气化钠对伊敏煤热解衍生碳黑微晶结构的影响

Effect of Vaporized Sodium on Microcrystalline Structure of Soot Derived from Yimin Coal Pyrolysis

为研究热解气中的气化钠对煤衍生碳黑微晶纳观结构的影响,本文进行了担载氯化钠前后伊敏酸洗煤粉的热解实验。通过高分辨透射电镜与拉曼光谱仪分析1250℃、不同停留时间条件下收集的碳黑样品,并分别采用图像处理技术与曲线拟合方法获得基本碳黑粒子内部结构参数。两种煤粉的对比实验表明:进入到微晶堆栈区的气化钠可以抑制微晶长大、增加微晶结构缺陷,导致类石墨微晶平均长度降低、曲率升高,碳黑颗粒内部结构组织化程度变弱。不同停留时间下实验表明:随反应时间增加,碳黑逐渐成熟,长度增加、曲率降低;但热解气中含氧物质作用于碳黑则会时长度降低、曲率增加。

In order to study the influence of vaporized sodium in pyrolysis gas on the microcrystalline nanostructure of coal-derived soot,pyrolysis experiment of acid-washed Yimin coal before and after loading sodium chloride was carried out.The soot collected at 1250℃and different residence time were analyzed by high-resolution transmission electron microscope and Raman spectrometer,and the basic soot particle internal structure parameters were obtained by image processing technology and curve fitting method respectively.The comparative experiments of two kinds of coal show that vaporized sodium entering the microcrystalline stack can inhibit the growth of microcrystalline and increase structural defects,resulting in decrease of average length and increase of curvature of graphite like microcrystals,and weakening of the internal structure of soot particles.Experiments under different residence times show that as the reaction time increases,soot gradually matures,the length increases,and the curvature decreases;however,when the oxygen-containing substances in pyrolysis gas act on soot,length decreases and curvature increases.