Refining kerosenes and gas oil by ternary azeotropic distillation with furfural and water

Claim 1

IN THE REFINING OF A MINERAL FEED OIL BOILING WITHIN THE RANGE ABOUT 275 TO 600* F. CONTAINING BOTH SATURATED AND UNSATURATED CONSTITUENTS SAID SATURATED CONSTITUENTS BEING CAPABLE OF ENTERING INTO TERNARY AZEOTROPE FORMATION WITH FURFURAL IN THE PRESENCE OF WATER, TO SEPARATE THEREFROM A FRACTION ENRICHED IN SAID SATURATED CONSTITUENTS BY AZEOTROPIC DISTILLATION WITH A POLAR SOLVENT LIQUID COMPRISING FURFURAL, THE METHOD COMPRISING CONTINUOSLY PASSING FRESH FEED OIL AND SAID POLAR SOLVENT TO A PRIMARY DISTILLATION ZONE, SUBJECTING SAID OIL TO AZEOTROPIC DISTILLATION THEREIN IN THE PRESENCE OF WATER AND SAID SOLVENT, SUPPLYING WATER AND SAID SOLVENT TO SAID PRIMARY DISTILLATION ZONE IN AMOUNTS SUFFICIENT TO FORM A DISTILLATE CONSISTING ESSENTIALLY OF A TERNARY AZEOTROPIC MIXTURE OF WATER, SOLVENT AND SATURATED CONSTITUENTS OF OIL, AND CONTAINING AT LEAST ABOUT 50% OF THE FEED OIL ENTERING THE EXTRACTION ZONE, AND SAID AZEOTROPIC MIXTURE BOILING BELOW THE BOILING TEMPERATURE OF WATER UNDER THE PRESSURE PREVAILING IN SAID ZONE, CONTINUOUSLY AND SEPARATELY WITHDRAWING FROM SAID ZONE SAID DISTILLATE AND A RESIDUAL LIQUID CONTAINING UNSATURATED CONSTITUENTS OF THE FEED OIL, CONDENSING SAID DISTILLATE, SUBJECTING RESULTING CONDENSATE TO STRATIFICATION IN A SETTLING ZONE AT A TEMPERATURE IN THE RANGE ABOUT 100 TO 150* F., FORMING IN SAID SETTING ZONE A WATER-RICH LIQUID LAYER, AN OIL-RICH LIQUID LAYER AND A SOLVENT-RICH LIQUID LAYER, RECYCLING AT LEAST A PORTION OF SAID SOLVENT-RICH LIQUID TO SAID PRIMARY DISTILLATION ZONE, PASSING SAID OIL-RICH LIQUID TO A SECONDARY DISTILLATION ZONE, INJECTING A PORTION OF SAID WATER-RICH LIQUID AS REFLUX TO SAID SECONDARY DISTILLATION ZONE, SUBJECTING THE OIL-RICH LIQUID TO AZEOTROPIC DISTILLATION THEREIN TO REMOVE AQUEOUS SOLVENT AS A DISTILLATE THEREFROM, RECYCLING SAID LAST MENTIONED DISTILLATE TO THE AFORESAID SETTLING ZONE AND WITHDRAWING SUBSTANTIALLY SOLVENT-FREE OIL AS RESIDUAL LIQUID FROM SAID SECONDARY DISTILLATION ZONE.