CONCENTRATION OF A TRACE COMPONENT BY PRESSURE SWING ADSORPTION

The possibility of concentrating a trace component by pressure swing a dsorption is examined both theoretically and experimentally. During th e blowdown of an equilibrated adsorption column the lighter component is desorbed first so that the adsorbed phase becomes progressively enr iched in the more strongly adsorbed species. If the selectivity is hig h, most of the lighter component can be removed by atmospheric blowdow n and the more strongly adsorbed species may then be recovered, in con centrated form, by vacuum desorption. The practical feasibility of a c ryogenic PSA process as a means of concentrating traces of hydrogen fr om a helium carrier is demonstrated. Hydrogen may be recovered at grea ter than 90% purity and approximately 80% recovery from a feed contain ing less than 0:2% hydrogen in helium.