Thermo-swelling Properties of Particle Size Cuts of Coal Maceral Concentrates

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• 作者：Wei Xie ; Rohan Stanger ; John Lucas ; Merrick Mahoney ; Liza Elliott ; Jianglong Yu ; Terry Wall
• 刊名：Energy & Fuels
• 出版年：2015
• 出版时间：August 20, 2015
• 年：2015
• 卷：29
• 期：8
• 页码：4893-4901
• 全文大小：562K
• ISSN：1520-5029

文摘

A suite of coal maceral concentrates were prepared from a single coal using a water-based method for two discrete particle size fractions. Coal macerals were produced with the vitrinite content varying from 91.2% to 26.1% for the 106鈥?12 渭m particle size fraction and 96.0% to 38.2% for the 212鈥?00 渭m particle size fraction. Thermo-swelling of coal maceral concentrates were evaluated by the Computer Aided Thermal Analysis (CATA) technique with extended volumetric measurements. This novel CATA technique allows the apparent specific heat, thermal conductivity, and transient volumetric swelling of the coal sample to be measured simultaneously, as a function of temperature. The experimental results indicated that the maximum swelling (鈭?10 掳C) and high-temperature contraction (600鈥?000 掳C), as well as exothermic heat during primary devolatilization and thermal conductivity at maximum swelling all increased with vitrinite content, with the data inferring a linear relationship, and was independent of particle size, when coal maceral concentrates contain more than 63% vitrinite. A hypothesis for intragranular (within particles) and intergranular (between particles) swelling was used to explain the association of swelling with vitrinite content and particle size. Optical microscopic results of the final pyrolytic residues of different coal maceral concentrates support this hypothesis.