Furfural recovery

Claim 1

THE METHOD FOR RECOVERING FURFURAL FROM A MIXTURE COMPRISING A MAJOR PROPORTION OF FURFURAL, A MINOR PROPORTION OF HYDROCARBON MATERIAL LESS VOLATILE THAN FURFURAL AND A SMALL PROPORTION OF ACIDIC FURFURAL DERIVATIVES WHICH COMPRISES; DISTILLING SAID MIXTURE IN A FIRST DISTILLATION ZONE; REMOVING FROM SAID FIRST DISTILLATION ZONE AN OVERHEAD FRACTION COMPRISING ESSENTIALLY FURFURAL AND A RESIDUE COMPRISING A MAJOR PROPORTION OF FURFURAL, A MINOR PROPORTION OF HYDROCARBON MATERIAL, AND A SMALL PROPORTION OF ACIDIC FURFURAL DERIVATIVES; DISTILLING SAID RESIDUE IN A SECOND DISTILLATION ZONE; REMOVING FROM SAID SECOND DISTILLATION ZONE AN OVERHEAD FRACTION COMPRISING ESSENTIALLY FURFURAL AND CONTAINING NO SUBSTANTIAL AMOUNT OF ACIDIC FURFURAL DERIVATIVES, A SIDESTREAM COMPRISING A MAJOR PROPORTION OF FURFURAL, A MINOR PROPORTION OF HYDROCARBON MATERIAL, AND A SUBSTANTIAL PROPORTION OF ACIDIC FURFURAL DERIVATIVES, AND A SECOND RASIDUE COMPRISING A MAJOR PROPORTION OF HYDROCARBON MATERIAL AND A MINOR PROPORTION OF FURFURAL; INTRODUCING SAID RESIDUE BETWEEN THE STRIPPING AND RECTIFYING ZONES OF A STREAM STRIPPING ZONE CONTAINING A STRIPPING ZONE AND A RECTIFYING ZONE; INTRODUCING SAID SIDESTREAM INTO SAID RECTIFYING ZONE OF SAID STEAM STRIPPING ZONE AT A LEVEL INTERMEDIATE OF THE ENDS OF SAID RECTIFYING ZONE; STRIPPING SAID SAID STREAM STRIPPING ZONE; AND REMOVING FROM SAID STREAM STRIPPING ZONE; AND REMOVING FROM SAID STREAM STRIPPING ZONE AS VAPOR A MIXTURE COMPRISING ESSENTIALLY FURFURAL AND WATER AND CONTAINING NO SUBSTANTIAL AMOUNT OF ACIDIC FURFURAL DERIVATIVES.