Study on the pyrolysis kinetics of low-medium rank coals with distributed activation energy model

Yan, Jingchong; Liu, Muxin; Feng, Zhihao; Bai, Zongqing; Shui, Hengfu; Li, Zhan-Ku; Lei, Zhiping; Wang, Zhicai; Ren, Shibiao; Kang, Shigang; Yan, Hong-Lei

doi:10.1016/j.fuel.2019.116359

Cited by 71 publications

(33 citation statements)

References 64 publications

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“…The synergy and interaction of blended samples in oxy-fuel atmosphere during the co-firing process were investigated, and the comparison of TG/DTG curves of blend samples with 50% bituminous coal between the experiment and calculation results is depicted in Figure 6. The calculation results are obtained based on Equation 2and (3). The variation trend of the TG and DTG curves demonstrates a good degree of similarity.…”

Section: Effects Of Blending Ratio On Oxy-fuel Co-combustionmentioning

confidence: 99%

“…2 The proportion of low-rank coal accounts for up to 55% in China. 3 The traditional direct combustion of low-rank coal brought about the energy and capital wastes to a large extent due to its high moisture. Therefore, the appropriate exploitation of low-rank coal can improve the energy efficiency and satisfy the requirements of chemical industry through the coal pyrolysis and gasification technologies.…”

Section: Introductionmentioning

confidence: 99%

“…Low‐rank coal (lignite and sub‐bituminous coal) refers to coals with bed moisture ≤75% and the mean random vitrinite reflectivity Rr <0.5% 2 . The proportion of low‐rank coal accounts for up to 55% in China 3 . The traditional direct combustion of low‐rank coal brought about the energy and capital wastes to a large extent due to its high moisture.…”

Section: Introductionmentioning

confidence: 99%

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Oxy‐fuel co‐combustion performances and kinetics of bituminous coal and ultra‐low volatile carbon‐based fuels

et al. 2020

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Summary The co‐firing of bituminous coal under oxy‐fuel conditions is a feasible measure to improve the ignition and combustion performances of ultra‐low volatile carbon‐based fuels and effectively control pollutants. The present study aimed at the co‐combustion performances and kinetics of bituminous coal and ultra‐low volatile carbon‐based fuels under oxy‐fuel condition by means of thermogravimetric experiments. The results indicate that the volatile content in fuels is likely to affect the ignition temperature and the oxy‐fuel co‐firing of bituminous coal accelerates the ignition and advances combustion of ultra‐low volatile fuels. The combustion behaviors of individual fuel are retained in the co‐firing process to a large extent, and there is a slight synergy at the 350 to 950°C temperature range. Enhancing the oxygen concentration is effective to improve the combustion performances of ultra‐low volatile fuels in oxy‐fuel atmosphere. The apparent activation energy of residual carbon from coal‐water‐slurry gasification in oxy‐fuel atmosphere exceeds that from fluidized bed gasification, which is highly related to gasification technology and raw fuel properties. The apparent activation energy under condition of co‐firing bituminous coal and residual carbon from coal‐water‐slurry varies considerably, changed from 100 to 46 kJ/mol. Therefore, the addition of bituminous coal significantly reduces the activation energy of ultra‐low volatile fuels to improve the co‐firing performances. Based on the present investigation, a better understanding on the oxy‐fuel co‐firing of various carbon‐based solid fuels is obtained, thereby promoting the efficient and clean utilization of solid waste in the coal chemical industry.

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Section: Effects Of Blending Ratio On Oxy-fuel Co-combustionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Oxy‐fuel co‐combustion performances and kinetics of bituminous coal and ultra‐low volatile carbon‐based fuels

et al. 2020

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“…The results showed that the initial pyrolysis temperature increased with the increase of heating rate, and the yield of solid semicoke decreased with the increase of heating rate, indicating that high heating rate is conducive to the formation of volatile substances. Yan [9] studied that DAEM could accurately predict the pyrolysis behavior of bituminous coals at very high heating rates, but the effectiveness of DAEM in modeling and predicting pyrolysis of lignite is less satisfying. Xu [10] studied that comparing with the single-step global model, the distributed activation energy model (DAEM) is more accurate to characterize the gasification kinetics for the studied cokes, and the activation energies are in the range of 159.80-254.10 kJ/mol.…”

Section: Introductionmentioning

confidence: 99%

Pyrolysis Reactive Behaviors and Kinetic Characteristics of HSW Vitrinite Coal based on Coats-Redfern and DAEM Models

Wang¹,

Wang²,

Li³

et al. 2021

Preprint

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In this work, the weight loss behavior of vitrinite in hongshiwan coal at different heating rates was investigated by thermogravimetric mass spectrometry (TG-MS). Then Coats-Redfern and DAEM models were established to analyze the kinetics of coal pyrolysis. The results show that the weight loss rate of pyrolysis decreased with the increase of heating rate. When the pyrolysis temperature reaches 400–500°C, the weight loss rate reaches the maximum, which is 0.1593, 0.1539, 0.1478 and 0.1414%/°C respectively at the heating rates of 5, 10, 15 and 20°C/min, With the increase of heating rate, the corresponding temperature peaks of the five pyrolysis gases are shifted to the high temperature direction, and the amount of gas escaping is increasing. The trend of higher heating rate delayed the release of volatile compounds was consistent with TG-DTG results. Two kinetic models both prove that the activation energy of coal pyrolysis increases with the increase of temperature. The maximum activation energy occurs between 600 ℃ and 900 ℃, because the multi condensation of coal tar and the re solidification of semi coke will occur in this temperature range.

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“… 5 In addition, coal pyrolysis is an essential step in coal conversion technologies, such as combustion, gasification, and liquefaction. 6 In recent years, scholars thoroughly examined coal pyrolysis under different conditions. The coal pyrolysis reaction and product distribution are significantly affected by certain coal properties such as the coal grade, 7 coal moisture content, 8 and inorganic matter content, 9 − 11 as well as pyrolysis conditions such as the pyrolysis temperature, 12 , 13 heating time, 12 , 13 atmosphere, 1 , 12 and pressure.…”

Section: Introductionmentioning

confidence: 99%

Effects of Vitrinite in Low-Rank Coal on the Structure and Combustion Reactivity of Pyrolysis Chars

Hong

et al. 2020

ACS Omega

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Pyrolysis is a highly promising technology for the efficient utilization of low-rank coal. The structure of coal plays an important role in its utilization. In this paper, the evolution of the char structure during heat treatment (200–800 °C) of Naomaohu coal and its different vitrinite-rich fractions was studied. The functional group structure, aromatic ring structure, and crystallite size of chars were determined by Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and X-ray diffraction (XRD) spectroscopy, respectively. The results indicated that minerals inhibit the condensation reaction of aromatic rings during pyrolysis. The high vitrinite content in coal is conducive to the formation of larger char crystallite average sizes ( L a ). The relationship between L a (1.69–3.10 nm) and the Raman band area ratio A (G R +V L +V R ) / A D or A D / A all was established. In addition, the combustion performance and kinetics of chars were also investigated. The results showed that the char from high contents of the liptinite fraction has lower combustion reactivity, and demineralization treatment has significantly reduced the combustion reactivity of char.

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Study on the pyrolysis kinetics of low-medium rank coals with distributed activation energy model

Cited by 71 publications

References 64 publications

Oxy‐fuel co‐combustion performances and kinetics of bituminous coal and ultra‐low volatile carbon‐based fuels

Oxy‐fuel co‐combustion performances and kinetics of bituminous coal and ultra‐low volatile carbon‐based fuels

Pyrolysis Reactive Behaviors and Kinetic Characteristics of HSW Vitrinite Coal based on Coats-Redfern and DAEM Models

Effects of Vitrinite in Low-Rank Coal on the Structure and Combustion Reactivity of Pyrolysis Chars

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