Research Of The Treatment Of Flue Gas Desulfurization By Gliding Arc Discharge Plasma In Thermal Power Plants

With the rapid development of economy, power demand is increasing, coal consumption is also rising rapidly. China's thermal power plants are mostly coal-fired power plants, there is a lot of sulfur containing waste gas in the power plant generation, these exhaust gases cause pollution to form acid rain. It is of great significance for the environmental management to control the emission of flue gas from coal-fired power plants. Plasma technology desulfurization has the advantages of small investment, small area and high efficiency, it has received the attention of scientists from all over the world. Gliding arc discharge is a new type of plasma, it has both cold and hot plasma characteristics, and it can provide large amounts of high-energy electrons and active free radicals, so it is widely used in the field of waste gas treatment and flue gas purification.In this study, SO₂ is selected as the research object, the impact of different discharge status on treatment effect is studied by changing the experimental conditions such as discharge power,flow rate of mixed gas, initial concentration of SO₂ and relative humidity etc. The results showed that the SO₂ removal increases as the discharge power and relative humidity increase,power that enhances the electric field of the gliding arc discharge plasma area, the energy density of the plasma region increased, the number of high energy electron and reactivity particles increased, and the energy of the reactive group is also improved. The SO₂ removal reduces as the gas flow rate decreases, the increase of air flow rate leads to a faster flow rate of the reaction gas, the time of gas stay in the area of the plasma reaction shortened, and it causes part of the gas does not have sufficient reaction in the plasma region. The relative humidity of the reaction environment increases the removal efficiency of SO₂ in the range of lower saturation humidity. The reaction between the OH group and SO₂ plays a key role in the whole removal process.The higher the initial concentration, the lower the removal efficiency, but the increase in processing amount per unit time, the energy utilization. But the energy efficiency improves with the increase of process amount per unit time.To improve the efficiency of the thermal power plant exhaust by the gas-liquid two-phase gliding arc discharge, the traditional pure water phase is replaced by NaOH solution. In this study, the applied voltage, discharging current and emission spectrum were measured to analyze the influence of electrical and optical characteristics of the discharge after the addition of NaOH.In this paper, the concentration of SO₂ is selected as observation index, the removal efficiency of SO₂ and the product concentration has been analyzed by changing the experimental conditions such as discharge time and gas flow rate under different liquid phase. Results show that the NaOH solution instead of pure water phase enhanced discharge strength under the same conditions,and intense ionization in the discharge produced a large number of OH radicals. At the same time, the sulphur removal efficiency of NaOH solution increased by 5%?7%compared to pure water, and the product of SO3 content also reduced by about 50% compared to pure water.The analysis show that the gliding arc discharge plasma studied in this paper has high efficiency for thermal power plant desulfurization. Which is beneficial to its wide application in the field of industrial waste gas treatment. The research work in this paper will help to further understand the desulfurization mechanism and influence mechanism of gas-liquid two-phase gliding arc discharge, and lay the foundation for its application in the field of waste gas treatment in thermal power plant.