GB355867A - Improvements in or relating to the catalytic production of amines - Google Patents

Abstract

Alumina suitable for use as a dehydrating catalyst is prepared by pouring a saturated alcoholic solution of aluminium ethylate into ethyl alcohol containing 2 per cent of water. The mixture sets to a gel, which is allowed to stand, then dried at a temperature gradually rising to 110 DEG C., and finally roasted at 500-600 DEG C.ALSO:In the manufacture of amines by passing a lower aliphatic alcohol and ammonia over a dehydrating catalyst at a raised temperature, the reaction is directed towards the production of primary, secondary, or tertiary amine, as may be desired, by including in the reaction mixture a quantity of the undesired amine or amines. The proportion of alcohol to ammonia may also be varied in accordance with the type of amine desired. Thus, primary amines may be prepared from a reaction mixture including the corresponding secondary and (or) tertiary amine, and containing a molecular excess of ammonia over alcohol. Secondary or tertiary amines may be prepared from a reaction mixture including one or both of the corresponding undesired amines, and containing a molecular excess of alcohol over ammonia. The undesired amines may be separated from the reaction products and recirculated. Examples are given of the manufacture of the methylamines from methyl alcohol and ammonia, with the use as catalyst of alumina prepared as described below. Alumina for use in the process described above is prepared by pouring a saturated alcoholic solution of aluminium ethylate into ethyl alcohol containing 2 per cent of water. The mixture sets to a gel, which is allowed to stand, then dried at a temperature gradually rising to 110 DEG C., and finally wasted at 500-600 DEG C.