Modelling of citral hydrogenation kinetics on an Ni/Al2O3 catalyst

The kinetics of citral hydrogenation in ethanol over an Ni/Al2O3 catalyst w as studied in a slurry reactor operating at atmospheric pressure and at a t emperature range of 60-77 degrees C. Citronellal was the primary reaction p roduct, whereas the amounts of unsaturated alcohols were very minor. Citron ellol was the dominating product, generated mainly through the hydrogenatio n of the carbonyl group of citronellal. Based on the experimental data, a k inetic model was developed for hydrogenation. The model comprises competiti ve and rapid adsorption steps as well as rate-determining hydrogenation ste ps. The mass transfer limitation of hydrogen was included in the mathematic al model. The kinetic parameters and the mass transfer parameter of hydroge n were estimated from the experimental data. A comparison of the model pred ictions with the experimental data revealed that the proposed kinetic appro ach gave a satisfactory reproduction of the data. (C) 1999 Elsevier Science B.V. All rights reserved.