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

An experimental study of the catalytic hydrogenation of adiponitrile in a mini-plant with a continuously operated slurry draft-tube bubble column is discussed. The purpose of this work is to determine the influence of operating parameters on the performance of the reactor, and to develop a complete model to describe its behaviour. The following basic 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 model is chosen, supposing surface reaction limitation and competitive adsorption between hydrogen and nitriles. This correctly describes the experimental data. From this first information, a model supposing well-mixed liquid phase is developed. It is not a completely predictive model, since two parameters have to be estimated: the volumetric liquid-phase mass transfer coefficient and the deactivation parameter. This complete model is available representing experimental data with good accuracy.