煤制活性焦性质对其脱除烟道气中二氧化硫性能的影响

摘要

A series of active cokes produced from Datong coal under the same conditions except activating time had been studied to elucidate the influence of the properties (BET surface area, micropore volume, pore size distribution, ratio of micropore area to total area, surface basicity) of the active coke on its adsorption ability for SO2 removal from flue gas. Furthermore, the desorption processes of the H2SO4-loaded active cokes was investigated. It is found that surface basicity in the form of meq benzoic acid/m2 micropore area can evaluate the desulfurization ability of active coke more rightly than in the form of meq benzoic acid/g active coke. Active coke adsorbing and oxidizing SO2 into H2SO4 is determined by surface basicity and micropore area. Moreover, micropore might be the main place for the storage of formed sulfuric acid. The results also further prove that micropore is the main place where SO2 is adsorbed and oxidized into sulfuric acid in the presence of oxygen and water vapor. The desorption process of H2SO4-loaded active coke is influenced not only by desorption temperature, but also by its physical and chemical properties. The H2SO4 adsorbed starts to react with carbon on the surface of active coke at about 210?℃ and reaches its maximum desorption rate at about 300 ℃.%讨论了四种煤制活性焦的性质对其脱除烟道气中SO2性能的影响。活性焦的表面碱性与微孔面积决定了其对烟道气中SO2的吸附与氧化。生成的硫酸主要贮存在活性焦的微孔内。活性焦内的硫酸在脱附温度为300?℃时达到最大脱附速率。