Exergy recuperative CO2 gas separation in pre-combustion capture

Abstract

The integrated coal gasification combined cycle (IGCC) can achieve higher power generation efficiency than conventional pulverized coal combustion power plants. However, a CO2 capture process prevents improving power generation efficiency of IGCC, because CO2 separation from gas mixtures requires huge amounts of energy. Therefore, in this study, we analyzed the CO2 separation process in the pre-combustion capture process using a process simulator (PRO/II) in the steady state, and proposed a new process using a modularity based on self-heat recuperation (SHR) technology to decrease energy consumption. Pre-combustion capture was applied in the IGCC plant, which involved coal gasification and CO-shift conversion with CO2 capture. The results show that the energy consumption for the CO2 separation process using SHR was decreased by two-thirds. This means that the power generation efficiency can be improved by SHR compared with conventional IGCC with a CO2 capture process.