PROCEDE DE PRODUCTION D'ESSENCE A HAUT INDICE D'OCTANE ET EN PARTICULIER D'ESSENCE UTILISABLE SANS PLOMB A PARTIR DE COUPES OLEFINIQUES C3/C4

PRODUCTION D'ESSENCE A HAUT INDICE D'OCTANE A PARTIR DE COUPES C ET C OU LEURS MELANGES.LE PROCEDE COMPREND L'OLIGOMERISATION DU PROPYLENE, L'OLIGOMERISATION SELECTIVE DE L'ISOBUTENE, L'ALKYLATION DES HYDROCARBURES C NON OLIGOMERISES ET LE MELANGE DES PRODUITS OBTENUS.L'ESSENCE OBTENUE PEUT ETRE UTILISEE SANS ADDITION D'AGENT ANTIDETONANT. Lead free gasoline of high octane number is obtained from C3 and C4 olefinic cuts as follows: propylene contained in the C3 cut is oligomerized, at least 80% of the isobutene and less than 40% of the n-butenes of the C4 cut are oligomerized to form an oligomerizate distilling in the gasoline range, which is separated from the unreacted C4 hydrocarbons, the latter are subsequently alkylated to form a gasoline fraction which can be admixed with the oligomerizates of the C3 and the C4 cuts to produce the desired high octane gasoline.