Removal of aromatic hydrocarbons from jet fuel mixtures

Claim 1

A PROCESS FOR REMOVING AROMATIC HYDROCARBONS FROM NONAROMATIC HYDROCARBONS BOILING AT SUBSTANTIALLY THE SAME TEMPERATURE WHICH COMPRISES INTRODUCING A HYDROCARBON CHARGE CONTAINING A MIXTURE OF AROMATIC AND NONAROMATIC HYDROCARBONS INTO AN EXTRACTION ZONE AT AN INTERMEDIATE LEVEL OF SAID ZONE, INTRODUCING AT LEAST A SUBSTANTIAL AMOUNT OF CARBON DISULFIDE UP TO ABOUT 30% BY WEIGHT OF THE HYDROCARBON CHARGE INTO THE EXTRACTION ZONE NEAR THE TOP THEREOF, INTRODUCING METHANOL INTO THE EXTRACTION ZONE NEAR THE BOTTOM THEREOF IN AN AMOUNT AT LEAST EQUAL TO THE AMOUNT OF AROMATICS IN THE HYDROCARBON CHARGE, INTRODUCING A LIMITED AMOUNT OF ABOUT 1-10% BY WEIGHT BASED ON THE METHANOL USED OF A MATERIAL SELECTED FROM THE GROUP CONSISTING OF WATER, ETHYLENE GLYCOL, GLYCEROL AND PROPYLENE GLYCOL INTO THE EXTRACTION ZONE AT A LEVEL BELOW BUT NO SUBSTANTIALLY BELOW THE LEVEL AT WHICH THE HYDROCABRON CHARGE IS INTRODUCED INTO SAID EXTRACTION ZONE, TAKING THE METHANOL, AROMATIC HYDROCARBONS AND MATERIAL SELECTED FROM THE GROUP CONSISTING OF WATER, ETHYLENE GLYCOL, GLYCEROL AND PROPYLENE GLYCOL OVERHEAD FROM SAID EXTRACTION ZONE TO AN EXTRACT DISTILLATION ZONE, REMOVING SUBSTANTIALLY PURE METHANOL, VAPOR FROM THE TOP OF SAID EXTRACT DISTILLATION ZONE, CONDENSING SAID METHANOL VAPOR AND INTRODUCING THE LIQUID METHONAL INTO THE LOWER PORTION OF SAID EXTRACTION ZONE, WITHDRAWING THE AROMATIC HYDROCARBONS AND THE MATERIAL SELECTED FROM THE GROUP CONSISTING OF WATER, ETHYLENE GLYCOL, GLYCEROL AND PROPYLENE GLYCOL FROM THE BOTTOM OF SAID EXTRACT DISTILLATION ZONE TO A SEPARATION ZONE, WITHDRAWING SAID MATERIAL SELECTED FROM THE GROUP CONSISTING OF WATER, ETHYLENE GLYCOL, GLYCEROL AND PROPYLENE GLYCOL FROM THE BOTTOM OF SAID SEPARATION ZONE AND RETURING SAID MATERIAL TO THE EXTRACTION ZONE, WITHDRAWING AROMATIC HYDROCARBONS FROM THE UPPER PORTION OF SAID SEPARATION ZONE, TAKING THE CARBON DISULFIDE AND NONAROMATIC HYDROCARBONS FROM BOTTOM OF SAID EXTRACTION ZONE TO A RAFFINATE DISTILLATION ZONE, REMOVING SUBSTANTIALLY PURE CARBON DISULFIDE VAPOR FROM THE TOP OF SAID RAFFINATE DISTILLATION ZONE, CONDENSING SAID CARBON DISULFIDE VAPOR AND INTRODUCING THE LIQUID CARBON DISULFIDE INTO THE UPPER PORTION OF SAID EXTRACTION ZONE, AND WITHDRAWING THE NONAROMATIC HYDROCARBONS FROM THE BOTTOM OF SAID RAFFINATE DISTILLATION ZONE, SUBSTANTIALLY FREE OF UNDESIRABLE AROMATIC HYDROCARBONS.