Energy Conversion and Management, Vol.194, 124-139, 2019
The retrofitting of a coal-fired subcritical steam power plant for carbon dioxide capture: A comparison between MCFC-based active systems and conventional MEA
The major technological driver in energy and industrial sectors is the reduction of CO2 emissions. Huge technological effort is ongoing towards efficiency improvement of conversion systems, to reduce fossil fuel consumption. Capture and sequestration of CO2 on the flue gases represents an invaluable technology and among the only ones able to sustain the fossil fuel energy economy which cannot be replaced in short-term. In many cases, it produces significant energy penalties on the reference plant, being implemented through passive systems. In other cases, defined as active systems, it fulfils the goal of carbon capture without energy consumption or with energy production. In this regard, Molten Carbonate Fuel Cell (MCFC) concentrates CO2 at the anode exhaust, making easier the separation phase and increasing, also, electrical energy production. Therefore, a physically-based model of the MCFC was developed to assess the positive aspects related to the CO2 remover application, when it is integrated to a 250 WV coal-fired power plant. The removal capacity has been evaluated up to 95% and the calculated additional electricity produced can increase the overall efficiency of about 4% with respect to original value. The steam needed by the fuel cell can be extracted from the original steam power plant or it can be produced by a dedicated steam generator. These two options have been compared in terms of energetic and environmental performance. A cost analysis has been done in order to evaluate the best integration opportunity and to provide a comparison to a more conventional MEA (monoethanolamine) system.