CONTINUOUS HYDROGENATION OF ADIPONITRILE ON RANEY-NICKEL IN A SLURRY BUBBLE-COLUMN

An experimental study of the catalytic hydrogenation of adiponitrile i n a mini-plant with a continuously operated slurry draft-tube bubble c olumn is discussed. The purpose of this work is to determine the influ ence of operating parameters on the performance of the reactor, and to develop a complete model to describe its behaviour. The following bas ic information was first obtained: hydrodynamic data; a mock-up of the same scale as the reactor is built to measure the characteristics of the fluid flow. intrinsic kinetics data; the Langmuir-Hinshelwood mode l is chosen, supposing surface reaction limitation and competitive ads orption between hydrogen and nitriles. This correctly describes the ex perimental data. From this first information, a model supposing well-m ixed liquid phase is developed. It is not a completely predictive mode l, since two parameters have to be estimated: the volumetric liquid-ph ase mass transfer coefficient and the deactivation parameter. This com plete model is available representing experimental data with good accu racy.