KINETIC ASPECTS OF SELECTIVITY AND STEREOSELECTIVITY FOR THE HYDROGENATION OF BUTA-1,3-DIENE OVER A PALLADIUM CATALYST

The gas-phase hydrogenation of buta-1,3-diene to but-1-ene, trans- and cis but-2-ene, and butane over Pd catalysts was studied. The reaction was investigated in a reactor operating at atmospheric pressure at 0- 20 degrees C over a wide range of conversions. Special. attention was focused on the selectivity as a function of conversion. Up to high con versions (low values of buta-1,3-diene mole fractions) selectivity and stereoselectivity toward reaction products were constant. At approxim ately 85% conversion the selectivity in but-1-ene was seen to decrease . The selectivity and stereoselectivity were described within a framew ork of the advanced reaction mechanism. Deactivation influenced the ac tivity and selectivity of the reaction. Deactivation kinetics was take n into account, assuming the formation of higher molecular weight olig omerized olefins. The parameters of the kinetic model were estimated w ith nonlinear regression analysis. Simulations showed that the kinetic model is able to describe selectivity and stereoselectivity behavior in buta-1,3-diene hydrogenation over the whole range of conversions.