| 摘要 |
A catalyst for the dehydrogenation or dehydrocyclization of hydrocarbons comprises chromia-alumina promoted by nickel and potassium or compounds thereof, each present in an amount expressed as oxide of not more than 50% of the chromia. The catalyst may contain, by weight of the total catalyst, 5-25% chromium oxide (expressed as Cr2O3), 0.1-5% nickel (expressed as NiO) and 0.1-5% potassium (expressed as K2O). In an example alumina was impregnated with an aqueous solution of chromium trioxide, nickel nitrate and potassium nitrate, dried at 120 DEG C. and calcined at 550 DEG C. for 2 hours.ALSO:The dehydrogenation or dehydrocyclization of feedstocks containing non-aromatic hydrocarbons is effected at 450-580 DEG C. in the presence of a supported chromia catalyst also containing nickel and an alkali metal or compounds thereof each present in an amount, expressed as oxide, not exceeding 50% by weight of the chromia. The catalyst preferably contains by weight of the total catalyst, 5-25% of chromium oxide (expressed as Cr2O3) 0.1-5% of nickel (expressed as NiO) and 0.1-5% of potassium (expressed as oxide) supported on alumina. The feedstock may be a straight run gasoline with an end point of of 80-120 DEG C., or a catalystic reformate, particularly a platinum reformate, or a fraction thereof, e.g. having an end point below 125 DEG C. or the raffinate from a solvent extraction. The treatment is preferably effected in the absence of added or recycled hydrogen at not more than 50 p.s.i.g. and a space velocity of 0.1-1 vol./vol./hr. over a fixed, fluidized or moving bed of catalyst. |
