摘要
在300℃下,胜利褐煤在乙酸乙酯中热溶2h,对所得热溶物进行了气相色谱/质谱联用（GC/MS）和实时直接分析离子源/离子阱质谱（DARTIS/IT-MS）分析.GC/MS共鉴定出127种有机化合物,包括芳烃、酚类、烷烃、烯烃、脂肪酸乙酯及含氮有机物等,其中芳烃和酚类含量较高,特别的是检测到一系列的直链烷基苯（LABs）.LABs与煤大分子骨架存在着强的π-π相互作用及相互缠绕,常温下难以萃取.由于乙酸乙酯具有π电子和n电子,在加热条件下可有效削弱煤中的非共价键作用;同时,乙酸乙酯能与煤中的脂肪酸反应生成脂肪酸乙酯,还可以定向打断煤中的酯键.DARTIS/IT-MS分析表明,热溶物的分子量主要集中在170~530之间,最高达740,且成正态分布.
Thermal dissolution of Shengli lignite in ethyl acetate（EA）was carried out in a 50 mL stainless-steel,magnetically stirred autoclave at 300℃for 2h,and then the thermally soluble fraction（i.e.extract）was analyzed with gas chromatography/mass spectrometry（GC/MS）and direct analysis in real-time ionization source/ion trap mass spectrometry（DARTIS/IT-MS）.127 organic components,including arenes,phenols,alkanes,alkenes,fatty acid ethyl esters and nitrogen-containing organic compounds,were identified by GC/MS.Arenes and phenols with 1~4 methyls are the most abundant compositions in the extract.In particular,a series of linear alkyl benzenes（LABs）were detected.The strongπ-πinteractions between aromatic rings and chain entanglements between long chain alkyls of LABs and macromolecular moieties in coal make LABs being fixed firmly to coal matrix and more difficult to extract than other arenes with common solvents at room temperature.EA withπelectron and nelectron can effectively weak non-covalent interactions in coal at elevated temperature,and probably react with fatty acids in coal to obtain fattyacid ethyl esters.Ester bonds in coal can be cleaved via transesterification reactions with EA.The DARTIS/IT-MS analysis shows that the main peaks of the molecular weight distribution of the extract are located at mass to charge ratio（m/z）170~530,and trace signals are still observed at m/z 740.Overall,the molecular weight distribution of the extract exhibits a normal distribution.
出处
《河北师范大学学报（自然科学版）》
CAS
北大核心
2014年第6期611-616,共6页
Journal of Hebei Normal University：Natural Science
基金
国家973计划项目(2011CB201302)
国家自然科学基金(20936007)
国家自然科学基金神华集团煤炭联合基金(51134021)
国家自然科学基金委员会创新研究群体科学基金(51221462)
枣庄学院博士科研基金
关键词
热溶
分子煤化学
直链烷基苯
煤的非燃料利用
thermal dissolution
molecular coal chemistry
linear alkyl benzene
non-fuel use of coal
