GB252609A - Improved manufacture of hexamethylenetetramine - Google Patents

Abstract

252,609. Wade, H., (Karpen Bros., S.). Oct. 23, 1925. Hexamethylenetetramine.-Ammonia is introduced into an aqueous solution of hexamethylenetetramine, whereby the saturation point of the latter is lowered and it is precipitated in a pure form, the means of purification being incorporated in the process for the, production of hexamethylenetetramine from formaldehyde and ammonia. A dilute solution of hexamethylene. tetramine received from a condenser K is passed from a tank A through scrubbers B, where it is mixed with formaldehyde before being introduced into a cooled tank C. Here the mixture is saturated with ammonia gas supplied from a tank D containing liquid ammonia, most of the hexamethylenetetramine formed being precipitated by the excess of ammonia. The precipitate and remaining solution are passed to a filter and washer E, whence the precipitate is passed through a dryer F to a storage tank G. The solution is passed to a still H, from which ammonia passes through a condenser J back to the tank D, and the remaining solution either to the tank K, or to an evaporator M, from which crude hexamethylenetetramine is passed to a dryer N and storage tank O. Or a concentrated solution of the crude compound from the chamber M may be passed to a cooled tank C' and then be treated with ammonia gas from the tank D, the resulting precipitate being passed from a filter E<1> to a dryer F<1> and storage tank G<1>, and the solution to a still H<1>, whence the ammonia is returned through the condenser J to the tank D. If the reaction in the tanks C, C' is carried out under sufficient pressure, they need not be cooled.