Studying the Selective Methylacetylene Hydrogenation Reaction in Methylacetylene–Propylene Mixtures on Palladium Oxide Nanocatalysts

The mechanism and kinetics of the selective catalytic methylacetylene hydrogenation reaction in propane–propylene gas mixtures were studied until the complete consumption of methylacetylene in them on the Pd nanocatalyst (Pd/α-Al 2 O 3 ) promoted by metals from Groups I, II, and VI of Mendeleev’s Periodic Table at a Pd content of 0.05 wt %. The experiments were performed in an isothermic plug flow reactor of 100 cm 3 in volume and a bench polytropic reactor of 8 dm 3 in volume. The experiments were carried out by varying the feedstock hourly space velocity from 2000 to 3000 h –1 , the reaction mixture temperature from 303 to 420 K, and the molar hydrogen/methylacetylene ratio from 1.5 to 3.0. Overall, 40 experiments in the isothermic flow-type reactor and 30 experiments in the bench polytropic reactor were carried out. Based on the results of laboratory experiments, a stagewise mechanism was proposed for this catalytic reaction, and the kinetic model corresponding to this mechanism was constructed. The model constants were estimated by the least-squares technique. For the studied reaction, the selective region where there was no methylacetylene, and the propylene concentration in the outlet flow was higher than in the initial flow of reagents, was determined.