A numerical comparison of heavy-purge and dual-reflux strategies in pressure swing adsorption for methane enrichment

Abstract

Dual reflux pressure swing adsorption (DR-PSA) has been regarded as a state-of-the-art adsorption-based process which can simultaneously obtain two streams of pure product gases with a narrow pressure window. However, the DR-PSA has not yet been reported in industrial applications. Herein, a DR-PSA and a heavy-purge pressure vacuum swing adsorption (HP-PVSA) were numerically investigated for the enrichment of 1%, 8% and 15% CH4 from N2 gas mixtures in pilot-scale. Key separation indicators such as purity, recovery and energy cost of the two cycles were compared to analyze the limitations of the DR-PSA process while scaling-up. This study reveals the impact of heavy to feed (H/F) ratios on pu..