Four-bed vacuum pressure swing adsorption for xenon recycling from semiconductor waste gas

Abstract

The development of the space industry, increasing semiconductor production, and growing demand for medical xenon has significantly boosted the xenon market. However, the commercial production of cryogenic distillation is an energy intensive process and results in economic and environmental issues. In this study, experimental adsorbent data collection and a vacuum pressure swing adsorption (VPSA) simulation are presented for recovering and purifying xenon from semiconductor waste gas containing 0.1 mol% Xe and 99.9 mol% N2. FMOFCu was used for xenon adsorption, and the adsorption data were collected through isotherm and breakthrough experiments using Xe and N2. Further, the VPSA process was designed and parametric studies were conducted using gPROMS simulations based on experimental data. Consequently, 99.9 % of the xenon product was produced through a two-stage VPSA process, and an economic and environmental evaluation of the produced xenon was conducted. The minimum selling price of the produced xenon ranged from 554.42 to 1482.08 $/kgXe, which was more than 1000 $/kgXe lower than the current wholesale price of xenon. The electricity consumption of the proposed VPSA process was 40.99 kWh, and the calculated global warming potential was 28.92 kg CO2 eq for 1 kg of Xe produced. Therefore, the proposed VPSA process was economical and environmentally sustainable.