A fuel cell system includes a fuel cell having a cathode and an anode configured to receive a portion of a hydrocarbon feed and to output an anode exhaust stream comprising carbon dioxide, hydrogen, and water; and an electrolyzer cell having a cathode and an anode. The anode of the electrolyzer cell is configured to receive a first portion of the anode exhaust stream and another portion of the hydrocarbon feed, and to generate a hydrogen stream.

A combined hydrogen and electrical power generation system includes a solid oxide fuel cell (SOFC) having a cathode and an anode and a protonic ceramic hydrogen separation membrane (PSM) having a cathode and an anode. The SOFC and the PSM are connected in electrical series having a common current.

An apparatus includes a proton-conducting electrolyte membrane, an anode, a cathode, a first flow path which is disposed on the anode and through which an anode fluid containing hydrogen as a constituent element flows, a second flow path which is disposed on the cathode and through which hydrogen flows, a voltage applicator, a detector which detects a hydrogen cross leak amount passing through the membrane, where the detector detects the hydrogen cross leak amount from, a natural potential of one electrode of the cathode and the anode after forming a state where hydrogen is present at the one electrode and hydrogen is not present at the other electrode of the cathode and the anode, or a current flowing between the anode and the cathode when the voltage is applied from the voltage applicator in a state where the first flow path and the second flow path are both sealed off.

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.

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.

An electrochemical hydrogen pump includes: at least one hydrogen pump unit including an electrolyte membrane, an anode, a cathode, an anode separator, and a cathode separator; an anode end plate disposed on the anode separator positioned in a first end in a stacking direction, the first end is one end and the second end is another end; a cathode end plate disposed on the cathode separator positioned in a second end in the stacking direction; a fixing member that prevents at least members from the cathode end plate to the cathode separator positioned in the second end from moving in the stacking direction; a first gas flow channel through which hydrogen generated in the cathode is supplied to a first space disposed between the cathode end plate and the cathode separator positioned in the second end; and a first pressure transmitting member disposed in the first space.

Provided is a water treatment system using an alkaline water electrolytic device and an alkaline fuel cell in which for continuing an electrolytic treatment, a hydrogen gas and an oxygen gas required in an alkaline water electrolytic device and an alkaline fuel cell, an amount of water corresponding to raw water lost through the electrolytic treatment, and an electrolytic solution are efficiently circulated and used in a water treatment system to considerably reduce electric power consumption. The water treatment system is a water treatment system using an alkaline water electrolytic device and an alkaline fuel cell in which an alkaline water electrolytic device and an alkaline fuel cell are connected to each other, the volume of raw water is reduced, an oxygen gas and a hydrogen gas that are generated from the alkaline water electrolytic device are fed to the alkaline fuel cell, the oxygen gas and hydrogen gas are used to generate electric power by the alkaline fuel cell, electric energy and water are collected, and the collected electric energy is fed to the alkaline water electrolytic device as an electric power source thereof.

A carbon dioxide capture system for capturing carbon dioxide from an exhaust stream. The system may include a fuel cell configured to output a first exhaust stream comprising carbon dioxide and water. The system may further include an electrolyzer cell configured to receive a first portion of the first exhaust stream and output a second exhaust stream comprising oxygen and carbon dioxide. The fuel cell may be a solid oxide fuel cell. The electrolyzer cell may be a molten carbonate electrolysis cell.

A fuel cell system includes a first fuel conduit configured to receive fuel from a fuel source, a reactor fluidly connected to the first fuel conduit and configured to selectively oxidize sulfur species in fuel received from the first fuel conduit, and fuel cells configured to generate power using fuel containing oxidized sulfur species received from the reactor.

A humidity transfer assembly includes a pressure vessel and a humidity transfer device disposed in the pressure vessel. The humidity transfer device includes an enclosure, a first inlet line fluidly coupled to the enclosure and configured to supply anode exhaust thereto, a first outlet line fluidly coupled to the enclosure and configured to output anode exhaust therefrom, and a second inlet line fluidly coupled to the enclosure and configured to supply feed gas thereto. The humidity transfer device is configured to transfer steam from anode exhaust to feed gas and to output feed gas into the pressure vessel.