Kinetics characteristics of coal low-temperature oxidation in oxygen-depleted air

Qi, Guansheng; Wang, Biao; Zheng, Keming; Xu, Jun; Qi, Xuyao; Zhong, Xiaoxing

doi:10.1016/j.jlp.2015.05.011

Cited by 114 publications

(29 citation statements)

References 31 publications

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“…In the lean‐oxygen smoldering combustion space of coalfield fires, the oxidation and combustion of low‐rank coal is a typical gas‐solid kinetic reaction process . With the limitation of oxygen, the oxidation and pyrolysis reaction paths advance in parallel and consume the coal competitively, leading to the expansion and merging of micropores and the evolution of gas passage in the inner structure of coal, which, in turn, produces an influence on the parallel but competitive consumption mechanism between oxidation and pyrolysis reaction paths .…”

Section: Resultsmentioning

confidence: 99%

The competitive reaction mechanism between oxidation and pyrolysis consumption during low‐rank coal combustion at lean‐oxygen conditions: A quantitative calculation based on thermogravimetric analyses

Wang

Xin

et al. 2018

Can J Chem Eng

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The evolution of the oxidation-pyrolysis competitive mechanism during low-rank coal combustion at lean-oxygen conditions determines the development of the coalfield fires and the burning loss rate of the coal resource. In the present work, the mass increments of oxygen-chemisorption were measured and calculated firstly. An abstract shrinking core model was built for distinguishing the oxidation and pyrolysis pathways. On this basis, the consumption rates of oxidation and pyrolysis were respectively calculated with the TGA data obtained under the lean-oxygen gradient of 21-0 %. The results demonstrate that the oxidation path gradually delays in temperature while the pyrolysis exhibits great temperature stability as the oxygen concentration decreases. Besides, the significant transition of the competitive consumption mechanism exists below 9 % for the oxidation phase before ignition and 5 % for the combustion phase after ignition, respectively. Two temperature indicators of T C1 and T C2 for guiding the optimal fire extinguishing schemes based on the actual oxygen concentrations and temperatures are proposed. Furthermore, 1 % is identified as the limiting oxygen concentration for the development of the coalfield fires where the ignition mechanisms of both the HST and WD coal transform into the homogeneous ignition. The WD lignite, which always maintains the coke state as the burnout mechanism, holds higher reactivity but wider dispersion degrees of combustion compared with the HST sub-bituminous coal.

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Section: Resultsmentioning

confidence: 99%

The competitive reaction mechanism between oxidation and pyrolysis consumption during low‐rank coal combustion at lean‐oxygen conditions: A quantitative calculation based on thermogravimetric analyses

Wang

Xin

et al. 2018

Can J Chem Eng

Self Cite

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“…Activation energy was a very important kinetic parameter in coal oxidation, which can re ect the coal reaction di culty to a certain extent. A great deal of work has been done (Qi et al 2015;Deng et al 2018b) in the study of oxidation reaction kinetics to obtain different methods for solving E a , A and deducing the most probable mechanism function.In this paper, Achar differential method and Coastal-Redfern integral method were used for kinetic analysis and calculation of coal oxidation reaction, and Bagchi method was used to infer the reaction mechanism function. The experimental data and the 18 solid reaction mechanism functions in the Table 3 were substituted into Eq.…”

Section: Kinetic Parametersmentioning

confidence: 99%

Study on the thermal kinetics of anthracite oxidation induced by water and associated pyrite

Wang

Duan

Bai

et al. 2020

Preprint

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Pyrite and water in coal have considerable influence on coal spontaneous combustion and threaten the safety of mine production gravely. To reveal the influence mechanism of water and associated pyrite on oxidation kinetics of coal–oxygen composite reaction, the pyrite of 0%, 1%, 2%, 4%, 6% and the moisture of 1%, 5%, 10%, 15% and 20% were mixed with the coal samples to obtain 25 coal samples. Thermogravimetric analysis technology was conducted to explore the changes of mass and characteristic temperatures of coal samples treated with water and associated pyrite during the low–temperature oxidation, and kinetic analysis of the oxidation process was discussed based on multiple heating rates(5 °C/min, 10 °C/min and15 °C/min).The results show that water and associated pyrite had a great influence on coal in oxygen absorption and weight gain stage ( T 3 ~ T 5 ), and there was a proportion range with the largest synergistic oxidation contribution. The apparent activation energy of the coal sample appeared changes, but the mechanism model did not, indicating that water and pyrite could affect the oxidation process of the coal sample externally. When water and associated pyrite exhibit synergistic interaction, there have a range that water was 10~15% and associate pyrite was 2~4% had the largest promotion and contribution to anthracite oxidation. The results have important scientific value and practical guiding significance for the further study on prediction, prevention and control of high sulfur anthracite spontaneous combustion.

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“…Li [15] tested the influence of temperature on the law of gaseous compound emission during the coal spontaneous combustion process with the method of programmed heating. Qi [16] tested the dynamics characteristics of oxidized coal samples under different oxygen concentration in the lean oxygen environment during the coal spontaneous combustion process. The lower the oxygen concentration was, the higher the activation energy needed.…”

Section: Dynamic Characteristics Of Spontaneous Combustion Of Oxidizementioning

confidence: 99%

A review of spontaneous combustibility of oxidized coal

Wang¹,

Zhai²,

Jiang³

et al. 2018

Proceedings of the 2017 3rd International Forum on Energy, Environment Science and Materials (IFEESM 2017)

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Abstract. Oxidized coal is the coal that recovered to environment temperature when the heat-storing environment is destroyed during the self-heating process, which is quite common in the process of coal mining and utilization. The spontaneous combustibility of oxidized coal differs from that of raw coal, which needs to be studied specially. In this paper, the development of microstructure characteristics, spontaneous combustibility and structure-function relationship of oxidized coal was reviewed. The proposed shortcomings, less of influence effects and factors, had been summarized. On the basis of deficiencies, the suggestions of studying microstructure mechanism and gross feature of coal secondary oxidation, also the structure-function relationship were put forward.

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Kinetics characteristics of coal low-temperature oxidation in oxygen-depleted air

Cited by 114 publications

References 31 publications

The competitive reaction mechanism between oxidation and pyrolysis consumption during low‐rank coal combustion at lean‐oxygen conditions: A quantitative calculation based on thermogravimetric analyses

The competitive reaction mechanism between oxidation and pyrolysis consumption during low‐rank coal combustion at lean‐oxygen conditions: A quantitative calculation based on thermogravimetric analyses

Study on the thermal kinetics of anthracite oxidation induced by water and associated pyrite

A review of spontaneous combustibility of oxidized coal

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