Extraction and mechanism exploration for separating cresols from coal tar by ionic liquid ethanolamine lactate

• Published in: Journal of molecular liquids 2020-05, Vol.305, p.112845, Article 112845
• Main Authors: Bing, Xiaobin, Meng, Xianglin, Li, Ao, Zhang, Lianzheng, Gao, Jun, Xu, Dongmei, Wang, Yinglong
• Format: Article
• Language: English
• Subjects: Coal tar; Cresols; Ethanolamine lactate; Extraction; Molecular dynamics simulation
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2020.112845

Separation of cresols from coal tar is of significance in chemical industry. In this work, a high-efficiency and green hydroxyl ammonium ionic liquid ethanolamine lactate ([HMEA]L) was applied as an extractant to extract three different cresols (o-, m-, and p-cresol) from low-temperature coal tar. The ionic liquid [HMEA]L was synthesized with ethanolamine and lactic acid and characterized by 1H NMR, TGA and FT-IR. The extraction efficiency and distribution coefficient were determined to assess the extraction performance of the [HMEA]L. The results show that [HMEA]L displays high extraction efficiency and distribution coefficient for separating p-cresol from model oil. In addition, molecular dynamics (MD) simulation has been applied to explore the extraction mechanism of cresols from the model oil. The interaction energies, radial and spatial distribution function, and self-diffusion coefficient were calculated from the MD simulation results, and the extraction mechanism was further explored by FT-IR. It can be concluded that both cation and anion took effect on extraction. However, the anion displayed a more important role on extracting cresols from the model oil. Finally, the recovery and reuse of the [HMEA]L were explored in this work. •The ionic liquid [HMEA]L was synthesized for separating cresols from coal tar.•The extraction capacity of [HMEA]L was evaluated by EE and D.•The molecule level interaction mechanism was explored by MD simulation.•The recovered [HMEA]L was reused with high extraction efficiency.