Analysis on the difference of coke microstructure in the same coking cycle during the production of coal-based needle coke

被引：0

作者：

Cheng J.-X. ^{[1
]}

Zhao X.-F. ^{[1
]}

Liu W. ^{[1
]}

Zhu Y.-M. ^{[1
]}

Gao L.-J. ^{[1
]}

Lai S.-Q. ^{[1
]}

机构：

[1] School of Chemical Engineering, University of Science and Technology Liaoning, Anshan

来源：

Ranliao Huaxue Xuebao/Journal of Fuel Chemistry and Technology | 2021年 / 49卷 / 08期

基金：

中国国家自然科学基金;

关键词：

Coal-based needle coke; Microcrystalline structure; Mixed oil; Optical structure;

D O I：

10.19906/j.cnki.JFCT.2021051

中图分类号：

学科分类号：

摘要：

8 kinds of mixed oil with different feeding time in the same coking cycle were the objects of the study. The optical structure, morphology structure and microcrystalline structure of needle coke formed by mixed oil with different feeding time in coking cycle were quantitatively analyzed by means of polarizing microscope, scanning electron microscope (SEM), XRD and Raman spectroscopy. The results show that the yield of coke after the thermal conversion of the mixed oil is higher than the theoretically calculated yield, indicating that the heavy oil participates in the thermal conversion reaction to form the coke with a streamlined optical structure. In the optical structure of calcined needle coke, MO-8" has the highest fiber content, followed by MO-16", and MO-32" has the lowest fiber content. SEM further proves that MO-8" has more lamellar number and more regular orientation. XRD analysis of needle coke confirms that the microcrystalline structure parameters (interlayer spacing d002, lamellar content N and the number of carbon atoms in each layer n) are very close. However, there are obvious differences in the content of graphite microcrystalline (Ig), and among which MO-8" has the highest content, followed by MO-4", and sample MO-32" has the lowest content. Furthermore Raman spectral analysis certifies that the basic microstructure of needle coke is similar. The fundamental reason is that the refined coal-tar pitch in the mixed oil determines the basic microstructure of needle coke. Due to the continuous circulation of heavy oil in the system, the microstructure of needle coke are different. Hence, the coking cycle is not easy to exceed 32 h in coal-based needle coke production, or else it will seriously affect the microstructure of needle coke. © 2021, Science Press. All right reserved.

引用

页码：1102 / 1110

页数：8

共 37 条

[1] KONDRASHEVA N K, RUDKO V A, NAZARENKO M Y, POVAROV V G, DERKUNSKII I O, KONOPLIN R R, GABDULKHAKOV R R, Influence of parameters of delayed coking process and subsequent calculation on the properties and morphology of petroleum needle coke from decant oil mixture of west siberian oil, Energy Fuels, 33, 7, pp. 6373-6379, (2019)
[2] LIU Wei, GAO Li-juan, CHENG Jun-xia, ZHAO Xue-fei, Determination of thermal conversion kinetics of mixed oil by FWO method, Carbon Technol, 36, 1, (2017)
[3] CAO Yan-hu, LIU Feng, YANG Wei-chao, WEI Bao-zhi, WANG Cheng-yang, Research progress of needle coke from patent perspective (III) - Delayed coking process, Carbon Technol, 38, 5, (2019)
[4] CHENG J X, ZHAO X F, GAO L J, ZHU Y M., Thermal conversion mechanism and thermodynamics of mixed oil in coal-based needle coke production[J], Asia-Pac J Chem Eng, 14, 5, pp. 1-13, (2019)
[5] CHENG Jun-xia, ZHU Ya-ming, GAO li-juan, ZHAO Xue-fei, FT-IR analysis of correlation between viscosity flow characteristics and molecular structure of mixed oil in production of coal-based needle coke, Spectrosc Spect Anal, 40, 6, pp. 1883-1888, (2020)
[6] ZHANG Ge, XIONG Chu-an, Main conditions affecting the formation of needle coke in industrial production, Carbon (China), 3, pp. 43-44, (2018)
[7] SAOWADEE N, AGERSTED K, BOWEN J R., Lattice constant measurement from electron backscatter diffraction patterns, J Microsc, 266, 2, pp. 200-210, (2017)
[8] MENDEZ A, SANTAMARIA R, GRANDA M., The effect of the reinforcing carbon on the microstructure of pitch-based granular composites, J Microsc, 209, 2, pp. 81-93, (2010)
[9] BRZOZOWAKA T, ZIELIFLAKI J, MACHNIKOWSKI J., Effect of polymeric additives to coal tar pitch on carbonization behaviour and optical texture of resultant coke, J Anal Appl Pyrolysis, 48, 1, pp. 45-58, (1998)
[10] ZENOU V Y, SNEJANA B., Microstructural analysis of undoped and moderately Sc-doped TiO<sub>2</sub>, anatase nanoparticles using Scherrer equation and Debye function analysis, Mater Charact, 144, pp. 287-296, (2018)

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