Simulation and experimental demonstration of helium purification from He/N2 mixtures by pressure swing adsorption

Terrestrial helium is an indispensable non-renewable resource used in medicine, space, electronics, and nuclear research. This paper reports a high-pressure five-step pressure swing adsorption (PSA) cycle using Zeolite 5A for purification of He from dilute He/N 2 mixtures. A Dual-Site Langmuir (DSL) model fitted both the low-pressure N 2 and high-pressure N 2 isotherm data. Dynamic column breakthrough (DCB) experiments were used to confirm volumetric equilibrium loadings. The DCB model predicted the experimental breakthrough curves for a wide range of feed compositions (100% N 2 , 74.5% N 2 , and 51.5% N 2 ) and feed pressures (1 bar and 11.2 bar). A large experimental campaign studied the impact of various operating conditions on the He purity and recovery achievable from the PSA process. The study showed that a single-stage PSA experiment could enrich He up to 13% purity with greater than 90% recovery from a feed containing 1% He. Helium purity of 95% and a recovery of 90% can be achieved from a feed containing 10% He. All trends were predicted well by numerical simulations. A multi-objective optimization was performed to maximize helium purity and recovery for various He feed compositions. The study also showed that points from the Pareto curve can be realized experimentally.