A method for producing propylene by simultaneous dehydration and skeletal isomerization of isobutanol over an acid catalyst followed by a metathesis step

摘要

A process for production of propylene can include simultaneously subjecting isobutanol to dehydration and skeletal isomerization to make a mixture of n-butenes and iso-butene. The n-butenes can be subjected to methathesis. The process can include introducing isobutanol into a dehydration/isomerization reactor and contacting the isobutanol with a catalyst at conditions effective to dehydrate and skeletal isomerase the isobutanol to make a mixture of n-butenes and iso-butene. A mixture of n-butenes and iso-butene can be recovered and fractionated to produce an n-butenes stream. The n-butenes stream can be sent to a methathesis reactor and contacted with a catalyst at conditions effective to produce propylene. A stream can be recovered from the methathesis reactor that includes propylene, unreacted n-butenes, heavies, and optionally unreacted ethylene. The stream can be fractionated to recover propylene, and the unreacted n-butenes and unreacted ethylene can optionally be recycled to the methathesis reactor.