Process for separating aromatic hydrocarbons

Claim 1

A PROCESS FOR THE EXTRACTION AND RECOVERY OF AROMATIC HYDROCARBONS FROM A LIQUID HYDROCARBON MIXTURE CONTAINING AROMATIC AND NON-AROMATIC HYDROCARBONS COMPRISING (1) INTRODUCING THE MIXTURE INTO A COUNTERFLOW MULTI-STAGE EXTRACTION SYSTEM WHEREIN THE TEMPERATURE IS MAINTAINED BETWEEN 130 AND 155*C., (2) INTRODUCING, AT ONE END OF THE SYSTEM, A HIGH BOILING AROMATIC SELECTIVE SOLVENT HAVING A NORMAL BOILING TEMPERATURE WITHIN THE RANGE OF 225*C. TO 295*C. AND WHICH SOLVENT CONTAINS DISSOLVED WATER IN THE PROPORTION OF NOT MORE THAN 2% BY WEIGHT; (3) PASSING THE SOLVENT IN COUMTERCURRENT FLOW TO THE HYDROCARBONS MIXTURE TO OBTAINED A SOLVENT EXTRACT PHASE ENRICHED IN AROMATICS; (4) WITHDRAWING THE EXTRACT PHASE FROM THE EXTRACTION SYSTEM AND INTRODUCING THE SAID EXTRACT PHASE AT A TEMPERATURE BETWEEN 125* AND 155*C. WITHOUT APPRECIABLE FLASH VAPORIZATION INTO A STRIPPING ZONE, WHICH IS OPERATED AT A PRESSURE OF AT LEAST 1.5 ATMOSPHERES ABSOLUTE AND AT A TOP TEMPERATURE BETWEEN 125 *C.AND 155*C. AND AT A BOTTOM TEMPERATURE OF AT LEAST 165*C. TO SEPERATE OVERHEAD A VAPOR PHASE ENRICHED IN NON-AROMATIC HYDROCARBONS; (5) CONDENSING THE VAPORS FROM SAID ZONE AND FORMING A FIRST