Parametric optimization for power de-rate reduction in the integrated coal-fired power plant with carbon capture and storage

Abstract

Carbon capture and storage (CCS) has attracted worldwide attention as a near-term technology to decelerate global warming. Postcombustion CO2 capture utilizes existing coal-fired power plants, and aqueous monoethanolamine (MEA) scrubbing is the most common capture technology. However, the heat and energy requirements of solvent regeneration and CO2 liquefaction cause a 30% decrease in net power output. This power de-rate is a major obstacle to implementing CCS. In this study, simulation-based parametric optimization was performed to minimize the power de-rate. Postcombustion CO2 capture with aqueous MEA scrubbing (85%, 90%, and 95% removals) and CO2 liquefaction integrated with a 550 MWe supercritical coal-fired power plant was simulated. The liquid to gas ratio and stripper operating pressure of the CO2 capture process were the manipulated variables with steam extracted from the intermediate pressure-low pressure crossover pipe and the first low pressure turbine as possible heat sources. The power de-rate was reduced to 17.7% when operating at optimum conditions.