EVOLUTION CHARACTERISTIC AND KINETIC MODEL FOR FUNCTIONAL GROUPS IN BITUMINOUS COAL DURING PYROLYSIS

YANG Qiling; WANG Ruwei

doi:10.13205/j.hjgc.202307019

Volume 41 Issue 7

Jul. 2023

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YANG Qiling, WANG Ruwei. EVOLUTION CHARACTERISTIC AND KINETIC MODEL FOR FUNCTIONAL GROUPS IN BITUMINOUS COAL DURING PYROLYSIS[J]. ENVIRONMENTAL ENGINEERING , 2023, 41(7): 138-144. doi: 10.13205/j.hjgc.202307019

Citation:

YANG Qiling, WANG Ruwei. EVOLUTION CHARACTERISTIC AND KINETIC MODEL FOR FUNCTIONAL GROUPS IN BITUMINOUS COAL DURING PYROLYSIS[J]. ENVIRONMENTAL ENGINEERING , 2023, 41(7): 138-144. doi: 10.13205/j.hjgc.202307019

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EVOLUTION CHARACTERISTIC AND KINETIC MODEL FOR FUNCTIONAL GROUPS IN BITUMINOUS COAL DURING PYROLYSIS

doi: 10.13205/j.hjgc.202307019

YANG Qiling¹,
WANG Ruwei^{1,2
,
,}

1. School of Environment, Jinan University, Guangzhou 511443, China;
2. Guangdong-Hongkong-Macao Joint Laboratory for Contaminants Exposure and Health, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China

Received Date: 2022-09-24

Abstract

Abstract

Understanding the mechanism of coal pyrolysis is of great significance to improving coal utilization efficiency and mitigating environmental impact. Fourier transform infrared spectroscopy (FTIR) and gas chromatogram-mass spectrum analyses were used to investigate changes in molecular functional groups and polycyclic aromatic hydrocarbons (PAHs) during pyrolysis of bituminous coal, and then kinetic models were constructed. Results showed that:the relative abundances of aromatic, aliphatic, and heteroatom functional groups decreased as pyrolysis temperature increased. When the temperature was lower than 300℃, the reduction of aromatic and aliphatic functional groups was mainly due to the volatilization of the small molecular groups, while the reduction of oxygen-containing functional groups was due to thermal breakage of self-associating hydroxyl hydrogen bonds; when the temperature was 300~600℃, the functional groups of C-O and aliphatics were decomposed at 300℃ and 400℃, leading to rapid decreases in relative abundances of aromatic, aliphatic and oxygen-containing functional groups. The activation energy of each functional group at high temperature stage was higher than that at low temperature stage. The kinetic models of ·OH and C-O in the whole pyrolysis process followed the second-order reaction mode. Changes in the aliphatic functional groups conformed to the two-phase interface model at 25 to 400℃, and conformed to the second-order reaction model at 400 to 600℃. C=O conformed to the three-way transport mode and the second-order reaction model at 25 to 300℃ and 300 to 600℃, respectively.
- pyrolysis of bituminous coal,
- functional groups,
- evolution characteristic,
- kinetic model

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References(34)

References

[1]	李刚.煤热解中间体和自由基表征及反应机理研究[D].大连:大连理工大学,2015:1-5.
[2]	卢昌义.现代环境科学概论[M].厦门:厦门大学出版社,2020:349-351.
[3]	WANG R W, SUN R Y, LIU G J, et al.A review of the biogeochemical controls on the occurrence and distribution of polycyclic aromatic compounds (PACs) in coals[J].Earth-Science Reviews, 2017, 171:400-418.
[4]	王楠.不同构造变形程度下高煤级煤分子结构演化特征[D].西安:西安科技大学, 2021, 2015:2-5.
[5]	张双全.煤化学[M].徐州:中国矿业大学出版社, 2019:169-179.
[6]	乐嘉炜.煤中小分子化合物及催化剂对煤热解产物分布的影响[D].上海:华东理工大学, 2017:4-5.
[7]	COATS A W, REDFERN J P.Thermogravimetric analysis:a review[J].Analyst, 1963, 88(1053):906-924.
[8]	FLYNN J H.Thermal analysis kinetics-past, present and future[J].Thermochimica Acta, 1992, 203:519-526.
[9]	BAMFORD C H, TIPPER C F H.Decomposition reactions of solids[M].Elsevier, 1980:177-200.
[10]	ZHOU C C, LIU G J, CHENG S, et al.Thermochemical and trace element behavior of coal gangue, agricultural biomass and their blends during co-combustion[J].Bioresource Technology, 2014, 166:243-251.
[11]	OZAWA T.A new method of analyzing thermogravimetric data[J].Bulletin of The Chemical Society of Japan, 1965, 38(11):1881-1886.
[12]	FLYNN J H, WALL L A.A quick, direct method for the determination of activation energy from thermogravimetric data[J].Journal of Polymer Science Part B:Polymer Letters, 1966, 4(5):323-328.
[13]	KISSINGER H E.Reaction kinetics in differential thermal analysis[J].Analytical Chemistry, 1957, 29(11):1702-1706.
[14]	SHI T, WANG X F, DENG J, et al.The mechanism at the initial stage of the room-temperature oxidation of coal[J].Combustion and Flame, 2005, 140(4):332-345.
[15]	LIN X C, WANG C H, IDETA K, et al.Insights into the functional group transformation of a Chinese brown coal during slow pyrolysis by combining various experiments[J].Fuel, 2014, 118:257-264.
[16]	IBARRA J V, MOLINER R, BONET A J.FTIR investigation on char formation during the early stages of coal pyrolysis[J].Fuel, 1994, 73(6):918-924.
[17]	MURAKAMI K, SHIRATO H, NISHIYAMA Y.In situ infrared spectroscopic study of the effects of exchanged cations on thermal decomposition of a brown coal[J].Fuel, 1997, 76(7):655-661.
[18]	NIU Z Y, LIU G J, YIN H, et al.Investigation of mechanism and kinetics of non-isothermal low temperature pyrolysis of perhydrous bituminous coal by in-situ FTIR[J].Fuel, 2016, 172:1-10.
[19]	YU J L, LUCAS J A, WALL T F.Formation of the structure of chars during devolatilization of pulverized coal and its thermoproperties:a review[J].Progress in Energy and Combustion Science, 2007, 33(2):135-170.
[20]	钮志远.典型煤的官能团热解机理、动力学分析及影响因素研究[D].合肥:中国科学技术大学, 2017:56-59.
[21]	郝长胜,袁迎春,贾廷贵,等.不同变质程度煤的化学结构红外光谱研究[J].煤矿安全, 2022, 53(11):15-22.
[22]	贾廷贵,李璕,曲国娜,等.不同变质程度煤样化学结构特征FTIR表征[J].光谱学与光分析, 2021, 41(11):3363-3369.
[23]	宋昱, 朱炎铭, 李伍.东胜长焰煤热解含氧官能团结构演化的¹³C-NMR和FTIR分析[J].燃料化学学报, 2015, 43(5):519-529.
[24]	张嬿妮, 刘春辉, 宋佳佳, 等.长焰煤低温氧化主要官能团迁移规律研究[J].煤炭科学技术, 2020, 48(3):188-196.
[25]	刘颖健.煤氧化过程中自由基-活性基团作用机理[D].唐山:华北理工大学, 2016.
[26]	石国京.新疆低质炼焦煤改质炼焦及热解过程煤化学结构演变规律研究[D].重庆:重庆大学, 2018.
[27]	苗树伟.煤热解及氧化过程中含氧官能团的演化[D].武汉:华中科技大学, 2018.
[28]	ZHAO J, DENG J, CHEN L, et al.Correlation analysis of the functional groups and exothermic characteristics of bituminous coal molecules during high-temperature oxidation[J].Energy, 2019, 181:136-147.
[29]	解强, 梁鼎成, 田萌, 等.升温速率对神木煤热解半焦结构性能的影响[J].燃料化学学报, 2015, 43(7):798-805.
[30]	常娜, 甘艳萍, 陈延信.升温速率及热解温度对煤热解过程的影响[J].煤炭转化, 2012, 35(3):1-5.
[31]	董洁.煤热解过程中PAHs的形成及其催化裂解特性[D].太原:太原理工大学, 2013.
[32]	CAI F X, WANG R W, CAI J W, et al.Investigation of the maturation effects on biomarker distributions in bituminous coals[J].Organic Geochemistry, 2022, 173:104496.
[33]	IBARRA J V, MUNOZ E, MOLINER R.FTIR study of the evolution of coal structure during the coalification process[J].Organic Geochemistry, 1996, 24(6/7):725-735.
[34]	MIURA K, MAE K, LI W, et al.Estimation of hydrogen bond distribution in coal through the analysis of OH stretching bands in diffuse reflectance infrared spectrum measured by in-situ technique[J].Energy & Fuels, 2001, 15(3):599-610.