油酚分离过程低共熔溶剂的筛选及萃取性能研究

低温煤焦油中酚类化合物的高效分离在工业上具有重要意义。采用COSMO-RS模型对40种用于间甲酚-异丙苯分离的低共熔溶剂进行筛选，结合σ-profile和σ-potential对筛选得到的低共熔溶剂的高萃取性能进行分析。并采用液液相平衡实验对筛选结果进行验证，优化了萃取工艺条件。结果表明，COSMO-RS模型筛选得到的氯化胆碱(ChCl)∶乙二醇(EG)(1∶2)、ChCl∶丙三醇(Gly)(1∶2)、ChCl∶乳酸(LA)(1∶2)三种低共熔溶剂与间甲酚之间存在较强的氢键相互作用，与异丙苯之间存在排斥作用。液液相平衡实验证实了COSMO-RS筛选结果的可靠性，其中ChCl∶EG(1∶2)具有最高的分配系数和选择性系数，且黏度最低，被选定为最佳的低共熔溶剂。在25℃、ChCl∶EG(1∶2)与模型油质量比为1∶1时，ChCl∶EG(1∶2)对间甲酚萃取率高达98.41%，同时异丙苯夹带量仅为8.41%，并且具有良好的循环使用性能。

Screening of deep eutectic solvents and study on extraction performance for oil-hydroxybenzene separation

The efficient separation of phenolic compounds from low-temperature coal tar is of great industrial significance. 40 deep eutectic solvents (DESs) were screened for m-cresol-cumene separation by conductor-like screening model for real solvents (COSMO-RS). The indexes of screening process included capacity, selectivity, and performance index at infinite dilution. In addition, the σ-profile and σ-potential of m-cresol, cumene, and the screened DESs were used to analyze the molecular interactions, which could interpret the high extraction performance of the screened DESs. The screening results were verified by liquid-liquid equilibrium (LLE) experiments, and the extraction process conditions were optimized. The results show that choline chloride (ChCl)∶ethylene glycol (EG) (1∶2), ChCl∶glycerol (Gly) (1∶2), ChCl∶lactic acid (LA) (1∶2) demonstrate the higher performance index and are preliminarily screened as extractants. There is a strong hydrogen bond between 3 screened DESs and m-cresol, as well as a repulsive interaction between 3 screened DESs and cumene. Both COSMO-RS calculation and LLE experimental results show that ChCl∶EG (1∶2) presents the highest distribution coefficient and selectivity. Moreover, ChCl∶EG (1∶2) has the lowest viscosity, which is selected as the most suitable extractant for m-cresol-cumene separation. When the temperature and the mass ratio of ChCl∶EG (1∶2) to model oil are 25℃ and 1∶1, respectively, the ChCl∶EG (1∶2) can extract 98.41% of the m-cresol with only 8.41% entrained cumene, and ChCl∶EG (1∶2) has good recycling performance.