Distribution and composition of phenolic compounds in coal-based liquid production

The composition and distribution of phenolic compounds in five kinds of coal derived oils in coal-based liquid production from the different process of coal chemical industry were investigated. Firstly, the fractions were isolated from different coal derived oils by distillation in 170-210℃, which is rich in phenols. The method of acid and alkali was used to extract the phenolic compounds in 170-210℃ fractions. Secondly, the rich phenolic compounds were pretreated by silicon ether derivatization, and the characterization of phenols was analyzed by GC/MS. It was found that three types of phenolic compounds, such as alkyl phenols, hydroquinones and indanol, were in each phenol-rich oil fractions from different coal derived oils, in which alkyl phenols is above 90%. There were three types of phenolic compounds, such as alkyl phenols, hydroquinones and indanol in the No. 4 CDO, in which alkylphenol contributed the 92.4% of the total phenols. The lower-rank phenols accounted for 86.1% of the total phenols, while the higher-rank phenols was about 13.9%. There were two types of phenolic compounds such as alkyl phenols and hydroquinones in the No. 2 CDO, in which alkylphenol contributed the 99.89% of the total phenols. The lower-rank phenols accounted for 99.5% of the total phenols, while the higher-rank phenols was only about 0.5%. There were one types of alkyl phenols in the No. 1 CDO and No. 3 CDO. The lower-rank phenols accounted for 100% of the total phenols in the No. 1 CDO, while in No. 3 CDO, the lower-rank phenols accounted for 98.4% of the total phenols, the higher-rank phenols was only about 1.6%. There were two types of phenolic compounds such as alkyl phenols and indanol in the No. 5 CDO, in which alkylphenol contributed the 94.8% of the total phenols. The lower-rank phenols accounted for 91.6% of the total phenols, while the higher-rank phenols was about 8.4%. Therefore, the extraction and utilization of lower-rank phenols in different coal derived oils should be paid enough attention. © 2018, Editorial Office of Journal of China Coal Society. All right reserved.