Kinetic and Mass Transfer Aspects of the Hydrogenation Stage of the Anthraquinone Process for Hydrogen Peroxide Production

Abstract

Hydrogenation of 2-ethylanthraquinone (EAQ) and 2-ethyltetrahydroanthraquinone (THEAQ) was carried out in a slurry reactor in a 1:1 xylene-2-octanol solvent and in the presence of a commercial size dispersed Raney nickel catalyst. The hydrogenation was found to be first order with respect to hydrogen and zero order with respect to anthraquinone. Accounting for mass transport resistances, the activation energies were found to be 34.4 ±1.7 kJ/mol and 41.3 ± 10.7 kJ/mol for EAQ and THEAQ, respectively. In hydrogenation of mixtures of EAQ and THEAQ, THEAQ reacts selectively in preference to EAQ and with a reaction rate dependent on the EAQ concentration. Mass transport resistances, especially in the pores of the catalyst, were found to play a significant role in hydrogenations with the commercial catalyst. © 1981, American Chemical Society. All rights reserved.