Integration of a coal fired power plant with calcium looping CO2 capture and concentrated solar power generation: Energy, exergy and economic analysis

Abstract

In conventional calcium looping (CaL) CO2 capture process, the heat of calcination is provided by burning additional fuel in the calciner that leads to thermal efficiency drop of the power plant. Coupling of CaL with concentrated solar power (CSP) can supply required heat and improve its drawback. In this study, a CaL-CSP system has been modeled to integrate with a 500 MW coal-fired power plant. Moreover, two steam cycles were designed to effectively recover available heat sources. The performance of the system was evaluated by employing energy, exergy and economic analysis. For CO2 capture efficiency of 93%, the calciner requires 1293 MWth thermal power which was supplied by heliostat field with efficiency of 88.56%. The net electrical efficiency of the overall system and the levelized cost of electricity were determined 33.22% and 120.27 $/MWh respectively. The results showed that the designed system does not impose any thermal efficiency drop on the power plant and its economic performance is competitive with other CO2 capture technologies. The exergy analysis indicated that the calciner side had a lower exergy efficiency (82.61%) in comparison with the carbonator side (88.51%) due to the higher exergy destruction in the calciner reactor and the compression unit.