ICOPE-15-1037 Development of Advanced Integrated coal Gasification Combined Cycle (A-IGCC) Power Generation Systems with a Gas Treating Unit

Abstract

Advanced Integrated coal Gasification Combined Cycle (A-IGCC) systems have been proposed to obtain higher power generation efficiency than IGCC systems by recycling the exhaust heat from a gas turbine as the heat source of the gasifier. To date, the A-IGCC system including gasification, gas treating including CO_2 capturing and combined cycle power generation units has not been designed. In this study, the performances of A-IGCC systems with these units were evaluated by using process simulator Aspen Plus[○!R] ver. 7.2. Results showed the net thermal efficiencies of A-IGCC models with water gas shift (WGS) and CO_2 capturing units were lower than that of models without these units by 3.5-5.2% because of reduction in gas turbine and steam turbine outputs and additional heat and electricity input to CO_2 capturing unit. Net thermal efficiency of the A-IGCC system with the hot gas desulfurization unit was higher than that with the cold gas desulfurization unit (CGDU) by 1.4-3.1% owing to decrease in heat loss in coolers at CGDU, subsequent increase of heating value of fuel gas into the gas turbine combustors. The CO_2 emission factor can be reduced from 744-769 kg-CO_2/MWh to 117-137 kg-CO_2/MWh by capturing of approximately 85% of CO_2 after WGS.