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

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.