Title: Coal tar refining by aromatic-aliphatic solvent extraction for preparing QI-free pitch

Authors: Yonggang Wang; Jianhong Hu; Dan Liu; Zhe Liu; Haiyong Zhang; Shu Zhang

Addresses: School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing, 100083, China ' School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing, 100083, China ' School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing, 100083, China ' School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing, 100083, China ' School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing, 100083, China ' Department of New Energy Science and Engineering, Nanjing Forestry University, Nanjing, 210037, China

Abstract: To obtain suitable material for making needle coke, the aromatic and aliphatic solvents were blended for extracting desirable compositions from coal tar and simultaneously removing heavy components, particularly quinoline insoluble (QI). The results show that the low QI content (0.06 Wt%) in refined coal tar was acquired when the aromatic portion in the mixed solvent was ~30 Wt%, while the yield of refined tar increased with increasing aromatic solvent. Under the given ratio of aromatic to aliphatic (2:3 by mass), the QI contents and refined tar yields both reduced as the ratio of mixed solvent to coal tar increased. The fractions (HS, HI-TS, TI-QS) in refined tar were largely affected by the nature of solvent and solvent-tar solution. The distribution of molecular sizes in refined tars were determined by the solubility of tarry compositions in mixed solvent and the precipitating process due to the agglomeration of QI-like materials in solvent. [Received: March 3, 2018; Accepted: April 9, 2018]

Keywords: coal tar; quinoline insoluble; QI; aromatic solvent; aliphatic solvent; solvent extraction.

DOI: 10.1504/IJOGCT.2020.105776

International Journal of Oil, Gas and Coal Technology, 2020 Vol.23 No.3, pp.395 - 408

Received: 03 Mar 2018
Accepted: 19 Apr 2018
Published online: 13 Mar 2020 *

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