International Fuel Cells, LLC

Ballard Power Systems Corporation

United Technologies Corporation

Ronald Cohen

Richard F Buswell

David S Watkins

Leonard McNeilly

Joseph V Clausi

George T Suljak, Jr

David P Bloomfield

Ole L Olesen

Craig Louie

Eugene W Hall

Stanley L Leavitt

Joseph J Faintani

An apparatus for the two-stage selective oxidation of carbon monoxide to carbon dioxide in a fuel stream comprising hydrogen and carbon monoxide. The apparatus includes primary and secondary reaction chambers, which deliver a hydrogen-rich outlet gas stream having a carbon monoxide concentration of less than about 5 ppm. When an increase in the carbon monoxide concentration in the outlet stream of the primary reaction chamber is detected, then the flow through the primary reaction chamber is reversed. The selective oxidizer employs a temperature-based control strategy as an oxygen-containing gas stream flow rate adjustment around the flow rate initially set in direct proportion to the fuel gas stream flow rate. The control strategy regulates the amount of oxygen-containing gas mixed with the gaseous fuel stream as a function of the difference between the temperature at a location at or near the end of the primary reaction chamber and the temperature at the outlet of the primary reaction chamber.

Apparatus for the two-stage selective oxidation of carbon monoxide in a

An apparatus and method are provided for the two-stage selective oxidation of carbon monoxide to carbon dioxide in a fuel stream comprising hydrogen and carbon monoxide. The apparatus includes primary and secondary reaction chambers, which deliver a hydrogen-rich outlet gas stream having a carbon monoxide concentration of less than about 5 ppm. When an increase in the carbon monoxide concentration in the outlet stream of the primary reaction chamber is detected, then the flow through the primary reaction chamber is reversed. The selective oxidizer employs a temperature-based control strategy as an oxygen-containing gas stream flow rate adjustment around the flow rate initially set in direct proportion to the fuel gas stream flow rate. The control strategy regulates the amount of oxygen-containing gas mixed with the gaseous fuel stream as a function of the difference between the temperature at a location at or near the end of the primary reaction chamber and the temperature at the outlet of the primary reaction chamber.

Method and apparatus for the two-stage selective oxidation of carbon

A catalytic hydrocarbon reformer operates at lower temperature and pressure relative to conventional reformers. Convective heat transfer between the hot combustion gas stream and the reactor tube is enhanced through use of a narrow gap heat transfer area, which induces turbulent flow of the combustion gas stream across the reactor tube. The reactor tube includes a catalyst fines collection tube to accumulate and retain catalyst particles or fines entrained in the reformate gas stream.

Catalytic hydrocarbon reformer with enhanced internal heat transfer

A power plant system produces utility grade electrical AC power from gaseous or liquid hydrocarbon fuels using a fuel cell stack employing ion exchange membranes. The fuel is desulfurized, mixed with water, heated and vaporized before being introduced into a reformer. The reformer produces a hydrogen-rich gas which is then directed through a series of heat exchangers, shift converters and a selective oxidizer. The processed fuel stream is combined in the fuel cell stack with a pressurized oxidant stream to generate DC power. Oxidant pressure is supplied by compressors driven by turbines using heated system exhaust gases. The DC power is converted into utility grade AC power using an inverter augmented by a battery peaking unit for rapid load following. The water generated in the fuel cell stack is recycled and used to cool the fuel cell stack and to humidify the fuel stream and oxidant stream prior to their introduction to the fuel cell stack. System integration results in an electrical efficiency of at least about 40%, and with heat recovery the overall fuel efficiency is greater than approximately 80%.

Hydrocarbon fueled solid polymer fuel cell electric power generation

A stacked fuel cell has a plurality of cell plaques, each plaque having a plurality of horizontally disposed fuel cells placed in an insulating frame. By utilizing a plurality of cell plaques, overall fuel cell stack voltage can be substantially increased by interconnecting adjacent plaque cells to form substacks which are in turn connected in series. Thus stack voltage is increased without requiring additional fuel cell height.

Plaque fuel cell stack

Removal of waste heat from a fuel cell is necessary for continuous operation. Evaporation, can be used to remove the heat produced by the exothermic reaction within the fuel cell. Water sprayed into a gaseous fuel stream is evaporated in an evaporative cooler adjacent to the fuel cell. The fuel/steam stream can then be utilized in the various other fuel cell system operations.

Fuel cell evaporative cooling using fuel as a carrier gas

The fuel cell power plant operates at higher reactant pressures, and thus higher power density (lower cost) and efficiency, by providing reactant reformer steam from a separate steam boiler. Instead of supplying coolant steam to the reformer, the coolant is operated in a closed loop apart from the reformer, and the coolant steam is used to drive a steam generator to produce additional electricity. A portion of the raw fuel is burned within the steam boiler and the remainder is passed through the reformer and thence to the fuel cells. Boiler exhaust is used to drive a turocompressor which pressurizes the air used on the cathode side of the fuel cells.

Fuel cell power plant with increased reactant pressures

The reformer is designed for use with a large fuel cell power plant capable of producing megawatts of power, as, for example, would be used by a public utility. The catalyst tubes in the reformer have their upper ends at staggered elevations so as to be capable of having their temperatures individually monitored by infrared temperature sensors. The catalyst tubes are mounted on a floating support within the reformer housing so as to be free to undergo expansion and contraction during periods of internal temperature variation as the reformer is operated. The floating support is preferably formed from fuel manifolds suspended in the reformer housing. Baffles are included in the reformer housing for evenly distributing heat to the catalyst tube arrays. The reformer has a long burner tube which is approximately the same length as the catalyst tubes.

Fuel cell power plant reformer

A fuel cell power plant for producing electricity uses pressurized reactants in the cells. The air is compressed by compressor apparatus which is powered by waste energy produced by the power plant in the form of a hot pressurized gaseous medium, such as the exhaust gases from the cathode side of the cells. For example, the compressor apparatus may comprise a compressor and a turbine which are operably connected. The exhaust gases from the cathode side of the cell are delivered into the turbine which drives the compressor for compressing the air delivered to the cells.

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West Hartford, CT, United States of America

Ronald Cohen