PROCESS COMPRISING TWO EXTRACTIVE DISTILLATION STEPS FOR THE PRODUCTION OF TERTIARY ETHERS FROM A C4 OR C5 FEEDSTOCK.

摘要

THE INVENTION CONCERNS A PROCESS FOR THE PRODUCTION OF TERTIARY ETHERS (MTBE, ETBE, TAME, ETAE) IN WHICH A HYDROCARBON CUT (1) CONTAINING FOUR OR FIVE CARBON ATOMS IS REACTED WITH METHANOL OR ETHANOL(2, 3) IN A REACTOR AND RECOVERING ETHERS (11) AND A DISTILLATE (10) AFTER DISTILLATION (CI). THE DISTILLATE UNDERGOES A FIRST EXTRACTIVE DISTILLATION STEP IN COLUMN (CII) IN THE PRESENCE OF A SOLVENT(27) WHICH IS SELECTIVE TOWARDS OLEFIN HYDROCARBONS. A SATURATED HYDROCARBON-RICH OVERHEAD FRACTION (15) IS RECOVERED ALONG WITH A BOTTOM FRACTION (18) WHICH IS RICH IN OLEFINS, SOLVENT AND ALCOHOL. THE OLEFINS (20) ARE SEPARATED FROM THE SOLVENT AND ALCOHOL (24) IN A SECOND EXTRACTIVE DISTILLATION STEP (CIII). THE OLEFINS ARE ISOMERISED IN A SKELETAL ISOMERISATION REACTOR (5) AND THE ISOMERATE ISRECYCLED (2) TO REACTOR (6). THE ALCOHOL AND SOLVENT ARE SEPARATED IN A STRIPPING COLUMN (CIV). ALCOHOL (26) IS RECYCLED TO THE SYNTHESIS REACTOR (6) WHILE THE SOLVENT (27) IS RECYCLED TO CII. THE TEMPERATURE AT THE BOTTOM OF THE SECOND COLUMN (CIII) CAN BE REDUCED BY ADDITION OF FRESH (4) OR RECYCLED (34) ALCOHOL. @@APPLICATION TO ADDITION WHICH INCREASE THE OCTANE NUMBER OF PETROLS.@@@(FIG. 1)