Effect of intermittent purge on O2 production with rapid pressure swing adsorption technology

The rapid pressure swing adsorption (RPSA) technology has been widely used for applications including portable oxygen generators due to high O2 productivities and low bed size factors (BSF, total amount of adsorbent per ton of O2 produced per day, kg/TPDO2). The improvement of RPSA process has been a key issue for efficient O2 production in terms of its generally lower O2 recovery as compared to other processes. In this work, a dual-column RPSA oxygen production system with an intermittent purge step (intermittently switching between purge and interruption) was designed to investigate the effects of interruption frequency (the number of interruptions during a purge step) and times on the O2 recovery, purity, productivity and BSF. Experimental results show the improvement on O2 production performance using the intermittent purge step in comparison to conventional continuous purge step. Under the optimized interruption frequency of 2 and time of 0.3 s, the O2 recovery, purity and productivity were increased from 36 to 39.2%, 89.5 to 93%, and 6.24 to 6.49 mmol/kg/s, respectively, while the BSF was decreased from 57.94 to 55.75 kg/TPDO2.