4E analysis of two novel H2S concentrators in dual-stage Selexol process of integrated gasification combined cycle

Abstract

Syngas purification unit of integrated gasification combined cycle (IGCC) has a significant impact on environmental and economic benefits. Dual-stage Selexol process of IGCC can simultaneously capture both CO2 and H2S. Two novel H2S concentrators in dual-stage Selexol process had been studied. Pressure drop method as the focus of this paper, 4E analysis method of two cases (depressurization combined with stripping and single depressurization) was applied. Two models of Selexol process were developed by ASPEN PLUS and validated by existing reports. The simulated results indicated that depressurization combined with stripping method had lower utilities consumption, 6.89 MW less in exergy destruction, 6.51 million dollars less in total annual cost, and better environmental benefit, comparing with single depressurization method, and this method also consumes less energy and costs up to 9.6 % less on capital cost than the traditional single stripping method. However, single depressurization method had better performance in H2 recovery and less system complexity. The sensitivity analysis is also employed to study the impact of some key parameters on 4E analysis. This study can be used as a comparative reference for advanced syngas purification technologies.