| 摘要 |
1489335 Ethylene oxide preparation SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ BV 24 Oct 1974 [26 Oct 1973] 49962/73 Heading C2C [Also in Division B1] Ethylene oxide is made by the vapour phase oxidation of ethylene with O 2 in the presence of a silver catalyst which has been prepared by (a) impregnating a porous refractory support of surface area 0À03-10 m.<SP>2</SP>/g. with a solution of a compound of K, Rb or Cs in such a concentration, having regard to any leachable alkali metal in the support prior to impregnation, as to produce-optionally after extraction with a solvent after either step (b) or step (c)-in the final catalyst a content of 0À25-16 mg. e.w. of alkali metal per kilogram total catalyst for each square metre of surface area per gram of support, (b) at least partly drying the impregnated support, (c) contacting the at least partly dried product with a liquid phase containing a dissolved compound of Ag or a slurry of particles of Ag or Ag compound in an amount sufficient to deposit 1-25 wt. per cent Ag, based on the total catalyst, on the support surface, and (d) thermally treating the product of (c), optionally in the presence of a reducing agent, to convert the Ag compound to Ag metal. Preferably the oxidation is performed at 210-285‹ C. in the presence of a fixed bed of catalyst, an inert diluent gas and a chlorine-containing moderator. |
