Economic and operational assessment of solar-assisted hybrid carbon capture system for combined cycle power plants

The paper presents a post-combustion CO2 capture process which involves two configurations for enhancing the CO2 separation driving force in the conventional amine-based Carbon Capture System (CCS): a multi-stage membrane module for selective exhaust gas recirculation (SEGR case) and the combination of turbine exhaust gas recirculation with SEGR (EGR + SEGR case). Furthermore, the stripper reboiler in both configurations is integrated with a parabolic trough solar collector field with a 4-h thermal energy storage to provide the required thermal duty for solvent regeneration. Various system components are designed, simulated, and integrated with an economic model to evaluate the system's techno-economic performance across a wide range of loads. The results show that the proposed designs have efficient part-load performance although efficiency degradation is inevitable during partial-loads. A stable supply of solar thermal energy results during the partial operation of NGCC even during night. The EGR + SEGR case represents the case with the lowest levelized cost of electricity and CO2 avoided cost, 81.43 $/MWh and 101.66 $/tonneCO2, among the CCS-equipped designs, which highlight the advantages of this design over baseline and SEGR case. The proposed hybrid system shows promise for significantly decarbonizing fossil-fuel power plants and increasing power sector flexibility.