Process for upgrading olefinic C4 cuts

摘要

A C4 cut is upgraded according to the following steps: (a) the dried C4 cut is polymerized in the presence of fluorinated alumina, boron-alumina or silica-alumina, to convert at least 95% of isobutene to dimers and trimers, the conversion of the normal butenes being at most 3%, (b) the whole polymerization effluent is hydro-isomerized in the presence of a group VIII metal catalyst, to isomerize at least 90% of the 1-butene of said effluent, (c) the hydro-isomerization effluent is fractionated and a resultant fraction is alkylated. Resultant alkylate and mixture of dimers and trimers can be mixed and used as gasoline.