Wang Xubin, Wang Linlin, Chen Xiaopeng, Zhou Dan, Xiao Han, Wei Xiaojie, Liang Jiezhen
Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, People's Republic of China.
College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, People's Republic of China.
R Soc Open Sci. 2018 May 2;5(5):172124. doi: 10.1098/rsos.172124. eCollection 2018 May.
A heterogeneous catalyst (ZnO/SFCCR) composed of ZnO supported on spent fluid cracking catalyst by wet impregnation was synthesized and applied to the esterification of colophony acids with methanol under subcritical CO conditions. The catalyst was characterized by SEM-EDS, BET, ICP, FTIR, XRD and Py-IR. An experimental set-up involving a new injection technique was designed to promote the heterogeneous methyl esterification, and the subcritical CO played a role in auxiliary acid catalysis (a pH range of 3.54-3.91), increasing the lifespan of ZnO/SFCCR, reducing the viscosity of the system to promote gas-liquid mass transfer. A maximum conversion rate of 97.01% was obtained in a relatively short time of 5 h. Kinetic experiments were performed from 190 to 220°C using a special high-temperature sampling device and analysing aliquots with high-performance liquid chromatography. A new reaction pathway, involving methyl abietate, methyl dehydroabietate, methyl neoabietate and methyl palustrate along with other kinds of colophony acids, was developed. The kinetic parameters were obtained using the Levenberg-Marquardt nonlinear least-squares method, and the activation energies for the isomerizations of neoabietic and palustric acids and for the methyl esterification of neoabietic, abietic, palustric and dehydroabietic acids were found to be 107.09, 113.95, 68.99, 49.85, 75.43 and 59.20 kJ mol, respectively. The results from the kinetic model were in good agreement with experimental values.
通过湿浸渍法制备了一种负载在废流化催化裂化催化剂上的ZnO组成的非均相催化剂（ZnO/SFCCR），并将其应用于亚临界CO条件下松香酸与甲醇的酯化反应。采用扫描电子显微镜-能谱仪（SEM-EDS）、比表面积分析仪（BET）、电感耦合等离子体质谱仪（ICP）、傅里叶变换红外光谱仪（FTIR）、X射线衍射仪（XRD）和吡啶吸附红外光谱仪（Py-IR）对催化剂进行了表征。设计了一种涉及新注入技术的实验装置以促进非均相甲酯化反应，亚临界CO起到辅助酸催化作用（pH范围为3.54 - 3.91），延长了ZnO/SFCCR的使用寿命，降低了体系粘度以促进气液传质。在相对较短的5小时内获得了97.01%的最大转化率。使用特殊的高温采样装置并通过高效液相色谱分析等分试样，在190至220°C下进行了动力学实验。开发了一条新的反应途径，涉及松香酸甲酯、脱氢枞酸甲酯、新枞酸甲酯和海松酸甲酯以及其他种类的松香酸。使用Levenberg-Marquardt非线性最小二乘法获得了动力学参数，发现新枞酸和海松酸异构化以及新枞酸、枞酸、海松酸和脱氢枞酸甲酯化的活化能分别为107.09、113.95、68.99、49.85、75.43和59.20 kJ/mol。动力学模型的结果与实验值吻合良好。
