Patent GB-931936-A (GB)
Title: Improvements relating to the production of alumina
IPC: C10G45/04
Filed: 1960-04-06
Abstract: Alumina suitable for a catalyst base and having a surface area greater than 200m2/g. and micropore volume greater than 0,5ml/g., is produced by hydrolysing under reflux an aluminium alcoholate dissolved in a hydrocarbon solvent, separating the alumina hydrate so produced and then drying and calcining the hydrate.  The hydrocarbon solvent may be a pure hydrocarbon e.g. an aromatic hydrocarbon such as benzene or toluene; or an aliphatic paraffin or a cycloparaffin; or a mixture of hydrocarbons e.g. a petroleum fraction boiling within the range 50 DEG  to 200 DEG C., may be used.  The hydrolysing medium may be water or any aqueous solution of a base, e.g. ammonia, or an organic acid, e.g. acetic acid.  Preferably the amounts of hydrocarbon solvent and hydrolysing medium employed vary between 1 part by weight of hydrocarbon solvent plus 1 part by weight of hydrolysing medium to 1 part by weight of aluminium alcoholate, and 10 parts by weight of hydrocarbon solvent plus 10 parts by weight of hydrolysing medium to 1 part by weight of aluminium alcoholate. The aluminium alcoholate may be prepared by reacting aluminium metal with an alcohol, preferably in the presence of mercury or a mercury compound.  The alumina may be used as a catalyst base to support, for example, a Group VIa or VIII metal (Mendel<\>aeef), in the treatment of hydrocarbons, e.g. in reforming, aromatization, hydrogenation, dehydrogenation, isomerization, desulphurization and cracking of hydrocarbons.  The catalytically active material may be introduced to the alumina hydrate by way of the hydrolysing medium which may contain a catalytically active material or a solution of a compound which will decompose on calcination to give a catalytically active material. Alternatively the material may be added to the alumina hydrate or alumina after hydrolysis, e.g. by impregnation of the resultant dried and calcined alumina.  Catalytic metals mentioned are chromium, molybdenum, tungsten, cobalt, nickel, palladium and platinum and in the example alumina is impregnated with cobalt nitrate and ammonium molybdate.ALSO:An aluminium alcoholate dissolved in a hydrocarbon solvent is hydrolysed under reflux to give alumina hydrate and the corresponding alcohol.  The temperature used depends on the hydrocarbon solvent which may be a pure hydrocarbon, e.g. an aromatic hydrocarbon such as benzene or toluene; or an aliphatic paraffin or cycloparaffin; or a mixture of hydrocarbons, e.g. a petroleum fraction boiling within the range 50 DEG  to 200 DEG  C. may be used.  Preferably the amounts of hydrocarbon solvent and hydrolysing medium employed vary between 1 part by weight of hydrocarbon solvent plus 1 part by weight of hydrolysing medium to 1 part by weight of aluminium alcoholate, and 10 parts by weight of hydrocarbon solvent plus 10 parts by weight of hydrolysing medium to 1 part by weight of aluminium alcoholate.  The aluminium alcoholate may be prepared by reacting aluminium metal with an alcohol, preferably in the presence of a small quantity of mercury or a mercury compound.