Although biodiesel production is undoubtedly a mature technology, there are still ways to improve it, especially through process intensification. The present study investigated the esterification of oleic acid with ethanol for biodiesel production in a nonconventional atomization reactor. The effects of the oleic acid flow rate (1.3, 2.6, and 3.9 g/min), atomization pressure (50, 100, and 150 kPa), and temperature (323, 333, and 343 K) were evaluated by a complete factorial experimental design. The size of droplets was determined by computational image processing. A mathematical model was also developed to describe the conversion of oleic acid to ethyl ester as a function of molar concentration of components and operating conditions of the reactor. A hybrid estimation of parameters (pre-exponential factor, activation energy, and equilibrium and solubility constants) was performed using particle swarm optimization followed by the Broyden–Fletcher–Goldfarb–Shanno method. The Pareto analysis has shown that the increase in temperature in the reactor and the increase in atomization pressure have improved the conversion of oleic acid. Higher pressure values in the atomization nozzle led to the generation of small oleic acid droplets, which accelerated reagent consumption during the reaction. On the other hand, conversion values were reduced by increasing the oleic acid flow rate. The highest conversion of oleic acid (86.7%) was obtained under the following reaction conditions: temperature of 343 K, atomization pressure of 150 kPa, oleic acid flow rate equal to 1.3 g/min using 0.7% sulfuric acid (mol of sulfuric acid/mol of oleic acid), and 2 h of reaction time. The simulations showed that esterification is governed by temperature, but it is possible to observe that the atomization pressure affects more conversion of oleic acid under a low temperature (<323 K).

中文翻译：

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使用半间歇式雾化装置酯化油酸用于生产生物柴油

尽管生物柴油生产无疑是一项成熟的技术，但仍有改进的方法，特别是通过工艺强化。本研究研究了在非常规雾化反应器中油酸与乙醇的酯化反应用于生产生物柴油。通过完整的析因实验评估了油酸流量（1.3、2.6 和 3.9 g/min）、雾化压力（50、100 和 150 kPa）以及温度（323、333 和 343 K）的影响设计。液滴的尺寸通过计算图像处理来确定。还开发了一个数学模型来描述油酸向乙酯的转化率与组分摩尔浓度和反应器操作条件的关系。使用粒子群优化和 Broyden-Fletcher-Goldfarb-Shanno 方法对参数（指前因子、活化能以及平衡和溶解度常数）进行混合估计。Pareto分析表明，反应器内温度的升高和雾化压力的增加提高了油酸的转化率。雾化喷嘴中较高的压力值导致产生小油酸液滴，这加速了反应过程中试剂的消耗。另一方面，增加油酸流量会降低转化值。在以下反应条件下获得了最高的油酸转化率（86.7%）：温度为343 K，雾化压力为150 kPa，油酸流量等于1.3 g/min，使用0.7%硫酸（摩尔硫酸/ mol 油酸），反应时间 2 小时。模拟表明酯化反应受温度控制，但可以观察到雾化压力在低温（<323 K）下影响油酸的转化率。