Study on coal pyrolysis characteristics by combining different pyrolysis reactors

doi:10.1016/j.cjche.2024.08.004

Chinese Journal of Chemical Engineering ›› 2024, Vol. 76 ›› Issue (12): 1-9.DOI: 10.1016/j.cjche.2024.08.004

Study on coal pyrolysis characteristics by combining different pyrolysis reactors

Xiaoping Su^1,2, Zhao Wang¹, Ning Li¹, Longjian Li¹, Ping Zhang¹, Ming Sun², Xiaoxun Ma²

1. School of Chemical Engineering, Northwest Minzu University, Key Laboratory of Environment-Friendly Composites of the State Ethnic Affairs Commission, Gansu Provincial Biomass Function Composites Engineering Research Center, Key Laboratory for Utility of Environment-Friendly Composites and Biomass in Universities of Gansu Province, Gansu Province Research Center for Basic Sciences of Surface and Interface Chemistry, Lanzhou 730030, China;
2. School of Chemical Engineering, Northwest University, International Science & Technology Cooperation Base of MOST for Clean Utilization of Hydrocarbon Resources, Chemical Engineering Research Center of the Ministry of Education for Advanced Use Technology of Shanbei Energy, Shaanxi Research Center of Engineering Technology for Clean Coal Conversion, Collaborative Innovation Center for Development of Energy and Chemical Industry in Northern Shaanxi, Xi'an 710069, China

Received:2024-04-07 Revised:2024-08-07 Accepted:2024-08-12 Online:2024-09-16 Published:2024-12-28
Contact: Ming Sun,E-mail:sunming1982@126.com;Xiaoxun Ma,E-mail:13772424852@163.com
Supported by:
This work was financed by the Department of Education of Gansu Province: Young Doctor Fund Project (2022QB-029), the Fundamental Research Funds for the Central Universities (31920240059, 3192024125-06), the Scientific Research Project of Introducing Talents of Northwest Minzu University (xbmuyjrc202215), the National Natural Science Foundation of China (22178289).

Study on coal pyrolysis characteristics by combining different pyrolysis reactors

Xiaoping Su^1,2, Zhao Wang¹, Ning Li¹, Longjian Li¹, Ping Zhang¹, Ming Sun², Xiaoxun Ma²

1. School of Chemical Engineering, Northwest Minzu University, Key Laboratory of Environment-Friendly Composites of the State Ethnic Affairs Commission, Gansu Provincial Biomass Function Composites Engineering Research Center, Key Laboratory for Utility of Environment-Friendly Composites and Biomass in Universities of Gansu Province, Gansu Province Research Center for Basic Sciences of Surface and Interface Chemistry, Lanzhou 730030, China;
2. School of Chemical Engineering, Northwest University, International Science & Technology Cooperation Base of MOST for Clean Utilization of Hydrocarbon Resources, Chemical Engineering Research Center of the Ministry of Education for Advanced Use Technology of Shanbei Energy, Shaanxi Research Center of Engineering Technology for Clean Coal Conversion, Collaborative Innovation Center for Development of Energy and Chemical Industry in Northern Shaanxi, Xi'an 710069, China

通讯作者: Ming Sun,E-mail:sunming1982@126.com;Xiaoxun Ma,E-mail:13772424852@163.com
基金资助:
This work was financed by the Department of Education of Gansu Province: Young Doctor Fund Project (2022QB-029), the Fundamental Research Funds for the Central Universities (31920240059, 3192024125-06), the Scientific Research Project of Introducing Talents of Northwest Minzu University (xbmuyjrc202215), the National Natural Science Foundation of China (22178289).

Abstract

Abstract: The pyrolysis process of Shendong coal (SD) was first studied by combining the characteristics of thermal gravimetric (TG), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and Gray-King assay (G-K). The results show that the order of coke yields is G-K (76.35% (mass))>TG (73.11% (mass))>Py (70.03% (mass)). G-K coke yield caused by condensation reaction and secondary reaction accounts for 3.08% (mass) and 3.24% (mass), respectively. Compared with slow pyrolysis, fast pyrolysis has stronger fracture ability to coal molecules and can obtain more O-compounds, mono-ring aromatics and aliphatics. Especially, the content of phenolics increases significantly from 15.49% to 35.17%, but the content of multi-ring aromatics decreases from 23.13% to 2.36%. By comparing the compositions of Py primary tar and G-K final tar, it is found that secondary reactions occurred during G-K pyrolysis process include the cleavage of alkane and esters, condensation of mono-ring aromatics with low carbon alkene, ring opening, isomerization of tri-ring aromatics, hydrogenation of aromatics and acids.

Key words: Shendong coal, Different pyrolysis reactors, Pyrolysis process

摘要： The pyrolysis process of Shendong coal (SD) was first studied by combining the characteristics of thermal gravimetric (TG), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and Gray-King assay (G-K). The results show that the order of coke yields is G-K (76.35% (mass))>TG (73.11% (mass))>Py (70.03% (mass)). G-K coke yield caused by condensation reaction and secondary reaction accounts for 3.08% (mass) and 3.24% (mass), respectively. Compared with slow pyrolysis, fast pyrolysis has stronger fracture ability to coal molecules and can obtain more O-compounds, mono-ring aromatics and aliphatics. Especially, the content of phenolics increases significantly from 15.49% to 35.17%, but the content of multi-ring aromatics decreases from 23.13% to 2.36%. By comparing the compositions of Py primary tar and G-K final tar, it is found that secondary reactions occurred during G-K pyrolysis process include the cleavage of alkane and esters, condensation of mono-ring aromatics with low carbon alkene, ring opening, isomerization of tri-ring aromatics, hydrogenation of aromatics and acids.

关键词: Shendong coal, Different pyrolysis reactors, Pyrolysis process

Xiaoping Su, Zhao Wang, Ning Li, Longjian Li, Ping Zhang, Ming Sun, Xiaoxun Ma. Study on coal pyrolysis characteristics by combining different pyrolysis reactors[J]. Chinese Journal of Chemical Engineering, 2024, 76(12): 1-9.

Xiaoping Su, Zhao Wang, Ning Li, Longjian Li, Ping Zhang, Ming Sun, Xiaoxun Ma. Study on coal pyrolysis characteristics by combining different pyrolysis reactors[J]. 中国化学工程学报, 2024, 76(12): 1-9.

References

[1] C.A. Wang, Y.H. Liu, X.M. Zhang, D.F. Che, A study on coal properties and combustion characteristics of blended coals in Northwestern China, Energy Fuels 25 (8) (2011) 3634-3645.
[2] J.W. Le, P. Liu, D.C. Liu, X.L. Lu, T.Y. Pan, D.X. Zhang, Effect of catalysts on the yields of light components and phenols derived from Shenmu coal low temperature pyrolysis, Energy Fuels 31 (7) (2017) 7033-7041.
[3] S.Q. Wang, D.X. Wang, Y.G. Tang, Y.B. Sun, D. Jiang, T. Su, Study of pyrolysis behavior of hydrogen-rich bark coal by TGA and Py-GC/MS, J. Anal. Appl. Pyrolysis 128 (2017) 136-142.
[4] K. Zhang, Y. Li, Z.H. Wang, Q. Li, R. Whiddon, Y. He, K.F. Cen, Pyrolysis behavior of a typical Chinese sub-bituminous Zhundong coal from moderate to high temperatures, Fuel 185 (2016) 701-708.
[5] Kech Lu Yongkang Chang Liping Xie. Effects of coal structure on its pyrolysis characteristics under N₂ and Ar atmosphere, Energy Sources 23 (8) (2001) 717-725.
[6] W.J. He, Z.Y. Liu, Q.Y. Liu, D.H. Ci, C. Lievens, X.F. Guo, Behaviors of radical fragments in tar generated from pyrolysis of 4 coals, Fuel 134 (2014) 375-380.
[7] W.C. Xia, C.K. Niu, C.C. Ren, Enhancement in floatability of sub-bituminous coal by low-temperature pyrolysis and its potential application in coal cleaning, J. Clean. Prod. 168 (2017) 1032-1038.
[8] Z.F. Gao, M.D. Zheng, D.L. Zhang, W.C. Zhang, Low temperature pyrolysis properties and kinetics of non-coking coal in Chinese western coals, J. Energy Inst. 89 (4) (2016) 544-559.
[9] L. Ding, Z.J. Zhou, Q.H. Guo, S.J. Lin, G.S. Yu, Gas evolution characteristics during pyrolysis and catalytic pyrolysis of coals by TG-MS and in a high-frequency furnace, Fuel 154 (2015) 222-232.
[10] B.H. Yan, C.X. Cao, Y. Cheng, Y. Jin, Y. Cheng, Experimental investigation on coal devolatilization at high temperatures with different heating rates, Fuel 117 (2014) 1215-1222.
[11] H.E. Jegers, M.T. Klein, Primary and secondary lignin pyrolysis reaction pathways, Ind. Eng. Chem. Proc. Des. Dev. 24 (1) (1985) 173-183.
[12] B. Tian, Y.Y. Qiao, Y.Y. Tian, Q. Liu, Investigation on the effect of particle size and heating rate on pyrolysis characteristics of a bituminous coal by TG-FTIR, J. Anal. Appl. Pyrolysis 121 (2016) 376-386.
[13] Y. Jiang, P.J. Zong, B. Tian, F.F. Xu, Y.Y. Tian, Y.Y. Qiao, J.H. Zhang, Pyrolysis behaviors and product distribution of Shenmu coal at high heating rate: A study using TG-FTIR and py-GC/MS, Energy Convers. Manag. 179 (2019) 72-80.
[14] Z.Y. Liu, X.J. Guo, L. Shi, W.J. He, J.F. Wu, Q.Y. Liu, J.H. Liu, Reaction of volatiles-A crucial step in pyrolysis of coals, Fuel 154 (2015) 361-369.
[15] J.I. Hayashi, H. Takahashi, S. Doi, H. Kumagai, T. Chiba, T. Yoshida, A. Tsutsumi, Reactions in brown coal pyrolysis responsible for heating rate effect on tar yield, Energy Fuels 14 (2) (2000) 400-408.
[16] C. Zhang, R.C. Wu, E.F. Hu, S.Y. Liu, G.W. Xu, Coal pyrolysis for high-quality tar and gas in 100 kg fixed bed enhanced with internals, Energy Fuels 28 (11) (2014) 7294-7302.
[17] L. Luo, W. Yao, J.X. Liu, H. Zhang, J.F. Ma, X.M. Jiang, The effect of the grinding process on pore structures, functional groups and release characteristic of flash pyrolysis of superfine pulverized coal, Fuel 235 (2019) 1337-1346.
[18] L. Shi, Q.Y. Liu, X.J. Guo, W.Z. Wu, Z.Y. Liu, Pyrolysis behavior and bonding information of coal-a TGA study, Fuel Process. Technol. 108 (2013) 125-132.
[19] M. Sun, M.M. Ma, B. Lv, Q.X. Yao, J.W. Gao, R.C. Wang, Y.J. Zhang, X.X. Ma, Pyrolysis characteristics of ethanol swelling Shendong coal and the composition distribution of its coal tar, J. Anal. Appl. Pyrolysis 138 (2019) 94-102.
[20] Q.X. Yao, Y.B. Li, X. Tang, J.W. Gao, R.C. Wang, Y.J. Zhang, M. Sun, X.X. Ma, Separation of petroleum ether extracted residue of low temperature coal tar by chromatography column and structural feature of fractions by TG-FTIR and PY-GC/MS, Fuel 245 (2019) 122-130.
[21] M. Sun, Q. Wang, C. He, J.W. Gao, R.C. Wang, Y.J. Zhang, L. Xu, Q.X. Yao, X.X. Ma, Pyrolysis characteristics of Shendong coal by CH₃OH-THF swelling coupled with in situ loading of metal ions, Fuel 253 (2019) 409-419.
[22] Y.Q. Liu, Q.X. Yao, M. Sun, T.T. Yuan, J.W. Gao, R.C. Wang, Y.J. Zhang, H.Y. Chen, X.X. Ma, Process characteristics and mechanisms for catalyzed pyrolysis of low-temperature coal tar, Energy Fuels 33 (8) (2019) 7052-7061.
[23] M. Sun, D. Zhang, Q.X. Yao, Y.Q. Liu, X.P. Su, C.Q. Jia, Q.Q. Hao, X.X. Ma, Separation and composition analysis of GC/MS analyzable and unanalyzable parts from coal tar, Energy Fuels 32 (7) (2018) 7404-7411.
[24] M.D. Casal, M.A. Diez, R. Alvarez, C. Barriocanal, Suitability of Gray-King pyrolysis to evaluate coking pressure, J. Anal. Appl. Pyrolysis 79 (1-2) (2007) 161-168.
[25] Q.X. Yao, M.L. Du, S.L. Wang, J. Liu, J.L. Yang, H.T. Shang, Distribution of sulfur forms in low temperature pyrolysis of coal, Adv. Mater. Res. 512-515 (2012) 834-837.
[26] P.F. Wang, L.J. Jin, J.H. Liu, S.W. Zhu, H.Q. Hu, Analysis of coal tar derived from pyrolysis at different atmospheres, Fuel 104 (2013) 14-21.
[27] Y.L. Li, S. Huang, Y.Q. Wu, S.Y. Wu, J.S. Gao, The roles of the low molecular weight compounds in the low-temperature pyrolysis of low-rank coal, J. Energy Inst. 92 (2) (2019) 203-209.
[28] C. Lievens, D.H. Ci, Y. Bai, L.G. Ma, R. Zhang, J.Y. Chen, Q.Q. Gai, Y.H. Long, X.F. Guo, A study of slow pyrolysis of one low rank coal via pyrolysis-GC/MS, Fuel Process. Technol. 116 (2013) 85-93.
[29] D. Zeng, S.T. Hu, A.N. Sayre, H. Sarv, On the rank-dependence of coal tar secondary reactions, Proc. Combust. Inst. 33 (2) (2011) 1707-1714.
[30] E.F. Hu, C.Q. Zhu, K. Rogers, X. Han, J. Wang, J. Zhao, X.H. Fu, Coal pyrolysis and its mechanism in indirectly heated fixed-bed with metallic heating plate enhancement, Fuel 185 (2016) 656-662.
[31] N. Devanathan, S.C. Saxena, Transport model for devolatilization of large nonplastic coal particles: The effect of secondary reactions, Ind. Eng. Chem. Res. 26 (3) (1987) 539-548.
[32] J. Hayashi, T. Kawakami, T. Taniguchi, K. Kusakabe, S. Morooka, M. Yumura, Control of molecular composition of tar by secondary reaction in fluidized-bed pyrolysis of a subbituminous coal, Energy Fuels 7 (1) (1993) 57-66.
[33] W.H. Yu, S. Han, Z.P. Lei, K. Zhang, J.C. Yan, Z.K. Li, H.F. Shui, S.G. Kang, Z.C. Wang, S.B. Ren, C.X. Pan, The reaction behavior of volatiles generated from lignite pyrolysis, Fuel 244 (2019) 22-30.
[34] J. LeBlanc, J. Quanci, M.J. Castaldi, Investigating secondary pyrolysis reactions of coal tar via mass spectrometry techniques, Energy Fuels 31 (2) (2017) 1269-1275.
[35] S. Cheng, D.G. Lai, Z. Shi, L.S. Hong, J.L. Zhang, X. Zeng, S.Q. Gao, G.W. Xu, Suppressing secondary reactions of coal pyrolysis by reducing pressure and mounting internals in fixed-bed reactor, Chin. J. Chem. Eng. 25 (4) (2017) 507-515.
[36] L. Dong, S. Han, W.H. Yu, Z.P. Lei, S.G. Kang, K. Zhang, J.C. Yan, Z.K. Li, H.F. Shui, Z.C. Wang, S.B. Ren, C.X. Pan, Effect of volatile reactions on the yield and quality of tar from pyrolysis of Shenhua bituminous coal, J. Anal. Appl. Pyrolysis 140 (2019) 321-330.
[37] K. Miura, Mild conversion of coal for producing valuable chemicals, Fuel Process. Technol. 62 (2-3) (2000) 119-135.
[38] Z.Y. Liu, Advancement in coal chemistry: Structure and reactivity, Sci. Sin. Chim. 44 (9) (2014) 1431-1439.
[39] C. He, X.J. Min, H.A. Zheng, Y.J. Fan, Q.X. Yao, D. zhang, X. Tang, C. Wan, M. Sun, X.X. Ma, C.Q. Jia, Study on the volatiles and kinetic of in situ catalytic pyrolysis of swelling low-rank coal, Energy Fuels 31 (12) (2017) 13558-13571.
[40] D.K. Hong, L. Liu, S. Zhang, X. Guo, Effect of cooling rate on the reaction of volatiles from low-rank coal pyrolysis: Molecular dynamics simulations using ReaxFF, Fuel Process. Technol. 178 (2018) 133-138.

Study on coal pyrolysis characteristics by combining different pyrolysis reactors

Study on coal pyrolysis characteristics by combining different pyrolysis reactors

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