Hydrogenation of 2-ethylanthraquinone is a key step in the industrial production of hydrogen peroxide via anthraquinone. This reaction on palladium-supported catalysts is normally carried out in trickle-bed reactors. A numerical model for simulation of a gas-liquid-solid hydrogenation trickle-bed reactor is presented. The model is based on the film theory and takes into account the axial dispersion effect on the performance of the reactor. Comparison of calculated values with data from pilot plant and industrial reactor shows that the agreement is quite satisfactory and the maximum variance is less than 5%. Gas-liquid and liquid-solid mass-transfer coefficients are determined by semi-empirical correlations available in the literature. The palladium-supported catalyst is extremely active and the reaction is always controlled by gas-liquid mass-transfer, and the overall effectiveness factor is always very low in agreement with the high catalytic activity of the palladium-supported catalyst.The overall effectiveness factor increases with decreasing catalyst hold-up. Therefore, it is feasible to improve the productivity of unit catalyst by decreasing the catalyst hold-up in a commercial plant with the hydrodynamic characters kept unchange.
