Integrated power generation and carbon capture using fuel cells
AssigneeExxonMobil Research and Engineering Company
InventorsPaul J. Berlowitz, Timothy Andrew Barckholtz, Frank H. Hershkowitz
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Abstract
Systems and methods are provided for capturing CO2 from a combustion source using molten carbonate fuel cells (MCFCs). At least a portion of the anode exhaust can be recycled for use as part of anode input stream. This can allow for a reduction in the amount of fuel cell area required for separating CO2 from the combustion source exhaust and/or modifications in how the fuel cells can be operated.
Claims21
A method for capturing carbon dioxide from a combustion source, said method comprising:
- capturing an output stream from a combustion source, the captured output stream comprising oxygen and carbon dioxide;
- processing the captured output stream with a fuel cell array of one or more molten carbonate fuel cells to form a cathode exhaust stream from at least one cathode outlet of the fuel cell array, the one or more molten carbonate fuel cells comprising one or more fuel cell anodes and one or more fuel cell cathodes, the one or more molten carbonate fuel cells being operatively connected to the captured output stream from the combustion source through at least one cathode inlet;
- reacting carbonate from the one or more fuel cell cathodes with H2 within the one or more fuel cell anodes to produce electricity and an anode exhaust stream from at least one anode outlet of the fuel cell array, the anode exhaust stream comprising CO2 and H2;
- passing the anode exhaust stream through a water gas shift reaction stage to form a shifted anode exhaust stream;
- separating carbon dioxide from the shifted anode exhaust stream in one or more separation stages to form a shifted CO2-depleted anode exhaust stream;
- and
- recycling at least a portion of the shifted CO2-depleted anode exhaust stream to the one or more fuel cell anodes, at least a portion of the H2 reacted with carbonate comprising H2 from the recycled at least a portion of the shifted CO2-depleted anode exhaust stream.
A method for capturing carbon dioxide from a combustion source, said method comprising:
- capturing an output stream from a combustion source, the captured output stream comprising oxygen and carbon dioxide;
- processing the captured output stream with a fuel cell array of one or more molten carbonate fuel cells to form a cathode exhaust stream from at least one cathode outlet of the fuel cell array, the one or more molten carbonate fuel cells comprising one or more fuel cell anodes and one or more fuel cell cathodes, the one or more molten carbonate fuel cells being operatively connected to the captured output stream from the combustion source through at least one cathode inlet;
- reacting carbonate from the one or more fuel cell cathodes with H2 within the one or more fuel cell anodes to produce electricity and an anode exhaust stream from at least one anode outlet of the fuel cell array, the anode exhaust steam comprising CO2 and H2, a fuel utilization of the one or more fuel cell anodes being about 60% or less;
- separating carbon dioxide from the anode exhaust stream in one or more separation stages to form a CO2-depleted anode exhaust stream;
- and
- recycling at least a portion of the CO2-depleted anode exhaust stream to the one or more fuel cell anodes, at least a portion of the H2 reacted with carbonate comprising H2 from the recycled at least a portion of the CO2-depleted anode exhaust stream.
Dependencies are inferred from the claim text.