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工程科学与技术:2019,51(6):10-16
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可逆反应辅助煤基乙二醇分离精制-缩醛交换反应动力学
(1.天津大学 化工学院 精馏技术国家工程研究中心, 天津 300072;2.天津化学化工协同创新中心, 天津 300072)
Reversible Reaction-assisted Separating Technology for Synthesis of Ethanediol from Coal—Kinetics of Acetal Exchange Reaction
(1.National Eng. Research Center of Distillation Technol. School of Chemical Eng. and Technol., Tianjin Univ., Tianjin 300072, China;2.Collaborative Innovation Center of Chemical Sci. and Eng. (Tianjin), Tianjin 300072, China)
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投稿时间:2019-07-08    修订日期:2019-09-20
中文摘要: 目前煤制乙二醇生产工艺中依然存在分离精制技术难题,即副产物1,2-丁二醇与乙二醇存在共沸现象,且相对挥发度极低,常规精馏分离方法能耗高、收率低、产品质量差。针对此难题,课题组前期提出一种利用可逆反应来强化分离精制的新方法,但该方法中缩醛反应步骤存在缩醛交换过程,对该工艺的设计计算造成较大影响。作者主要针对缩醛反应步骤中的1,2-丁二醇与2-乙基-1,3-二氧戊环的缩醛交换反应动力学进行探究,通过催化剂粒径、研究转速、催化剂用量、反应温度、反应物进料摩尔比例等因素对反应过程的影响,得到了正逆反应的活化能分别为70.48 kJ/mol和80.14 kJ/mol,正逆反应的指前因子分别为3.79×1010 L/(mol·min·g)和1.95×1012 L/(mol·min·g),采用二级拟均相模型可以很好的对实验数据进行拟合。研究结果还表明该反应为可逆放热反应,反应热为-7.83 kJ/mol。通过该反应动力学的研究发现,合理控制反应条件可以有效提高1,2-丁二醇转化率,降低乙二醇转化率,从而实现分离,为该过程的模拟设计提供了可靠的基础数据,有助于工业化推广应用。
Abstract:In the parallel acetalization of EG and 1,2-BDO towards aldehyde, the existence of trans-acetalization has significant effect on the design and optimization of reversible reaction intensified separation method for EG recovery in syngas-based EG production process. Thus, aimed at exploring the reaction of 1,2-butanediol (1,2-BDO) with 2-ethyl-1,3-dioxolane (2ED) under acidic ion exchange resin catalyst, the impacts of main variables, such as the string speed, catalyst particle size and loading, reaction temperature and reactants feed molar ratio, on trans-acetalization reaction conversion were studied. High reaction temperature and 2ED to 1,2-BDO molar ratio facilitated the conversion of 2ED to 2-ethyl-4-ethyl-1,3-dioxolane (24DED). The activation energies (Ea) of the forward and backward reaction were 70.48 kJ/mol and 80.14 kJ/mol, respectively, and the corresponding pre-exponential factors were 3.79×1010 L/(mol·min·g) and 1.95×1012 L/(mol·min·g), respectively. The results also showed that the trans-acetalization reaction was exothermic with a reaction heat of -7.83 kJ/mol. The study of trans-acetalization reaction can provide guidance on properly altering the reaction conditions to promote the 1,2-BDO conversion and decrease the EG conversion and provide reliable basic data for process design as well as industrial application.
文章编号:201900685     中图分类号:    文献标志码:
基金项目:国家自然科学基金重大项目(21690084)
作者简介:李鑫钢(1961-),男,教授,博士.研究方向:化工分离过程.E-mail:lxg@tju.edu.cn
引用文本:
李鑫钢,闫宇陶,王瑞,李洪,高鑫.可逆反应辅助煤基乙二醇分离精制-缩醛交换反应动力学[J].工程科学与技术,2019,51(6):10-16.
LI Xingang,YAN Yutao,WANG Rui,LI Hong,GAO Xin.Reversible Reaction-assisted Separating Technology for Synthesis of Ethanediol from Coal—Kinetics of Acetal Exchange Reaction[J].Advanced Engineering Sciences,2019,51(6):10-16.