O2/CO2气氛下污泥/煤混燃中半挥发性重金属的释放特性  

Release properties of semi-volatile heavy metals in sewage sludge/coal co-incineration under O2/CO2 atmosphere

作　　者：卢平[1] 解佳乐 张雪伟 王佳熠 冯朝钰 宋昕 布雨薇 LU Ping;XIE Jia-le;ZHANG Xue-wei;WANG Jia-yi;FENG Chao-yu;SONG Xin;BU Yu-wei(School of Energy&Mechanical Engineering,Nanjing Normal University,Nanjing 210023,China)

机构地区：[1]南京师范大学能源与机械工程学院,江苏南京210023

出　　处：《燃料化学学报》2020年第5期533-542,I0002,共11页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(51476079)资助。

摘　　要：在固定床焚烧实验装置上,采用正交实验法研究了焚烧温度(tc)、污泥掺混比(Xs)、O2体积分数(φO2)、初始含水率(φH2O)、焚烧时间(τ)和含氯量(φCl)六个因素对O2/CO2气氛下污泥/煤混燃中半挥发性重金属(Zn、Pb、Cd、Cu、Ni和Cr)释放特性的影响。结果表明,六种因素对重金属释放率影响程度排序为tc>Xs>φH2O>φO2≈τ>φCl。相同焚烧工况下,Zn释放率最大,Pb和Cd次之,Cu、Ni和Cr较小。提高温度会促进重金属释放,且高温(1000-1100℃)对重金属释放的影响显著强于低温(700-900℃)。随着温度由700℃升高至1100℃,Zn和Pb释放率分别由36.1%和12.2%上升至70.9%和63.5%,Cd在900℃下达到40.0%的最大释放率,而Cu、Ni和Cr释放率大都维持在20.0%以下,温度对重金属释放率影响程度排序为Pb>Zn>Cd>Cu>Cr>Ni。重金属释放率随着污泥掺混比增加逐渐下降,却随着初始含水率增加呈现波浪式变化趋势,且在30%O2体积分数下重金属释放率取得最小值。焚烧时间和含氯量对Pb释放的影响程度显著强于其他五种重金属。O2/CO2气氛下污泥/煤混燃的最佳工况为:焚烧温度为900-1000℃、污泥掺混比为25%左右、O2体积分数为30%、初始含水率小于10%,并尽可能的缩短焚烧时间。The effects of six factors involving incineration temperature(t c),sludge blending ratio(X s),O2 concentration(φO2),initial moisture content(φH2O),incineration time(τ)and chlorine content(φCl)on the release properties of semi-volatile heavy metals(SVHMs)(such as Zn,Pb,Cd,Cu,Ni and Cr)in co-incineration of sewage sludge and coal under O2/CO2 atmosphere were investigated in a fixed-bed incinerator based on orthogonal experiment.The results indicate that the influence of six factors on the release fraction of SVHMs is ordered as t c>>X s>φH2O>φO2≈τ>φCl.The release fraction of Zn is the largest,followed by Pb and Cd,and the release fractions of Cu,Ni and Cr are the least at the same co-incineration condition.Increasing temperature is helpful for SVHMs release,and the promotion at high temperatures of 1000-1100℃on SVHMs release is significantly stronger than that at the low temperature of 700-900℃.The release fractions of Zn and Pb increase remarkably from 36.1%and 12.2%to 70.9%and 63.5%with increasing t c from 700 to 1100℃,respectively,and the release fraction of Cd achieves the maximum of 40.0%at t c=900℃,however,the release fractions of Cu,Ni and Cr mostly keep below 20.0%.The influence of incineration temperature on the heavy metal release fraction is ordered as Pb>Zn>Cd>Cu>Cr>Ni.The release fractions of SVHMs decrease with increasing sludge blending ratio,but present a wave-like trend with increasing initial moisture content.The lower release fraction of SVHMs is achieved atφH2O=0 or 40%.O2 concentration has a certain influence on SVHMs release,and the lowest release fraction of SVHMs is achieved atφO2=30%.The influence of incineration time and chlorin content on the release of Pb is significantly stronger than that of other five SVHMs.The suggested optimal conditions of co-incineration of sludge and coal in O2/CO2 atmosphere are:the incineration temperature is 900-1000℃,the sludge blending ratio is about 25%,the O2 concentration is 30%,the initial moisture content is less than 10%,and the i

关 键 词：污水污泥 混合焚烧 O2/CO2 半挥发性重金属 释放特性 正交实验 

分 类 号：TK16[动力工程及工程热物理—热能工程]