Extractive distillation of hydrocarbon mixtures of varying unsaturation

Claim 1

A PROCESS FOR THE SEPARATION OF MIXTURES OF HYDROCARBONS OF VARYING DEGREES OF UNSATURATIN HAVING NO GREATER THAN 7 CARBON ATOMS PER MOLECULE WHICH COMPRISES EXTRACTIVELY DISTILLING SAID MIXTURES IN THE PRESENCE OF A SOLVENT COMPRISING 75 TO 95 PERCENT BY WEIGHT OF FURFURAL, 1 TO 15 PERCENT BY WEIGHT OF DIMER OIL, SAID DIMER OIL CONSISTING ESSENTIALLY OF DIETHYLENICALLY UNSATURATED HYDROCARBONS HAVING A NUMBER OF CARBON ATOMS APPROXIMATELY TWICE THAT OF THE MORE UNSATURATED HYDROCARBONS CONTAINED IN SAID MIXTURES, 3 TO 18 PERCENT OF WATER, AND 0.05 TO 5 PERCENT BY WEIGHT OF AN ALKYL AMINE, RECOVERING AN OVERHEAD DISTILLATE FRACTION FROM SAID DISTILLATION SUBSTANTIALLY RICHER IN HYDROCARBONS OF A LESSER DEGREE OF UNSATURATION THAN SAID ORIGINAL MIXTURE, REMOVING THE SOLVENT FRACTION RICH IN THE MORE UNSATURATED HYDROCARBONS OF SAID MIXTURE FROM SAID DISTILLATION AND RECOVERING FROM SAID RICH SOLVENT A FRACTION SUBSTANTIALLY RICHER IN SAID MORE UNSATURATED HYDROCARBONS.