微波脱水改性对我国典型褐煤热解特性的影响  

Influence of Microwave Irradiation Treatment on the Pyrolysis Characteristics of Typical Chinese Brown Coal

作　　者：葛立超[1] 张彦威[1] 王智化[1] 闫科[1] 周俊虎[1] 岑可法[1] 

机构地区：[1]能源清洁利用国家重点实验室(浙江大学),浙江省杭州市310027

出　　处：《中国电机工程学报》2014年第11期1717-1724,共8页Proceedings of the CSEE

基　　金：国家重点基础研究发展计划项目(973计划)(2012CB214906)~~

摘　　要：选取了我国主要褐煤产区不同变质程度的3种典型褐煤用微波进行了脱水改性处理,采用热重–红外联用仪着重研究了改性前后褐煤热解特性的变化。结果表明,经过微波处理后,褐煤中的水分大幅度下降,固定碳和热值上升,颗粒断裂和收缩,褐煤煤阶上升。改性褐煤热稳定性增强,热解曲线向高温区和烟煤方向移动,热解开始温度、失重峰温和结束温度升高,最大和平均失重速率及最终失重量降低,热解综合特征参数下降,活化能上升,热解活性变差。热解产物中的CO2、CO和甲酸等小分子活性物质在改性后的析出量减少,CH4和稳定的芳香类物质对二甲苯、苯酚的析出量增加,表明褐煤在改性后不稳定的结构发生分解和转变,稳定相组分增加。Three typical brown coals with different metamorphic grades in China were upgraded by microwave irradiation treatment. The influences on the pyrolysis characteristic were obtained through thermogravimetric- Fourier transform infrared spectroscopy measurement. Results show that the upgrading process significantly decreases the coals＇ inherent moisture, increases their calorific value and fixed carbon content, breaks the coal particle to pieces, and increases the coal rank. After upgrading, the pyrolysis processes are delayed toward the high-temperature region, exhibiting weak pyrolysis characteristics similar to bituminous coal. The start, peak and end temperatures increase, but the maximum and average rates of devolatilization, and the final weight loss decrease. Meanwhile, the comprehensive pyrolysis parameter decreases, and the activation energy increases after treatment. The releasing amounts of active micro-molecules of CO2, CO and formic acid in the gas products decrease, but the amounts of CH4 and aromatic macro-molecules of p-xylene and phenol increase. All these results indicate that the unstable components in the coal are decomposed and converted into stable components during the upgrading process, the thermal stability of coal structure is enhanced, and the pyrolysis characteristic and activity decrease after the treatment.

关 键 词：褐煤 微波 脱水改性 热解 挥发分 热重-傅 里叶变换红外光谱(TG-FTIR) 

分 类 号：TQ536[化学工程—煤化学工程]