Using MCFC for high efficiency CO2 capture from natural gas combined cycles: Comparison of internal and external reforming

In recent years, several research groups have proposed the combination of Molten Carbonate Fuel Cells (MCFCs) and gas turbine cycles for the application to CO2 capture. One of the most promising configuration relies on the use of MCFCs as “active CO2 concentrator” in combined cycles (CCs): the fuel cell is placed downstream the gas turbine and ahead the heat recovery steam generator (HRSG), to concentrate the CO2 from the gas turbine exhaust feeding the cathode, to the anode (where CO2 is transferred together with oxygen) and generate electricity; while exhaust heat released by the cell effluents is recovered by the steam cycle. It has been shown that such plant configuration can capture 70–85% of CO2 with small efficiency penalties compared to the combined cycle, and increasing by about 20% the overall power output (mainly given by the MCFC section); hence, this configuration could have relevant advantages with respect to competitive carbon capture technologies.