Molten Carbonate Fuel Cells (MCFC) for the carbon capture in Energy-from-Waste (EfW) plants

This paper explores the Molten Carbonate Fuel Cell (MCFC) technology for CO2 capture from the flue gas of a state-of-the-art Energy-from-Waste (EfW) plant. The possible layout of the MCFC section is defined and discussed, as well as auxiliary equipment and the needed changes for the upstream EfW plant. Mass and energy balances are drawn, and the overall performances of the proposed system are presented in comparison with those of a reference EfW plant without CO2 capture, and a benchmark case with amine-based CO2 capture. The MCFC-based plant requires an increased energy input (+48%) to be provided by Natural Gas, exploited to capture 90% and 100% respectively of the carbon content of waste and NG. Moreover, the proposed configuration features increased power output (+90%) and electric efficiency (+10%) while co-generating the same thermal power of the reference case and increasing the capacity of cogeneration of about 3%. These excellent performances compare with those of the benchmark plant, which achieve the same carbon capture by giving up between 10 and 11 percentage point of electric efficiency. The Specific Primary Energy for Carbon Avoidance appears to be below 1 MJ/kg for the MCFC-based plant, against about 2.4 MJ/kg of the benchmark case.