Kinetics of the Hydrogenation of Silicon Tetrachloride

The hydrogenation of , in the presence of silicon, was investigated at temperatures between 525° and 650°C and at various pressures. It was found that increasing the temperature increased the conversion efficiency and throughput. Increasing the pressure increased the conversion efficiency at the expense of the reaction rate and adding catalyst enhanced the conversion efficiency and throughput. An energy of activation of 10–15 kcal/mol was found for the hydrogenation with catalyst and 20–25 kcal/mol without catalyst. A throughput rate of 2578 kg/m 3 h was observed at 5.1 atm with a residence time of ∼0.5s and conversion efficiency of 18.5%. Finally, the effect of being added to the reactants and products was examined and a reaction mechanism was proposed. Without catalyst, the addition of slightly enhances the concentration of in the products; with catalyst, the addition of slightly reduces the concentration of in the products. When is added to the effluents of the hydrogenation reaction in a cooler zone (∼325°C) above the first stage, then conversion efficiencies and throughputs are markedly increased. Virtually 100% of the is converted into .