High-efficiency negative-carbon emission power generation from integrated solid-oxide fuel cell and calciner

Abstract

Direct air capture of CO2 has the potential to help meet the ambitious environmental targets established by the Paris Agreement. This study assessed the techno-economic feasibility of a process for simultaneous power generation and CO2 removal from the air using solid sorbents. The process uses a solid-oxide fuel cell to convert the chemical energy of fuel to electricity and high-grade heat, the latter of which can be utilised to calcine a carbonate material that, in turn, can remove CO2 from the air. The proposed process was shown to operate with a net thermal efficiency of 43.7–47.7%LHV and to have the potential to remove 463.5–882.3 gCO2/kWelh, depending on the fresh material used in the calciner. Importantly, the estimated capital cost of the proposed process (1397.9–1740.5 £/kWel,gross) was found to be lower than that for other low-carbon emission power generation systems using fossil fuels. The proposed process was also shown to achieve a levelised cost of electricity of 50 £/MWelh, which is competitive with other low-carbon power generation technologies, for a carbon tax varying between 39.2 and 74.9 £/tCO2. Such figure associated with the levelised cost of CO2 capture from air is lower than for other direct air concepts.