【摘要】 燃煤烟气中SO₃的生成与排放严重威胁着电厂的安全经济运行与大气环境，碱性物质吸收法的SO₃脱除技术布置灵活，应用前景广阔，为此，对不同条件下倍半碳酸钠、Na₂CO₃与NaCl这3种钠基吸收剂对SO₃的脱除特性进行研究。研究结果表明：温度以及吸收剂与SO₃的化学当量比增加有利于SO₃的脱除，这3种吸收剂对SO₃的脱除效果存在差异，SO₃脱除性能最好的是倍半碳酸钠，其次是Na₂CO₃，最差的是NaCl；随着反应进行，不同吸收剂表面均会形成硫酸盐产物；当化学当量比降低后，吸收剂表面同时会形成更多的硫酸盐产物，影响SO₃向未反应界面的扩散，并导致反应速率下降；在低化学当量比下，影响SO₃脱除反应速率的主要因素是吸收剂本身的化学特性；对于具有相同化学性质的吸收剂，在本实验中，吸收反应特性速率主要受外扩散控制，但吸收剂内部孔隙结构导致内扩散性能不同，也会影响吸收反应速率。更多还原

【Abstract】 :The generation and emission of SO₃ in coal-fired flue gas plays a critical role in the safety of economic operation of power plants and the atmospheric environment.The SO₃ removal technology by the alkaline substance absorption method is flexible in layout and has application prospects.The SO₃ removal characteristics of three sodium-based absorbents,i.e.,sodium sesquicarbonate,Na₂CO₃ and NaCl,under different conditions were explored.The results show that the increase of temperature and stoichiometric ratio can help to promote the removal of SO₃.The selective removal of SO₃ by the three absorbents is different,and the removal performance of SO₃ from the best to the worst is sodium sesquicarbonate,Na₂CO₃ and NaCl.As the reaction progresses,the surface of the different absorbent forms a sulfate product.The reduction in the chemical metering ratio will result in a relatively large sulfate product formed on the surface of the absorbent,which will not only affect the diffusion of SO₃ to the unreacted interface,but also make the reaction rate decrease.Under the condition of low stoichiometric ratio,the chemical properties of the absorbent are the main factor that determines the SO₃ removal reaction rate.For absorbents with the same chemical properties,the absorption reaction characteristic rate in this experiment is mainly controlled by external diffusion.However,if the internal pore structure of the absorbent leads to different internal diffusion performances,it will affect the absorption reaction rate as well.更多还原