Economical Configuration of Oxygen-Enriched Air Production Process Using Polysulfone-Based Composite Membranes

Oxygen-enriched combustion technology is an emerging incineration method suitable for waste treatment. In this study, we investigated an economical modular configuration method for oxygen-enriched air production using gas separation membrane technology. Various module configurations were examined based on input pressure, gas temperature, sweep, and multistage module arrangement, and an optimal economically viable configuration was proposed. Using a polysulfone-based polymer membrane module, oxygen-enriched air with an oxygen concentration of 40–65% was produced. Even in cases of low input pressures achieved using a vacuum pump at the permeate side, oxygen-enriched air with concentrations >40% was achieved, with an approximately 20% increase in the permeation flow rate. As the permeation rate increased with increasing temperature, the oxygen recovery efficiency decreased. When the membrane area was increased, the corresponding increase in the input pressure did not result in a proportional increase in the permeation rate compared with single-module setups. Through multistage module arrangements, oxygen-enriched air with a maximum oxygen concentration of 66% was produced. By employing sweep that recirculated a portion of input air to the permeate side, the production of oxygen-enriched air was enhanced by approximately 38%. Therefore, the proposed process involving low input pressure, vacuum pumps, and sweeping was optimal for oxygen-enriched air production.