萃取精馏分离苯和环己烷的二元混合溶剂

Binary Mixed Solvents for Separating Benzene-Cyclohexane by Extractive Distillation

混合溶剂萃取精馏技术是一种极具发展潜力的新型分离技术．通过一个简单实用的气液平衡实验装置考察了多个萃取精馏分离苯／环已烷近沸点体系的二元混合溶剂:二甲基亚砜和N,N-二甲基甲酰胺、二甲基亚砜和 N-甲基吡咯烷酮以及N-甲基吡咯烷酮和N,N-二甲基甲酰胺的性能．结果发现,混合溶剂分离效果比简单溶剂更好,且混合溶剂存在最佳组成;当混合溶剂的摩尔比接近1时,其性能最佳;N,N-二甲基亚砜和N,N-二甲基甲酰胺组成的混合溶剂是所有被考察萃取剂中最好的混合溶剂;另外还发现了优于文献报道的简单溶剂N,N-二甲基甲酰胺．

A number of binary mixed solvents for separation of benzene and cyclohexane by extractive distillation was examined in a vapor-liquid equilibrium （VLE） experiment apparatus. The integrated properties of the binary mixed solvents were investigated. It is found that the binary solvent is superior to the single solvent, and that N, N-dimethylformamide （DMF） and dimethyl sulfoxide （DMSO） are the best mixed solvent for separation of benzene and cyclohexane among all those tested solvents; it has an optimal compostion that the molar ratio of DMSO/DMF is near to 1.0, when the maximum relative volatility is 3.48. In addition, DMF show excellent selectivity and solubility for separating benzene and cyclohexane by extractive distillation as a single solvent.