This invention provides a preparation method of a catalyst for preferential oxidization of CO in a hydrogen-enriched atmosphere, and a catalyst product obtained from the method and its applications thereof. Particularly, in this invention, a wide-temperature catalyst for preferential oxidization of CO in a hydrogen-enriched atmosphere is obtained by depositing one or more of an iron oxide, cobalt oxide, and nickel oxide as a promoter onto the surface of a supported Pt-group noble metal catalyst precursor via chemical vapor deposition or atomic layer deposition. In the wide-temperature catalyst, the active noble metal component has a content of 0.1 to 10 wt %, and the promoter has a content of 0.1 to 10 wt % in terms of the metal element thereof. In the reaction of preferential oxidation of CO in a hydrogen-enriched atmosphere, the catalyst prepared by this invention can exhibit excellent catalytic performance and can achieve high conversion of CO with high selectivity in a wide temperature range of −80 to 200° C., for example. Also, the catalyst can remain stable for a long time even in a case where steam and CO.sub.2 are present in the hydrogen-enriched atmosphere.

A fuel cell system includes a fuel cell having a cathode and an anode configured to receive a portion of a hhydrocarbon 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 fuel cell system includes a fuel cell having a cathode and an anode configured to receive a portion of a hhydrocarbon 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 method for controlling a carbon dioxide utilization in a fuel cell assembly includes: measuring a voltage across the fuel cell assembly; determining an estimated carbon dioxide utilization of the fuel cell assembly based on at least the measured voltage across the fuel cell assembly by determining an expected voltage of the fuel cell assembly based on at least a temperature of the fuel cell assembly, a current density across the fuel cell assembly, a fuel utilization of the fuel cell assembly, and a cathode oxygen utilization of the fuel cell assembly; determining the estimated carbon dioxide utilization based on a comparison between the measured voltage and the determined expected voltage; comparing the determined estimated carbon dioxide utilization to a predetermined threshold utilization; and upon determining that the determined estimated carbon dioxide utilization is higher than the predetermined threshold utilization, reducing the carbon utilization of the fuel cell assembly.

A method for controlling a carbon dioxide utilization in a fuel cell assembly includes: measuring a voltage across the fuel cell assembly; determining an estimated carbon dioxide utilization of the fuel cell assembly based on at least the measured voltage across the fuel cell assembly by determining an expected voltage of the fuel cell assembly based on at least a temperature of the fuel cell assembly, a current density across the fuel cell assembly, a fuel utilization of the fuel cell assembly, and a cathode oxygen utilization of the fuel cell assembly; determining the estimated carbon dioxide utilization based on a comparison between the measured voltage and the determined expected voltage; comparing the determined estimated carbon dioxide utilization to a predetermined threshold utilization; and upon determining that the determined estimated carbon dioxide utilization is higher than the predetermined threshold utilization, reducing the carbon utilization of the fuel cell assembly.

A biogas-utilizing methanation system includes: a solid oxide fuel cell using a to-be-treated gas as a fuel gas; a hydrogen production device capable of producing hydrogen by using power of a renewable energy power generation device; and a methanation device capable of methanating carbon dioxide in the system with the hydrogen produced by the hydrogen production device. The carbon dioxide in the system can be stored in a storage device on the basis of the supply amount of the to-be-treated gas or the power of the renewable energy power generation device.

A biogas-utilizing methanation system includes: a solid oxide fuel cell using a to-be-treated gas as a fuel gas; a hydrogen production device capable of producing hydrogen by using power of a renewable energy power generation device; and a methanation device capable of methanating carbon dioxide in the system with the hydrogen produced by the hydrogen production device. The carbon dioxide in the system can be stored in a storage device on the basis of the supply amount of the to-be-treated gas or the power of the renewable energy power generation device.

The embodiment relates to an energy conversion system having: a Solid Oxide Fuel Cell (SOFC) unit (A) having an anode and a cathode side, for receiving a fuel (1) and a steam of oxidant (4) and for converting a fraction of chemical power of the fuel (1) into electric power; a combustor unit (B) to receive unconverted fuel (5) and unconverted oxidant (6), configured for converting the unconverted fuel (5) and the unconverted oxidant (6) into product gas (10); an expander unit (C) to receive the product gas (10) and configured for expanding said product gas (10) into flue gas (12); a cooler unit (E) in thermal relationship with a heat sink (27) and configured for cooling said flue gas (12); a separator (F) for removing condensed species (15) from the cooled gas (14) exiting the cooler unit (E); and a first compression unit (K) for increasing the pressure of said oxidant (26, 4, 8) to a value suitable for the SOFC unit (A) and the combustor unit (B).

A method of upgrading oil using supercritical fluids generated by a fuel cell. The process uses supercritical carbon dioxide to control the specific gravity of the oil and supercritical water, the amount of which is controlled to achieve a desired oil/water ratio in processing oils to be upgraded. The process recovers the GHG emission stream from a fuel cell anode exhaust to produce supercritical fluids.

In an aspect, a bipolar membrane cell comprises a separation layer located in between an anode half-cell and a cathode half-cell; wherein the anode half-cell comprises a proton exchange membrane and an anode; where the proton exchange membrane is located in between the anode and the separation layer; wherein the cathode half-cell comprises an anion exchange membrane and a cathode; wherein the anion exchange membrane is located in between the cathode and the separation layer; and an external circuit connecting the anode and the cathode.