摘要 |
The present invention is a process to make isoprene comprising: a) providing a reaction zone comprising an acidic aqueous solution, b) introducing, continuously or intermittently, in said reaction zone a mixture comprising (i) isobutanol and optionally (ii) t-butanol or an iso-butene precursor which is not isobutanol and not t-butanol or iso-butene or any combination of two or three of these (ii) components, an aqueous solution of formaldehyde, c) operating said reaction zone at conditions effective to dehydrate isobutanol and optionally (ii) t-butanol and optionally the iso-butene precursor to iso-butene and produce isoprene by reaction of formaldehyde and iso-butene while distilling away a mixture comprising produced isoprene, water, unreacted starting materials and other low boiling point components from this reaction zone to the outside of the reaction zone. In another embodiment isobutanol provides 10% or more of the iso-butene for the isoprene synthesis. In another embodiment isobutanol provides 20% or more of the iso-butene for the isoprene synthesis. In another embodiment isobutanol provides 30% or more of the iso-butene for the isoprene synthesis. In another embodiment isobutanol provides 40% or more of the iso-butene for the isoprene synthesis. In another embodiment isobutanol provides 50% to 100% of the iso-butene for the isoprene synthesis.
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