| 摘要 |
1,159,055. Disproportionating olefins. BRITISH PETROLEUM CO. Ltd. 26 Jan., 1968 [14 Feb., 1967], No. 6915/67. Heading C5E. Olefins are prepared by co-disproportionating an initial mixture of an olefin of the formula R(R 1 )C =CR 2 (R 3 ) where R substituents are H, alkyl or aryl groups, with an easily polymerizable tertiary olefin containing the grouping or a secondary olefin containing the grouping wherein Ar is an aromatic radical, in the presence of a catalyst prepared by heating rhenium heptoxide in a stream of carrier gas whereby the Re 2 O 7 , is sublimed on to Al 2 O 3 located downstream of the Re 2 O 7 . The Re 2 O 7 may be heated to 150-700‹ C. using air as a carrier, and after deposition of the Al 2 O 3 the catalyst may be activated by fluidizing it in a stream of dry air at 200-800‹ C. Alternatively the Re 2 O 7 may be generated in situ by thermally decomposing ammonium perborate in the bottom of a vertical tube, and the Re 2 O 7 so formed carried in an ascending stream of dry air into a fluidized bed of pre-heated Al 2 O 3 in the top of the tube. Examples describe the co-disporportionation of an initial mixture of butene-2 and isobutene to give a product containing propylene and 2 methylbutene-2. |
