Furfural solvent separation of aromatics from liquid mixtures

Claim 1

A METHOD FOR THE SEPARATION OF AN AROMATIC FRACTION CONTAINING AT LEAST 90 PERCENT BY VOLUME OF AROMATIC HYDROCARBONS FROM A CATALYTIC CRACKED GAS OIL WHICH COMPRISES CONTACTING SAID GAS OIL WITH A LIQUID SOLVENT COMPRISING FURFURAL AT A SOLVENT RATIO WITHIN THE RANGE OF ABOUT 120 TO 300 VOLUMES OF SOLVENT TO 100 VOLUMES OF SAID GAS OIL IN A SOLVENT EXTRACTION ZONE, WITHDRAWING EXTRACT MIX COMPRISING FURFURAL AND DISSOLVED HYDROCARBONS CONSISTING OF 70 TO 85 PERCENT AROMATIC HYDROCARBONS FROM SAID EXTRACTION ZONE AT A TEMPERATURE WITHIN THE RANGE OF ABOUT 80 TO 100*F. WHILE MAINTAINING A TEMPERATURE GRADIENT THROUGH SAID EXTRACTION ZONE LESS THAN ABOUT 50*F., PASSING AT LEAST A PART OF SAID EXTRACT MIX TO A DISTILLATION ZONE IN CONTACT WITH A REFLUX AS HEREINAFTER PROVIDED AND ADDED STEAM AT A RATE OF ABOUT 0.1 POUND OF STEAM PER POUND OF EXTRACT MIX PASSED TO SAID DISTILLATION ZONE, DISTILLATIVELY SEPARATING AN OVERHEAD VAPOR COMPRISING AN AZEOTROPE OF WATER, FURFURAL AND HYDROCARBON FROM A BOTTOMS PRODUCT COMPRISING AROMATIC HYDROCARBONS OF AT LEAST 90 PERCENT BY VOLUME PURITY, CONDENSING SAID OVERHEAD VAPOR FORMING AN OIL-RICH PHASE, A WATER-RICH PHASE AND A FURFURAL-RICH PHASE, AND PASSING AT LEAST A PORTION OF SAID FURFURAL RICH PHASE AS SAID REFLUX TO SAID DISTILLATION ZONE.