Simulation of a sorption-enhanced water gas-shift pilot technology for pure hydrogen production from a waste gasification plant

This study has analysed and optimised a 5-column sorption enhanced water gas shift (SEWGS) pilot unit, set to operate for the first time in a waste gasification facility for the production of transport-grade hydrogen and CO2 streams. Full process simulation was undertaken by developing a one-dimensional model of each reactor, with boundary conditions directly informed by real plant operation. From the sensitivity analysis performed, syngas flowrate variations were seen to have a minor but temporary, impact on hydrogen product specifications, while changes to syngas composition were shown to have a longer-lasting effect on system performance. Based on full cycle operation results, the current 5-column SEWGS unit design was concluded to be inadequate for fuel-cell-grade H2 production, despite obtaining a high H2 purity of 99.5%, mainly due to its excessive steam consumption. However, the process achieved an exceptionally high CO2 purity of 99.9%, and 88.6% hydrogen recovery rate, suggesting its potential use in carbon capture and heat-grade hydrogen production applications.