Applied Basic Studies On Desulfurization And Denitrification Using Microwave Swing Irradiation Over Activated Carbon

Mainly power plants of our country are coal-fired power plants. The combustion of coal produces air pollutants such as SO2, NOX, CO, VOC, carbon particles and dust. SO2 is a precursor of acid rain and sulfurous smog, while NOx is the precursor of photochemical smog. If the emission of SO2 and NOx can not be effectively controlled, it will bring great harm to the environment, and also not healthy to the development of our economy. Presently many flue gas purification technology have been used in China such as wet-FGD and selective catalytic reduction denitrification. These technologies only aim at some kind of pollutant, bringing the resources waste, high investment and operating cost. Therefore, researching flue gas purification technology which has a high efficiency and low cost, so multi-pollutant control technology is an important topic which the sustainable development faces.Desulfurization and denitrification using microwave swing irradiation over activated carbon technology which reduce SO2 and NO into sulfur and nitrogen at the same time is a highly efficient desulfurization and denitration technology. This article studied the effect of oxygen in the flue gas on physical and chemical properties of activated carbon under microwave irradiation through experiments. The adsorption characteristics of SO2 and NO on activated carbon and the generate mechanism of CO were also studied. The results showed that, oxygen in flue gas accelerated the mass loss of activated carbon, when the oxygen content is 2-4.5% the loss rate of activated carbon increased fastest; the reaction between oxygen and activated carbon destroyed the pore structure of activated carbon, and the specific surface area of activated carbon is reduced, the amount of acidic groups over activated carbon surface increased while the amount of alkaline groups were decreased at the same time; With the increasing of oxygen(O2) content in flue gas, the efficiency of desulfurization increased by 95.3% to 100%, and the efficiency of denitrification inceased by 81.5% to 96.8%. The result of adsorption experiments showed that, With the increase of the microwave regeneration times and flue gas velocity, the adsorption performance of SO2 and NO on activated carbon gradually reduced; oxygen and water vapor in flue gas enhanced the adsorption of SO2 and NO. The results of desulfurization and denitrification under microwave irradiation showed that, with the increase of power of microwave irradiation,irradiation time,adsorption capacity,the content of oxygen and CO2, the amount of CO increased. The activation energy of the reaction between SO2 and activated carbon which generated CO was 28.31kJ/mol, while the activation energy of the reaction between NO and activated carbon which generated CO was 16.24kJ/mol. The theoretical feasibility and economic feasibility and environmental benefits were also analyzed in this paper.