针对煤焦油特性,选择N,N-二甲基甲酰胺在优化工艺条件下对煤焦油进行萃取精制,在温度50 ℃,剂油比为1.5的优化条件下,得到20.8%的非芳烃油,38.7%的富芳烃油(小于360 ℃)和40.5%的软沥青.与直接对煤焦油进行蒸馏所得产品相比,经溶剂处理后蒸馏得到的小于360 ℃馏分油中芳烃更为富集.所得软沥青与直接蒸馏所得软沥青相比,甲苯不溶物和喹啉不溶物含量没有明显差别,但将两者在常压、420 ℃条件下热聚2.8 h后,前者β树脂的含量有较大幅度提升,达到23.1%,软化点达到101.6 ℃,能够满足电极用沥青黏结剂质量要求.此外,所得非芳烃油主要由环烷烃类和链烷烃类结构构成,可作裂化原料.%The non-aromatic hydrocarbon (NAH),fraction rich in aromatic(< 360 ℃) and soft pitch were separated from coal tar by DMF extraction under optimal conditions:50 ℃,solvent/coal tar of 1.5,with yields of 20.8%,38.7% and 40.5%,respectively.Compared with the components distilled directly from coal tar,aromatics content was more enriched in <360 ℃ fraction from solvent extraction.No significant difference in content of TI and QI of the refined soft pitch and the soft pitch distilled directly is found.However,after the pitches were thermally polymerized at 420 ℃ for 2.8 h at atmospheric pressure,the content of beta resin in refined soft pitch is greatly improved,reaching to 23.1% with a softening point of 101.6 ℃,meeting the quality of binder pitch for electrodes.In addition,NAH is made up of naphthenes and paraffins,which can be used as a catalytic cracking feedstock.
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