Patent ID: 7612246

Claim:
A process for the production of a RON isomerate that is at least equal to 80 and for co-production of an aromatic fraction that for the most part contains toluene, staffing from a C7 fraction containing paraffins, naphthenes and aromatic compounds in any proportion, whereby said process employs at least one step comprising passing fresh feedstock ( 11 ) into an extractive distillation unit for extracting aromatic compounds (EA) so as to produce an aromatic fraction ( 23 ) containing mostly toluene, and a dearomatized C7 fraction ( 12 ) that is introduced into a distillation column (CD) from which are extracted: a) A top flow ( 13 ) that constitutes an isomerate produced in isomerization unit (IS), b) A lateral flow ( 14 ) that feeds isomerization unit (IS), c) A bottom flow ( 15 ), at least in part feeds a unit for opening naphthene rings (OC) from which is extracted an effluent ( 16 ) that is sent at least in part to isomerization unit (IS), within said isomerization unit (IS), conducting at least one step of isomerization of linear paraffins and mono-branched paraffins into multi-branched paraffins wherein the resultant isomerate contains less than 1% by weight of aromatic compounds, and at least one step of separating resultant stream of linear and mono-branched paraffins from di- and tri-branched paraffins.