The chemical equilibrium and reaction kinetics in homogeneously and heterogeneously catalyzed systems were investigated for the reversible esterification reaction of glycolic acid with ethanol. In a first approach, the thermodynamic equilibrium of the reaction was established for temperatures between 50 °C and 75 °C. To differentiate catalytic from homogeneous contribution, the esterification was first studied without a catalyst and the data obtained were then used to model the autocatalyzed homogeneous reaction kinetics. The impact of different commercial solid catalysts such as zeolites, oxides and ion exchange resins on the esterification reaction was also investigated. For the latter, the amount of total acid sites was quantified in order to correlate this parameter to the reaction rate and glycolic acid conversion. Finally, the effects of catalyst loading, temperature, presence of water and recyclability were examined for the most efficient catalyst, Amberlyst 70. Moreover, a kinetic adjustment of the experimental results was carried out by fitting the data to a pseudo-homogeneous model and comparing to adsorption-based models.

中文翻译：

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乙醇酸与乙醇的自催化和非均相催化酯化动力学

研究了乙醇酸与乙醇的可逆酯化反应在均相和非均相催化体系中的化学平衡和反应动力学。在第一种方法中，反应的热力学平衡是在 50 °C 和 75 °C 之间的温度下建立的。为了区分催化作用和均相反应，首先在没有催化剂的情况下研究酯化反应，然后将获得的数据用于模拟自催化均相反应动力学。还研究了不同的商业固体催化剂如沸石、氧化物和离子交换树脂对酯化反应的影响。对于后者，总酸位点的数量被量化以便将该参数与反应速率和乙醇酸转化率相关联。最后，