Solvent recovery with liquid carbon dioxide

Claim 1

IN A SOLVENT RECOVERY FOLLOWING A SOLVENT EXTRACTION TREATMENT OF A MIXTURE SELECTED FROM THE GROUP CONSISTING OF HYDROCARBON MIXTURES RANGING FROM GAS OILS TO LUBRICATING OIL STOCKS, WITH A SOLVENT IDENTIFIED HEREINBELOW, AND IN WHICH SOLVENT EXTRACTION TREATMENT A PHASE COMPRISING RAFFINATE COMPRISING SOLVENT AND A PHASE COMPRISING SOLVENT CONTAINING EXTRACT ARE FORMED, SAID SOLVENT EX TRACTION TREATMENT BEING CONDUCTED IN THE ABSENCE OF LIQUID CARBON DIOXIDE, THE IMPROVEMENT WHICH COMPRISES: EXTRACTING A SOLVENT-EXTRACTION PHASE WITH LIQUID CARBON DIOXIDE UNDER PRESSURE SUFFICIENT TO MAINTAIN A CARBON DIOXIDE-RICH PHASE IN THE LIQUID STATE, WHEREUPON A SOLVENTLIQUID CARBON DIOXIDE PHASE AND A HYDROCARBON PHASE ARE FORMED; SEPARATING SAID SOLVENT-LIQUID CARBON DIOXIDE PHASE AND SAID HYDROCARBON PHASE; AND REMOVING CARBON DIOXIDE FROM SAID SOLVENT-LIQUID CRBON DIOXIDE PHASE, WHEREBY SAID SOLVENT IS RECOVERED SUBSTANTIALLY FREE FROM COMPONENTS OF SAID MIXTURE; THE SOLVENT BEING SELECTED FROM THE GROUP CONSISTING OF; ACETIC ANHYDRIDE, ACETONITRILE, ACETONYL ACETONE, ACETOPHENONE, BENZALDEHYDE, BENZOIC ANHYDRIDE, BENZONITRILE, BUTYL PHTHALATE, CARBITOL (DIETHYLENE GLYCOL MONOETHYL ETHER), CHLORACETIC ACID, BCHLOROETHANOL (ETHYLENE CHLOROHYDRIN), B-CHLOROETHYL ACETATE, CHLOREX (B,B''-DICHLORODIETHYL ETHER), O-CHLOROPHENOL, CINNAMALDEHYDE, CINNAMYL ALCOHOL, DIACETONE ALCOHOL, DIMETHYL FORMAMIDE, DIPROPYLENE GLYCOL, ETHYL ACETOACETATE, ETHYLCHLOROACETATE, ETHYLENE DIFORMATE, ETHYL LACTATE, ETHYL MALEATE, ETHYL OXALATE, B-ETHOXYETHANOL, ETHYL SUCCINATE, ETHYL SULFATE, FURFURAL, FURFURYL ALCOHOL, HYDROCINNAMALDEHYDE, B-METHOXYETHANOL, METHYL PHTHALATE, METHYL SALICYLATE, METHYL SULFATE, NITROBENZENE, O-NITROPHENOL, ZENE, NITROETHANE, NITROMETHANE, O-NITROPHENOL, 1-NITROPROPANE, P-NITROTOLUENE, PHENOL, PHENYLACETONITRILE, PHENYLETHANOL, PHENYLETHANOLAMINE, PHENYL SALICYLATE, PINACOL, SALICYLALDEHYDE, TETRAHYDROFURFURYL ALCOHOL, TRIACETIN, AND TRIETHYLENE GLYCOL.