液液萃取分离乙酸甲酯与甲醇水溶液的模拟计算

设计了乙酸甲酯和甲醇水溶液错流萃取分离工艺,通过实验确定了以甘油和水的复合溶液作为分离乙酸甲酯和甲醇水溶液的最佳萃取溶剂。以UNIQUAC方程为计算活度系数的模型,采用色谱法测定了甲醇在甘油中的无限稀释活度系数,并利用单参数法计算UNIQUAC方程中的模型参数。采用相分配系数和物料守恒方程模拟错流萃取分离过程,建立了模拟计算程序框图。将模拟值和实验值进行比较,相对误差仅为0.01%。模拟结果表明:在理论级数N=3时,经过一次萃取乙酸甲酯质量分数可达99.7%以上,收率达97.0%,此结果为进一步研究提供理论依据。

Modeling calculation of liquid-liquid extraction of methyl acetate and methanol aqueous solution

The technological process of cross-extractive separation of methyl acetate and methanol aqueous solution was designed.Glycerol and water were selected as the best solvents of extractive separation.Activity coefficients were calculated by UNIQUAC equation.The infinite dilution activity coefficient of methanol in glycerol was measured by the gas chromatogram apparatus,and the parameters of UNIQUAC equation were calculated by the single parameter method.The cross-extractive separation was simulated by phase separation coefficients and material balance equation.The simulation program diagram was established.The optimization results were compared with the experimental data,and the relative error was only 0.01%.The results show that the mass fraction and the yield of methyl acetate reach 99.7% and 97.0% respectively when theoretical stage is 3.The simulation results can provide theoretical basis for further research.