Process for removing .alpha.-acetylenes from diolefins
US4174355A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 19, 1978 |
| Grant date | Nov 13, 1979 |
| Priority date | — |
| Expiry date | Jun 19, 1998 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C7/148
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Conjugated diolefins contaminated with relatively high levels of acetylenic impurities in a hydrocarbon feedstream are purified by a cyclic, vapor phase, predominantly catalytic cracking process which selectively removes alpha-cetylenes in a single pass. A feedstream containing about equal weights of isoprene and mixed monoolefins and alkanes contaminated with alpha-acetylenes including isopropenyl acetylene inter alia, up to about 5.0 percent by weight (% by wt) of the feedstream, and a larger amount of cyclopentadiene, is contacted in the vapor phase with a supported Group I B metal oxide catalyst in the absence of hydrogen, at a temperature in the range from about 300.degree. F. to about 360.degree. F. In this narrow temperature range, the loss of diolefin is less than 1% by weight. Essentially all the cyclopentadiene (CPD) is left unconverted. Isopropenyl acetylene content of the effluent is generally less than about 25 ppm in the single pass process which is carried out in a fixed bed reactor operating at substantially atmospheric pressure. In an analogous process, from a crude butadiene feedstream containing less than about 1.0 percent by weight of vinyl acetylene and methyl …
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