Correlation between the Combustion Behavior of Brown Coal Char and Its Aromaticity and Pore Structure

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• 作者：Yan-Na Han ; Jun-Jie Liao ; Zong-Qing Bai ; Jin Bai ; Xiao Li ; Wen Li
• 刊名：Energy & Fuels
• 出版年：2016
• 出版时间：April 21, 2016
• 年：2016
• 卷：30
• 期：4
• 页码：3419-3427
• 全文大小：462K
• 年卷期：0
• ISSN：1520-5029

文摘

In this study, the effects of aromaticity and pore structure, particularly fractal dimension, on the combustion behavior of brown coal char were investigated. For this purpose, several partially steam-gasified brown coal char samples with diverse pore structures and predictable aromaticity were chosen. Thermogravimetry was employed for analyzing the combustion behavior of the chars, and their apparent activation energies were obtained by the Arrhenius equation. Results from combustion experiments showed that the ignition temperature increased with char aromaticity, the changes in the temperature of the maximum combustion rate and burnout primarily depended upon the ratio of small aromatic rings to large rings of chars, and the total pore volume of chars predominantly affected their combustion reactivities. Two activation energies (i.e., chemical and diffusion activation energies) were distinguished. The chemical activation energy was controlled by the total aromatic C═C and ratio of small aromatic rings to large rings of chars. The diffusion activation energy was mainly affected by the pore surface roughness of chars.