Study of removal of sulfur dioxide by gas — Liquid two — Phase gliding arc plasma combined with photocatalyst

摘要

High energy consumption limits low - temperature plasma application in terms of waste gas treatment. In order to further improve the efficiency of handling waste gas by using gliding arc plasma, it is put forward that gliding arc plasma is cooperated with photocatalyst to deal with exhaust gas. In this paper, sulfur dioxide was acted as target gas to be dealt with. The molecular sieve loading TiO was selected as photocatalyst. Based on the traditional two knife - shaped gliding arc plasma experiment device, it is designed that a gas - liquid two - phase gliding arc plasma is combined with photocatalyst to treat waste gas. The research was done to investigate the effect of different parameters including the loading times, catalyst dosagev and pH value of liquid phase solution, etc on removal efficiency of sulfur dioxide gas under different operating conditions. TiO2 sol was made by sol - gel method, it was supported on the molecular sieve by means of the impregnation method, finally, supported catalyst was placed in gliding arc plasma reactor with the way of a paragraph. By using emission spectrometer, the Spectral characteristics was observed to comparing the amount of hydroxyl radicals produced by plasma respectively under the different conditions of neutral solution, alkaline solution and adding catalyst with alkaline solution. The change of sulfur dioxide gas concentration before and after the reaction was measured by means of a flue gas analyzer, to analyze the influence of different parameters on removal efficiency of sulfur dioxide gas. The acidity and alkalinity property of liquid phase is changed by adding HCl solution and NaOH solution. The pH value of liquid phase solution in a gas - liquid two - phase gliding arc plasma is measured by utilizing pH meter, to reach the aim of studying the action of pH value on the removal efficiency of sulfur dioxide gas at synergistic device. The result shows, with loading 4 times, catalyst dosage 25 g, pH value of liquid phase solution 14, the removal efficiency can approach over 96%. The gas - liquid two - phase gliding arc plasma assisted with supported photocatalyst as an emerging technology to remove the exhaust gas, via exploring its mechanism and synergistic effect, the technology will provide the basis for the realization of industrial waste gas treatment.