| 摘要 |
A catalyst comprises supported chromium oxide and a minor proportion of a germanium compound. The preferred support is alumina and the preferred germanium compound is the oxide. The catalyst may be prepared by coprecipitation or impregnation and the preferred proportions (by weight of the material stable at 1020 DEG F.) are 5 to 25% of chromium oxide, 0.1 to 5% of germanium oxide and the balance alumina. The catalyst may also contain minor proportions of other promoters, e.g. an alkali metal compound such as potassium oxide, or ceric oxide. In an example germanium dioxide is suspended in aluminium nitrate solution, ammonia is added and the resulting precipitate is dried, roasted, impregnated with chromium trioxide solution, and again dried and roasted. The catalyst may be used for the dehydrogenation or dehydrocyclization of non-aromatic hydrocarbons (see Group IV (b)).ALSO:Feedstocks consisting of or comprising nonaromatic hydrocarbons are dehydrogenated or dehydrocyclized in the presence of a catalyst (see Group III) comprising chromium oxide and a germanium compound on a support and optionally other promoters such as potassium oxide. The catalyst may be used as a fixed, moving or fluidized bed. Preferred operating conditions are not more than 50 p.s.i.g. (including sub-atmospheric pressures); 450 DEG to 850 DEG C., particularly to 525 DEG C.; 0.1 to 1.0 v/v/Hr; and no addition or recycle of hydrogen. Feedstocks mentioned are pure hydrocarbons, e.g. stright-chain paraffins or cycloparaffins; mixtures of hydrocarbons, e.g. gasoline or naphtha fractions, especially a C5 to C7 fraction; and platinum reformates which may first be fractionated or solvent extracted. In examples: (i) a light fraction of a naphtha hydroformate (where the catalyst was halided platinum on alumina) having a F.B.P. of 108 DEG C. was reformed with a catalyst consisting of 10% Cr2O3, 1% GeO2, and alumina (balance), at atmospheric pressure, 0.2 v/v/Hr, and 475 DEG or 530 DEG C. for five hours, using no recycle gas; (ii) a 42.5 DEG to 112 DEG C. straight-run gasoline is similarly reformed at temperatures of 475, DEG 500 DEG , 525 DEG and 550 DEG C., the other conditions being the same as in (i). |
