Direct Reaction of Silicon with Ethyl Chloride in a Fluidized Bed Reactor

The aim of this work was to study the production of diethyldichlorosilane [(C2H5)2SiCl2]. The catalytic reaction of silicon (Si) of purity 99.9% with ethylchloride (C2H5Cl) was investigated in a fluidized bed reactor. Cuprous chloride (CuCl) of purity 99.9% was used as a catalyst of the reaction. Gas chromatography was used on-line for analysis of the reaction products. The experimental work was carried out using a stainless steel column of 5cm internal diameter and 50cm height as the fluidized bed reactor.The experiments start with different bed temperatures between 200 and 300 C to identify the optimum reaction temperature. This temperature was found to be at 250 C, which resulted in the maximum of ethylchloride (EtCl) conversion and diethyldichlorosilane yield. In fifteen runs, the variables considered were sieve-analysis average particle size dp (50,100, and 150 µm), contact mass weight wt (100 – 200 gm) and reacted gas velocity Ug (1.41 – 2.83 cm/s). It was found that the conversion of EtCl increases with decreasing reacted gas velocity, increasing bed contact mass and particle diameter. The yield of Et2SiCl2 was not affected by these variables, but bed temperature was found to have a significant affect.Two mathematical models, the Orcut model and the continuous CSTR model were used to predict theoretical data for the conversion of EtCl. The comparison between the experimental and the theoretical data showed good agreement with an absolute error of less than 9%.