Synergistic mechanism of CO2 and active functional groups during low temperature oxidation of lignite

Low temperature oxidation of two different low rank coals was measured by in-situ FTIR. Curve-fitting analysis was employed to identify functional groups types of raw coals, and series technology was carried out on in-situ infrared spectrum of sample coals at low-temperature oxidation process to analyze the changes of main active functional groups with temperature. The results indicate that -CH3, -CH2, -OH, C=O, COOH are the main active functional groups in low rank coal. In the oxidation process, with temperature increasing, the methyl and methylene show the tendency of increase after decrease and then decrease, and all of hydroxyl, carboxyl and carbonyl group present the tendency of increase after decrease, there exists some differences among the main functional groups in the coal low-temperature process.

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B-Mode Grey Relational Analysis of Surface Functional Groups Change Rules in Coal Spontaneous Combustion

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.236-238.762 ◽

2011 ◽

Vol 236-238 ◽

pp. 762-766 ◽

Cited By ~ 1

Author(s):

Wei Qing Zhang ◽

Shu Guang Jiang ◽

Lan Yun Wang ◽

Zheng Yan Wu ◽

Hao Shao ◽

...

Keyword(s):

Low Temperature ◽

Functional Groups ◽

Grey Relational Analysis ◽

Spontaneous Combustion ◽

Surface Functional Groups ◽

Low Temperature Oxidation ◽

Coal Spontaneous Combustion ◽

Temperature Oxidation ◽

Relational Analysis ◽

Grey Relational

Based on the results of Fourier Transform Infrared Spectroscopy (FTIR) test of surface functional groups of different coal samples in low-temperature oxidation, the quantitative variation between functional groups and temperature was analyzed by B-mode grey relational analysis. According to the grey B-mode degrees and orders, a summary is given that: 1)the aromatic ketone and aldehyde carbonyl groups are mostly produced during the process of coal oxidation and the oxygen-containing functional groups existed mainly in the form of stable ether bond; 2)the methylene groups make major contribution to coal spontaneous combustion, so that the methylene structures should be disposed firstly in order to suppress coal spontaneous combustion effectively; 3)the degree range of gas coal is the largest, which shows that the process of gas coal spontaneous combustion is mostly affected by active groups to some extent. These quantitative results will be helpful to find the functional groups affecting deeply the process of low-temperature oxidation of coal.

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Heat Release Characteristic of Key Functional Groups during Low-Temperature Oxidation of Coal

Combustion Science and Technology ◽

10.1080/00102202.2020.1755970 ◽

2020 ◽

pp. 1-12

Author(s):

Yanni Zhang ◽

Yunchao Hou ◽

Jingyu Zhao ◽

Jun Deng ◽

Xinyu Wen ◽

...

Keyword(s):

Low Temperature ◽

Heat Release ◽

Functional Groups ◽

Low Temperature Oxidation ◽

Temperature Oxidation ◽

Key Functional Groups ◽

Release Characteristic

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Experimental Study on Infrared Spectrum Characteristics of Coal in Low Temperature Oxidation

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.184-185.1394 ◽

2012 ◽

Vol 184-185 ◽

pp. 1394-1399 ◽

Cited By ~ 2

Author(s):

Yan Ni Zhang ◽

Jun Deng ◽

Wei Feng Wang ◽

Shi Rong Li ◽

Shuang Hou

Keyword(s):

Low Temperature ◽

Infrared Spectrum ◽

Functional Groups ◽

Spontaneous Combustion ◽

Low Temperature Oxidation ◽

Temperature Oxidation ◽

Complex Procedure ◽

The Difference ◽

The Fourier Transform ◽

Physical And Chemical

Coal spontaneous combustion is a complex procedure of physical and chemical changing, in which the macro characters is the reflection of micro changes of coal molecule structure in low temperature oxidation. In order to understand the essence of coal-oxygen composition, the Fourier transform infrared spectrum apparatus is used to test and analyze different kinds of coal samples in different oxidation temperature. According to main characteristic spectrum peaks, the activity of coal functional groups is studied. The difference and change of the type and quantity of functional groups in different kinds of coal sample in different temperature are analyzed. The relation between the macro structure change and spontaneous combustion property of coal in low temperature oxidation process is discussed.

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