| abstract |
Processes using heterogeneous adsorbents are disclosed for purification of olefins such as are typically produced by thermal cracking of suitable hydrocarbon feedstocks, by passing a stream of olefin having from 2 to about 8 carbon atoms, containing acetylenic impurities having the same or similar carbon content, and optionally saturated hydrocarbon gases, through a particulate bed of predominantly a support material having high surface area on which is dispersed at least one metallic element. Adsorption is carried out in an essentially dihydrogen-free atmosphere within the bed, selective and reversible adsorption and/or complexing of the contained acetylenic contaminants with the adsorbent, and thereby obtain 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. |