摘要:
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.
摘要:
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.
摘要:
Compact reaction apparatus, such as for steam reforming a hydrocarbon feedstock to produce hydrogen, includes a plurality of reactor tubes disposed within a furnace. A portion of each reactor extends into the burner cavity or combustion volume of the furnace. Baffles, such as sleeves, are disposed around these portions of the reactor tubes to shield the tubes from excessive radiant heat from the wall of the burner cavity and to more evenly distribute heat among and around all of the reactors. These baffles permit the reactor tubes to be closely packed within the furnace and reduce temperature differences between the tubes.
摘要:
A fuel cell system is provided that is capable of operating at high temperatures and near-ambient pressure with partial humidification of air supplied to the fuel cell stack. The fuel cells of the stack incorporate gas diffusion barrier layers at the cathode side thereof. The system includes a cooling loop for circulating a liquid coolant through the stack. In some embodiments, an incoming air stream is partially humidified with water vapor transferred from a cathode exhaust stream in a gas-exchange humidifier or enthalpy wheel. In other embodiments, a cathode recycle is employed to partially humidify the incoming air. The humidity of the air and cathode exhaust streams is maintained below a stack saturation point. Methods of operating the fuel cell system are also provided.
摘要:
A fuel processing system is operative to remove substantially all of the sulfur present in a logistic fuel stock supply. The fuel stock can be gasoline, diesel fuel, or other like fuels which contain relatively high levels of organic sulfur compounds such as mercaptans, sulfides, disulfides, and the like. The system is a part of a fuel cell power plant. The fuel stock supply is fed through a reformer where the fuel is converted to a hydrogen rich fuel which contains hydrogen sulfide. The hydrogen sulfide-containg reformer exhaust is passed through a sulfur scrubber, to which is added a small quantity of air, which scrubber removes substantially all of the sulfur in the exhaust stream by means of the Claus reaction. The desulfurizing step causes sulfur to deposit on the scrubber bed, which after a period of time, will prevent further sulfur from being removed from the reformer exhaust stream. The sulfur scrubber station is rejuvenated by passing a gas stream containing a relatively small amount (about 1% by volume) of carbon monoxide. The carbon monoxide is converted to carbonyl sulfide which is then burned in power plant burner so as to form sulfur dioxide in the power plant exhaust stream.
摘要:
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.
摘要:
An apparatus, process and use for making hydrogen from a hydrocarbon feedstock and steam using heat stored in a vessel followed by the regeneration of the vessel to restore the heat. Regeneration is done by preheating within the vessel a hydrogen purge gas and regeneration combustion products recycle and mixing the preheated gases with an oxygen containing gas so that they combust within the vessel in a fuel rich mode and heat material disposed in the vessel. This is the heat which is used in converting the hydrocarbon feedstock to hydrogen. The regeneration combustion products are recycled (and substituted for the cooling capacity of the oxygen containing gas) to recover the heat remaining in the vessel following the hydrogen make cycle simplifying reactor bed design and improving operational flexibility. The process is applied to provide hydrogen to a fuel cell.
摘要:
Electrolyte vapor entrained in the hot exhaust gas stream from a fuel cell is removed by passing the gas stream through a saturator, over high surface area material, in direct contact with water circulating in a loop which also passes through the saturator. The hot gas stream evaporates a small portion of the water, resulting in cooling of the gas stream and condensing of electrolyte therein as it cools. The electrolyte dissolves into the recirculating water. The water is exchanged at predetermined intervals or when the concentration of electrolyte reaches a predetermined level. At least 99% of the electrolyte can be removed from the gas stream in this manner.
摘要:
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.
摘要:
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.