Plasma-Chemical Treatment of Process Gases with Low-Concentration Fluorine-Containing Components

The problems of recycling of the gases with low concentration of fluorine-containing components have been considered. The model of their plasma-chemical treatment with the heat recovery of effluent gases is proposed. The process thermodynamics for various compounds of reacting gases is considered. The heat- and mass transfer processes are simulated in the plasma-chemical reactor. Temperature and velocity profiles of treated gas flows have been obtained within the recovery zone, mixing area with the plasma jet as well as in the reactor working zone. The compliance of the resulting distributions and the temperature range needed for the full conversion is demonstrated. The experiments on the plasma-chemical treatment of carbon tetrafluoride and nitrogen trifluoride have been conducted. The resulting degrees of CF₄ and NF₃ decomposition turned out to be above 90% providing more than double reduction of specific energy cost as compared with the available facilities of similar purposes. An approach is proposed to reduce nitrogen oxide content in effluent gases at reactor outlet and to decrease in future the specific energy cost of conversion of halogen-containing gases.