Hydrogenation of acetylene in excess ethylene on an alumina-supported palladium catalyst at atmospheric pressure in a spinning basket reactor

Abstract

The hydrogenation of acetylene in the presence of ethylene and carbon monoxide has been investigated in a spinning-basket reactor on a commercial supported palladium catalyst. The rate of disappearance of acetylene was found to be controlled by pore diffusion at low acetylene concentrations and was independent of acetylene at high acetylene pressures. In the non-diffusion-controlled region the reaction of acetylene was first order in hydrogen, and the rate of ethane formation was independent of both the acetylene and ethylene pressures. This latter observation is consistent with the presence of sites which can hydrogenate ethylene even in the presence of acetylene. The nature of the C 4 products has been shown to be dependent on the packing of adsorbed acetylene molecules and on the availability of surface hydrogen. The analysis of a heavy involatile product is also reported.