Patent ID: 8362308

Claim:
A process for preparing a C4-olefin mixture comprising a 1,3-butadiene content of from 100 to 500 ppm and a content in cumulated dienes of less than 10 ppm, by hydrogenation of a C4 stream coming from steam crackers, wherein the hydrogenation in the first hydrogenation stage is carried out over a catalyst which comprises at least one metal of group VIII of the Periodic Table of the Elements as hydrogenation metal and, in addition, a promoter on an oxidic support, with at least 80% of the metal of group VIII of the Periodic Table of the Elements being distributed essentially homogeneously in a layer between the surface of the catalyst and a penetration depth corresponding to not more than 80% of the radius of the catalyst, calculated from the surface of the catalyst, and the promoter being distributed essentially homogeneously over the entire cross section of the catalyst.