Recovery of aromatics by extraction or extractive distillation with solvent mixtures

Claim 1

A PROCESS FOR SEPARATING A HYDROCARBON MIXTURE CONTAINING AROMATIC AND NON-AROMATIC HYDROCARBONS INTO FRACTIONS OF DIFFERENT DEGREES OF AROMATICALLY BY TREATMENT WITH A SOLVENT MIXTURE AND RECOVERING A MORE CONCENTRATED AROMATICS FRACTION FROM SAID MIXTURE WHICH COMPRISES CONTACTING THE MIXTURE WITH A WATER FREE SOLVENT MIXTURE WHICH AS A WHOLE BASIS ABOVE THE AROMATICS TO BE RECOVERED, SAID SOLVENT MIXTURE CONSISTING OF SOLVENT (A), N-METHYL-PYRRLIDONE, AND SOLVENT (C), ETHYLENE GYLCOL, THE RATIO OF THE QUANTITY OF SAID SOLVENT A TO THE QUANTITY OF SAID SOLVENT C IN SAID SOLVENT MIXTURE BEING FROM X:Y TO X:Y$10 WEIGHT PERCENT, THE RATIO X:Y BEING THE RATIO OF SOLVENTS A AND C AT THE CRITICAL POINT IN THE THREE COINPONENT SYSTEM SOLVENT A, SOLVENT C AND BENZENE, SAID SOLVENT MIXTURE BEING A MIXTURE OF 45 TO 65 WEIGHT PERCENT OF ETHYLENE GLYCOL AND 55 TO 35 WEIGHT PERCENT OF N-METHYL-PYRROLIDONE, EFFECTING PHASE SEPARATION OF THE PHASESE THUS FORMED AN EXTRACT PHASE IN WHICH THE HYDROCARBONS EXTRACTED FROM SAID MIXTURE HAS A HIGHER AROMATIC CONCENTRATION THAN SAID MIXTURE AND A RAFFINATE PHASE LESS AROMATIC THAN SAID MIXTURE AND DISTILLING AN AROMATICS RICH HYDROCARBONS FRACTION FROM THE SOLVENT MIXTURE IN SAID EXTRACT PHASE.