A process for obtaining trichlorosilane (TCS or SiHCl3) from hydrogenation of silicon tetrachloride (STC or SiCl4) through control of the temperature along a one-dimensional plug-flow reactor at atmospheric pressure was simulated using a reaction model that was built based on a literature review: Rate coefficients for reactions that occur in silicon CVD processes were adopted from published data. A compact model made available recently in the literature for simulating reactions occurring in silicon chemical vapor deposition (CVD) reactors was used as a basis, and more reactions from other sources were added for better description of the thermal decomposition of STC. The kinetic model built in this work comprised 63 elementary reactions occurring among 26 species. This model was applied to the calculation of the species concentration profiles along the reactor, which was divided into two parts: a STC hydrogenation step, proceeding at a high and constant temperature in the first, and a cooling step, where the gases are brought to room temperature, in the second part. When the hydrogenation temperature was set to 1273 K or higher, the first step was just a stage where the gases reached chemical equilibrium. More interesting reactions occur in the second step, where cooling prevents reactions from reaching equilibrium. This leads to the production of TCS from SiCl2 and HCl, with efficiencies that depend on the conditions. Among the conditions investigated in this work, hydrogenation of a mixture of molar composition STC:H2 = 1:4 at 1473 K followed by cooling at a rate of −50.92 K cm–1 gave the highest conversion efficiency from STC into TCS.
ASJC Scopus subject areas
- Inorganic Chemistry
- Organic Chemistry
- Physical and Theoretical Chemistry