Performance analysis of VPSA process for separating N2O from adipic acid tail gas

A four-bed and six-bed vacuum pressure swing adsorption (VPSA) process with silical gel were proposed to separate and purify N2O from adipic acid tail gas (N2O/N-2/O-2 = 0.3933/0.5657/0.041 mol%) in nylon plants and then the N2O could be rectified to produce ultra-high purity N2O. The four-bed VPSA process was developed to study the relationship between vacuum pressure and simulation performances, the resulting recovery of N2O exceeds 90% with a purity over 95%. Meanwhile, the six-bed process was designed to explore the effects of vacuum and feed flow rate. The results indicated that a 95.55% purity N2O stream is attained for a process N2O recovery of 97.45%, when the feed flow rate was 1434.8 NL/s and vacuum pressure was 0.247 bar and N2O energy was 4.95 KJ/mol N2O respectively.