Total Integrated Operation of Gasifier, Hot Gas Desulfurizer, and SEWGS Process for Pre-combustion CO2 Capture Using Real Syngas from Coal

摘要

SEWGS (Sorption Enhanced Water Gas Shift) process is one of options for pre-combustion CO2 capture using dry absorbent and water gas shift catalyst. In this process, the thermodynamic equilibrium in the shift reaction can be enhanced to give more hydrogen yield by adding a CO2 absorbent into the shift reactor. Total integrated system consists of coal gasifier, hot gas clean-up process (two interconnected fluidized bed desulfurizer), and one loop SEWGS process. In this presentation, continuous operation results of the hot gas clean-up process and one loop SEWGS process using dry absorbents at high temperature and pressure conditions were discussed. Dry absorbents (for desulfurization, CO2 absorption) were produced by KEPCO RI (Korea Electric Power Corporation Research Institute) by means of spray-drying method. Continuous operation was performed at high pressure (21 bar for gasifier, 20 bar for hot gas clean-up process, and 18 bar for SEWGS process) and reaction temperature was 550°C for desulfurizer and 236°C for SEWGS reactor. Totally integrated operation was maintained up to 50 hours. We could get high sulfur capture efficiency (99.6%) in the desulfurizer, high CO conversion (98.9%) and CO2 capture efficiency (98.0%) in the SEWGS reactor.