| 摘要 |
Olefines are prepared from chlorinated normal paraffins having between 4 and 20 carbon atoms by contacting said paraffins at an elevated temperature e.g. 200-500 DEG C. with a silica catalyst which has been pre-treated with an alkali metal compound. The silica catalyst may be a silica gel and may be pre-treated with alkali metal hydroxide, carbonate or halide so that the catalyst contains 0.001-0.25 g-equivalents of alkali metal compound/100 g. of catalyst. The reaction may be carried out in the vapour state when an inert diluent e.g. nitrogen or a lower paraffin hydrocarbon, may be employed. The examples describe the dehydrohalogenation of chloropentane and a chlorinated mixture of C10-C13 normal paraffins.ALSO:Catalysts employed in the production of olefines from chlorinated n-paraffins consist of a silica gel with an average pore diameter over 40 or a silica/alumina catalyst either of which has been pre-treated with an alkali-metal compound, e.g. an aqueous solution of alkali-metal hydroxide, carbonate or halide. The catalysts contains 0,001-0,25 g,-equivalents of alkali-metal compound per 100 g. of catalyst. |
