Solvent extraction

Claim 2

THE PROCESS OF SEPARATING A HYDROCARBON MIXTURE SELECTED FROM THE GROUP CONSISTING OF HYDROCARBON MIXTURES WITHIN THE RANGE OF GAS OILS TO LUBRICATING OIL STOCKS; INTO FRACTIONS AT LEAST ONE OF WHICH HAS A HIGHER VISCOSITY INDEX THAN THE ORIGINAL MIXTURE, WHICH COMPRISES: CONTACTING THE MIXTURE WITH LIQUID CARBON DIOXIDE AND A SOLVENT UNDER SUFFICIENT PRESSURE TO MAINTAIN A CARBON DIOXIDE-RICH PHASE IN THE LIQUID STATE, WHEREUPON A CARBON DIOXIDE EXTRACT PHASE, A SOLVENT EXTRACT PHASE, AND AN OIL PHASE ARE FORMED, SAID SOLVENT BEING SELECTED FROM THE GROUP CONSISTING OF: ALDOL, ANILINE, B-CHLOROETHANOL, A-CHLOROPROPIONIC ACID, INNAMYL ALCOHOL, DIETHYLENE GLYCOL, DIPROPYLENE GLYCOL, ETHYLENE GLYCOL, 2,4-DINITROCHLOROBENZENE, FORMALDEHYDE, FORMANILIDE, FURFURYL ALCOHOL, GLYCEROL, B-HYDROXYETHYLACETATE, B-HYDROXYPROPIONITRILE, LACTIC ACID, MALEIC ANHYDRIDE, MONOACETIN, O-NITROANISOLE, PHENYLETHANOLAMINE, PIPERORAL, SUCCINONITRILE, PROPYLENE GLYCOL, AND TRIETHYLENE GLYCOL; EFFECTING PHASE SEPARATION UNDER PRESSURE OF THE CARBON DIOXIDE EXTRACT, SOLVENT EXTRACT AND OIL PHASE; REMOVING CARBON DIOXIDE AND SOLVENT FROM THE CARBON DIOXIDE EXTRACT, THEREBY OBTAINING A HYDROCARBON FRACTION OF HIGHER VISCOSITY INDEX THAN THE ORIGINAL HYDROCARBON MIXTURE.

Claim 3

THE PROCESS OF SEPARATING A POLYCYLIC HYDROCARBON AND A MONOCYCLIC HYDROCARBON OF SIMILAR BOILING POINT FROM A MIXTURE CONTAINING THE SAME, WHICH COMPRISES: CONTACTING THE MIXTURE WITH LIQUID CARBON DIOXIDE AND A SOLVENT UNDER SUFFICIENT PRESSURE TO MAINTAIN A CARBON DIOXIDE-RICH PHASE IN THE LIQUID STATE, WHEREUPON A CARBON DIOXIDE EXTRACT PHASE, A SOLVENT EXTRACT PHASE, AND A PHASE CONSISTING ESSENTIALLY OF SAID ORIGINAL MIXTURE ARE FORMED, SAID SOLVENT BEING SELECTED FROM THE GROUP CONSISTING OF: ALDOL, ANILINE, B-CHLOROETHANOL, A-CHLOROPROIONIC ACID, CINNAMYL ALCOHOL, DIETHYLENE GLYCOL, DIPROPYLENE GLYCOL, ETHYLENE GLYCOL, 2,4-DINITROCHLOROBENZENE, FORMAMIDE, FORMANILIDE, FURFURYL ALCOHOL, GLYCEROL, B-HYDROXYETHYLACETATE, B-HYDROXPROPIONITRILE, LACTIC ACID, MALEIC ANHYDRIDE, MONOACETIN, O-NITROANISOLE, PHENYLETHANOLAMINE, PIPERONAL, SUCCINONITROLE, PROPYLENE GLYCOL AND TRIETHYLELE GLYCOL; EFFECTING PHASE SEPARATION UNDER PRESSURE OF THE CARBON DIOXIDE EXTRACT, SOLVENT EXTRACT, AND THE PHASE CONSISTING ESSENTIALLY OF SAID ORIGINAL MIXTURE; REMOVING CARBON DIOXIDE AND SOLVENT FROM SAID CARBON DIOXIDE EXTRACT PHASE, THEREBY OBTAINING A FRACTION SUBSTANTIALLY RICHER IN SAID MONCYCLIC HYDROCARBON THAN SAID ORIGINAL MIXTURE; AND REMOVING CARBON DIOXIDE AND SOLVENT FROM SAID SOLVENT EXTRACT PHASE, THEREBY OBTAINING A FRACTION SUBSTANTIALLY RICHER IN SAID POLYCYCLIC HYDROCARBON THAN SAID ORIGINAL MIXTURE.

Claim 4

THE PROCESS OF SEPARATING A POLYCYLIC HYDROCARBON AND A MONOCYCLIC HYDROCARBON OF SIMILAR BOILING POINT FROM A MIXTURE CONTAINING THE SAME, WHICH COMPRISES: CONTACTING THE MIXTURE WITH LIQUID CARBON DIOXIDE AND A SOLVENT UNDER SUFFICIENT PRESSURE TO MAINTAIN A CARBON DIOXIDE-RICH PHASE IN THE LIQUID STATE, WHEREUPON A CARBON DIOXIDE EXTRACT PHASE, A SOLVENT EXTRACT PHASE, AND A PHASE CONSISTING ESSENTIALLY OF SAID ORIGINAL MIXTURE ARE FORMED, SAID SOLVENT BEING SELECTED FROM THE GROUP CONSISTING OF: ALDOL, ANILINE, B-CHLOROETHANOL, A-CHLOROPROIONIC ACID, CINNAMYL ALCOHOL, DIETHYLENE GLYCOL, DIPROPYLENE GLYCOL, ETHYLENE GLYCOL, 2,4-DINITROCHLOROBENZENE, FORMAMIDE, FORMANILIDE, FURFURYL ALCOHOL, GLYCEROL, B-HYDROXYETHYLACETATE, B-HYDROXPROPIONITRILE, LACTIC ACID, MALEIC ANHYDRIDE, MONOACETIN, O-NITROANISOLE, PHENYLETHANOLAMINE, PIPERONAL, SUCCINONITROLE, PROPYLENE GLYCOL AND TRIETHYLELE GLYCOL; EFFECTING PHASE SEPARATION UNDER PRESSURE OF THE CARBON DIOXIDE EXTRACT, SOLVENT EXTRACT, AND THE PHASE CONSISTING ESSENTIALLY OF SAID ORIGINAL MIXTURE; REMOVING CARBON DIOXIDE AND SOLVENT FROM SAID CARBON DIOXIDE EXTRACT PHASE, THEREBY OBTAINING A FRACTION SUBSTANTIALLY RICHER IN SAID MONCYCLIC HYDROCARBON THAN SAID ORIGINAL MIXTURE; AND REMOVING CARBON DIOXIDE AND SOLVENT FROM SAID SOLVENT EXTRACT PHASE, THEREBY OBTAINING A FRACTION SUBSTANTIALLY RICHER IN SAID POLYCYCLIC HYDROCARBON THAN SAID ORIGINAL MIXTURE.