| Popis: |
A large amount of coal tar residues (CTRs) produced in the coal coking or gasification industry has not been effectively utilized in China. In this study, CTRs are extracted by 12 organic solvents. Detailed investigations are carried out via ultimate analysis, Fourier transform infrared spectroscopy (FTIR) and thermogravimetry (TG) analyzer. The pyrolysis process of CTRs and their extraction residues (RCTRs) can be accurately fitted by Coast-Redfern integral model. The results indicate that the reaction order (n), apparent activation energy (Ea) and pre-exponential factor (A) were in the range of 2–7, 34.42–60.08 kJ mol−1 and 102-105 min−1, respectively. Correlations are observed between parameters (H, C, O, H/C, WT, Rmax, n, Ea, and lnA) and the yield of RCTRs, suggesting that the composition and pyrolysis behavior are controlled by the solvent extraction. Specifically, extraction with n-heptane, methanol and ethanol could reduce the Ea and promote CTRs decomposition by disrupting the noncovalent bonds. When extracted with CS2, DMF, benzene, toluene, acetone, etc. the recovery rate of tar and the yield of pyrolysis products are improved, however, the reactivity decrease due to the increase in activation energy. |
