聚甲氧基二甲醚+水+环己烷+氯化钠四元体系的液液平衡研究  

Liquid-liquid equilibria for quaternary systems polyoxymethylene dimethyl ethers + water + cyclohexane + sodium chloride

作　　者：寇超兴 刘洋 曾爱武[1] KOU Chaoxing;LIU Yang;ZENG Aiwu(State Key Laboratory of Chemical Engineering,School of Chemical Engineering and Technology,Tianjin University,Tianjin 300350,China)

机构地区：[1]天津大学化工学院化学工程联合国家重点实验室

出　　处：《化工学报》2020年第2期507-515,共9页CIESC Journal

摘　　要：聚甲氧基二甲醚(DMMn)是一种低分子缩醛类聚合物,被认为是新型环保柴油添加剂。研究了常压下,293.15 K和308.15 K时DMM1-4+水+环己烷+氯化钠体系的液液相平衡。经Eisen-Joffe方程关联检验,各体系的液液平衡数据具有良好的一致性。在氯化钠盐析作用下,体系油水分离效果得到明显的改善,DMM1-4的分配系数均大于1;当NaCl的含量为10%(质量)时,有机相中的水可忽略不计。对平衡数据采用NRTL和CHEN-NRTL热力学模型关联拟合,结果表明CHEN-NRTL模型更适用于描述此体系在研究温度下的液液平衡关系。实验数据以及拟合得到的模型参数将为DMMn的产物萃取及精馏的过程模拟提供有效参考。Polyoxymethylene dimethyl ethers(DMMn)are low molecular acetal polymer,which were considered as new environmentally friendly diesel additive.The liquid-liquid equilibria(LLE)data of the systems(DMM1-4+water+cyclohexane+NaCl)at T=293.15,308.15 K and pressure p=101.325 kPa were measured.According to the verification with the Eisen-Joffe equation,the experimental data has good consistency with R2 being approximately unity.Under the salting effect of NaCl,the separation effect of oil-water is improved obviously and the distribution coefficients of DMM1-4 are greater than 1.When the content of NaCl is 10%(mass),the water in the organic phase is negligible.All the experimental LLE data obtained were correlated with the NRTL and the CHENNRTL activity coefficient models.The results show that the CHEN-NRTL model is superior to NRTL model for these systems at studied temperature.The experimental data and model parameters obtained from the fitting will provide an effective reference for the process simulation of DMMn product extraction and distillation.

关 键 词：聚甲氧基二甲醚 液液平衡 环己烷 CHEN-NRTL 

分 类 号：TQ028.4[化学工程]