Highly Efficient Solvent Screening for Separating Carbazole from Crude Anthracene
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- 作者：Cui-Ping Ye ; Xiao-Xiao Ding ; Wen-Ying Li ; Ting-Ting Wu ; Ming-Ming Fan ; Jie Feng
- 刊名：Energy & Fuels
- 出版年：2016
- 出版时间：April 21, 2016
- 年：2016
- 卷：30
- 期：4
- 页码：3529-3534
- 全文大小：226K
- 年卷期：0
- ISSN：1520-5029
文摘
Anthracene and carbazole are both highly value-added products in the anthracene fraction of coal tar, and it is a difficult task to separate and purify anthracene and carbazole from the anthracene fraction/crude anthracene, which consists of many components, differing only slightly in boiling points. To seek a highly efficient solvent to separate carbazole from crude anthracene, the solubilities of anthracene and carbazole in tetrachloroethylene (PCE) and the mixtures of xylene + PCE, N,N-dimethylformamide (DMF) + urea, and DMF + H2O were measured. The separation efficiencies of DMF + 30% H2O, DMF + urea, and DMF + isopropanolamine mixtures with different percentages of urea or isopropanolamine were examined by the cooling crystallization process. Chlorobenzene, PCE, and xylene + 40% PCE mixture were used in the carbazole refining process. The results showed that, with the addition of the third component of urea, isopropanolamine, or water to DMF, the solubility of anthracene and carbazole is inhibited to some extent and the selectivity is increased. The separation efficiency is improved using the mixed solvents, DMF + urea and DMF + isopropanolamine, when the percentage of urea or isopropanolamine in DMF is below 15 or 40%, respectively. The content of carbazole in crude carbazole is higher than 58.14 or 64.80 wt % using DMF + urea or DMF + isopropanolamine, respectively. The yield is greater than 84.43 wt %, and the impurity of anthracene is less than 10.28 wt %. In addition, the content of anthracene in refined anthracene is higher than 92.31 wt % with the yield above 80.23 wt %. During the carbazole refining process when using chlorobenzene as the solvent, the purity of carbazole can reach 98.97 wt % and the total yield was 67.89 wt %.