萃取精馏法分离正丁醇-异丁醇的模拟和实验研究（英文）

Simulation and experimental study of the separation of butanol-isobutanol by extractive distillation

采用连续侧线出料精馏法对原料进行预处理,切取正丁醇-异丁醇富集液。采用色谱法在汽液平衡釜上探索正丁醇-异丁醇在溶剂中的分配效果,选择甘油为最适合的萃取溶剂。运用Aspen Plus模拟软件对正丁醇-异丁醇萃取精馏塔进行过程模拟,考察了蒸馏流率、理论塔板数、原料和溶剂的进料位置、回流比、溶剂比对正丁醇异-丁醇混合物分离效果的影响。通过正交化设计优化和验证实验,得到最佳萃取精馏塔的操作条件,即蒸馏流率D9=17 kg/br,理论塔板数N=49,原料进料位置NF--29,溶剂进料位置NS=8,回流比R=6,溶剂比S:F=11:1。研究结果表明在最佳操作条件下,塔顶异丁醇纯度可以提高到99.80%,得率为89.38%,塔底正丁醇纯度可达到97.53%,得率为99.96%,验证实验结果与模拟结果相对误差小于1%。研究结果为进一步实验研究提供基础参数。

The raw material was pretreated by the method of continuous side-steam distillation. The remaining mixture was rich in butanol and isobutanol. Relative volatilities of butanol and isobutanol in different extracting solvent were obtained in a vapor-liquid equilibrium device. Glycerol was selected as the appropriate extracting solvent for the extractive distillation process. The process of extractive distillation was simulated based on Aspen Plus. A series of parameters were explored. The orthogonal experiment and the confirmatory experiment were carried out and the optimum operating conditions were obtained. When the number of theoretical plate （N） was 49, the feed-in place of raw material （NF） and solvent （NS） was 29 and 8, the distillate rate （D） was 17 kg/hr, the ratio of solvent （S：F） was11：1, and the reflux ratio （R） was 6, the purity of isobutanol could be reached to 99.80 % and the recovery ratio could be reached to 89.38 %. Meanwhile the purity of butanol could be reached to 97.53 % and the recovery ratio could be reached to 99.96 %. The simulation result was compared with the experimental data, and the relative error is less than 1%.The results provide a foundation for the further research.