甲基丙烯酸甲酯-甲醇体系的双溶剂萃取

针对甲基丙烯酸甲酯（MMA）-甲醇共沸体系，常规精馏难以分离。提出采用己烷-水双溶剂体系萃取分离MMA的新工艺。测定了不同温度下MMA（1）+甲醇（2）+正己烷（3）+水（4）、MMA（1）+甲醇（2）+环己烷（3）+水（4）两个体系的相平衡数据，考察了不同温度下溶剂正己烷/环己烷、水的用量对萃取分配系数和选择性系数的影响。在实验数据的基础上，进一步采用UNIQUAC模型对该体系的相平衡进行了拟合，获得了模型参数。

Liquid-liquid equilibrium for double solvent extraction of methyl methacrylate from methanol

Methyl methacrylate (MMA) is an important monomer, which is widely used for producing acrylic resins or polymer dispersions. The two-step selective oxidation process which selectively oxidizes isobutylene to MMA via methacrolein is regarded as a promising process for its high atomic efficiency. In the process, separation of MMA is a critical technique due to high methanol concentration in the reaction. Traditional distillation could not be used for separation of MMA from methanol because of azeotrope mixture. Double solvent extraction is a good alternative. The liquid-liquid equilibrium (LLE) data for MMA-methanol-hexane-water quaternary system were determined at 293.15 K and 303.15 K under atmospheric pressure. N-Hexane-water solvent system and cyclohexane-water solvent system were used for the MMA extraction from methanol. The activity coefficient model of universal quasi-chemical (UNIQUAC) was used to regress the LLE data of the investigated systems. The parameters of the UNIQUAC model were obtained.