SIMULTANEOUS DEHYDRATION AND SKELETAL ISOMERISATION OF ISOBUTANOL ON ACID CATALYSTS

摘要

The present invention (in a first embodiment) relates to a process for the simu ltaneou s dehyd ration and skeletal isomerisation of isobuta nol to ma ke substantially corresponding olefins, having the same number of carbons and consisting essentially of a mixture of n-butenes and iso-butene, said process comprising: a) introducing in a reactor a stream (A) comprising isobutanol, optionally water, optionally an inert component, b) contacting said stream with a catalyst in said reactor at conditions effective to dehydrate and skeletal isomerise at least a portion of the isobutanol to make a mixture of n-butenes and iso-butene, c) recovering from said reactor a stream (B), removing water, the inert component if any and unconverted isobutanol if any to get a mixture of n-butenes and iso-butene, Wherein, the WHSV of the isobutanol is at least 1 h-1 or the temperature is from 200°C to 600°C and the catalyst is capable to make simultaneously the dehydration and skeletal isomerization of butene. The catalyst is a crystalline silicate of the group FER, MWW, EUO, MFS, ZSM-48, MTT, MFI, MEL or TON having Si/AI higher than 10, or a dealuminated crystalline silicate of the group FER, MWW, EUO, MFS, ZSM- 48, MTT, MFI, MEL or TON having Si/AI higher than 10, or a phosphorus modified crystalline silicate of the group FER, MWW, EUO, MFS, ZSM-48, MTT, MFI, MEL or TON having Si/AI higher than 10, or a silicoaluminaphosphate molecular sieve of the group AEL, or a silicated, zirconated or titanated or fluorinated alumina. Advantageously the stream (B) is fractionated in a step d) to produce a n-butenes stream (N) and to remove the essential part of isobutene optionally recycled with stream (A) to the dehydration/isomerization reactor of step b).