The present research investigates the kinetics of ultrasound‐assisted synthesis of dibutyl maleate using a heterogeneous catalyst (Amberlyst‐15) in solvent‐free system. Reaction parameters were optimized based on conversion by varying the various parameters such as n‐butanol to maleic acid mole ratio, temperature, molecular sieves, catalyst loading, power, and duty cycle. Optimization of parameters resulted in 56.2% yield at 343 K, alcohol to acid mole ratio as 4:1, catalyst loading of 4%, molecular sieves of 4% with an ultrasound power input of 100 W with 60% duty cycle and 22 kHz frequency. In the presence of ultrasound, the reaction time reduced to 120 min in comparison with 240 min of the conventional process. The experimental kinetic data were correlated using Pseudo‐Homogeneous model as well as heterogeneous models like Eley‐Rideal model and Langmuir‐Hinshelwood‐Hougen‐Watson (LHHW) model based on single as well as dual‐site mechanisms. LHHW (reactants and products) model was found to be the best fit. The results proved that the reaction follows second‐order kinetics. The activation energy of the reaction was calculated as 14.64 kJ/mol.

中文翻译：

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异相催化剂超声辅助马来酸和丁醇酯化反应的动力学

本研究研究了在无溶剂体系中使用多相催化剂（Amberlyst-15）进行超声辅助的马来酸二丁酯合成的动力学。通过改变各种参数（例如正丁醇与顺丁烯二酸的摩尔比），温度，分子筛，催化剂负载量，功率和占空比，可以基于转化率优化反应参数。优化参数后，在343 K时产率为56.2％，醇酸比为4：1，催化剂负载率为4％，分子筛为4％，超声功率输入为100 W，占空比为60％，频率为22 kHz 。在超声的存在下，与传统工艺的240分钟相比，反应时间减少到120分钟。基于单站点和双站点机制，使用伪均质模型以及Eley-Rideal模型和Langmuir-Hinshelwood-Hougen-Watson（LHHW）模型等异质模型对实验动力学数据进行关联。发现LHHW（反应物和产物）模型是最合适的。结果证明该反应遵循二级动力学。反应的活化能经计算为14.64kJ / mol。