamber to a negative pressure. This negative pressure may be adjusted in accordance with the electrical output of the fuel cell stack (160).
A voltage monitor for monitoring the voltages of fuel cells (10) in a stack, is structured as a hierarchy of monitoring units. It comprises several slave monitoring units (60), each comprising a voltage- measuring circuit (60) and a plurality of voltage- measuring connections (5), each connection (5) being connected to one of the fuel cells, and the circuit (60) being arranged to generate a signal indicative of the voltage. A master monitoring unit (40) is arranged to receive the signals from all the slave monitoring units (50) and to monitor them for deviation from an acceptable range.
A liquid electrolyte fuel cell comprises means to define an electrolyte chamber (208), and two electrodes (10), one on either side of the electrolyte chamber (208), each electrode comprising: - a sheet (11) of metal through which are defined a multiplicity of through-holes (14), and - a gas-permeable layer (16) of fibrous and/or particulate electrically-conductive material which is bonded to and in electrical contact with the sheet of metal (11), and which comprises catalytic material (18). The electrode (10) may be arranged such that the gas-permeable layer (16) faces the electrolyte chamber (208).
A fuel cell stack (10) comprises a plurality of fuel cells each with a chamber (K) for electrolyte with at least one inlet and at least one outlet, and at least one header (30) to supply electrolyte to all the cells in parallel, and means (14) to collect electrolyte that has flowed through the cells. For each cell, the electrolyte outlets (34) feed into an electrolyte flow channel arranged such that in use there is a free surface of electrolyte within the electrolyte flow channel, the electrolyte flow channel being separate from the corresponding electrolyte flow channels for other cells, but such that the free surfaces of all the electrolyte flow channels are at a common pressure. Electrolyte is maintained at a constant depth in this open flow channel by a weir (38), and then flows over the weir to trickle or drip down the outside of the stack. This ensures uniform outlet electrolyte pressure throughout the stack (10) and across the individual cells, and avoids or reduces ionic leakage currents through the electrolyte outlets.
A liquid electrolyte fuel cell comprises means to define an electrolyte chamber, and electrodes on opposite sides of the electrolyte chamber. The electrode comprises an electrically conductive sheet (10) through which are defined a multiplicity of through-pores or holes (14). These may be formed by laser drilling through the sheet. The electrode would normally also include a layer (16) of catalytic material. The margin (15) of the sheet is not perforated or porous, to simplify sealing.
