【作者】 李洋；

【导师】 童张法；

【作者基本信息】 广西大学 ， 化学工程， 2021， 硕士

【摘要】 乙酸正戊酯（AmAc）是一种重要的有机化合物和化工生产原料,在化妆品、人造皮革、火药、胶卷等产品的工业化生产过程中被用作溶剂和稀释剂,有着广阔的市场前景。目前最常见的AmAc制备工艺是用浓硫酸催化醋酸（HAc）和正戊醇（AmOH）的酯化反应,酯化反应的初产物经过一系列分离纯化处理得到纯度较高的AmAc。但是使用浓硫酸作为催化剂存在很多难以解决的问题,例如环境污染,副产物的生成,设备腐蚀以及产率低下等等。固载离子液体（ILs）作为新兴的绿色催化剂在酯化反应方面有着良好的应用前景。同时,反应精馏技术作为一种化工生产过程的强化工艺,在酯化反应中也得到了广泛使用。本文采用溶胶-凝胶法制备了一种新型固载ILs催化剂[HSO₃-pmim][HSO₄]/SiO₂,利用FT-IR、SEM、EDS、BET、TG-DTG、NH₃-TPD等表征手段对其形貌、表面元素分布、结构稳定性、孔径、比表面积、热稳定性和表面酸强度分布进行了表征。采用以丙酮为溶剂的索氏萃取法测定了该固载ILs催化剂[HSO₃-pmim][HSO₄]/SiO₂的固载率,并对其抗腐蚀性和稳定性进行了检验。研究了用[HSO₃-pmim][HSO₄]/SiO₂催化醋酸和正戊醇酯化反应动力学实验,考察搅拌速率、催化剂粒径、反应温度、催化剂浓度、反应物初始摩尔比的影响,同时确定该酯化反应的最佳反应条件。根据反应机理,基于理想拟均相动力学（IQH）模型和非均相动力学（LHHW）模型分别建立了HAc与AmOH酯化反应的动力学方程,通过4-5阶Runge-Kutta算法得到动力学参数并对动力学方程的准确性进行了验证。为了探究固载ILs催化剂[HSO₃-pmim][HSO₄]/SiO₂在反应精馏过程中的催化性能,在实验室规模玻璃反应精馏塔内开展了反应精馏实验,考察回流比、提馏段,反应段塔板数、进料酸醇摩尔比等实验参数对反应精馏的影响。最佳反应条件如下:HAc和AmOH进料流量分别为10.0 m L?min^-1和20.0 m L?min^-1（初始进料酸醇摩尔比1.0）,催化剂提供氢质子浓度0.5665mol·L^-1,回流比1.75,塔釜持液量1000.0 m L,精馏段塔板数1块,反应段塔板数16块,提馏段塔板数11块。AmOH的转化率接近100.0%,塔釜产物AmAc的纯度可以达到96.46 wt.%。利用Aspen plus软件建立了醋酸和正戊醇酯化反应精馏工艺流程,通过对比产物产率和纯度的模拟值和实验值证明了模拟计算结果的可靠性。采用加入夹带剂的方法对塔釜产物进行纯化,证明了该方法在产物AmAc纯化方面的可行性。更多还原

【Abstract】 As an important organic compound and chemical raw material,n-amyl acetate（AmAc）is widely used as solvent and diluents in the industrial production of cosmetics,artificial leather,gunpowder,film and so on.The most common preparation process of AmAc is the esterification of acetic acid（HAc）and n-amyl alcohol（AmOH）catalyzed by concentrated sulfuric acid at present.The primary product of the esterification of HAc and AmOH is separated and purified to obtain high purity AmAc.The application of concentrated sulfuric acid catalyst has many disadvantages such as low selectivity,formation of by-products,equipment corrosion and environmental pollution.As a new type of“green”catalyst,supported ionic liquids（ILs）have high catalytic performance and good application prospect in esterification production.At the same time,reactive distillation technology is widely used in the production process as a strengthening process of chemical production process.A novel supported ILs catalyst[HSO₃-pmim][HSO₄]/SiO₂ was synthesized by sol-gel method.The morphology,surface elements,structural stability,pore diameter,specific surface area,thermal stability and distribution of acid strength of the fabricated catalysts were characterized in detail,while immobilization yield,corrosiveness and stability of the catalyst were also evaluated.The supported ILs catalyst[HSO₃-pmim][HSO₄]/SiO₂ was used to catalyze the esterification reaction of HAc and AmOH.The effect of stirring rate,catalyst particle size,reaction temperature,catalyst concentration and initial molar ratio of reactants on the kinetic experiments of esterification of acetic acid and n-amyl alcohol catalyzed by[HSO₃-pmim][HSO₄]/SiO₂ were characterized in detail.According to the reaction mechanism,the kinetic equations of esterification of acetic acid with n-amyl alcohol were established through IQH and LHHW models and their accuracy was verified by the experimental data,the kinetic parameters were obtained by 4-5 order Runge Kutta algorithm.In order to explore the catalytic performance of[HSO₃-pmim][HSO₄]/SiO₂in reactive distillation process,the effects of reflux ratio,the number of plates in stripping section,reaction section,feed acid-alcohol molar ratio and other experimental parameters on reactive distillation process were investigated.Under the best operating conditions:The feed flow rates of HAc and AmOH were 10.0 m L?min^-1 and 20.0 m L?min^-1（initial feed molar ratio was 1.0）,the concentration of hydrogen proton provided by catalyst was 0.5665 mol·L^-1,the reflux ratio was 1.75,the liquid holdup of tower kettle was 1000.0 m L,the number of plates in distillation section was 1,the number of plates in reaction section was 16,and the number of plates in stripping section was 11.The highest conversion of AmOH was 100.0%,and the purity of AmAc was 96.46%.At the same time,the whole process was established in Aspen Plus,the reliability of the simulation results was proved by comparing the simulated and experimental values of product yield and purity.The method of adding entrainer was used to purify the product in the bottom of the tower,which proved the feasibility and high efficiency of this method in product purification.更多还原