Staged water-gas shift configuration: Key to efficiency penalty reduction during pre-combustion decarbonisation in IGCC

This paper presents the results of system assessments that were conducted to compare conventional and advanced water-gas shift reaction section in Integrated Gasification Combined Cycles (IGCC) with pre-combustion CO2 capture. The advanced shift reaction section comprises four staged reactors with distributed feeds of syngas and quench water in between the reactors. This configuration reduces the steam requirement of the shift reaction up to 70% in comparison with conventional configurations, at carbon capture ratios of approximately 85%. The specific lost work per amount of CO2 was used to determine the optimum carbon capture ratio for each case.