KINETIC-ANALYSIS OF RATE DATA FOR PROPYLENE AND METHYLACETYLENE HYDROGENATION

The kinetics of the hydrogenation of propylene and methylacetylene hav e been individually studied in a plug-flow reactor under similar condi tions to the industrial tail-end selective hydrogenation of a steam-cr acking C-3 cut, using 0.05% Pd/gamma-Al2O3 catalyst. These two reactio ns represent the two consecutive steps of the actual process in the ga s phase. Various homogeneous and heterogeneous models have been derive d and compared with the data. The LH-HW and the power-law models have been tested. The power-law models fit the data for both reactions in t he operating conditions used. Pseudo-reaction orders of zero for propy lene and three for hydrogen for propylene hydrogenation, and orders of zero for methylacetylene and one for hydrogen for methylacetylene hyd rogenation, were obtained. Reaction orders obtained for the latter cas e may also be explained by a LH-HW type model if hydrogen is adsorbed atomically and the hydrogen adsorption is the controlling step of the reaction rate.