Performance analysis of the acid gas removal from syngas based on self-heat recuperation technology

Abstract

Considering the high energy consumption of the acid gas removal (AGR) unit in integrated gasification combined cycle (IGCC) systems, this paper innovatively combines the two self-heat recuperation technology (SHRT) forms with the syngas purification process. The AGR unit and the power generation unit in this paper are simulated by Hysys V11. By establishing the energy balance and exergy balance equation for each component, the change of energy consumption and exergy loss of the unit before and after the process modification is analyzed. Compared with the two improved methods, Case1 uses low-pressure water as the working medium of SHRT process, which has the characteristics of high COP of heat pump and low throttling loss, and achieves good results in terms of operating cost and exergy loss. Case1 has 3.75% lower operating cost compared with the basic process, the annual operating cost of H2S removal is reduced by 144,200$, and the exergy loss of the AGR unit is reduced by 23.48 kW. Case2 does not have advantages under the two evaluation indexes. Subsequently, sensitivity analysis of the inlet pressure of Case1 heat pump exchanger further improves the energy-saving potential of this retrofit solution. The article explains the effect of the SHRT process in the AGR unit on the exergy loss of the rich solvent regeneration process and the distillate cooling process, and verifies the energy-saving potential of the SHRT in the acid gas removal unit of IGCC.