Research on the Synthesis of Tri (long-chain alkyl) amines

Abstract

Tri (long-chain alkyl) amines are very important fatty chemicals. For example, they are used as extraction agents to recover various acids such as acetic acid from water solutions and as reaction additives which accelerate the rate of reaction as in the hydrogenation of unsaturated fatty acids.
Recently many researchers have investigated catalysts by which these tri (long-chain alkyl) amines are synthesized directly from fatty alcohols having a long chain alkyl group. But most of them are not satisfactory for industrial use from the stand-point of catalytic activity, selectivity and cost involved. We already reported that the Cu-Ni catalyst gives very high activity and selectivity in the synthesis of aliphatic amines such as N, N-dimethyl (long-chain alkyl) amines and N, N-di (long-chain alkyl) methylamines.
Thus, in this work, catalytic activity and selectivity of Cu-Ni catalyst in tri (long-chain alkyl) amine synthesis, especially in tridodecylamine synthesis, especially in tridodecylamine synthesis from dodecyl alcohol and ammonia were studied.
Tridodecylamine was formed with high selectivity (95%) and high dodecyl alcohol conversion (99%). In this reaction, transformation from the secondary amine to tertiary amine is considered to be a rate determining step of the total reaction. The valency of copper and nickel atoms on the catalyst surface under the reaction conditions was determined by ESCA, and that of copper was clearly shown to be 0 or 1 while that of nickel 2. From the results of comparative experiments using Cu and NiO individually as catalysts of the same reaction, Cu and Ni atoms of Cu-Ni catalyst have special valency and further investigation should be conducted.