A fuel cell system includes: a first fuel cell including a first anode and a first cathode, wherein the first anode is configured to output a first anode exhaust gas; a first oxidizer configured to receive the first anode exhaust gas and air from a first air supply, to react the first anode exhaust gas and the air in a preferential oxidation reaction, and to output an oxidized gas; a second fuel cell configured to act as an electrochemical hydrogen separator, the second fuel cell including: a second anode configured to receive the oxidized gas from the first oxidizer and to output a second anode exhaust gas, and a second cathode configured to output a hydrogen stream; and a condenser configured to receive the second anode exhaust gas and to separate water and CO.sub.2.

Electrochemical devices including electrochemical pumps (ECPs) and fuel cell systems comprising a fuel cell and an ECP are disclosed. In particular, this electrochemical device can be an ECP that comprises an anode, a cathode and an anion exchange polymer separating the anode from the cathode. The ECP can be coupled to a hydroxide exchange membrane fuel cell (HEMFC) that is disclosed herein as a fuel cell system. These devices can be used in methods for removing carbon dioxide from air and for generating electricity.

Fuel cell systems configured for efficient byproduct recovery and reuse are disclosed herein. In one embodiment, a fuel cell system includes a reformer configured to reform a fuel containing methane (CH.sub.4) with steam to produce a reformed fuel having methane (CH.sub.4), carbon monoxide (CO), and hydrogen (H.sub.2). The fuel cell system also includes a fuel cell configured to perform an electrochemical reaction between a first portion of the reformed fuel and oxygen (O.sub.2) to produce electricity and an exhaust having carbon dioxide (CO.sub.2), water (H.sub.2O), and a second portion of the reformed fuel. The fuel cell system further includes an oxygen enricher configured to generate an oxygen enriched gas and a combustion chamber configured to combust the second portion of the reformed fuel with the oxygen enriched gas.

A hydrogen generation system for generating hydrogen and electrical power includes a power supply, a reformer-electrolyzer-purifier (REP) assembly including at least one fuel cell including an anode and a cathode separated by an electrolyte matrix, at least one low temperature fuel cell, and a hydrogen storage. The at least one fuel cell is configured to receive a reverse voltage supplied by the power supply and generate hydrogen-containing gas in the anode of the at least one fuel cell. The at least one low temperature fuel cell is configured to receive the hydrogen-containing gas output from the REP assembly. The at least one low temperature fuel cell is configured to selectably operate in a power generation mode in which the hydrogen-containing gas is used to generate electrical power and a power storage mode in which the hydrogen-containing gas is pressurized and stored in the hydrogen storage.

A proton conducting membrane (16) for a fuel cell comprises light-transmissive proton conducting material (102, 104) and light scattering material (106) for scattering light within the membrane, the membrane further comprising a light guide (108) through which light can enter the membrane. Also disclosed is a fuel cell comprising the membrane.

A hydrogen supply system includes an electrochemical hydrogen pump which includes: an electrolyte membrane; an anode provided on a first surface of the electrolyte membrane; a cathode provided on a second surface of the electrolyte membrane opposite to the first surface; and a current adjuster adjusting a current amount flowing between the anode and the cathode, and which performs a hydrogen supply operation by allowing a current to flow between the anode and the cathode using the current adjuster so as to boost the pressure of hydrogen which is supplied to an anode side at a cathode side and to supply the pressure-boosted hydrogen to a hydrogen demander; and a dew point adjuster adjusting a dew point of a mixed gas in which a hydrogen-containing gas which is discharged from the anode side and a hydrogen-containing gas which is supplied from an outside are mixed together.

Electrochemical devices including electrochemical pumps (ECPs) and fuel cell systems comprising a fuel cell and an ECP are disclosed. In particular, this electrochemical device can be an ECP that comprises an anode, a cathode and an anion exchange polymer separating the anode from the cathode. The ECP can be coupled to a hydroxide exchange membrane fuel cell (HEMFC) that is disclosed herein as a fuel cell system. These devices can be used in methods for removing carbon dioxide from air and for generating electricity.

A fuel cell system includes a fuel cell stack, a fuel inlet conduit configured to provide a fuel to a fuel inlet of the fuel cell stack, an electrochemical pump separator containing an electrolyte, a cathode, and a carbon monoxide tolerant anode, a fuel exhaust conduit that operatively connects a fuel exhaust outlet of the fuel cell stack to an anode inlet of the electrochemical pump separator, and a product conduit which operatively connects a cathode outlet of the electrochemical pump separator to the fuel inlet conduit.

A hydrogen supply system includes: an electrochemical hydrogen pump including an electrolyte membrane, an anode and a cathode provided to a first and second main surfaces of the electrolyte membrane, respectively, an anode flow path and cathode flow path through which hydrogen flows, and a voltage applicator applying a voltage between the anode and cathode, pressurizing and sending hydrogen supplied to the anode via the anode flow path to the cathode by applying a voltage by the voltage applicator, and supplying the pressurized hydrogen in the cathode flow path to a hydrogen reservoir; a pressure adjuster adjusting a cathode flow path pressure; and a controller controlling the pressure adjuster and making the cathode flow path pressure higher than an anode flow path pressure before starting a hydrogen pressurization action for pressurizing and supplying hydrogen supplied to the anode flow path to the cathode flow path.

A metal/air battery includes an oxygen management system that delivers oxygen to the battery during a discharge cycle. The oxygen management system includes an oxygen separations unit and an oxygenated gas supply reservoir that are fluidly coupled to a positive electrode of the battery via a valve system. The valve system selectively places the oxygen separations unit and the oxygenated gas supply reservoir in fluid communication with the positive electrode during the discharge cycle. The oxygen management system also includes a compressor with an outlet fluidly coupled to the oxygenated gas supply reservoir and an inlet fluidly connected to the oxygen separations unit via the valve system. The valve system selectively places the oxygen separations unit in fluid communication with the oxygenated gas supply reservoir during one or more of the discharge cycle and a charge cycle of the battery.