水-乙酸-乙酸丁酯体系汽液平衡研究

用改进Rose釜测定了乙酸-乙酸丁酯、水-乙酸-乙酸丁酯(完全互溶区)体系在101.33 kPa下的汽液平衡数据。考虑乙酸的缔合效应,利用维里方程和Hayden-O'Connell(HOC)模型计算各组分的汽相逸度系数,校正汽相的非理想性,液相的非理想性全部归结到液相活度系数中予以校正。用NRTL,UNIQUAC模型对乙酸-乙酸丁酯的汽液平衡数据进行关联,并得到相应的模型参数、温度偏差和汽相组成偏差。比较二元体系的关联结果,用NRTL模型参数预测了三元汽液平衡数据,计算值与实验值吻合良好,预测精度较好,说明采用的模型参数是可靠的,能够为精馏的设计和模拟计算提供基础热力学数据。

Vapor-liquid equilibrium for water-acetic acid-n-butyl acetate system

The vapor-liquid equilibrium(VLE) data for acetic acid-n-butyl acetate and water-acetic acid-n-butyl acetate systems were measured at 101.33 kPa by using an improved Rose still.Considering the association of acetic acid molecules,the Virial equation and Hayden-O′Connell(HOC) model were used to calculate the vapor fugacity coefficient of each composition,and correct the nonideality of vapor phase,while the nonideality of liquid phase was corrected in the calculation of its activity coefficient.The NRTL and UNIQUAC models were applied to correlate the VLE data of acetic acid-n-butyl acetate system,and the model parameters together with the deviations of temperature and molar fraction in vapor phase were obtained.The obtained NRTL model parameters from binary data were used to predict the ternary VLE data,and the value of calculation and experiment were well fitted,which had better prediction accuracy.So it is concluded that the above selected model parameters are reliable,and these model parameters can be used as the basic thermodynamic data for the design and simulation of distillation.