低阶煤显微组分含氧官能团的分布特征与差异  

Distribution characteristics and differences of oxygen-containing functional groups in macerals of low rank coal

作　　者：何鑫[1,3] 王文峰 章新喜 杨奕涛[1,3] 孙浩[4] HE Xin;WANG Wenfeng;ZHANG Xinxi;YANG Yitao;SUN Hao(Key Laboratory of Coalbed Methane Resource&Reservoir Formation Process,Ministry of Education,China University of Mining&Technology,Xuzhou 221008,China;College of Geology and Mining Engineering,Xinjiang University,Urumqi 830047,China;School of Resources and Geosciences,China University of Mining&Technology,Xuzhou 221116,China;School of Chemical Engineering and Technology,China University of Mining&Technology,Xuzhou 221116,China)

机构地区：[1]中国矿业大学煤层气资源与成藏过程教育部重点实验室,江苏徐州221008 [2]新疆大学地质与矿业工程学院,新疆乌鲁木齐830047 [3]中国矿业大学资源与地球科学学院,江苏徐州221116 [4]中国矿业大学化工学院,江苏徐州221116

出　　处：《煤炭学报》2021年第9期2804-2812,共9页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(41972176,42002184,U1903207)。

摘　　要：含氧官能团组成是决定低阶煤显微组分分选策略及分离效率的关键因素,同时对其在后续加工转化过程中的反应活性具有重要影响,因此探明低阶煤显微组分中含氧官能团的分布特征与差异尤为必要。结合元素分析、XPS、^(13)C-NMR与化学滴定法等分析手段,分别从表面和内部结构层面探究了神华(富镜质组)与准东(富惰质组)低阶煤中显微组分的含氧官能团分布特征与差异。研究结果如下:元素分析结果显示准东煤显微组分的O含量高于神华煤,2种低阶煤镜质组的原子比O/C值均高于惰质组。但XPS测试中2显微组分的表面原子比O/C值十分接近,说明惰质组中含氧官能团相对集中在外表面,而镜质组的含氧基团则在外表面和内部孔隙的分布更加均匀。XPS定量分析结果表明C=O(羰基或O—C—O)与COOH分别为镜质组与惰质组表面特有的含氧官能团,而—O—与—OH分别为镜质组与惰质组表面主导型含氧基团。^(13)C-NMR测试结果显示,神华煤惰质组及准东煤显微组分中不同含氧官能团占比排序一致:芳香族含氧基团>羰基>COOH>脂肪族含氧基团,而神华煤镜质组中排序如下:芳香族含氧基团>脂肪族含氧基团>羰基>COOH。其中镜质组的COOH比例较低,而脂肪族含氧基团在惰质组中分布最少,甚至在准东煤惰质组中完全消失。化学滴定结果指出酸性含氧官能团更易富集在惰质组表面,不同酸性含氧基团的含量分布在具体显微组分类别中具有较大差异,其中准东煤惰质组具有突出的酚羟基含量。Composition of oxygen-containing functional groups is considered as a critical factor in determining the sorting strategy and separating efficiency of macerals in low rank coal,and a significant role in their subsequent processing and transforming as well,therefore it is particularly indispensable to ascertain the distribution characteristics and differences of oxygen-containing functional groups in macerals of low rank coal.By using elemental analysis,XPS,^(13)C-NMR and chemical titration in combination,the distribution characteristics and differences of oxy-gen-containing functional groups of macerals in Shenhua(vitrinite-rich)and Zhundong(inertinite-rich)low rank coal were investigated from surface and inner structure respectively.The research findings are as follows:the elemental analysis shows the oxygen content of macerals in Zhundong coal is higher than those in Shenhua coal,and the O/C atomic ratio of vitrinite are higher than inertinite in both coals.However,vitrinite and inertinite share a similar surface O/C ratio in XPS test,which indicates the oxygen-containing functional groups are mainly concentrated on the surface of inertinite while these groups are much well distributed inside and outside of vitrinite.C=O(carbonyl or O—C—O)and COOH are the typical oxygen-containing group of vitrinite and inertinite respectively based on quantitative analysis of XPS,while the dominant oxygen-containing group in vitrinite and inertinite are—O—and—OH respectively.According to ^(13)C-NMR measurement,all macerals have the same proportion rank of oxygen-containing groups:aromatic oxygen-containing groups>carbonyl>COOH>aliphatic oxygen-containing groups except that aliphatic oxygen-containing groups in Shenhua vitrinite ranked up to second.There is a lower percentage of COOH in vitrinite whereas aliphatic oxygen-containing groups possess the least distribution in inertinite even disappeared in Zhundong inertinite.Results of chemical titration show that the acid oxygen-containing groups are more easily gathere

关 键 词：低阶煤 显微组分 含氧官能团 XPS 13 C-NMR 

分 类 号：TQ530[化学工程—煤化学工程]