H2 pressure swing adsorption for high pressure syngas from an integrated gasification combined cycle with a carbon capture process

The integrated gasification combined cycle (IGCC) process, possessing high efficiency and environmental advantages, produces H2-rich syngas at high pressures (30-35 bar) after capturing CO2. Since the syngas pressure is very high for conventional PSA processes, development of an efficient PSA process at the pressure conditions is required for H2 production. In this study, the H2 PSA process for IGCC syngas was developed experimentally and theoretically. Breakthrough and PSA experiments using activated carbon or activated carbon/zeolite LiX were performed at 25-35 bar by using a five-component hydrogen mixture (H2:CO:N2:CO2:Ar = 88:3:6:2:1 mol%) as a simulated syngas. The overall PSA performance was evaluated in terms of the purity, recovery and productivity of H2 product. According to the results from using single or layered beds, the two-bed PSA process produced 99.77-99.95% H2 with 73.30-77.64% recovery experimentally. A four-layered bed PSA at 35 bar was able to produce 99.97%-purity H2 with 79% recovery, and it contained Ar and N2 impurities. The quality of tail gas from the PSA process could be used for the gas turbine without losing H2 and CO. A rigorous mathematical model that included mass, energy, and momentum balances was employed to elucidate the dynamic behaviors and separation performance of the adsorption bed and PSA process.