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采用萃取精馏的方法分离甲醇-苯的共沸物系。首先采用UNIFAC基团贡献理论并结合经验选取萃取剂,最终确定萃取剂为氯苯。对常压下甲醇-苯物系应用UNIFAC模型计算各组分的汽液相组成,并进行汽液平衡实验验证,计算结果与实验数据吻合较好。通过间歇萃取精馏实验进一步考察验证所选萃取剂的分离效果。结果表明,氯苯能够打破甲醇-苯的共沸,进而分离甲醇和苯。溶剂物质的量之比为1、回流比为3、填料塔理论板数为30、溶剂回收段理论塔板数为4时产品甲醇回收率达到98%,说明氯苯能够作为萃取剂分离甲醇-苯二元共沸物系。最后,对甲醇-苯物系的连续精馏过程应用Aspen Plus进行了模拟计算,并且考察了回流比、萃取剂进料流率等参数对产品纯度的影响规律,为进一步实验研究及工业应用提供理论和实践基础。
The separation of methanol - benzene azeotropic system by extractive distillation. First of all UNIFAC group contribution theory combined with experience extract, finally determine the extractant is chlorobenzene. The vapor-liquid phase composition of each component was calculated by UNIFAC model under the atmospheric pressure of methanol-benzene system. The vapor-liquid equilibrium experiment was carried out. The calculated results are in good agreement with the experimental data. Through intermittent extractive distillation experiments to further verify the separation efficiency of the selected extractant. The results show that chlorobenzene can break methanol-benzene azeotropic, and then separate methanol and benzene. The ratio of the amount of solvent substance is 1, the reflux ratio is 3, the theoretical plate number of packed tower is 30, the recovery rate of methanol of the product reaches 98% when the number of theoretical plates in the solvent recovery section is 4, indicating that chlorobenzene can be used as an extractant to separate the methanol- Benzene binary azeotrope system. Finally, the Aspen Plus was used to simulate the continuous distillation process of methanol-benzene system, and the effects of reflux ratio, extractant flow rate and other parameters on product purity were investigated, and the results were provided for further experimental research and industrial application Theoretical and practical basis.