常压下甲醇-碳酸二甲酯汽液平衡测定及其萃取剂选择  

Vapor-liquid equilibrium of methanol-dimethyl carbonate at normal pressure and selection of extractant

作　　者：李群生[1] 朱炜[1] 付永泉[1] 高东江 王海川[1] 王浩[1] 李仑[1] 

机构地区：[1]北京化工大学化学工程学院,北京100029 [2]兰州新西部维尼龙有限公司,甘肃兰州730094

出　　处：《化学工程》2011年第8期44-47,共4页Chemical Engineering(China)

基　　金：国家自然科学基金资助项目(20476005);国家科技支撑计划课题子课题(2006BA109B07-01)

摘　　要：甲醇(MeOH)与尿素催化合成碳酸二甲酯的工艺路线是目前最有发展前途的一种合成方法,但该过程中由于使用了过量的甲醇,在合成中形成了碳酸二甲酯和甲醇的共沸物,分离困难。已报道的分离方法中萃取精馏,在经济效益、操作和安全方面都优于其他方法。草酸二甲酯,碳酸乙烯酯,碳酸丙烯酯均可作为萃取精馏分离DMC的萃取剂,但MeOH-DMC-萃取剂萃取精馏的数学模型尚未见报道,所以有必要研究MeOH-DMC及其与萃取剂体系的汽液平衡数据。本文在常压下,用改进的Othmer釜测定了MeOH-DMC二元汽液平衡数据,并用Margules,VanLaar,Wilson,NRTL,UNIQUAC方程对实验数据进行了关联,并利用UNIFAC方程模拟推算了MeOH-DMC-萃取剂(草酸二甲酯、碳酸乙烯酯、碳酸丙烯酯)三元体系在常压下的汽液平衡,为建立萃取精馏法分离DMC与甲醇共沸体系的数学模型提供了必要的汽液平衡(VLE)数据。The route of catalytic synthesizing dimethyl carbonate by methanol （MeOH） and urea is the most promising synthetic method. But because of the excessive use of methanol, it is difficult to separate dimethyl carbonate and methanol mixture due to the existence of azeotrope in this process. Extractive distillation is more economical, simple, safe and effective than the other separation methods reported, and dimethyl oxalate （DMO）, ethylene carbonate （EC） and propylene carbonate （PC） can be used as the extractant. However, the mathematical model of MeOH-DMC-extractant was not reported. So, it is necessary to study the vapor-liquid equilibrium （VLE） data of MeOH-DMC and its extractant. The vapor-liquid equilibrium data for the dimethyl carbonate and methanol were measured at normal pressure in a modified Othmer still. The measured binary data were correlated by using Margules, Van Laar, Wilson, NRTL and UNIQUAC models. The normal atmosphere vapor-liquid equilibrium of ternary system MeOH-DMC-extractant （dimethyl oxalate, ethylene carbonate, propylene carbonate） was simulated by using the UNIFAC equation. The VLE data are necessary to separate methanol from DMC by extraction distillation.

关 键 词：碳酸二甲酯 甲醇 萃取剂 汽液平衡 

分 类 号：TQ013.1[化学工程]