Olefin purification by adsorption of acetylenics and regeneration of

Abstract

Processes using heterogeneous adsorbents are disclosed for purification of relatively impure unsaturated hydrocarbons such as olefins, which are typically produced by thermal cracking of suitable hydrocarbon feedstocks, by passing a feed stream, containing acetylenic impurities, and, optionally, saturated hydrocarbon gases, through a particulate bed predominantly comprising a support material having high a surface area on which is dispersed at least one metallic element. Adsorption is carried out in an essentially dihydrogen-free atmosphere within the bed, effecting selective and reversible adsorption and/or complexing of the contained acetylenic contaminants with the adsorbent, thereby obtaining purified effluent which contains less than a predetermined level of the acetylenic impurities. Selective and reversible adsorption and/or complexing of the contained acetylenic impurities with the adsorbent is continued until levels of acetylenic impurities in the effluent stream increase to a predetermined level. Thereafter, the resulting bed of adsorbent is regenerated in the presence of a reducing gas containing dihydrogen to effect release of the contained acetylenic impurities from the adsorbent.