甲基丙烯酸甲酯-甲醇体系的双溶剂萃取

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

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。

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.