Manufacture of high octane gasoline

Claim 1

IN THE MANUFACTURE OF A HIGH OCTANE GASOLINE FROM A GASOLINE SELECTED FROM THE GROUP CONSISTING A STRAIGHT-RUN AND NATURAL GASOLINE THE STEPS WHICH COMPRISE IN COMBINATION, AND IN THE ORDER AS FOLLOWS, (A) DEPENTANIZING ONE OF SAID GASOLINES BOILING SUBSTANTIALLY THROUGHOUT THE APPROXIMATE RANGE OF 90*-400* F. (GASOLINE BOILING RANGE), SAID GASOLINE CONTAINING SUBSTANTIAL PROPORTIONS OF LIGHT AND HEAVY NAPTHTHENES, LIGHT AND HEAVY PARAFFINS, AROMATICS AND INCLUDING HEXANES; (B) SUBJECTING SAID DEPENTANIZED GASOLINE TO A SOLVENT EXTRACTION WITH A SOLVENT AND UNDER CONDITIONS CAUSING FORMATION OF AN EXTRACT PHASE CONTAINING SAID LIGHT NAPHTHENES AND SUBSTANTIALLY ALL OF SAID AROMATICS, AND A RAFFINATE PHASE CONTAINING SAID HEAVY NAPHTHENES AND SAID LIGHT AND HEAVY PARAFFINS; (C) RECOVERING SEPARATELY FROM SAID EXTRACT PHASE AN AROMATICS AND LIGHT NAPHTHENES FRACTION ON THE ONE HAND AND SOLVENT ON THE OTHER; (D) SUBJECTING SAID RAFFINATE (OBTAINED IN STEP (B) HEREOF) TO SOLVENT EXTRACTION WITH SAID RECOVERED SOLVENT AND UNDER CONDITIONS CAUSING FORMATION OF A SECOND EXTRACT PHASE CONTAINING HEAVY NAPHTHENES AND LIGHT PARAFFINS AND A SECOND RAFFINATE PHASE; AND (E) RECOVERING SEPARATELY FROM SAID SECOND EXTRACT PHASE A LIGHT PARAFFIN CONCENTRATE CONTAINING HEXANES, A HEAVY NAPHTHENSE CONCENTRATE AND SOLVENT.