Application of transient methods in three-phase catalysis: Hydrogenation of a dione in a catalytic plate column

The continuous enantioselective hydrogenation of 1-phenyl-1,2-propanedione was investigated in fixed-bed reactor at 25°C and 5 bar H₂ over a knitted Pt silica fibre catalyst modified with (-)-cinchonidine. Transient data were quantitatively modelled based on the reaction mechanism which assumes two parallel and tilted adsorption modes for the modifier and two distinct adsorption modes for 1- and 2-carbonyls, each of them requiring different number of surface sites. A dynamic axial dispersion model described the tube reactor with the Peclet number estimated from the separate impulse experiments carried out with an inert tracer. The modelling revealed that inclusion of sorption dynamics of components is of critical importance for the adequate description of transient data.