Time evolution of coal structure during low temperature air oxidation

Wang, Guangheng; Zhou, Anning

doi:10.1016/j.ijmst.2012.01.013

Cited by 32 publications

(18 citation statements)

References 14 publications

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“…The oxygen content was thought to be related to the abundance of sites reactive with oxygen [6], oxygen content of A and B were respectively 8.95% and 9.62% which were more than twice compared to C (4.17%). And sub-bituminous coal (A and B) may contain large number of aliphatic carbon and oxygen-containing functional groups [14,16]. In summary, it could be concluded that coal A and coal B had strong oxidation ability and high reactivity during low temperature oxidation.…”

Section: Mechanismsmentioning

confidence: 93%

Study on thermochemical kinetic characteristics and interaction during low temperature oxidation of blended coals

Chen

Lin

et al. 2015

Journal of the Energy Institute

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Section: Mechanismsmentioning

confidence: 93%

Study on thermochemical kinetic characteristics and interaction during low temperature oxidation of blended coals

Chen

Lin

et al. 2015

Journal of the Energy Institute

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“…Different concentration of sample may lead to different peak intensities. To reduce this error, base-line correction and normalization processing of the spectrum were performed in this study [14]. The FTIR peaks locating at 3000-3600 cm 1 correspond to the hydroxyl group, and those at 2800-3000 cm 1 attribute to aliphatic hydrocarbon, those at 1000-1800 cm 1 are ascribed to oxygen containing functional groups, and those at 700-900 cm 1 correspond to the aromatic CH outside surface deformation and vibration.…”

Section: Qualitative and Semi-quantitative Analysismentioning

confidence: 99%

“…In this study, the software origin was used to perform peak fitting (using Gaussian distribution) [14]. The contents of the functional groups before and after deformation at three temperatures are listed in Table 4.…”

Section: Qualitative and Semi-quantitative Analysismentioning

confidence: 99%

“…In order to eliminate the influence of these two factors, peak intensity ratios (peak ratios or peak height ratios) is adopted to illustrate the characteristics and changes of various coal structures. The reason of doing this is that the peak areas of the FTIR spectrum are affected less by sample and instrument then peak height [14]. In this study, the peak area ratio (I 1 -I 5 in Table 5) were used for quantitative analysis of the microstructure of coal [14,16,17].…”

Section: Infrared Structure Parametermentioning

confidence: 99%

“…The reason of doing this is that the peak areas of the FTIR spectrum are affected less by sample and instrument then peak height [14]. In this study, the peak area ratio (I 1 -I 5 in Table 5) were used for quantitative analysis of the microstructure of coal [14,16,17]. In Table 5, I 1 =A2944/A1579 (where A represents the area of certain peak, the number after it represents the wavenumber of the peak, same as below) represents the degree of the falling off of CH 3 ; I 2 =A2831/A1579 represents the degree of the falling off of CH 2 ; I 3 =A2924/A2964 characterizes aliphatic chain length and branched degree, the larger the I 3 , the longer the aliphatic chain and the less the branched degree is; I 4 =(A1703+1745)/A1579 characterizes of the relative content of oxygen containing functional groups C=O and aromatic hydrocarbons; and I 5 =(A1330-A1110)/A1579 characterizes the relative content of C-O and the aromatic hydrocarbons.…”

Section: Infrared Structure Parametermentioning

confidence: 99%

See 2 more Smart Citations

Effect of temperature and stress on molecular structure and carbon monoxide generation of lignite from Kailuan mining area

Chi

Wei

Guo

et al. 2016

International Journal of Mining Science and Technology

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In order to analyze the origin of carbon monoxide (CO) in coal seams, stress-strain experiments under temperature of 50, 150 and 250 ℃ were conducted using lignite from Kailuan mining area. Fourier transform infrared spectroscopy and elemental analysis were carried out before and after deformation of the samples. The results indicated that CO generated at 150 and 250 ℃; the gas component was mostly oxygen (O 2), with small amount of carbon dioxide (CO 2), methane (CH 4) and hydrogen (H 2). At 50 ℃, O 2 and a little CO 2 were observed and no CO was found. The carbon content of the coal samples increased slightly after deformation, and the oxygen content, H/C ratio, and O/C ratio decreased. The molecular structure of coal displayed different evolution characteristics at various temperatures. At 50 and 150 ℃, the falling off of side chains, broken of ether bond and directional realignment of the aliphatic chains resulting in the formation of long chains were the main performance of coal molecular structure evolution. While at 250 ℃, the side chains fell off and short chains formed. Furthermore, at both 150 and 250 ℃, condensed degree of aromatic ring increased. Under the action of temperature and pressure, CO forms in two ways. The first is that ether bond breaks, oxygen and carbon atoms combine together and forms CO, or O 2 forming in the broken of ether-oxygen bond leads to the oxidation of free radicals and resulting in the formation of CO. And the second is that CO derives from falling off of C=O group.

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Coal Oxidation under Mild Conditions: Current Status and Applications

Jiang

Tahmasebi

et al. 2014

Chem Eng & Technol

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A comprehensive overview of coal oxidation methods under mild conditions is provided, including oxidation with oxygen, ozone, ruthenium ion catalysis, oxidizing acid, electrolysis, sodium hypochlorite, and hydrogen peroxide. The changes in chemical structure of coal during oxidation, the mechanism of different types of oxidation methods, and the possible applications of oxidation products are summarized. Comparison of these oxidation methods demonstrated that hydrogen peroxide and sodium hypochlorite oxidation of coal under mild conditions are the most suitable methods to study the molecular structure of coal and to obtain high‐value organic chemicals. Applications of different analytical techniques for determination and quantification of products and coal structures are also reviewed.

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Time evolution of coal structure during low temperature air oxidation

Cited by 32 publications

References 14 publications

Study on thermochemical kinetic characteristics and interaction during low temperature oxidation of blended coals

Study on thermochemical kinetic characteristics and interaction during low temperature oxidation of blended coals

Effect of temperature and stress on molecular structure and carbon monoxide generation of lignite from Kailuan mining area

Coal Oxidation under Mild Conditions: Current Status and Applications

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