摘要
为了探索熔融结晶法提纯EC(碳酸乙烯酯)的可行性,并为后续的熔融结晶动力学研究及其工艺开发提供数据支撑,文中采用步冷曲线法测定碳酸乙烯酯+2-噁唑烷酮二元混合物体系不同组成的凝固点,得到了碳酸乙烯酯+2-噁唑烷酮二元体系固液平衡相图,并采用理想溶液模型、Wilson与NRTL活度系数模型对相平衡数据进行拟合。实验结果表明:碳酸乙烯酯和2-噁唑烷酮有最低共熔点,其二元体系固液平衡相图为简单低共熔固液相图,其低共熔点温度为297.05 K,最低共熔点处碳酸乙烯酯的摩尔分数为0.7479。其中Wilson方程和NRTL方程2种活度系数模型均可较好关联此二元体系的固液平衡,其模型计算值与实验值的最大相对偏差分别是0.0461%、0.0606%,平均相对偏差0.0292%、0.0322%,说明该物系符合Wilson方程和NRTL方程。
In order to investigate the viability of purifying EC(ethylene carbonate)by melt crystallization and to provide data support for subsequent research on melt crystallization kinetics and its process development,the freezing points of the various components of the ethylene carbonate+2-oxazolidinone binary mixture system were determined by the step cold curve method,and the solid-liquid equilibrium phase diagram of the ethylene carbonate+2-oxazolidinone binary system was obtained.The Ideal solution model,Wilson and NRTL activity coefficient model were used to fit the phase equilibrium data.The results show that 2-oxazolidinone and ethylene carbonate have the lowest eutectic points,and the solid-liquid equilibrium phase diagram of the binary system is a simple low eutectic solid-liquid phase diagram,the low eutectic point temperature is 297.05 K,and the molar fraction of ethylene carbonate at the lowest eutectic point is 0.7479.The solid-liquid equilibrium of this binary system can be well correlated with the two activity coefficient models of the Wilson equation and NRTL equation.The maximum relative deviation between the calculated value of the model and the experimental value is 0.0461%and 0.0606%,respectively,and the average relative deviation is 0.0292%and 0.0322%,respectively,indicating that the system conforms to the Wilson equation and NRTL equation.
作者
包秀
吴顺
沈卫华
方云进
BAO Xiu;WU Shun;SHEN Weihua;FANG Yunjin(State Key Laboratory of Chemical Engineering,School of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China)
出处
《化学工程》
CAS
CSCD
北大核心
2023年第10期64-67,78,共5页
Chemical Engineering(China)
基金
国家自然科学基金资助项目(51676146)。
关键词
碳酸乙烯酯
步冷曲线
固液相图
热力学模型
数据关联
ethylene carbonate
step cooling curve
solid-liquid phase diagram
thermodynamic model
data correlation
