Study On Synthesis And Kinetics Of Methyl(hydro) Chlorosilane

The Rochow direct process which is used to produce methylchlorosilanes has been widely applied into the modern industry since 1940's. However, the research on kinetics of direct process is behindhand relatively in our country. It has been attached much importance that how to produce methylhydrochlorosilane better which is a kind of high added-value product in direct process.The kinetics of Rochow direct process was studied in a fixed-bed reactor of 10 mm inner diameter. Based on the conservation of chlorine atom, the methyl chloride conversion was measured. A method to determine the silicon average conversion by thermogravimetric analyzer (TGA) was also suggested, and the existence of η-phase alloy Cu₃Si was testified by Field Scanning Electron Micrograph characterization of solid residue. The experimental results show that the tendency of methyl chloride conversion versus reaction time was similar to the selectivity of methyltrichlorosilane at the same pressure, so controlling the gas velocity of methyl chloride would be beneficial to reduce the yield of methyltrichlorosilane. At the range of 0 to 0.27 MPa, methyl chloride and silicon average conversion increased with reaction pressure, and the average appearance reaction rate was direct ratio to the 0.61 exponent of reaction pressure. So increasing the reaction pressure makes for the process optimization.The direct process with hydrogen and hydrogenation process of methylchlorosilane to produce methylhydrochlorosilane were studied with the same fiexed-bed reactor. The following factors in direct process with hydrogen were researched: the selectivity of methylhydrochlorosilane, dimethylchlorosilane and methyltrichlorosilane versus reaction time, the effect of Ni and AgCl in catalysts and reaction temperature. Meanwhile, the reaction mechanism of direct process with hydrogen was supposed by Field Field Scanning Electron Micrograph characterization of solid residue to testify the existence of η-phase alloy Cu₃Si. The result indicated that selectivity of methylhydrochlorosilane versus reaction time wasdecreasing after increasing, and the tendency of selectivity of methylhydrochlorosilane and dimethyldichlorosilane versus reaction time was opposite under the same reaction condition. The profit of Ni as a better co-catalyst for process was also revealed, and 320℃ was a suitable temperature for direct process with hydrogen. According to the study on hydrogenation process of methylchlorosilanes, the catalyzing mechanism of [Ru(SnCl₃)_6-nCl_n]^4- was supposed by researching on the effect of reaction temperature and pressure, the diameter of catalyst supporter and composing of catalyst. It was found out that the effect of reaction temperature was greater than reaction pressure and the catalyzing effect was optimal when Ru/Sn was 1:6 and the catalyst supporter of nanometer diameter was used.