A process for conversion of aliphatic bicyclic amines to aliphatic diamines including contacting one or more bicyclic amines selected from the group consisting of 3-azabicyclo[3.3.1]nonane and azabicyclo[3.3.1]non-2-ene with ammonia and hydrogen, and alcohols in the presence of heterogeneous metal based catalyst systems, a metal selected from the group consisting of Co, Ni, Ru, Fe, Cu, Re, Pd, and their oxides at a temperature from 140° C. to 200° C. and a pressure from 1540 to 1735 psig for at least one hour reactor systems; forming a product mixture comprising aliphatic diamine(s), bicyclic amine(s), ammonia, hydrogen, and alcohol(s); removing said product mixture from the reactor system; removing at least some of the ammonia, hydrogen, water, alcohols, bicyclic amines from said product mixture; thereby separating the aliphatic diamines from said product mixture.