Abstract: The present invention involves a process for separating and purifying gas mixtures comprising H.sub.2, CO and C.sub.1 + hydrocarbons. The gas is initially cooled in a high pressure dephlegmator to condense and rectify the C.sub.1 + hydrocarbons leaving a combined H.sub.2 --CO vapor. The condensed C.sub.1 + hydrocarbons are partially vaporized and subsequently recondensed in a second, low pressure dephlegmator with further rectification. This process yields H.sub.2 --CO vapor streams and a C.sub.1 + liquid hydrocarbon product at purities suitable for subsequent commercial operations.

Abstract: In the process for purifying hydrocarbon gas streams containing hydrogen sulfide and carbon dioxide as impurities by contact thereof with zeolitic molecular sieve adsorbents to selectively adsorb the impurities, the formation of carbonyl sulfide by the zeolite catalyzed reaction of H.sub.2 S with CO.sub.2 is greatly suppressed by employing as the selective adsorbent certain cation forms of molecular sieve zeolites which contain from 0.7 to 3 weight percent adsorbed water.