Esterification of oleic acid with ethanol was conducted under subcritical and supercritical conditions in a packed-bed reactor containing γ-Al₂O₃. The presence of γ-Al₂O₃ significantly improved the reaction rate such that the 42% yield achieved at 325 °C, 200 bar, and 1-min residence time without the alumina was increased to 98% at the same conditions when alumina was present. The catalytic capacity was attributed to Lewis acid sites on the surface of alumina, and non Brønsted acid sites were detected. Experiments to study the kinetics were executed at a pressure of 200 bar, elevated temperatures (200, 225, 275, 300, and 325 °C), and residence times of half to 8 minutes. Mass transfer limitations were estimated to be negligible via the Mears and Weisz-Prater criteria. Kinetic analysis based on the one-step model demonstrates that the overall reaction was endothermic, and an Eley-Rideal (ER) reaction mechanism was proposed to describe each elementary reaction step. The stability of γ-Al₂O₃ on product conversion was tested via a 25 h operation under 325 °C, 200 bar, and 1 min residence time, and decrease of the conversion was not observed. However, results of the catalyst analytical characterization shows a decrease of the acid site density and surface area, supporting the occurrence of catalyst degradation. The addition of water slightly decreased the yield, while the pressure change from 200 to 100 bar did not have an obvious effect on the conversion.

油酸与乙醇的酯化在含有的γ-Al填充床反应器中的亚临界和超临界的条件下进行₂ ö ₃。的存在下的γ-Al ₂ ö ₃显着提高了反应速率，因此在存在氧化铝的相同条件下，在不使用氧化铝的情况下，在325°C，200 bar和1分钟的停留时间下所获得的42％的收率提高至98％。催化能力归因于氧化铝表面的路易斯酸位点，未检测到布朗斯台德酸位点。研究动力学的实验是在200 bar的压力，升高的温度（200、225、275、300和325°C）和一半至八分钟的停留时间下进行的。根据Mears和Weisz-Prater标准，传质限制估计可以忽略不计。基于一步模型的动力学分析表明，整个反应是吸热的，并提出了一种Eley-Rideal（ER）反应机理来描述每个基本反应步骤。的稳定性的γ-Al ₂通过在325°C，200 bar和1分钟的停留时间下进行25小时的操作测试了产品转化率上的O ₃，未观察到转化率降低。然而，催化剂分析表征的结果表明酸位密度和表面积的降低，支持了催化剂降解的发生。加入水会稍微降低产率，而压力从200 bar变为100 bar则对转化率没有明显影响。