Techno-economic analysis of the effects of heat integration and different carbon capture technologies on the performance of coal-based IGCC power plants

Abstract

Coal-based Integrated Gasification Combined Cycle (IGCC) power plants show obvious gains over conventional pulverized coal power plants by achieving higher efficiency, lower carbon emissions and lower energy penalty for incorporating different carbon capture and storage (CCS) technologies. However, due to the lack of standardised designs, current IGCC-CCS projects are hindered by higher capital expenditures limiting their commercial implementation. Therefore, the key challenge is carrying out a techno-economic optimisation of IGCC-CCS power plants to ensure compatible power generation efficiency and accessibility. This study aims to optimise the performance of a coal-based IGCC plant with two different CCS technologies (double-stage Selexol absorption cycle and Ni-based chemical looping combustion (CLC) process) through intensive process simulation, heat integration and economic analysis. Heat integration has increased the net plant efficiency by more than 12% and decreased the levelised cost of electricity (LCOE) no less than 5 cents kWh−1. The CLC technology offered near-zero carbon emissions with higher plant efficiency and lower value of LCOE. Decreasing the CO2 capture rate by Selexol caused a decrease in LCOE and an increase in the corresponding CO2 specific emissions. Therefore, an appropriate decarbonisation scenario depends on a trade-off between the degree of carbon capture and the allowed CO2 specific emissions.