摘要
采用不同溶剂对褐煤、焦煤、低级无烟煤及中级无烟煤等煤样分级超声萃取的方法,结合孔隙结构测试,研究了煤和萃余物吸附水分过程水分含量的变化规律,探讨了煤吸附水分的内在机理.研究发现:1)单位时间内煤中含水率增量与吸附时间呈负向幂函数关系;2)褐煤及其萃余物对水的吸附能力远大于其他三类煤样,达到饱和含水量所需的时间更长.从焦煤到无烟煤,随煤级增加,对水的吸附能力增大和达到饱和含水量所需的时间加长;3)原煤吸附水分的能力大于萃余物.由于CS2溶剂的强渗入作用,更多超微孔中的分子化合物被溶出,使得孔道疏通,孔隙变大,得到的萃余物能够容纳更多的水分.THF溶剂的萃取使得亲水性基团溶出,降低了残余煤样吸附水的能力.
Using the fractional ultrasonic-extraction on four different metamorphism coals, including lignite, coking coal, lower-metamorphism and higher-metamorphism anthracite by different solvent, the dynamic change law of water-bearing accessioned into raw coals and each residue during absorption water and the adsorption mechanism was discovered. The research shows the increment of the variation rate of water-bearing per unit time in raw coals and each residue is negative-going power-function relationship. The water-adsorption capacity of lignite and its residues is far stronger and the time attaining the water-saturation is longer than the other coal samples and their residues. The water-adsorption capacity of raw coals is stronger than its residues. And the stronger penetration capacity of solvent CS2 makes more small-molecular phase dissolve and depart from the residues, which cause pores become large and pore canals grow clear, so more moisture is adsorbed in its residues than the other solvent residues. The solvent THF make more polar functional groups, which are hydrophilic, be dissolved, so the water-adsorption capacity of its residues grow weak.
出处
《煤炭转化》
CAS
CSCD
北大核心
2008年第2期8-11,15,共5页
Coal Conversion
基金
国家自然科学基金资助项目(40602017,40572095)
河南理工大学博士基金资助项目(648513)
关键词
煤
分级萃取
水分含量
吸附机理
coal, fractional extraction, water-bearing ,adsorption mechanism
