Mechanistic and reaction engineering aspects of nitrile hydrogenation
Advancing the chemical engineering fundamentals
Chemical Reaction Engineering (T2-2P)
Keywords: Multi-phase reaction, Trickle-bed reactor, Hydrogenation, Cobalt catalyst, Nitrile
Liquid phase hydrogenation of nitriles is an important method for the production of primary amines, which find a variety of applications as intermediates in chemical and pharmaceutical industry. Raney-Co or supported Cobalt catalysts are frequently used due to the relatively high selectivity to primary amines. However, selectivities in excess of 95% can only be achieved, when ammonia is used as solvent. Thereby, thermodynamic control of the reaction is achieved as condensation reactions, where ammonia is released, are suppressed. However, liquid ammonia is difficult to handle and it is highly interesting to avoid, or at least to minimise, the addition of ammonia. This requires kinetic control of the reaction by optimizing catalyst properties and process conditions. In this study, nitrile hydrogenation in a stirred autoclave and a laboratory-scale trickle-bed reactor is compared. It is shown that changes in the distribution of ammonia between gas and liquid phase is the key parameter in terms of selectivity. Co-hydrogenation of acetonitrile and butyronitrile over Raney-Co provides detailed insight into the mechanism of alkyl group transfer, which leads to the formation of secondary and tertiary amines.
See the full pdf manuscript of the abstract.
Presented Tuesday 18, 13:30 to 15:00, in session Chemical Reaction Engineering (T2-2P).
