富钠液化残渣CO_(2)气化过程煤焦结构演化及钠赋存形态迁移规律  

Char structure evolution and behaviors of sodium species during catalytic gasification of sodium-rich direct coal liquefaction residue under CO_(2) atmosphere

作　　者：李佩 朱超超 韩露 李晓[1] 冯晓博 姚钦 俞时 孟献梁[1] 王鹏[2] 卫帅 LI Pei;ZHU Chao-chao;HAN Lu;LI Xiao;FENG Xiao-bo;YAO Qin;YU Shi;MENG Xian-liang;WANG Peng;WEI Shuai(Key Laboratory of Coal Processing and Efficient Utilization,Ministry of Education,China University of Mining and Technology,Xuzhou 221116,China;School of Materials and Chemical Engineering,Xuzhou University of Technology,Xuzhou 221018,China)

机构地区：[1]中国矿业大学化工学院,江苏徐州221116 [2]徐州工程学院材料与化学工程学院,江苏徐州221018

出　　处：《燃料化学学报（中英文）》2023年第5期598-607,共10页Journal of Fuel Chemistry and Technology

基　　金：supported by National Key Research and Development Program of China(2022YFC2905900);Xuzhou Science and Technology Plan Project(KC20190);the National Natural Science Foundation of China(21903087,22201243);Experimental technology research and development project of China University of Mining and Technology(S2021Y006)。

摘　　要：本研究采用N2吸附-脱附、FT-IR、XRD、SEM和Raman分析,考察了富钠液化残渣CO_(2)气化过程煤焦结构演化和钠赋存形态变迁规律。实验结果表明,富钠液化残渣钠离子高温下易诱导液化残渣孔结构发生变化,拓展了介孔结构,介孔体积由0.05 cm^(3)/g增加至最大0.16 cm^(3)/g。随气化反应进行,煤焦中相继出现不同晶体化合物,XRD分析显示多数晶体矿物质为含钙矿物质,没有明显含钠矿物质的衍射峰,是钠离子高温下易挥发及含钠化合物晶体存在缺陷所致。与含钠矿物质相比,含钙矿物质更易与液化残渣中铝硅酸盐反应,从而使含钠矿物质气化过程保持了催化活性。煤焦(GR+VL+VR)/D的比率先升高后降低,分别与芳香族的解离及小芳香环结构重排成大芳香环结构有关。此外,钠离子释放率与气化反应时间密切相关,液化残渣中大部分钠离子在气化初期挥发至气相,与负载水溶性钠盐液化残渣相比,富钠液化残渣钠离子高温释放率较低。In this work,to better understand catalytic gasification process of direct coal liquefaction residue rich in sodium species,char structure evolution and behaviors of sodium species during gasification under CO_(2) atmosphere were investigated in detail by N_(2) adsorption and desorption,FT-IR,XRD,SEM,and Raman analyses.The results show that sodium species developed pore structure of direct coal liquefaction residue during gasification,especially expanded mesoporous structures which increased from 0.05 to 0.16 cm^(3)/g at maximum.With the increase of gasification time,different crystalline compounds were formed in chars.Most of the mineral matters identified by XRD were calcium-containing ones,whereas no obvious sodium-containing crystalline compounds were found.This was because that most of sodium species volatilized at high temperature and the crystalline forms of sodium-containing compounds had defects.Compared with sodium species,calcium species were more prone to react with aluminosilicates,which happened to make sodium species remain active during gasification process.The ratio of(GR+VL+VR)/D rose initially and then decreased,which could be explained as the dissociation of the large aromatic and the rearrangement of small aromatic rings into large aromatic structures.Moreover,release ratio of sodium species was closely related with gasification time and 49.8% of them released in the initial stage of gasification process(within 15 min).Compared with that of direct coal liquefaction residue reloaded with water-soluble sodium species,the release ratio of sodium species in the original direct coal liquefaction residue was on a lower level(85.2% versus 89.7%).

关 键 词：煤焦结构 钠离子 赋存形态 催化气化 液化残渣 

分 类 号：TQ541[化学工程—煤化学工程]