基于SEM与XPS对焦炉上升管内壁结焦炭层织构的研究  

Research of Texture Structure for Coke Layer in Ascension Pipe of Coke Oven Based on SEM and XPS

作　　者：王浩 金保昇[1] 王晓佳 余波 曹俊[1] 吕冬强 WANG Hao;JIN Bao-sheng;WANG Xiao-jia;YU Bo;CAO Jun;Lv Dong-qiang(Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education,School of Energy and Environment, Southeast University,Nanjing 210096,China;Huatian Engineering & Technology Corporation,MCC,Ma’anshan 243005,China)

机构地区：[1]东南大学能源与环境学院,能源热转换及其过程测控教育部重点实验室,江苏南京210096 [2]中冶华天工程技术有限公司,安徽马鞍山243005

出　　处：《光谱学与光谱分析》2019年第11期3333-3339,共7页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(51676038,51806035,51741603);安徽省重点研究与开发计划面上攻关项目(1804a0802195)资助

摘　　要：以焦炉上升管内壁结焦炭层为研究对象,采用扫描电子显微镜(SEM)和X射线光电子能谱仪(XPS)研究各结焦炭层的微观形貌、元素组成及键合状态,分析结焦炭层织构形成及演化规律。SEM研究表明,焦炉上升管内壁各结焦炭层形貌呈现较大的差异性,1#结焦炭层呈现0.1~1.0μm颗粒化炭颗粒松散堆叠的多孔结构,2#和3#结焦炭层呈现粒径为1.0~3.0μm的炭颗粒堆积形貌且致密性有所提高,4#结焦炭层呈现大量花纹状致密结构。以上现象可说明结焦炭层的形成过程为:首先由荒煤气中多环芳烃形成0.1~1.0μm的颗粒状初级炭层,颗粒状初级炭层在荒煤气粉尘中金属元素(如Fe)的催化作用下相互反应,形成更为致密的1.0~3.0μm的中级炭层结构,中级炭层在高温条件下进一步形成致密的终级炭层结构。XPS分析表明,1#—4#结焦炭层含C量分别为91.78%,91.95%,92.74%和94.01%,含O量分别为5.58%,5.42%,4.39%和2.86%,C/O比分别为16.45,16.96,21.12和32.87,说明在炭层结构变化的同时,炭层中含氧基团在高温及粉尘中金属元素(如Fe)作用下发生脱除反应,使得炭层中宏观C/O比逐渐升高。在此基础上,通过对C元素键合状态分峰发现,1^#—4^#结焦炭层中C—C/C—H结构含量分别为80.42%,78.00%,75.50%和81.29%,C—O/C—N结构含量分别为10.22%,11.93%,13.54%和9.35%,C=O/C=N结构含量分别为9.36%,10.07%,10.96%和9.36%。O元素键合状态分峰发现,1^#—4^#结焦炭层中=O结构含量分别为20.40%,22.21%,19.93%,18.36%,—O—结构含量分别为24.60%,27.80%,31.35%,37.82%,O2/H2O结构含量分别为55.00%,49.99%,48.72%和43.82%。以上现象说明结焦炭层上发生如下化学变化:初级炭层中多孔结构会吸附荒煤气中的氧气(O2)和水分子(H2O)在高温条件下对炭层进行氧化。脱除反应和氧化反应使得炭层中O元素在微观键合状态发生明显改变,最终使得炭层中O2/H2O和=O结构含量降低,—O—结构含量升高。以上In this work,the coke layer on the surface of ascension pipe is investigated,and scanning electron microscope(SEM) and X-ray photoelectron spectrometer(XPS)are applied to research microscopic appearance,elemental composition and bonding state of different coke layers,and further analyze texture formation and evolution law of the coke layer.SEM analysis displays that:coke layer on the surface of ascension pipe presents different microscopic appearance,1# coke layer presents porous structure with 0.1~1.0μm carbon particle loosely stacked;2^# and 3^# coke layer show enhanced compactness with 1.0~3.0 μm carbon particle stacked;4^#coke layer displays lots of compact patterned structure.The phenomenon indicates the formation process of the coke layer as follows:the polycyclic aromatic hydrocarbons react to form primary coke layer with particle size of 0.1~1.0μm;primary coke layer react with each other to form compact intermediate coke layer with particle size of 1.0~3.0 μm in catalysis of metal element(Fe,et al)of dust in raw gas;intermediate coke layer further to form ultimate layer at high temperature.XPS analysis displays that,1^#-4^# coke layer present C element content of 91.78%,91.95%,92.74% and 94.01%,O element content of 5.58%,5.42%,4.39%and 2.86%,corresponding to the C/O ratio of 16.45,16.96,21.12 and 32.87,indicating at the same time of structure change for the coke layers,oxygen-containing groups in coke layer conduct removal reaction under the condition of metal element(Fe,et al)of dust in raw gas,resulting the macroscopic increase of C/O ratio.Furthermore,peak fitting for bonding state of C element shows that 1^#-4^# coke layer present C-C/C-H structure content of 80.42%,78.00%,75.50% and 81.29%,C-O/C-N structure content of 10.22%,11.93%,13.54% and 9.35%, C =O/C=N structure content of 9.36%,10.07%,10.96%and 9.36%.Peak fitting for bonding state of O element shows that 1^#-4^# coke layer present -O structure content of 20.40%,22.21%,19.93%,18.36%,corresponding to -O-structure content of 24.60%,27.80%,31.

关 键 词：光谱学分析 结焦机理 织构 扫描电子显微镜 X射线光电子能谱 分峰拟合 

分 类 号：TQ522.15[化学工程—煤化学工程]