Experimental study of the front-end selective hydrogenation of steam-cracking C2-C3 mixture

Selective hydrogenation of steam-cracking cuts is the industrial process used to eliminate most of the alkynes, dienes and similar troublesome compounds in olefinic streams. The purpose of this paper is present a kinetic study of the selective hydrogenation of a C2-C3 mixture over two palladium/alumina catalysts with front-end variant. Experiments have been carried out to monitor the effect of temperature, hydrogen content in the feed, hydrocarbon volumetric flow and carbon monoxide content on the corresponding activity and selectivity. The experiments were performed in an integral plug-flow reactor, and the integral method was used for the kinetic analysis. Data treatment led to apparent kinetic models. The minimization of the objetive function was made by the Marquardt algorithm for multiple response, and the continuity equation set was integrated by a fourth-order Runge-Kutta technique. From the results of the minimization, the most adequate power-law-type models were selected. The calculated values of the acetylene, ethylene, ethane, MAPD, propylene and propane molar fractions in the product stream are in complete agreement with the experimental ones.