Kinetic evaluation of the set of reactions in the selective hydrogenation of 1-butyne and 1,3-butadiene in presence of n-butenes

Abstract

The selective hydrogenation in the liquid phase of 1-butyne and 1,3-butadiene in the presence of n-butenes over a commercial Pd/Al 2O3 egg-shell catalyst has been studied. Although hydrogenation of the n-butenes and their isomerization are normally undesirable, kinetics of these reactions should also be evaluated in order to carry out the process at efficient operating conditions. Here, the effect of temperature, in the range 25-65 C, on the specific rate coefficients of 1,3-butadiene hydrogenation reactions and 1-butene, cis-2-butene, and trans-2-butene hydrogenation and isomerization reactions was evaluated from measurements in a batch reactor system. Further experiments were conducted for the evaluation of selectivity between 1-butyne and 1,3-butadiene hydrogenations at 44 C. The present results and previous kinetic characterization allow evaluating the most relevant parameters of a set of kinetic expressions for the 10 overall reactions that govern the system transformation.