在湿法脱硫中实现脱硝的试验研究

Experimental Study on Denitration in Wet Desulfurization System

针对如何在现有湿法脱硫的基础上实现中小型燃煤锅炉经济有效的脱硝,研究在中小型燃煤锅炉原有的石灰石-石膏法脱硫工艺和设备的基础上添加脱硝剂,实现同时脱硫、脱硝,从而使我国中小型锅炉排放达到国家标准。在研究二氧化氯、臭氧、过氧化氢作为脱硝添加剂的脱硝效果,并在考虑运行成本和使用性能的基础上,优选了二氧化氯作为脱硝添加剂。研究确定了二氧化氯作为脱硝添加剂在湿法脱硫中实现同时脱硝的最佳工艺条件,结果如下:二氧化氯浓度为175mg/L,石灰石浆液浓度为10g/L,液气比为15L/m^3。在此条件下,脱硫、脱硝效率分别为100%和97.07%。采用本方法不需改造原有工艺设备,可以实现低成本脱硝。

Considering how to realize economical and effective denitration for medium and small coal-fired boilers on basis of present wet desulfurization,the method to add denitration agents in previous limestone gypsum FGD system is studied,to achieve simultaneous desulfurization and denitration and meet the emission standard of medium and small coal-fired boilers.The study chooses chlorine dioxide,ozone and hydrogen peroxide as denitration additives to test denitration results.On the basis of running cost and denitration efficiency,chlorine dioxide is determined as the denitration absorption additive.The optimum conditions for denitration in wet desulfurization system are as follows：the concentration of ClO2 is 175 mg/L,the limestone slurry concentration is 10 g/L,and the ratio of liquid and gas is 15 L/m^3.Under the optimum conditions,the efficiencies of desulfurization and denitration are 100%and 97.07%,respectively.The process can be used to prepare alphasemi-hydrated gypsum to achieve the low cost of denitration without improving process equipment.