低阶煤中含氧官能团分布的研究  

Determination of O-containing functional groups distribution in low-rank coals by chemical titration

作　　者：周剑林[1] 王永刚[1] 黄鑫[1] 张书[1] 林雄超[1] 

机构地区：[1]中国矿业大学(北京)化学与环境工程学院,北京100083

出　　处：《燃料化学学报》2013年第2期134-138,共5页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(21076222)

摘　　要：采用化学法测定了四种典型中国低阶煤中羧基、醇羟基、酚羟基、甲氧基和羰基含氧官能团。其中,羧基的定量分析采用醋酸钙溶液和pH值为8.3的缓冲溶液进行,分析了测定条件对羧基和酸性含氧官能团测定结果的影响。结果表明,在N2气氛下比空气条件下测定羧基含量准确,褐煤中羧酸根的主要存在形式为羧酸盐,酸洗后煤样中酚羟基的测定值随着离子交换溶液pH值的增加而增大;褐煤中的含氧官能团主要是羧基和羟基,分别占总氧量的34.49%和34.79%;在不同低阶煤中存在不同含量的羰基,甲氧基含量较小。Distribution of oxygen-functional groups （carboxyl, alcohol-hydroxyl, phenol-hydroxyl, methoxyl and carbonyl） in 4 Chinese low-rank coals was evaluated based on chemical analysis. Concentration of carboxyl was quantitated by acetic acid calcium ion exchange method and the buffer （pH = 8.3 ）. The effect of analysis condition on the concentration of carboxyl and total acidity was studied. The results show that the reliable results are obtained in N2 atmosphere other than in air. The occurrence of carboxyl in coal is carboxylate. When quantitating the concentration of phenol-hydroxyl in the acid-washing brown coal with ion exchanged method, its concentration increases with increasing pH value. Concentration of carboxyl and hydroxyl account for 34.49 % and 34.79%, respectively, in the total oxygen for the dry ash free basis brown coal. Different concentrations of carbonyl exist in the low-rank coals, but that of methoxyl is little.

关 键 词：低阶煤 含氧官能团 赋存状态 化学滴定法 

分 类 号：TQ533.9[化学工程—煤化学工程]