Integrating mid-temperature solar heat and post-combustion CO2-capture in a coal-fired power plant

Abstract This article proposed a hybrid power system combining mid-temperature solar heat and a coal-fired power plant for CO2 capture. In this system, solar heat at around 300 °C replaces the high-quality steam extractions of the Rankine cycle to heat the feed water, so the steam that was to be extracted can expand efficiently in the high-pressure turbines. In this hybrid system, the CO2 capture penalty is completely compensated for by the enhanced work output contributed by the solar heat. The annual solar field cost is reduced to 10.8 $/ton-CO2, compared to 25.8 $/ton-CO2 in a system with solar heat for direct solvent regeneration. Additionally, the mid-temperature solar heat is converted into work with an improved efficiency of 27%. Thus, this system offers a promising approach to reduce the CO2 capture penalty in CCS with attractive cost-effective utilization of mid-temperature solar heat.