萃取精馏分离丙酮-四氢呋喃的研究

Separation of acetone-tetrahydrofuran by extractive distillation

为了分离丙酮-四氢呋喃共沸混合物,研究了萃取精馏在丙酮-四氢呋喃物系中的应用。通过溶剂选择原理初选出乙苯作为萃取精馏分离此共沸物系的溶剂,同时采用NRTL模型对常压下丙酮-四氢呋喃物系和加入溶剂乙苯后的汽液平衡进行模拟和实验验证,模拟结果与实验数据吻合较好。然后进行了间歇萃取精馏分离此共沸物的实验研究来进一步考察所选萃取剂的效果。结果表明:乙苯能够消除丙酮-四氢呋喃共沸物系的共沸点,采用有40块理论板的填料塔,回流比为5,溶剂摩尔比为2.5∶1时塔顶可以得到质量分数为99.34%的丙酮产品,说明采用乙苯作萃取剂分离丙酮-四氢呋喃共沸物是可行的。最后又对连续和间歇萃取精馏分离丙酮-四氢呋喃共沸物的流程进行了模拟,得到的工艺参数将为进一步的工业应用提供了理论依据。

In order to separate acetone-tetrahydrofuran mixture, ethylbenzene as the solvent for separating acetone- tetrahydrofuran mixture by extractive distillation was chosen according to the basic selection rules. The simulation of vapor-liquid equilibrium using NRTL model for acetone-tetrahydrofuran system with and without ethylbenzene under atmospheric pressure and the vapor-liquid equilibrium experiment were performed. The simulation results agree well with the experimental data. The effectiveness of the solvent selected was also investigated by the batch extractive distillation experiments. The results show that ethylbenzene can eliminate the azeotropic point of acetone- tetrahydrofuran system. The batch distillation was carried out in a packed column of 40 theoretical plates. With the reflux ratio of 5 and the solvent mole ratio of 2.5 ： 1, the product mass fraction of acetone reaches 99.34%, which reveals that the extractive distillation with ethylbenzene as solvent is useful in the separation of acetone- tetrahydrofuran. At last, the flow sheet of separating this azeotrope by batch and continual extractive distillation were simulated. The technological parameters obtained can provide the theoretical basis for further industrial application.