Modeling and simulation of trickle bed reactors for the purification of 1-butene

Abstract

In this contribution, a mathematical model of an industrial trickle-bed reactor employed in the purification of a C4 cut by selective hydrogenation of acetylenic or dienes compounds to obtain high purity 1-butene is presented. A reaction network of ten reactions is included in the model, with kinetics expressions and parameter estimation obtained from previous experimental studies on a commercial catalyst. Internal mass transfer resistances in the catalyst particles are significant; therefore the reaction-diffusion equations must be solved. External mass transfer resistances in the liquid phase were retained, while those in the vapor phase were negligible. The model was employed to analyze the reactor behavior by varying the inlet molar flow rate of hydrogen, the operating pressure, inlet temperature and the level of activity of the catalyst, taking into account its deactivation. It was demonstrated that the mass transfer resistances, inside and outside the catalyst particles, have a significant impact on the selectivity, but a careful operation of the reactor can improve the selectivity and extent the catalyst life. On the other hand, an alternative system was proposed, with two beds and a distributed input of H2, which led to a significant improvement in the selectivity.

Mass transport effects in gas-phase selective hydrogenation of 1,3-butadiene over supported Pd

“…33–36 The Barreto group studied the kinetics of selective hydrogenation of butyne- and butadiene–butene mixtures in trickle bed reactors. 37,38 They demonstrated that the local concentration of polyunsaturated molecules sharply dropped inside the catalyst grains due to internal mass transfer limitations. These results gave valuable insights into some parameters determining selectivity during selective hydrogenation reactions.…”