离子液体催化乙酸和乙醇酯化反应动力学的分析  

Kinetic analysis of acetic acid and ethanol esterification catalyzed by ionic liquids

作　　者：夏成康 徐浩 何瑞宁 邹昀 韦藤幼 童张法 XIA Cheng-kang;XU Hao;HE Rui-ning;ZOU Yun;WEI Teng-you;TONG Zhang-fa(School of Chemistry and Chemical Engineering,Guangxi University,Guangxi Petrochemical Resource Processing and Process Strengthening Technology Key Laboratory,Nanning 530004,China;National non grain Biomass Energy Engineering Technology Research Center Guangxi University,Nanning 530004,China)

机构地区：[1]广西大学化学化工学院,广西石化资源加工及过程强化技术重点实验室,广西南宁530004 [2]国家非粮生物质能源工程技术研究中心,广西南宁530004

出　　处：《高校化学工程学报》2021年第6期1027-1034,共8页Journal of Chemical Engineering of Chinese Universities

基　　金：广西自然科学基金重点项目(2017GXNSFDA198047);广西自然科学基金创新团队项目(2016GXNSFGA380003);广西石化资源加工及过程强化技术重点实验室主任基金(2017Z001,2017Z010)。

摘　　要：针对传统催化剂浓硫酸腐蚀性强、无法回收等问题,以绿色环保的离子液体1-磺酸丁基-2-甲基吡啶硫酸氢盐为催化剂,探讨离子液体对乙酸和乙醇酯化反应合成乙酸乙酯的动力学性能影响。在温度为313.15~333.15 K、催化剂浓度在0.07~0.27 mol·L^(-1)、初始乙酸和乙醇的量比为0.56~1.5的条件下,考察各因素对反应转化率的影响。根据二级可逆反应机理建立酯化反应动力学的溶液非理想均相(NIH)模型,并采用溶液理论中非随机双液体模型方程(NRTL模型)修正混合液体的非理想性质。通过动力学数据拟合获得模型中的动力学常数、反应活化能和指前因子等参数。随着温度和离子液体催化剂浓度上升,乙酸的反应速率逐渐增大,但平衡转化率基本不变,当初始乙酸和乙醇的量比为1时,乙酸乙酯产量最高。正反应活化能为49.48 kJ·mol^(-1),逆反应活化能为53.78 kJ·mol^(-1);正反应指前因子为7.25×10^(5)L^(2)·mol^(-2)·min^(-1),逆反应指前因子为3.87×10^(5)L^(2)·mol^(-2)·min^(-1)。结果表明模型预测值与实验值一致,证明了NIH模型适用于该离子液体催化乙酸乙酯反应动力学体系。Concentrated sulfuric acid as catalyst has problems including corrosion and unable to recover.1-sulfonate butyl-2-methyl pyridine bisulfate ionic liquid was used as a catalyst in this study,and its effects on kinetic properties in the synthesis of ethyl acetate via acetic acid and ethanol esterification was investigated.The impact of factors on reaction conversion was investigated under the conditions of temperature 313.15-333.15 K,catalyst concentration 0.07-0.27 mol·L^(-1) and acid-alcohol molar ratio 0.56-1.5.The non-ideal homogeneous(NIH)model of kinetics was established based on the two-stage reversible reaction mechanism,and the NRTL activity equation was adopted to correlate the non-ideal properties of the mixed liquid.Parameters such as kinetic constants,reaction activation energy and pre-exponential factors in the model were obtained by fitting kinetic data.The results show that the reaction rate increased gradually with the increase of temperature and concentration of ionic liquid catalyst,but the equilibrium conversion stayed unchanged and the highest conversion was obtained with molar ratio of acid to alcohol=1.The positive reaction activation energy was 49.48 kJ·mol^(-1) and the negative reaction activation energy was 53.78 kJ·mol^(-1).The positive predigital factor was 7.25×10^(5)L^(2)·mol^(-2)·min^(-1) and the negative predigital factor was 3.87×10^(5)L^(2)·mol^(-2)·min^(-1).The predicted values of the model were consistent with the experimental values,which indicates that the NIH model is suitable for the kinetic study.

关 键 词：离子液体催化剂 1-磺酸丁基-2-甲基吡啶硫酸氢盐 动力学模型 酯化反应 

分 类 号：TQ216[化学工程—有机化工]