污泥与煤以一定比例掺烧，有望提高其综合燃烧性，促进污泥的减量化、无害化处理处置及资源化利用。前人对污泥与煤的燃烧及掺烧特性进行了大量的研究，但对燃料中N、S的赋存形态及其对污染物释放的影响，以及污染物在掺烧交互作用中的减排机制尚不清楚。利用热重傅里叶红外联用技术研究了市政污泥与徐州烟煤掺烧综合燃烧性能、交互作用及动力学特性，重点讨论了燃料中N、S赋存形态以及热转化规律。结果表明：污泥与煤掺烧在300～750 ℃存在显著交互作用，并有利于提高其燃烧性能，随着污泥比例增加，混合样着火温度和燃尽温度逐渐降低。动力学结果表明，掺烧活化能介于两单样之间，掺烧少量污泥的反应机理与煤接近。污泥中N主要以吡咯氮(90.58%)和季氮(9.42%)形式存在，其分解导致大量NH3及HCN释放；而烟煤中主要以吡咯氮(N-5)的形式存在，其分解主要以NO和HCN逸出；污泥与煤掺烧过程中氮化物排放强度均低于两单样。污泥中S主要为砜硫和非芳香硫类有机硫化合物，其在400 ℃前分解并释放大量SO2。而烟煤中S元素主要以硫酸盐(66.24%)、硫铁矿(21.97%)和噻吩硫(11.79%)的形式存在，由于其硫化物稳定性高，在350～650 ℃其硫化物发生分解并释放SO2。

Co-combustion of sludge with coal is expected to improve the comprehensive combustion behavior of fuel,and promote reduction,harmless disposal,and resource utilization of sludge. Much study has been done on the combustion and co-combustion characteristics of sludge and coal,but the research on the occurrence of N and S in fuel and its effect on the release characteristic and control of pollutants during co-combustion is still insufficient. The co-combustion characteristics,interaction,and kinetic behavior of Xuzhou bituminous coal and municipal sewage sludge using a thermogravimetric analyzer coupled with a Fourier transform infrared spectrometer (TG-FTIR) were carried out. In addition,the occurrence of N and S elements in fuel and its thermal transformation behavior were studied. The results show that a significant interaction occurred during the co-combustion of Xuzhou bituminous coal and municipal sewage sludge at 300-750 ℃,improving the co-combustion performance. The ignition and burnout temperature decrease with the increasing proportion of municipal sewage sludge. The kinetic results show that the activation energy of the co-combustion process is between both of the single samples. The reaction mechanism of mixed combustion of a small amount of sludge is close to that of coal. In the sewage sludge sample,pyrrolic-N and quaternary nitrogen are the main N-containing species. A large amount of NH3 and HCN emission are released due to its decomposition. As for bituminous coal,pyrrolic-N is the main N-containing species,and its decomposition leads to the emission of NO and HCN. The N-containing gaseous release intensity during co-combustion is lower than that of coal or sewage sludge mono-combustion. Sulfone sulfur,and non-aromatic sulfur are the main S-containing species in sewage sludge. Meanwhile,organic sulfur in sewage sludge decomposes below 400 ℃,resulting in a large amount of SO2 released. The S-containing species exist in coal mainly as the formation of sulfate (66.24%) and pyrite (21.97%),thiophene sulfur (11.79%),which is contributed to the SO2 released at high temperature (350-650 ℃) due to the higher thermal stability of its sulfur compounds. 

0 引言

1 试验材料与方法

   1.1 试验材料

   1.2 试验装置及方法

   1.3 动力学分析

   1.4 综合燃烧特性指数

   1.5 交互作用

2 结果与讨论

   2.1 样品的理化特性分析

   2.2 烟煤与污泥掺烧特性分析

   2.3 掺烧交互作用分析

   2.4 动力学分析

   2.5 气体逸出特性分析

3 结论