(125d) An Energy-Saving CO2 Gas Separation Based on Self-Heat Recuperation in Pre-Combustion Capture

The effects of global warming through increasing global energy consumption are currently becoming more obvious. Thus, it is necessary to have an adequate discussion about mitigating global warming. It is believed that anthropogenic emissions of greenhouse gases (GHGs) are a factor in global warming, and one of the major gases involved is CO2 gas. Thus, some approaches for CO2 reduction and energy saving have been proposed in industrial processes. Power generation plants using fossil fuels exhaust large amounts of CO2 gas.

The integrated coal gasification combined cycle (IGCC) can achieve higher power generation efficiency than conventional pulverized coal combustion power plants. However, IGCC with a CO2 separation does not improve power generation efficiency, 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 energy saving by self-heat recuperation (SHR). Pre-combustion capture was applied in the IGCC plant, which involved coal gasification and CO-shift conversion with CO2 separation. The results show that the energy consumption for the CO2 separation using SHR was decreased by two thirds. This means that the electric generation efficiency can be improved by SHR compared with conventional IGCC with a CO2 separation.