International Fuel Cells, LLC

United Technologies Corporation

Richard A Sederquist

Donald F Szydlowski

Thomas J Corrigan

Stanley P Bonk

Roger R Lesieur

John C Trocciola

Ole L Olesen

Harold R Kunz

Richard F Buswell

Leslie L VanDine

Daniel J Snopkowski

Raymond M Smith

Theodore S Malinowski

Paul A Grubb

Valerie A Maston

Albert P Grasso

Glenn W Scheffler

John L Preston

Richard D Sawyer

Peter F Foley

Leonard J Bonville

Ronald J Spiegel

Herbert C Healy

Ronald J Wertheim

Gregory J Sandelli

Francis A Kocum

Paul J Farris

Dale W Blake

Murdo J Smith, Ii

George R Krar

A fuel cell power plant, generally, has a fuel cell stack for electrochemically converting a hydrocarbon fuel into electricity. In order for the hydrocarbon fuel to be used by the fuel cell stack, it must be steam reformed into a hydrogen-rich process gas. This process gas has a carbon monoxide level that would be detrimental to the fuel cell stack, so the process gas is passed through a shift converter to decrease the carbon monoxide level therein prior to feeding the process gas to the fuel cell stack. In order to decrease the level of carbon monoxide without the need to increase the size of the shift converter catalyst bed, or lower the temperature of the process gas as it enters the shift converter to an undesirably low temperature, the shift converter design that utilizes an upstream adiabatic zone and a downstream actively cooled zone. The actively cooled zone is cooled by a pressurized water coolant which boils as it cools the process gas stream. The coolant entering the shift converter is essentially a single phase water stream, and the coolant exiting the shift converter is a two phase water-steam mixture.

Shift converter

A compact and efficient fuel reformer which is operable to produce a hydrogen-enriched process fuel from a raw fuel such as natural gas, or the like includes a compact array of catalyst tubes which are contained in a heat-insulated housing. The catalyst tube array preferably includes a multitude of catalyst tubes that are arranged in a hexagonal array. The housing includes internal hexagonal thermal insulation so as to ensure even heating of the catalyst tubes. The diameter of the tubes is sized so that spacing between adjacent tubes in the array can be minimized for efficient heat transfer. The interior of each of the catalyst tubes includes a hollow dead-ended central tube which serves as a fines trap for collecting catalyst fines that may become entrained in the fuel stream. The catalyst tubes are also provided with an upper frusto-conical portion which serves to extend the catalyst bed and provide a catalyst reserve. The assembly includes a side-fired startup burner which allows for an improved diffusion burner orifice array at the top of the reformer. The catalyst tubes are supported by side walls of the assembly in a manner that stabilizes the tubes in the assembly. In the assembly, the internal transverse manifold plates are tied together by portions of the tube assemblies so as to form a composite beam that supports the weight of the catalyst tube array.

Hydrocarbon fuel gas reformer assembly for a fuel cell power plant

A water recovery fuel cell system includes a fuel cell defining a cathode flow field including a cathode input port and a cathode output port, and an anode flow field including an anode input port and an anode output port A humidity exchange device defines a supply gas input port, a supply gas output port, a process exhaust gas input port and a process exhaust gas output port. The supply gas input port is to be coupled to a source of oxidant gas, and the supply gas output port is coupled to the fuel cell power plant oxidant air supply including the cathode input port of the fuel cell. The process exhaust gas output port communicates at a junction with the cathode output port and a combustor exhaust derived from the anode flow field of the fuel cell, and the exhaust gas output port communicates with a power plant exhaust conduit. A power plant exhaust path is defined from the cathode output port to the power plant exhaust conduit via the humidity exchange device. A water recovery condenser is disposed along the power plant exhaust path between the junction and the power plant exhaust conduit.

Apparatus for humidifying the air stream of a fuel cell power plant

A control system and method for controlling a fuel processing system operational to produce a gas for a downstream process from a fuel, wherein the fuel processing system uses a plurality of fuel processing elements, a fuel input and a waste gas input, each of the fuel processing elements having an individual output and the plurality of fuel processing elements having a collective output, and wherein the downstream process has a waste gas output and a dynamic gas load demand. The control system includes a device for receiving communication from the downstream process indicative of the dynamic load demand and a device for controlling the collective output level of the gas in response to the dynamic load demand. The device for controlling is operative to at least one of substantially equally distribute the dynamic load demand among the plurality of fuel processing elements such that the individual outputs from each of the fuel processing elements are substantially equal to each other for forming the collective output and most efficiently distribute the dynamic load among the plurality of fuel processing elements such that at least one of the individual outputs contributes to the collective output.

Control system and method for controlling a gas generating system

A fuel atomizer for a liquid hydrocarbon fuel reformer/processor creates a high velocity atomized stream of a liquid fuel and steam, wherein the liquid fuel is quickly vaporized so as to limit carbon deposition from the fuel on the fuel vaporizer surfaces. The injector includes a small diameter fuel injection tube through which the liquid fuel and steam mixture is ejected at relatively high velocities. The liquid fuel forms an annular film which surrounds a steam core in the tube, which liquid droplet film and steam core composite are ejected from the tube into a stream of super heated steam, or steam and air. The stream of super heated steam substantially instantaneously vaporizes the fuel droplets from the film after the latter leaves the injection tube.

Method and apparatus for injecting a liquid hydrocarbon fuel into a fuel

A system for generating a desired output gas from an input fuel for use in a downstream process is disclosed. The system includes a plurality of fuel processing units to generate the desired output gas, wherein each of the plurality of fuel processing units includes a reformer which uses waste gas output from the downstream process to facilitate the processing of the fuel. Each of the fuel processing units is operational over a range up to full capacity, wherein the plurality of fuel processing units are interconnected in an collective operating scheme to process the fuel. A control system is provided for controlling the plurality of fuel processing units in response to requirements of a dynamic load demand from the downstream operation. The control system is operative to adjust the operational level of each of the plurality of fuel processing units to produce individual responses from each of the fuel processing units. The individual responses are combined to produce a collective response for meeting the requirements of the dynamic load demand. A method for generating a desired output gas from an input fuel for use in a downstream process is also provided.

Gas generating system and method

A fuel cell system, generally, has a fuel processing apparatus for steam reforming a hydrocarbon fuel and steam into a product gas, and a fuel cell stack for converting the product gas into electricity. The fuel processing apparatus is a catalytic reaction apparatus having a furnace and a catalytic reactor. In an effort to increase the efficiency of the catalytic reaction apparatus and decrease the size and/or number of catalytic reactors, the present invention relates to a furnace that utilizes air and fuel pre-heat chambers to increase the flame temperature within the furnace.

Fuel cell power plant furnace

The gas stream which is produced in and emanates from landfills, anaerobic digesters and other waste gas streams, is treated to produce a purified gas which is essentially a hydrocarbon such as methane and which can be used as the fuel source in a fuel cell power plant. The gas stream passes through a simplified purification system which removes essentially all of the sulfur compounds, hydrogen sulfide, and halogen compounds from the gas stream. The resultant gas stream can be used to power a fuel cell power plant which produces electricity, or as a hydrocarbon fuel gas for other applications.

Waste gas treatment system

Sulfur and sulfur compounds are removed from a gas stream, such as a hydrocarbon fuel gas stream so as to render the gas stream suitable for use in a fuel cell power plant. Natural gas and recycled hydrogen enters the hydrodesulfurizer assembly at a temperature of about 120.degree. F. The gas stream is heated to a temperature of about 625.degree. F. whereupon it enters a desulfurizing bed formed from a mixture of platinum catalyst deposited on alumina pellets, and a pelletized zinc oxide hydrogen sulfide absorbent. The gas is cooled to an exit temperature of about 525.degree.F. as it passes through the desulfurizer bed. The desulfurizer bed is combined with a shift converter which reduces carbon monoxide in the desulfurized gas stream after the latter has passed through a steam reformer bed.

Method and apparatus for desulfurizing fuel gas

A steam reformer for converting a reactor fuel into a product gas includes a segmented catalyst bed. The steam reformer side walls have a thermal coefficient of expansion which is greater than the thermal coefficient of expansion of the catalyst. By forming low volume catalyst bed segments in the hotter portions of the catalyst bed, slumping and subsequent damage of the catalyst pellets is minimized. The catalyst bed is divided into segments whose volumes are inversely proportional to the temperatures of the various zones in the reformer. The segments are formed by utilizing sequential catalyst support assemblies which include perforated catalyst support members that are differentially spaced apart from each other by support assembly legs having varying lengths. Catalyst support assemblies with shorter length legs are used in the hotter zones of the reformer, and support assemblies with progressively longer length legs are used in the cooler zones of the reformer.

Catalytic reactor designed to reduce catalyst slumping and crushing

The fuel gas reformer of a fuel cell power plant is provided with burner gas flow baffles which are annular in configuration, and which are concentric with the axis of the burner tube. The annular burner gas flow baffles form annular burner gas flow passages. The reformer has a plurality of annular arrays of catalyst filled tubes disposed in concentric rings about the burner tube. Each of the adjacent catalyst tube rings is separated from the next filled tube ring by one of the annular baffles. Burner gases are deflected downwardly and outwardly by the reformer housing top piece onto the catalyst filled tube rings. The baffles prevent inward flow of the burner gases and direct the burner gases uniformly downwardly along the catalyst filled tubes. Each ring of catalyst filled tubes is thus properly heated so as to enhance reforming of the fuel gas reactant.

Fuel cell power plant reformer burner gas flow control system

The gas stream which emanates from landfills is treated to produce a purified gas which is essentially a hydrocarbon such as methane which can be used as the fuel source in a fuel cell power plant, or can be used in other power plants which use natural gas as a fuel. The landfill gas passes through a system which removes essentially all of the hydrogen sulfide; water; organic sulfur and halogen compounds; and solid contaminants from the gas stream. The resultant purified gas stream can be cleanly flared; used to power an energy plant; or put to other useful purposes.

Landfill gas treatment system

High-purity nitrogen gas is generated by reducing at least the residual oxygen content of at least the cathode exhaust gas stream of a fuel cell device. The oxygen reduction is achieved either by controlling the passage of an oxidant gas through the cathode side of the fuel cell device in such a manner as to increase the oxygen utilization at the cathode side of the fuel cell device relative to the optimum electric power generation operating conditions of the fuel cell device, or by removing most of the residual oxygen from the cathode exhaust gas stream exhausted from the cathode side of the fuel cell device, while maintaining both oxygen and nitrogen contained in the cathode exhaust gas in their gaseous states throughout, or both. Moreover, anode exhaust gas can be reacted in a reformer burner with a reduced amount of excess oxygen and/or the reformer burner exhaust gas can be purified to remove combustion products and/or oxygen therefrom.

Method of generating high-purity nitrogen gas

Sulfur compounds poison catalysts, such as the anode catalysts and reformer catalysts within molten carbonate fuel cell systems. This poisoning is eliminated using a sulfur scrubber 29 located prior to the inlet of the cathode chamber 13. Anode exhaust 19 which contains water, carbon dioxide and possibly sulfur impurities, is combined with a cathode exhaust recycle stream 22 and an oxidant stream 25 and burned in a burner 33 to produce water, carbon dioxide. If sulfur compounds are present in either the anode exhaust, cathode exhaust stream, or oxidant stream, sulfur trioxide and sulfur dioxide are produced. The combined oxidant-combustion stream 27 from the burner 33 is then directed through a sulfur scrubber 29 prior to entering the cathode chamber 13. The sulfur scrubber 29 absorbs sulfur compounds from the combined oxidant-combustion stream 27. Removal of the sulfur compounds at this point prevents concentration of the sulfur in the molten carbonate fuel cell system. Therefore, neither the reformer catalysts nor the anode 17 experience sulfur poisoning.

Molten carbonate fuel cell sulfur scrubber and method using same

Sulfur compounds poison catalysts, such as the anode catalysts and reformer catalysts within molten carbonate fuel cell systems. This poisoning is eliminated using a sulfur scrubber 29 located prior to the inlet of the cathode chamber 13. Anode exhaust 19 which contains water, carbon dioxide and possibly sulfur impurities, is combined with a cathode exhaust recycle stream 22 and an oxidant stream 25 and burned in a burner 33 to produce water, carbon dioxide. If sulfur compounds are present in either the anode exhaust, cathode exhaust stream, or oxidant stream, sulfur trioxide and sulfur dioxide are produced. The combined oxidant-combustion stream 27 from the burner 33 is then directed through a sulfur scrubber 29 prior to entering the cathode chamber 13. The sulfur scrubber 29 absorbs sulfur compounds from the combined oxidant-combustion stream 27. Removal of the sulfur compounds at this point prevents concentration of the sulfur in the molten carbonate fuel cell system. Therefore, neither the reformer catalyst nor the anode 17 experience sulfur poisoning.

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Newington, CT, United States of America

Richard A Sederquist