Patent GB-792644-A (GB)
Title: Improvements in or relating to catalytic dehydrogenation of secondary alcohols to ketones
IPC: B01J23/18
Filed: 1955-11-10
Abstract: Ketones are produced by passing secondary alcohols, under conversion conditions of temperature and pressure, over a catalyst comprising an oxide of a Group II metal coated on lumps of calcined coke having a total ash content (including silica) of no more than 1.5 per cent by weight.  Preferably, the silica content should not exceed 0.75 per cent by weight, and the total ash content should not exceed 1.0 per cent by weight of the coke. The preferred metallic oxides are those of zinc, magnesium and beryllium, and oxides of Group IV or V metals such as bismuth, antimony, zirconium, thorium and vanadium may be used as stabilizers in amounts of 1 to 15 wt. per cent, preferably 6 wt. per cent, based on the total weight of the mixture.  The calcined coke, before use in the catalyst composition, is advantageously water-washed or treated with an alkaline-reacting material, such as sodium or potassium hydroxide, or ammonium hydroxide or carbonate. Zinc acetate is also useful as a pre-treating agent to minimize olefine formation.  The dehydrogenation process is carried out in conventional manner, e.g. using temperatures of 400 DEG  to 1000 DEG F., useful conversions being the dehydrogenation of secondary butanol to methyl ethyl ketone and of isopropanol to acetone.  Examples demonstrate the effectiveness of the calcined coke-based catalyst and its superiority over brass-turning supported catalysts in the conversion of secondary butanol to methyl ethyl ketone.ALSO:A catalyst suitable for the dehydrogenation of secondary alcohols to ketones, comprises an oxide of a group II metal coated on lumps of calcined coke having a total ash content (including silica) of not more than 1.5 per cent by weight.  Preferably the silica content of the coke should not exceed 0.75 per cent by weight and the total ash content should not exceed 1 per cent by weight.  The preferred metallic oxides are those of zinc, magnesium and beryllium, and oxides of Group IV or V metals such as bismuth, antimony, zirconium, thorium, and vanadium may be used as stabilizers in amounts of 1 to 15 wt. per cent, preferably 6 wt. per cent, based on the total weight of the mixture.  The catalyst is applied to the carrier by forming a slurry of the metallic oxide or oxides with water or other solvent until a paste-like consistency is obtained and mixing the calcined coke in the form of lumps or granules, preferably 1/2 X 1/2 X 1/2 inch with the paste and depositing the oxide thereon by known methods such as by tumbling in a ball mill.  The particles are removed and dried at 100-150 DEG  C.  The calcined coke, before use in the catalyst composition, is advantageously water-washed or treated with an aqueous solution of an alkaline reacting material, such as sodium or potassium hydroxide, or ammonium hydroxide or the corresponding carbonate.  Zinc acetate is also useful as a pretreating agent in minimizing olefin formation.  An example demonstrates the effectiveness of a calcined coke-based catalyst coated with 94 per cent zinc oxide and 6 per cent bismuth oxide in the dehydrogenation of secondary butanol to methyl ethyl ketone.