Effect of leakage of volatile synthesis products on silicon carbide yield in an electrothermal fluidized bed reactor

Abstract

Objectives. To calculate the effect of leakage of volatile synthesis products on silicon carbide yield in an electrothermal fluidized bed reactor, as well as to develop a general model of the synthesis of finely divided silicon carbide. This will be achieved by particularizing a mathematical model of leakage of volatile products of chemical reactions from the reaction volume of the reactor with the fluidizing inert gas.Methods. As a method to produce silicon carbide, synthesis in an electrothermal fluidized bed was studied. The model of leakage of volatile products was validated by comparing the calculation results with existing experimental data on the SiC synthesis in a hightemperature fluidized bed reactor. The comparison parameters were: mass yield of silicon carbide, and the total synthesis time in a reactor with batch loading of silicon dioxide into the reaction volume.Results. The value of the parameter p in the general model of SiC synthesis in a fluidized bed was established. The parameter p is equal to the ratio of the number of carbon-containing particles involved in the formation of SiO, to the total number of silicon dioxide particles. It also characterizes the composition of stable complexes of particles of the charge at various operating temperatures of the fluidized bed. The discrepancy between the calculated and experimental values of the masses of the synthesized silicon carbide was shown not to exceed 15.5% at a high temperature of the fluidized bed (T = 1800°C) and decreases with a decrease in the operating temperature to 4.7% at T = 1450°C.Conclusions. The general computational model for silicon carbide synthesis with a built-in procedure for calculating the leakage of volatile products of chemical reactions enables the variants of SiC production in electrothermal fluidized bed reactors to be analyzed. In this case, it is important to establish an energy-efficient working cycle without preliminary expensive experimental studies.