污泥/煤泥混合燃烧过程中N和S污染物迁移规律

Migration law of N and S pollutants duringmixed combustion of sludge/slime

为探究污泥/煤泥混合燃烧过程中N、S污染物的排放机理,开展N、S污染物迁移规律研究.基于热重-质谱分析仪获得的污泥/煤泥混合燃烧时气态污染物的基础生成规律,建立污泥/煤泥混合燃烧实验系统,研究不同污泥质量分数、温度下污泥/煤泥混合燃烧的SO_(2)、NO的排放规律,并通过对4个不同阶段燃烧产物的X射线光电子能谱(XPS)检测,研究N、S官能团在燃烧过程中的转化规律.结果表明,污泥质量分数为40%时固硫固氮效果最明显;随污泥质量分数增加,吡啶类氮更多转化为吡咯类氮,使HCN产量增加以及胺类和腈类生成量增加,导致总NO排放量随污泥质量分数增加先增加后减少;有机硫类释放更为完全,燃烧产生的含S污染物增多,灰分中硫酸盐含量同步增长,因此总SO_(2)的释放量随污泥质量分数增加变化较小.

To explore the emission mechanism of N and S pollutants during the mixed combustion of sludge/slime,the migration law of N and S pollutants was studied.Based on the basic generation law of gaseous pollutants during mixed combustion of sludge/slime obtained by thermogravimetry-mass spectrometry analyzer,a sludge/slime mixed combustion experimental system was established to study the emission laws of SO_(2) and NO in the mixed combustion of sludge and slime under different mass fractions of sludge and temperatures.The conversion law of N and S functional groups in the combustion process was studied through X-ray photoelectron spectroscopy(XPS)detection of combustion products in four different stages.The results show that the effect of sulfur and nitrogen fixation is the most obvious when the mass fraction of sludge is 40%.With the increase of sludge mass fraction,more pyridine nitrogen is converted to pyrrole nitrogen,which increases the yield of HCN and the production of amines and nitriles,resulting in the total NO emission increasing first and then decreasing with the increase of sludge mass fraction.The release of organic sulfur is more complete,the S-containing pollutants produced by combustion increase,and the sulfate content in ash increases simultaneously.Therefore,the total SO_(2) release changes little with the increase of sludge mass fraction.