草酸二乙酯新合成过程的热力学分析和实验验证  

Thermodynamic analysis and experimental verification of a new route for direct diethyl oxalate synthesis

作　　者：万思玉 石磊[1,2] WAN Si-yu;SHI Lei(Key Laboratory on Resources Chemicals and Materials of Ministry of Education,Shenyang University of Chemical Technology,Shenyang 110142,China;Institute of Industrial Chemistry and Energy Technology,Shenyang University of Chemical Technology,Shenyang 110142,China;College of Science,Shenyang University of Chemical Technology,Shenyang 110142,China)

机构地区：[1]沈阳化工大学资源化工与材料教育部重点实验室,辽宁沈阳110142 [2]沈阳化工大学能源与化工产业技术研究院,辽宁沈阳110142 [3]沈阳化工大学理学院,辽宁沈阳110142

出　　处：《燃料化学学报》2021年第1期121-128,共8页Journal of Fuel Chemistry and Technology

基　　金：辽宁省教育厅重点攻关和服务地方项目(LDB2019005);高水平创新团队国(境)外培养重点项目(2018LNGXGJWPY-ZD002);国家自然科学基金(21303106);辽宁省高等学校创新人才(LR2016015)项目资助。

摘　　要：报道新颖的草酸二甲酯(DMO)与乙醇(EtOH)通过酯交换路径一步合成高品质草酸二乙酯(DEO)。采用基团贡献法及Watson公式估算过程中各物质的热力学参数,并通过经典热力学公式计算在常压和温度323−368 K时合成DEO各步反应的焓变、熵变、吉布斯自由能及平衡常数。通过实验测定不同温度和原料比例下DMO转化率、产物组成和反应平衡常数并与理论估算值比较。发现实测DMO转化率与估算值误差在1%内,实测平衡常数与估算值基本一致。经过严格的实验验证,证明经热力学方法估算的热力学参数比较可靠。模拟真实催化精馏条件,以塔釜DEO纯度达99.9%为目标计算353 K时塔釜的初始原料和最终产物组成,当塔釜EtOH含量高于2.59%,初始n(EtOH)/n(DMO)大于2.10时可使DEO纯度达到指标,并显著降低整体工艺能耗,是一个高效绿色的DEO生产工艺。The synthesis of high quality diethyl oxalate(DEO)via transesterification of dimethyl oxalate(DMO)and ethanol(EtOH)was reported.The thermodynamic data of each substance involved in the reaction were estimated by Benson and Joback's group contribution method and Watson formula,and the enthalpy change,entropy change,Gibbs free energy and equilibrium constant of each step of DEO synthesis were calculated by classical thermodynamic formula under atmospheric pressure and in the temperature range of 323−368 K.The DMO conversion,product composition and reaction equilibrium constant at different temperatures and raw material ratios were measured by experiments and compared with the theoretical data.It is found that the error between the measured DMO conversion and the estimated value is less than 1%,and the measured equilibrium constant is basically consistent with the estimated value.After strict experimental verification,it is proved that the thermodynamic data estimated by thermodynamic analysis are reliable.The actual catalytic distillation conditions were simulated,and the composition of the initial raw materials and the final products at 353 K was calculated with the hypothesis of 99.9% DEO purity at the bottom.When the content of EtOH in the bottom was higher than 2.59% and the molar ratio of initial EtOH to DMO was higher than 2.10,the purity of DEO could reach the target,and the overall process energy consumption was significantly reduced.It would be an efficient and green route for DEO synthesis.

关 键 词：草酸二甲酯 草酸二乙酯 酯交换 热力学 基团贡献法 催化精馏 

分 类 号：O642.1[理学—物理化学]