| 摘要 |
Hydrocarbon dehydrogenation processes may be carried out at 500 DEG to 750 DEG C. in the presence of a catalyst comprising at least one bismuth compound on a support composed of material which has a pore size distribution such that at least 60% of the total pore volume is contributed by pores having diameters in the range 1000A to 8000A (see Division B1). Supports referred to are calcium phosphate, magnesium phosphate, calcium nickel phosphate and sintered alumina. There is specific reference to the dehydrogenation of butene-1 and butene-2 to butadiene, isoamylene to isoprene, ethyl benzene to styrene, and of a mixture of n-butene and isoamylene; and to the dehydrogenation in the presence of molecular oxygen of C3 to C8 paraffinic hydrocarbons, for example butanes to butenes and butadiene, and of C5 to C7 cycloalkanes. The reactions are preferably carried out in the presence of steam which may be used in amounts between 5 and 40 V/V. Examples refer to oxidative and non-oxidative dehydrogenation of butene-1.ALSO:A hydrocarbon dehydrogenation catalyst comprises at least one bismuth compound on a support composed of material which has a pore size distribution such that at least 60% of the total pore volume is constituted by pores having diameters in the range 1000-8000A, or which will acquire such pore size distribution when heated in the absence of the bismuth compound to a temperature of at least 500 DEG C. The amount of bismuth compound may be 1% to 80% by weight based on total catalyst. Support exemplified are calcium nickel phosphate, calcium phosphate, magnesium phosphate, sintered alumina. The catalyst may also contain 0.5% to 5% by weight chromic oxide. The bismuth compound which may be the oxide, hydroxide, chloride, phosphate, sulphate, phosphomolybdate or phosphotungstate may be incorporated in the support by (a) dry mixing of the bismuth compound and the support (b) coprecipitation (c) impregnation of the preformed support with an acidic solution of the bismuth compound(s). The catalyst may be used in a cyclic process comprising alternate dehydrogenation and regeneration reactions. |
