GB808114A - Process for the conversion of ethanolamine into ethylene diamine, piperazine and diethylene triamine - Google Patents

Abstract

Ethanolamine is continuously converted to a mixture of piperazine, ethylene diamine and diethylene triamine by passing a stream thereof admixed with ammonia, wherein the molar ratio of ammonia to ethanolamine is at least 3:1, respectively, under pressure over a fixed bed of a hydrogenation catalyst comprising nickel (preferably Raney nickel), cobalt (preferably Raney cobalt), copper chromite, platinum, palladium, or any one of these catalysts supported on a conventional carrier such as, for example, alumina or finely divided silica, which is maintained at an elevated temperature. Unconverted ammonia and ethanolamine may be separated from the reaction products and recycled to the reaction. Pressures are preferably between 1000 and 2500 p.s.i. and temperatures are preferably between 150 DEG and 225 DEG C. Preferably one pound of catalyst is employed for each three to four pounds of ethanolamine being converted per hour, the residence time being kept below one hour. The proportion of piperazine in the reaction products may be kept to a maximum by adjusting the reaction conditions to a temperature of 200 DEG C., a pressure of 2000 p.s.i., an ammonia to ethanolamine molar ratio of at least 5:1 and a catalyst quantity of one pound for each one to two pounds of ethanolamine being converted per hour.