Patent ID: 7452407

Claim:
A process for generating an essentially carbon monoxide-free hydrogen gas stream, the process comprising: (a) (i) feeding a high-purity hydrogen gas feed stream for around 30 minutes or more through a first of two adsorbers that are fluidly connected in parallel or in series and that are each packed with an adsorbent consisting of a zeolite which is cation exchanged with a metal other than a transition metal and which contains less than about 0.5% by weight of a transition metal, and (ii) recovering a first essentially carbon monoxide-free hydrogen gas stream from the first adsorber; (b) thereafter purging the first adsorber by (1) depressurizing it to less than atmospheric pressure, and by (2) (i) recycling a portion of the first essentially carbon monoxide-free hydrogen gas stream through the first adsorber, and/or (ii) feeding an inert gas stream through the first adsorber; and (c) as the first adsorber is purged, feeding a second portion of the high-purity hydrogen gas feed stream for around 30 minutes or more through the second of the two adsorbers and recovering a second essentially carbon monoxide-free hydrogen gas stream from the second adsorber.