Liquid-liquid solvent extraction and azeotropic distillation

Claim 2

IN A PROCESS FOR THE SEPARATION BY DISTILLATION OF A MIXTURE COMPRISING FURFURAL AND A HIGHER BOILING LIQUID HYDROCARBON COMPONENT WHEREIN THE LIQUID HYDROCARBON OF HIGHER BOILING POINT POSSESSES AZEOTROPE-FORMING TENDENCIES WITH THE FURFURAL AND SOME OF SAID HIGHER BOILING COMPONENT PASSES OVERHEAD WITH THE FURFURAL, THE METHOD OF CARRYING OUT A DISTILLATION OPERATION TO SEPARATE THE FURFURAL FROM SAID HIGHER BOILING COMPONENT COMPRISING, IN COMBINATION, THE STEPS OF INTRODUCING ONLY SAID MIXTURE OF LIQIDS AND A NARROW BOILING RANGE LIQUID PARAFFINIC NAPHTHA HAVING AN AVERAGE BOILING POINT NEAR BUT BELOW THE MINIMUM BOILING POINT OF SAID HIGHER BOILING POINT LIQUID HYDROCARBON COMPONENT INTO A DISTILLATION ZONE AND THEREIN SUBJECTING SAID MIXTURE OF LIQUIDS AND SAID NAPHTHA TO DISTILLATION CONDITIONS, REMOVING OVERHEAD ONLY VAPORS OF FURFURAL AND NAPHTHA FROM SAID ZONE, AND REMOVING LIQUID BOTTOMS FROM A LOWER PORTION OF SAID ZONE.

Claim 3

A PROCESS COMPRISING THE STEPS OF SOLVENT EXTRACTING A GAS-OIL HAVING A MINIMUM BOILING POINT ABOVE 350* F. WITH ONLY FURFURAL TO PRODUCE A RAFFINATE PHASE AND AN EXTRACT PHASE, SEPARATING THE RAFFINATE PHASE FROM THE EXTRACT PHASE, SUBJECTING THE RAFFINATE PHASE TO DISTILLATION CONDITIONS AND SEPARATING RAFFFINATE OIL FROM SOLVENT, RECYCLING THE SEPARATED SOLVENT TO THE EXTRACTION STEP AND REMOVING THE RAFFINATE OIL AS ONE PRODUCT OF THE PROCESS, SUBJECTING THE EXTRACT PHASE TO DISTILLATION CONDITIONS IN THE PRESENCE OF ONLY A PARAFFINIC NAPHTHA HAVING A MAXIMUM BOILING RANGE OF 50* F. AND AN AVERAGE BOILING POINT BETWEEN 300* AND 350* F. AND SEPARATING EXTRACT OIL AS BOTTOMS FROM AN OVERHEAD PRODUCT OF ONLY A FURFURAL-NAPHTHA MIXTURE, SEPARATING THIS LATTER MIXTURE INTO A FIRST COMPONENT COMPRISING FURFURAL AND A SECOND COMPONENT COMPRISING NAPHTHA, RECYCLING SAID FIRST COMPONENT INTO THE EXTRACTION STEP AS THE EXTRACTANT FURFURAL AND INTRODUCING SAID SECOND COMPONENT INTO SAID EXTRACT DISTILLATION STEP AS SAID PARAFFINIC NAPHTHA, AND RECOVERING SAID EXTRACT OIL AS THE SECOND PRODUCT OF THE PROCESS.

Claim 4

A PROCESS COMPRISING THE STEPS OF SOLVENT EXTRACTING A GAS-OIL HAVING A MINIMUM BOILING POINT ABOVE 350* F. WITH ONLY FURFURAL TO PRODUCE A RAFFINATE PHASE AND AN EXTRACT PHASE, SEPARATING THE RAFFINATE PHASE FROM THE EXTRACT PHASE, SUBJECTING THE RAFFINATE PHASE TO DISTILLATION CONDITIONS AND SEPARATING RAFFFINATE OIL FROM SOLVENT, RECYCLING THE SEPARATED SOLVENT TO THE EXTRACTION STEP AND REMOVING THE RAFFINATE OIL AS ONE PRODUCT OF THE PROCESS, SUBJECTING THE EXTRACT PHASE TO DISTILLATION CONDITIONS IN THE PRESENCE OF ONLY A PARAFFINIC NAPHTHA HAVING A MAXIMUM BOILING RANGE OF 50* F. AND AN AVERAGE BOILING POINT BETWEEN 300* AND 350* F. AND SEPARATING EXTRACT OIL AS BOTTOMS FROM AN OVERHEAD PRODUCT OF ONLY A FURFURAL-NAPHTHA MIXTURE, SEPARATING THIS LATTER MIXTURE INTO A FIRST COMPONENT COMPRISING FURFURAL AND A SECOND COMPONENT COMPRISING NAPHTHA, RECYCLING SAID FIRST COMPONENT INTO THE EXTRACTION STEP AS THE EXTRACTANT FURFURAL AND INTRODUCING SAID SECOND COMPONENT INTO SAID EXTRACT DISTILLATION STEP AS SAID PARAFFINIC NAPHTHA, AND RECOVERING SAID EXTRACT OIL AS THE SECOND PRODUCT OF THE PROCESS.