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.