The concentration of trace hydrogen from helium carrier gas was conducted by cryogenic pressure swing adsorption, using the molecular sieve 5A as adsorbents in a fixed column. Hydrogen may be recovered at greater than 90% purity from a feed containing 0.5% hydrogen in helium. A model including axial diffusion coefficient with tridimensional graphic simulation results shows good agreement with the experimental results. (C) 2003 Elsevier B.V. All rights reserved.