Experimental study on oxygen concentrator with wide product flow rate range: individual parametric effect and process improvement strategy.

[Display omitted] • Flexible improvement on PSA O 2 production at wide product flow rate range is studied. • Individual effects of process parameters on O 2 production performance are obtained. • Adjusted/unadjusted PSA experiments using appropriate valve settings are conducted. • Process improvement strategies for different product flow rate ranges are proposed. • Higher O 2 purity, recovery and productivity with lower energy consumption are gained. Improvement on oxygen (O 2) concentrator using pressure swing adsorption (PSA) technology according to variable product demands is of great significance, which, for instance, provides the key step for success in practical O 2 therapy for COVID-19 patients who need to be delivered with a wide product flow rate range (1–15 standard liter per minute (SLPM)) of medical O 2 (purity > 82%). This work studied the individual effects of major PSA process parameters on O 2 production performance at the product flow rate of 3.46–19.88 SLPM (0.64–3.68 SLPM per kilogram of adsorbent (SLPM/kg)), based on a self-designed two-bed PSA unit with a modified Skarstom cycle using Li-LSX zeolite adsorbents. The improvement strategies were accordingly proposed based upon influential mechanisms of each parameter: 1) at lower product flow rates (≤2.00 SLPM/kg), increasing the purge flow rate and decreasing the adsorption pressure to suppress excess O 2 adsorption, and decreasing the feed flow rate to ensure low energy consumption; 2) at higher product flow rates (≥2.00 SLPM/kg), decreasing the purge flow rate and increasing the adsorption pressure to eliminate N 2 breakthrough and O 2 -rich product waste, and appropriately increasing the feed flow rate to enhance cost-effectiveness. An improved set of parameters rendered O 2 purity (95.67–74.86%), recovery (11.28–49.05%), productivity (0.47–2.04 mmol/kg/s) increased by up to 3.52–20.08%, 0.36–20.47%, 6.82–19.61%, and energy consumption (4.07–0.95 kWh/kgO 2) decreased by up to 10.56–18.10%, in comparison to two conventional sets, respectively. The results are beneficial for developing intellectualized and flexibly-controlled O 2 concentrators for practical applications. [ABSTRACT FROM AUTHOR]