褐煤微波脱水过程中水分的迁移规律和界面改性研究

针对褐煤脱水能耗高、易复吸的难题，运用自制微波脱水系统，对蒙东褐煤进行5种不同功率和4种不同粒度的脱水实验。建立了褐煤微波脱水的数学模型并采用有限差分法求解，实验结果与模型计算结果吻合良好。采用扫描电镜（SEM）和低温氮吸附仪测定脱水前后煤样的表面形态和孔隙结构。采用化学滴定法测定羧基和酚羟基官能团的变化。通过恒温恒湿复吸实验和热重分析确定煤样的复吸和自燃特性。发现微波脱水后褐煤复吸水分远低于热风干燥褐煤的19．87％，着火点也由原煤的275℃提高到295℃以上。说明微波脱水后褐煤的界面稳定性得到改善，不易复吸和自燃。...

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Bibliographic Details
Published in煤炭学报 Vol. 39; no. 1; pp. 147 - 153
Main Author 徐志强 辛凡文 涂亚楠
Format Journal Article
LanguageChinese
Published 2014
Subjects
含氧官能团
孔隙结构
微波脱水
水分迁移
界面改性
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ISSN0253-9993

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Summary:针对褐煤脱水能耗高、易复吸的难题，运用自制微波脱水系统，对蒙东褐煤进行5种不同功率和4种不同粒度的脱水实验。建立了褐煤微波脱水的数学模型并采用有限差分法求解，实验结果与模型计算结果吻合良好。采用扫描电镜（SEM）和低温氮吸附仪测定脱水前后煤样的表面形态和孔隙结构。采用化学滴定法测定羧基和酚羟基官能团的变化。通过恒温恒湿复吸实验和热重分析确定煤样的复吸和自燃特性。发现微波脱水后褐煤复吸水分远低于热风干燥褐煤的19．87％，着火点也由原煤的275℃提高到295℃以上。说明微波脱水后褐煤的界面稳定性得到改善，不易复吸和自燃。
Bibliography:microwave drying; moisture migration ; interracial modification ; pore structure ; oxygen-functional groups
XU Zhi-qiang,XIN Fan-wen,TU Ya-nan （ School of Chemical ＆ Environmental Engineering, China University of Mining and Technology （Beijing） , Beijing 100083, China ）
In order to solve the problems of high energy consumption and high reabsorption, microwave dehydration technology of lignite was applied in this paper. The lignite with four different particle sizes from eastern Inner Mongolia was treated by a self-developed microwave system under five different powers. The mathematical model for the moisture changes of lignite was developed and the relevant results were determined by finite difference method. And the compu- tational results were in good agreement with the experimental results. The scanning electron microscope （SEM） and low temperature nitrogen absorption method were applied to study the surface features and porous structure of coal sam- ples. Distribution of oxygen-functional groups of carboxyl
ISSN:0253-9993