Effects of Parent Coal Properties on the Pyrolytic Char Chemical Structure: Insights from Micro-Raman Spectroscopy Based on 32 Kinds of Chinese Coals

Processes

Xinyu Ning¹  Wen Tang¹  Jun Xu²  Yi Wang²  Hengda Han²  Limo He²  Sheng Su²  Jun Xiang²  Dezhi Chen²  Kai Xu²  Song Hu²  Long Jiang² 

[1] China Power Huachuang Electricity Technology Research Co., Ltd., Suzhou 215123, China;State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China;

关键词: Raman spectroscopy;    coal property;    pyrolysis;    char;    chemical structure;   

DOI  :  10.3390/pr9091575

来源: DOAJ

【 摘 要 】

The chemical structures of pyrolytic chars prepared from 32 kinds of Chinese coals were investigated with micro-Raman spectroscopy in this study. Both first-order and second-order Raman spectra of the chars were curve-fitted and analyzed. The effects of the parent coal properties, including coal rank, volatile, fixed carbon, and ash content, on the pyrolytic char structures were detailed discussed and the correlations between these coal properties and pyrolytic char chemical structures were set up. Multiple-factor analysis was done to propose a comprehensive coal property index that relates well to the pyrolytic char chemical structure. The results indicate that the aromatization degree is the key distinguishable structure of pyrolytic chars prepared from coals with various rank, and the alkyl C−H and aryl C−H structures have no significant difference. The aromatization degree of pyrolytic char decreases with the increase of coal rank, while it increases with the increase of the fixed carbon content in parent coals. The high content of moisture in parent coal can induce condensation of the pyrolytic char, but the inorganic composition probably prevents the condensation of the char. Limited correlations between the coal rank, fixed carbon, moisture and ash content, and the aromatization degree of pyrolytic chars were found. A comprehensive coal property index: (fixed carbon content + moisture content)/(volatile content + ash content) (in air dry basis) combining the coal properties together relates well to the aromatization degree of pyrolytic char and can act as a good indicator for the pyrolytic char chemical structure. This study reveals the effects of the parent coal properties, including coal rank, fixed carbon, moisture, and ash content, on the pyrolytic char chemical structure, and provides a new comprehensive coal property index to predict the pyrolytic char chemical structure.

【 授权许可】

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