Extraction process wherein the desired material is recovered by azeotropic distillation of the extract

Claim 1

THE PROCESS OF SEPARATING AROMATIC HYDROCARBONS FROM PARAFFINIC HYDROCARBON MIXTURES CONTAINING SAME WHICH COMPRISES CONTACTING SAID MIXTURE WITH A STABLE N-SUBSTITUTED AMMONIUM CARBAMATE SOLVENT WHEREIN THE SUBSTITUENT RADICALS ARE SELECTED FROM THE GROUP OF METHYL, ETHYL, PHENYL AND BENZYL RADICALS IN AN EXTRACTING TREATMENT, SAID SOLVENT BEING CAPABLE OF FORMING AN AZEOTROPE WITH SAID PARAFFINIC HYDROCARBONS, SEPARATING THE COMPOSITE MIXTURE INTO TWO COMPONENT PARTS CONSISTING OF A RAFFINATE PHASE AND AN EXTRACT PHASE, HEATING SAID EXTRACT FRACTION COMPRISING AN AZEOTROPE OF SAID AN OVERHEAD FRACTION COMPRISING AN AZEOTROPE OF SAID SOLVENT AND A SUBSTANTIAL PORTRION OF THE PARAFFINIC HYDROCARBONS CONTAINED THEREIN, AND A BOTTOMS FRACTION, TOTALLY CONDENSING SAID OVERHEAD FRACTION TO THEREBY FROM TWO LIQUID PHASES, SEPARATING SAID PHASES, ONE COMPRISING PARAFFINIC HYDROCARBONS AND THE OTHER COMPRISING SAID SOLVENT, AND RECOVERING PURIFIED AROMATIC HYDROCARBONS FROM SAID BOTTOMS FRACTION.