Abstract: Processes using heterogeneous adsorbents are disclosed for purification of olefin streams, such as are produced by thermal cracking of hydrocarbons, to obtain a feedstock suitable for formation of olefin polymers. These purification processes comprises: providing an impure gaseous mixture; passing the impure mixture through a bed of regenerated adsorbent which is free of a substantial amount of carbon monoxide; effecting, in the presence of an essentially dihydrogen-free atmosphere within the bed, selective adsorption of the contained acetylenic impurities with the adsorbent until levels of the acetylenic impurities in the effluent mixture increase to a limiting level in a range downward from about 1 parts per million by volume; and thereafter regenerating the resulting bed of adsorbent in the presence of a reducing gas comprising dihydrogen which reducing gas is free of a substantial amount of carbon monoxide.

Abstract: A process wherein a coked, deactivated iridium-containing catalyst can be reactivated in a sequence of burn steps, inclusive of a low temperature primary burn step and a subsequent high temperature burn step. In (1) the low temperature primary burn step (i) the chloride level of the catalyst is raised and the catalyst passivated by contact with a hydrogen chloride containing gas, (ii) and coke is then burned from the catalyst by contact with a gas which contains hydrogen chloride at level sufficient to suppress iridium agglomeration at a level of oxygen providing burn temperatures which do not exceed about 425.degree. C., this being sufficient to remove a preponderance of the coke without agglomeration of the iridium component.