Method and system for electrochemically compressing gaseous hydrogen
Method and system for electrochemically compressing hydrogen. In one embodiment, the system includes a membrane electrode assembly (MEA) that includes a polymer electrolyte membrane (PEM), an anode, and a cathode. First and second gas diffusion media are positioned adjacent the cathode and anode, respectively. A humidifying membrane is positioned next to the second gas diffusion medium on a side opposite the anode. A water supply is connected to the humidifying membrane, and a hydrogen gas supply is connected to the second gas diffusion medium. A hydrogen gas collector including a back pressure regulator is connected to the first gas diffusion medium. Separators, positioned on opposite sides of the MEA, are connected to a power source. In use, hydrogen is electrochemically pumped across the MEA and collected in the hydrogen gas collector. The PEM is kept properly humidified by the humidifying membrane, which releases water into the second gas diffusion medium.
1 . An electrochemical device comprising:
(a) a polymer electrolyte membrane, said polymer electrolyte membrane having opposing first and second faces;
(b) an anode coupled to the first face of said polymer electrolyte membrane;
(c) a cathode coupled to the second face of said polymer electrolyte membrane; and
(d) a water management device in fluid communication with a source of water and extending through a gas diffusion medium to directly contact the anode or the cathode at a first point and a second point to deliver water to the anode or the cathode via said water management device, the first point spaced laterally from the second point, said water management device separated from the anode or the cathode between the first point and the second point, said water management device being electrically non-conductive, permeable to liquids, and substantially impermeable to gases, said anode or said cathode being positioned between the water management device and the polymer electrolyte membrane.
2 . The electrochemical device as claimed in claim 1 further comprising an anodic gas diffusion medium, said anodic gas diffusion medium defining an anode chamber, said anode chamber being in fluid communication with said anode, said anodic gas diffusion medium being positioned between at least a portion of said water management device and said anode.
3 . The electrochemical device as claimed in claim 2 wherein said anodic gas diffusion medium consists of a single layer of an electrically conductive, porous material.
4 . The electrochemical device as claimed in claim 2 wherein said anodic gas diffusion medium comprises a plurality of layers, each of the plurality of layers comprising one or more electrically conductive, porous materials.
5 . The electrochemical device as claimed in claim 1 wherein said water management device comprises a portion vertically spaced from the anode or the cathode between the first point and the second point.
6 . The electrochemical device as claimed in claim 1 further comprising:
a frame mounted around the water management device in a fluid-tight manner, the frame comprising a fluid port therethrough to allow a flow of water from the source of water to the water management device.
7 . The electrochemical device as claimed in claim 1 wherein said water management device consists of a single monolithic material.
8 . The electrochemical device as claimed in claim 7 wherein said water management device is a solid polymer electrolyte membrane.
9 . The electrochemical device as claimed in claim 1 wherein said water management device comprises a plurality of layers and/or materials.
10 . The electrochemical device as claimed in claim 9 wherein said water management device comprises a support having a plurality of pores and a solid polymer electrolyte disposed within the pores of the support.
11 . The electrochemical device as claimed in claim 1 wherein said water management device comprises a solid polymer electrolyte.
12 . The electrochemical device as claimed in claim 11 wherein the solid polymer electrolyte comprises at least one member selected from the group consisting of polyethylene, polyethylene-polystyrene block with copolymers, polystyrene, polysulfone, polyphenylene, polyphenylene oxide, poly(arylene), poly(arylene pieridinium), poly(diallypiperidinium hydroxide), poly(dimethylammonium hydroxide), sulfonated polystyrene, sulfonated polysulfone, sulfonated poly(ether ether ketone), sulfonated poly(benzophenone), sulfonated poly(arylene ether sulfone), sulfonated poly(arylene ether ketone), sulfonated poly(arylene thioether), sulfonated poly(ether amide), sulfonated polybenzimidazole, sulfonated poly(phthalazinone ether), perfluorosulfonic acid, poly(vinylidene fluoride), and combinations or mixtures thereof.
13 . The electrochemical device as claimed in claim 1 wherein said polymer electrolyte membrane, said anode, and said cathode collectively form a membrane electrode assembly and wherein the electrochemical device further comprises an annular seal, the annular seal being mounted around the membrane electrode assembly.
14 . The electrochemical device as claimed in claim 1 wherein said polymer electrolyte membrane, said anode, and said cathode collectively form a membrane electrode assembly, the electrochemical device further comprising a first separator and a second separator, wherein each of said first separator and said second separator are electrically conductive and wherein said first separator and said second separator are positioned on opposite sides of said membrane electrode assembly, with said second separator positioned between said membrane electrode assembly and said water management device.
15 . The electrochemical device as claimed in claim 1 wherein the electrochemical device is an electrochemical hydrogen compressor.
16 . The electrochemical device as claimed in claim 1 wherein the water management device comprises a first water management device and a second water management device, wherein the first water management device is coupled to the anode for use in delivering water thereto, wherein said first water management device is electrically non-conductive, permeable to liquids, and substantially impermeable to gases, wherein said anode is positioned between the first water management device and the polymer electrolyte membrane, wherein the second water management device is coupled to the cathode for use in delivering water thereto, wherein said second water management device is electrically non-conductive, permeable to liquids, and substantially impermeable to gases, and wherein said cathode is positioned between the second water management device and the polymer electrolyte membrane.
17 . The electrochemical device as claimed in claim 16 wherein said water management device comprises a solid polymer electrolyte in which one or more types of electrically conductive materials are dispersed.
18 . The electrochemical device of claim 16 wherein said water management device is hot pressed in the pores of the porous support.
19 . An electrochemical device comprising:
(a) a polymer electrolyte membrane, said polymer electrolyte membrane having opposing first and second faces;
(b) an anode coupled to the first face of said polymer electrolyte membrane;
(c) a cathode coupled to the second face of said polymer electrolyte membrane;
(d) a water management device in fluid communication with a source of water and coupled to the anode or the cathode for use in delivering water thereto, said water management device being permeable to liquids and substantially impermeable to gases, said water management device comprising opposing first and second faces; and
(e) a porous support for providing dimensional stability, said the water management device received in pores of the porous support and wherein said water management device is electrically conductive.