Process for the separation of aromatic hydrocarbons from a mixed hydrocarbon feedstock

Abstract

Abstract A CONTINUOUS SOLVENT EXTRACTION-STEAM DISTILLATION PROCESS FOR THE RECOVERY OF AROMATIC HYDROCARBONS HAVING BOILING POINTS IN THE RANGE OF ABOUT 80% C. TO ABOUT 175* C. FROM A FEEDSTOCK CONTAINING ALIPHATIC HYDROCARBONS AND SAID AROMATIC HYDROCARBONS COMPRISING THE FOLLOWING STEPS: (A) CONTACTING THE FEEDSTOCK IN AN EXTRACTION ZONE WITH A MIXTURE OF WATER AND A SOLVENT, SAID SOLVENT BEING A WATER-MISCIBLE ORGANIC LIQUID HAVING A BOILING POINT OF AT LEAST ABOUT 200* C. AND HAVING A DECOMPOSITION TEMPERATURE OF AT LEAST ABOUT 225* C., AND WITH REFLUX HYDROCARBONS TO PROVIDE AN EXTRACT COMPRISING AROMATIC HYDROCARBONS, REFLUX ALIPHATIC HYDROCARBONS, SOLVENT, AND WATER AND A RAFFINATE COMPRISING ESSENTIALLY ALIPHATIC HYDROCARBONS; (B) CONTACTING THE EXTRACT WITH STEAM IN I DISTILLATION ZONE TO PROVIDE AN OVERHEAD DISTILLATE COMPRISING A REFLUX HYDROCARBONS PHASE AND A WATER PHASE, A SIDE CUT DISTILLATE COMPRISING AN AROMATIC HYDROCARBONS PHASE AND A WATER PHASE, AND BOTTOMS COMPRISING A MIXTURE OF SOLVENT AND WATER; (C) DIVIDING THE WATER PHASE OF THE OVERHEAD DISTILLATE INTO FIRST AND SECOND STREAMS; (D) CONTACTING THE RAFFINATE WITH THE FIRST STREAM TO PROVIDE AN ALIPHATIC HYDROCARBONS PHASE AND A WATER PHASE; (E) CONTACTING THE SECOND STREAM WITH AN AROMATIC HYDROCARBONS STREAM CONTAINING AT LEAST 95 PERCENT AROMATIC HYDROCARBONS, THE AMOUNT OF SAID STREAM BEING IN THE RANGE OF ABOUT 0.1 PERCENT TO ABOUT 5 PERCENT BY WEIGHT OF THE TOTAL AROMATIC HYDROCARBONS IN THE FEEDSTOCK, TO FORM AN AROMATIC HYDRFOCARBONS PHASE AND A WATER PHASE; (F) CONTACTING THE AROMATIC HYDROCARBONS PHASE OF THE SIDE-CUT DISTILLATE WITH THE WATER PHASE OF (E) TO FORM AN AROMATIC HYDROCARBONS PHASE AND A WATER PHASE; (G) CONTACTING THE WATER PHASE OF STEP (D) WITH AN AROMATIC HYDROCARBONS STREAM CONTAINING AT LEAST 95 PERCENT AROMATIC HYDROCARBONS, THE AMOUNT OF SAID STREAM BEING IN THE RANGE OF ABOUT 0.1 PERCENT TO ABOUT 5 PERCENT BY WEIGHT OF THE TOTAL AROMATIC HYDROCARBONS IN THE FEEDSTOCK TO FORM AN AROMATIC HYDROCARBONS PHASE AND A WATER PHASE; (H) RECYCLING THE WATER PHASES OF STEPS (F) AND (G) TO THE DISTILLATION ZONE WHERE SAID WATER PHASES ARE ESSENTIALLY CONVERTED TO STEAM; (I) RECYCLING THE REFLUX HYDROCARBONS PHASE OF THE OVERHEAD DISTILLATE AND THE BOTTOMS OF STEP (B) TO THE EXTRACTION ZONE TO PROVIDE REFLUX HYDROCARBONS AND MIXTURE OF WATER AND SOLVENT, RESPECTIVELY, FOR STEP (A); AND (J) RECOVERING THE AROMATIC HYDROCARBONS PHASE OF STEP (F) AND THE ALIPHATIC HYDROCARBONS PHASE OF STEP (D). D R A W I N G

Inventors

• 👤 G Somekh
• 👤 D Kubek
• 👤 A Kosseim

Bibliographic Details