Adiabatic operation of chromatographic fixed-bed reactors

Adiabatic operation of single column chromatographic reactors was investigated experimentally and using numerical simulations. Esterification of acetic acid with alcohols to produce methyl acetate and ethyl acetate was carried out under isothermal and adiabatic conditions. Higher conversions of the acids, as well as higher ester/water mole ratio in the product fraction, were obtained in the adiabatic reactor than in the isothermal reactor. Improved performance was attributed to a thermal wave that travels through the reactor together with the reaction front. It was shown that thermal effects in such systems originate from reaction heat, adsorption enthalpies, as well as the enthalpy of mixing. Numerical simulations were carried out to investigate under which conditions adiabatic operation of a fixed-bed chromatographic reactor is potentially beneficial. The influence of physical properties of the reaction system (heat capacities of the liquid and solid phases, reaction rate, and separation factor) and operating parameters (injection volume of reactant and residence time) on the process performance was demonstrated. Copyright © 2011 Elsevier B.V. All rights reserved. [accessed April 15th 2011