Method of refining oil with a solvent

Claim 1

IN THE SOLVENT REFINING OF FEED OIL OF THE CLASS CONSISTING OF KEROSINE AND LOW BOILING GAS OIL AND CONTAINING AT LEAST A SMALL PROPORTION OF CONSTITUENTS HAVING TRUE BOILING POINTS IN THE RANGE OF THE SOLVENT BOILING TEMPERATURE AND BELOW WHEREIN THE FEED OIL IS SUBJECTED TO CONTACT IN AN EXTRACTION ZONE IN THE PRESENCE OF WATER WITH A WATER-MISCIBLE ORGANIC SOLVENT LIQUID COMPRISING FURFURAL HAVING SELECTIVE ACTION AS BETWEEN THE PARAFFINIC AND NON-PARAFFINIC CONSTITUENTS, EXTRACT AND RAFFINATE PHASES ARE FORMED RESPECTIVELY LEAN IN AND RICH IN SAID PARAFFINIC CONSTITUENTS, SAID PHASES SEPARATELY REMOVED FROM THE EXTRACTION ZONE, EACH OF SAID REMOVED PHASES COMPRISING OIL, SOLVENT AND WATER, AND THE REMOVED PHASES SEPARATELY TREATED TO RECOVER SOLVENT FROM THE OIL FOR REUSE IN THE EXTRACTION ZONE, THE METHOD COMPRISING DISTILLING FROM SAID RAFFINATE PHASE IN THE PRESENCE OF STEAM A TERNARY AZEOTROPE DISTILLATE CONTAINING SUBSTANTIALLY ALL OF THE SOLVENT IN THE REMOVED RAFFINATE PHASE AND LEAVING A SUBSTANTIALLY SOLVENT-FREE RAFFINATE OIL, DISCHARGING RAFFINATE OIL, SEPARATELY DISTILLING FROM SAID EXTRACT PHASE IN THE PRESENCE OF STEAM A TERNARY AZEOTROPE DISTILLATE CONTAINING AT LEAST THE BULK OF THE EXTRACT OIL IN THE REMOVED EXTRACT PHASE AND LEAVING THE BULK OF THE SOLVENT CONTENT OF THE REMOVED EXTRACT PHASE AS A RESIDUAL LIQUID FRACTION, RECYCLING RESULTING RESIDUAL FRACTION TO THE EXTRACTION ZONE, SEPARATELY SUBJECTING EACH OF SAID DISTILATES TO SUBSTANTIALLY COMPLETE CONDENSATION, SEPARATELY SUBJECTING THE RESULTING CONDENSATES TO SETTLING AT A TEMPERATURE OF ABOUT 70* TO 150* IN SEPARATE SETTLING ZONES UNDER CONDITIONS SUCH THAT THERE IS NO SUBSTANTIAL VAPORIZATION OF WATER, FORMING IN EACH SETTLING ZONE, OILRICH, WATER-RICH AND SOLVENT-RICH LIQUID LAYERS RESPECTIVELY, SEPARATELY WITHDRAWING LIQUID FROM EACH LAYER, RECYCLING WITHDRAWN SOLVENT-RICH LIQUIDS FROM BOTH SETTLING ZONES TO SAID EXTRACTION ZONE, SEPARATELY DISTILLING RESIDUAL SOLVENT FROM EACH OF SAID WITHDRAWN OIL-RICH LIQUIDS, COMBINING SAID WITHDRAWN WATER-RICH LIQUIDS, SUBJECTING RESULTING COMBINED LIQUID TO A FURTHER DISTILLATION TO REMOVE EXCESS WATER FROM RESIDUAL SOLVENT, DISCHARGING RESULTING AQUEOUS DISTILLATE, AND RECYCLING RESULTING RESIDUAL SOLVENT RECOVERED FROM THE OIL-RICH LIQUIDS AND ALSO FROM THE COMBINED LIQUIDS TO THE EXTRACTION ZONE.