不同煤焦微观表征及其对燃烧反应性的影响  

Microscopic Characterization of Different Coal Chars and Their Influence on Combustion Reactivity

作　　者：李静渊 张缦[1] 张扬[1] 吴玉新[1] 吕俊复[1] LI Jingyuan;ZHANG Man;ZHANG Yang;WU Yuxin;LYU Junfu(Department of Energy and Power Engineering, Tsinghua University, 100084 Beijing, China)

机构地区：[1]清华大学能源与动力工程系热能工程研究所,北京100084

出　　处：《煤炭转化》2021年第1期1-8,共8页Coal Conversion

基　　金：山西省科技重大专项项目(20181102001).

摘　　要：从时间尺度和放热量来看,焦炭的反应在煤的整个燃烧过程中占有主导地位,而煤焦的微观结构与燃烧反应性有很大的关系,因此有必要进一步研究其影响因素和关系。本次研究选取了22种样品(涵盖了无烟煤、烟煤、贫煤、褐煤、煤泥和气化细渣)进行实验,用XRD对煤焦的微观晶体结构进行测量,用TGA对煤焦的燃烧反应性进行测量,从统计上研究不同煤种微观结构与燃烧反应性的关系。将表征煤焦微晶结构的层片间距d002和芳香性fa同表征燃烧反应活性的综合燃烧特性指数SN和活化能E相关联,发现煤焦的微晶结构参数同燃烧反应性参数之间存在很强的相关性。这种相关性表明:随着煤焦微观结构有序性的增加,燃烧反应性下降,煤焦微晶结构的有序化是导致燃烧反应性下降的主要原因之一。根据煤焦芳香性与活化能的关系,可以将芳香性作为表征煤焦活化能的参数。Reaction of char dominates the combustion of coal in terms of the time scale and heat release,thus the reactivity of char is essential.Some researchers found that the coal char combustion reactivity is the function of its microstructure and the devolatilization temperature,so it is necessary to further study the relationships between the combustion reactivity and the microstructure of char.In order to study their relationships,22 samples were selected for the experiment,including anthracite,bituminous coal,lean coal,lignite,slime and gasification fine slag.The thermogravimetry analyzer(TGA)was employed to evaluate the char combustion reactivity.Moreover,the microstructure of the char was measured by X-Ray Diffraction(XRD).It is found that there is a strong correlation between the microcrystalline structure parameters of coal char and combustion reactivity parameters.This correlation shows that the combustion reactivity decreases with the increase of microstructure order of coal char.According to the relationship between coal char aromaticity and activation energy,aromaticity can be used as a parameter to characterize activation energy of coal char.

关 键 词：煤焦 燃烧活性 XRD 微观结构 动力学 

分 类 号：TQ530[化学工程—煤化学工程]