Process for separating one or more aliphatic diamines from reductive amination reaction solvents and impurities

Abstract

The instant invention provides a process for separating one or more aliphatic diamines from reductive amination reaction solvents and impurities, and aliphatic diamines obtained via such a process. The process for separating one or more aliphatic diamines from reductive amination reaction solvents and impurities according to the instant invention comprises the steps of: (1) feeding one or more cycloaliphatic cyanoaldehydes, hydrogen, ammonia, and optionally one or more solvents into a continuous reductive amination reactor system; (2) contacting said one or more cycloaliphatic cyanoaldehydes, hydrogen, and ammonia with each other in the presence of one or more heterogeneous metal based catalyst systems at a temperature in the range of from 80° C. to about 160° C. and a pressure in the range of from 700 to 3500 psig; (3) thereby forming a product mixture comprising one or more cycloaliphatic diamines, optionally one or more bicyclic by-products, optionally one or more cycloaliphatic aminonitriles, optionally one or more cycloaliphatic aminoalcohols, optionally one or more oligomeric by-products, ammonia, water, hydrogen, and optionally one or more solvents; (4) removing said product mixture from the reactor system; (5) removing at least a portion of said ammonia, said hydrogen, or mixture thereof from said product mixture via distillation; (6) removing at least a portion of said water and said one or more optional solvents via distillation; (7) removing at least a portion of one or more optional bicyclic by-products via distillation; (8) removing one or more optional cycloaliphatic aminonitriles, one or more optional cycloaliphatic aminoalcohols, one or more optional oligomeric by-products via distillation; and (9) thereby separating said one or more cycloaliphatic diamines from said product mixture.