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 simultaneous dehydration and skeletal isomerization of isobutanol to make 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 isomerize 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/Al higher than 10,
or a dealuminated crystalline silicate of the group FER, MWW, EUO, MFS, ZSM-48, MTT, MFI, MEL or TON having Si/Al 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/Al 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).

主权项

1. A process for the simultaneous dehydration and skeletal isomerisation of isobutanol to make substantially corresponding olefins, having the same number of carbons and including a mixture of n-butenes and iso-butene, said process comprising:
a) introducing in a reactor a stream (A) comprising isobutanol, optionally water, and optionally an inert component, wherein the isobutanol is present in the stream (A) in an amount ranging from 30 to 100 weight percent based on a total weight of the stream (A), b) contacting said stream (A) with a catalyst in said reactor at conditions effective to dehydrate and skeletal isomerase the iso-butyl moiety of 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 and the catalyst is capable of simultaneously catalyzing the dehydration of the isobutanol and skeletal isomerization of butene; and wherein the catalyst is:
a crystalline silicate of the group FER, MWW, EUO, MFS, ZSM-48, MTT, MFI, MEL or TON having Si/Al higher than 10,or a dealuminated crystalline silicate of the group FER, MWW, EUO, MFS, ZSM-48, MTT, MFI, MEL or TON having Si/Al 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/Al higher than 10,or a silicoaluminaphosphate molecular sieve of the group AEL,or a silicated, zirconated or titanated or fluorinated alumina.