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.