铜基催化剂在甲基氯硅烷直接合成过程中的工艺特性

Process Characteristics of Cu-based Catalyst in Direct Synthesis of Methylchlorosilanes

在搅拌床反应器中使用铜基催化剂(辅以少量Zn,Sn,P助剂)催化硅粉与氯甲烷反应合成甲基氯硅烷,考察了温度、压力和催化剂用量对反应速率和产物选择性的影响.结果表明,在温度320℃、压力0.1MPa条件下,平稳期的催化反应速率可达210g/(kg?h),二甲基二氯硅烷的选择性可达87.7%;升高温度可大幅提高反应速率,但超过330℃会显著降低反应选择性;压力在0.3MPa以下反应速率对氯甲烷近似为一级反应,选择性受压力影响较小;一定范围内增加催化剂用量可提高速率,但会缩短反应平稳期,造成硅粉利用效率下降.

The copper-based catalyst promoted by a small quantity of zinc, tin and phosphorus was applied in the reaction between silicon powder and methyl chloride to synthesize methylchlorosilanes in a stirred bed. The effects of temperature, pressure and content of catalyst on the reaction rate and product selectivity were investigated. Under the conditions of 320 ℃ and 0.1 MPa, the reaction rate of 210 g/（kg.h） and the selectivity of 87.7% for dimethyldichlorosilane could be achieved in the steady period. Raising the temperature increased the reaction rate remarkably, while the selectivity began to decline above 330℃. The reaction rate obeyed first-order kinetic model to methyl chloride and the selectivity was hardly affected by the pressure below 0.3 MPa. Increasing the content of catalyst benefitted the reaction rate within limits, yet the steady period was shortened and the utilization efficiency of silicon reduced.