Integrated dual-stage VPSA with distillation process for the recovery of xenon from spent nuclear reprocessing off-gas

Xenon (Xe) recovery from nuclear off-gas (0.04% Xe) is valuable but challenging for single-technology methods to achieve both high recovery and purity. This study proposes a novel integrated process that couples a dual-stage vacuum pressure swing adsorption (VPSA) system with cryogenic distillation for efficient Xe recovery with high recovery and ultra-purification. Experimentally determined adsorption data on H-ZSM-5 zeolite informed the simulation. The dual-stage VPSA processes consist of a stripping reflux VPSA stage for flow reduction and pre-concentration of Xe, a dual reflux VPSA stage for Xe deep purification, and cryogenic distillation unit for final purification of Xe. Simulation results demonstrate that under optimized conditions, the integrated system achieves an overall Xe recovery of 98.70% and a Xe product purity >99.998%, And the specific energy consumption of xenon produced in the optimized integrated process is 489.56 MJ/kg Xe. This integrated strategy effectively overcomes the limitations of single separation technologies and provides a reliable technical pathway for recovering high-value components from nuclear off-gas and similar dilute gas streams with low energy consumption.