Heat transfer effect on selective hydrogenation of butadiene in presence of butane and benzene using a structured catalytic packing

The effect of radial heat transfer in a structured catalytic packing was studied by simulating the selective hydrogenation of butadiene in presence of butane and benzene on PdNiCe structured catalytic packing. The catalytic packing operated in a co-current downflow – cooled by the wall (temperature-programmed) – trickle-bed reactor. The model takes into account the presence of mass and heat transfer resistance and uses a heterogeneous kinetic rates model. The program solved, point by point, the mass and energy differential equation of a bidimensional plug flow type reactor model using a numerical method. To calculate the liquid concentrations, an adiabatic flash implemented along the reactor length takes into account the gas-liquid equilibrium. Several mass and heat transfer correlations and own kinetic and deactivation rate constants were used. The program calculates the volume of the reactor for a given conversion and characteristic of the catalysts, as well as the radial and axial profiles of concentrations, temperature, and activities along the cycle length. The sensitivity study performed for the heat transfer parameter demonstrated the influence of benzene, reactor geometry, and the type of heat transfer correlation used in activity, selectivity and stability for the selective hydrogenation of butadiene to butane. The effective heat radial conductivities obtained from published correlations are compared to our experimental values.