JOURNAL OF MOLECULAR LIQUIDS
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2022
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IF 6.633
Xudong Zhang,Wenbo Zhao,Jun Shen,Yugao Wang,Gang Liu,Yanxia Niu,Qingtao Sheng
Carbazole is an important organic chemical raw material with high added value, mainly derived from crude anthracene. In this research, three quaternary ammonium salts (QASs), containing triethylmethylammonium chloride (TEMAC), tetraethylammonium chloride (TEAC) and tetrapropylammonium chloride (TPAC), were innovatively used to separate carbazole from model anthracene oil by forming deep eutectic solvents (DESs). The results indicated that TEAC showed the highest separation ability among three QASs. Afterwards, the influences of mass ratio of TEAC to model anthracene oil (MO), stirring time, extraction temperature and initial concentration on the separation effect of carbazole were investigated. Under the optimized conditions (25℃, 25 min, mass ratio 1:5), the extraction efficiency (EE), distribution coefficient (DI) and selectivity (SE) of carbazole could reach up to 91.25 %, 24.26 and 66.09 %, respectively. The purity and yield of carbazole product separated from model anthracene oil were 91.02 % and 76.89 %, respectively. Moreover, carbazole with purity of 90.42 % could be separated from real crude anthracene with TEAC under the above optimized conditions. In addition, environment friendly water was used to regenerate the TEAC. After recycled for five times, the extraction ability of TEAC for carbazole did not change obviously. Finally, the hydrogen bond (N H…Cl) and van der Waals interaction (C H…π) existed between QASs and carbazole were revealed by FT-IR analysis and quantum calculations. The green and novel method presented in this work has implications for the separation of other high value-added products from coal tar.
研究领域:
化学工程
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环境科学
✓ 已验证
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
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2020
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IF 4.982
Xin Jin,Xiaorong Li,Jiao Kong,Wei Xie,Meijun Wang,Jiancheng Wang,Weiren Bao,Liping Chang
The high yields of coke and tar pitch relating to volatile reactions can cause plug in the product lines during low temperature pyrolysis of low-rank coals. To study the potential transformation of volatile into coke during its migration in the pyrolysis process, six distillates and their blends from the same coal tar were heated at 400–600 °C. The composition , radicals of six distillates and coke structure were characterized by GC × GC–MS, ESR and Raman techniques, respectively. The results show that the coke yields increase with temperature during thermal reaction for all six distillates. When light oil and pitch are blended, the interaction between the two distillates compresses the transformation of volatile into coke above 500 °C. This can be ascribed to that the reactive hydrogen radicals generated from light oil may weaken the bonding between large molecules. By contrast, other distillates (phenolic oil, naphthalic oil, wash oil and anthracene oil) promote coke formation, resulting in higher coke yields than expected. It is also observed that the highest extent of interaction occurs between phenolic oil and pitch, which may be related to the high content of oxygen containing compounds in phenolic oil and the high electron density of the compounds in pitch.
研究领域:
化学工程
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2023
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IF 3.8
Xudong Zhang,Yanhua Liu,Jun Shen,Yugao Wang,Gang Liu,Yanxia Niu,Qingtao Sheng
Carbazole is an irreplaceable basic organic chemical raw material and intermediate in industry. The separation of carbazole from anthracene oil by environmental benign solvents is important but still a challenge in chemical engineering. Deep eutectic solvents (DESs) as a sustainable green separation solvent have been proposed for the separation of carbazole from model anthracene oil. In this research, three quaternary ammonium-based DESs were prepared using ethylene glycol (EG) as hydrogen bond donor and tetrabutylammonium chloride (TBAC), tetrabutylammonium bromide or choline chloride as hydrogen bond acceptors. To explore their extraction performance of carbazole, the conductor-like screening model for real solvents (COSMO-RS) model was used to predict the activity coefficient at infinite dilution ( γ ∞ ) of carbazole in DESs, and the result indicated TBAC:EG (1:2) had the stronger extraction ability for carbazole due to the higher capacity at infinite dilution ( C ∞ ) value. Then, the separation performance of these three DESs was evaluated by experiments, and the experimental results were in good agreement with the COSMO-RS prediction results. The TBAC:EG (1:2) was determined as the most promising solvent. Additionally, the extraction conditions of TBAC:EG (1:2) were optimized, and the extraction efficiency, distribution coefficient and selectivity of carbazole could reach up to 85.74%, 30.18 and 66.10%, respectively. Moreover, the TBAC:EG (1:2) could be recycled by using environmentally friendly water as antisolvent. In addition, the separation performance of TBAC:EG (1:2) was also evaluated by real crude anthracene, the carbazole was obtained with purity and yield of 85.32%, 60.27%, respectively. Lastly, the extraction mechanism was elucidated by σ -profiles and interaction energy analysis. Theoretical calculation results showed that the main driving force for the extraction process was the hydrogen bonding ((N–H … Cl) and van der Waals interactions (C–H … O and C–H … π), which corresponding to the blue and green isosurfaces in IGMH analysis. This work presented a novel method for separating carbazole from crude anthracene oil, and will provide an important reference for the separation of other high value-added products from coal tar.
研究领域:
化学工程
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绿色化学
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溶剂萃取
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工艺化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）