| 摘要 |
A catalyst for the hydrogenation of aromatic hydrocarbons is made by impregnating alumina with compounds of nickel and molybdenum, calcining, and then treating with a mixture of hydrogen and hydrogen sulphide for at least 30 mins. at 110 DEG to 215 DEG C., to produce a partially sulphided catalyst. The proportions of nickel and molybdenum used are in atomic ratio between 1/4 and 2/3 to 1, and preferably 1/2 to 1. The total metal content is 5 to 15 per cent by weight of the product. The alumina used is microporous and preferably contains 1 to 7 per cent of silica, and is calcined at 500 DEG to 600 DEG C. to convert the alumina to the gamma form. The proportions of hydrogen and hydrogen sulphide used in the sulphiding treatment are in the mole, ratio between 1 and 40 to 1 and preferably about 12 to 1. Nickel compounds used are nickel carbonate dissolved in ammonium hydrate, nickel nitrate, or nickel acetate. The molybdenum compound specified is ammonium molybdate. These compounds may be added together to the alumina and then calcined to form the oxides at about 500 DEG C., or the impregnation and calcining may be effected with each compound separately, preferably the nickel compound is added first. The catalyst may in addition contain tungsten added as ammonium tungstate, to form a mixture of oxides in which the proportions of tungsten and molybdenum are between 1/4 and 1 to 1. In a preferred form, the alumina is impregnated with the 3 metal compounds mixed in equal atomic ratios, and after calcining, the product is further treated with ammonium molybdate to bring the atomic ratios of Ni/Mo/W to 1/2/1. The total metal content of the product is from 8 to 25 per cent by weight. The catalyst may be used to hydrogenate aromatic hydrocarbons or petroleum oils containing nitrogen or sulphur, and in liquid phase or vapour phase. The catalyst may be used in a fixed or moving bed of granules or formed pieces, as a recirculated powder suspended in reactant vapours, or in a fluidized bed. The catalyst may be regenerated by treatment with hydrogen, or by burning off the contaminants with oxygen alone or admixed with nitrogen. U.S.A. Specifications 2,687,370 and 2,687,381 are referred to. |
