Alkyl levulinates are green chemicals that have the ability to modify physical properties of both gasoline and diesel, which makes their use as fuel additives of great importance. An interesting route for their production is the ethyl esterification using solid catalysts, which still needs improvement. The use of supercritical CO₂ (scCO₂) as solvent may enhance the reaction yield, in such a way that the objective of this work was to combine the use of a solid catalyst (montmorillonite K10) and scCO₂ to achieve the esterification of levulinic acid to obtain ethyl levulinate. Moreover, understanding the relationship between the amount of CO₂, reactants and the catalyst can be a key to determine how scCO₂ works in this type of reaction. The results obtained after a systematic study have shown that the combined effect of scCO₂ and montmorillonite K10 allow the obtainment of 90.9 % of conversion after 126 min of reaction at 180 °C, with a molar ratio of 6:1 and 10 wt% of catalyst, while reactions performed using the same conditions and without scCO₂ provided 82.9 % of conversion after 138 min. Furthermore, the presence of scCO₂ also helped montmorillonite K10 to retain its catalytic activity after 4 reuse cycles, while under the absence of scCO₂, a decrease in the levulinic acid conversion was already observed in the first reuse cycle. The results presented in this work are a step further for the use of montmorillonite K10 along with scCO₂ in industrial scale.

乙酰丙酸烷基酯是绿色化学物质，具有改变汽油和柴油的物理性能的能力，这使其用作燃料添加剂非常重要。一种有趣的生产方法是使用固体催化剂进行乙基酯化，这仍然需要改进。使用超临界CO ₂（scCO ₂）作为溶剂可以提高反应产率，因此该工作的目的是结合使用固体催化剂（蒙脱土K10）和scCO ₂来实现乙酰丙酸酯的酯化。酸得到乙酰丙酸乙酯。此外，了解CO ₂的量，反应物和催化剂之间的关系可能是确定scCO的关键。₂在这种类型的反应中起作用。经过系统研究后获得的结果表明，scCO ₂和蒙脱土K10的共同作用在180°C下反应126分钟后，可实现90.9％的转化率，摩尔比为6：1和10 wt％在138分钟后，使用相同条件在无scCO _2的条件下进行的反应可提供82.9％的转化率。此外，scCO ₂的存在还有助于蒙脱石K10在4次重复使用循环后保持其催化活性，而在没有scCO ₂的情况下，在第一个重复使用周期中已经观察到乙酰丙酸转化率下降。这项工作中提出的结果是将蒙脱石K10与scCO ₂一起以工业规模使用的又一个步骤。