Oo Ye Min, Juera-Ong Panupong, Somnuk Krit
Department of Mechanical and Mechatronics Engineering, Faculty of Engineering, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand.
Sci Rep. 2024 Nov 12;14(1):27732. doi: 10.1038/s41598-024-78974-3.
This study aims to optimize the reduction of free fatty acids (FFAs) in palm fatty acid distillate (PFAD) using hydrodynamic cavitation reactors (HCRs) in series and a solid acid catalyst for biodiesel production. Hydrodynamic cavitation is used to accelerate the esterification of FFAs using a heterogeneous acid catalyst. There are three HCRs units, and each HCR composed of a 3D-printed rotor and stator, is separated by flanges and equipped with a basket for holding Amberlyst-15 catalyst. Through response surface methodology (RSM), the esterification process is optimized by adjusting its optimal parameters, namely, methanol (2-12 wt%), circulation time (30-170 min), and rotor speed (1000-3000 rpm). The optimal conditions for achieving a maximum methyl ester purity of 89.76 wt% in converting FFA in first-step esterified oil are 9 wt% methanol (molar ratio of methanol to oil of 4:1), 133 min of circulation time, and 2000 rpm of rotor speed. An 82.48 wt% biodiesel yield is achieved from the HCRs in series under the optimal conditions. Scanning electron microscope images reveal that after the esterification process, there are minor cracks and defects on the catalyst's resin surface, indicating the presence of residual reactants. Further examination of the catalyst after the esterification process, reveals an average absorption pore diameter of 341.41 Å and BET surface area of approximately 41.68 m/g. Although there were slight physical changes in the catalyst, HCRs technology offers a viable FFA reduction process that could enhance biodiesel production efficiency. Moreover, the optimized conditions achieved in this study contribute to the advancement of biodiesel production processes and provide insights into the performance of the catalyst used.
本研究旨在利用串联的水力空化反应器（HCR）和固体酸催化剂优化棕榈脂肪酸馏出物（PFAD）中游离脂肪酸（FFA）的还原，以生产生物柴油。水力空化用于使用非均相酸催化剂加速FFA的酯化反应。有三个HCR单元，每个HCR由3D打印的转子和定子组成，通过法兰隔开，并配备有用于容纳Amberlyst-15催化剂的篮子。通过响应面法（RSM），通过调整其最佳参数，即甲醇（2-12 wt%）、循环时间（30-170分钟）和转子速度（1000-3000转/分钟），对酯化过程进行优化。在第一步酯化油中转化FFA时，实现最大甲酯纯度为89.76 wt%的最佳条件是9 wt%的甲醇（甲醇与油的摩尔比为4:1）、133分钟的循环时间和2000转/分钟的转子速度。在最佳条件下，串联的HCR实现了82.48 wt%的生物柴油产率。扫描电子显微镜图像显示，酯化过程后，催化剂树脂表面存在微小裂纹和缺陷，表明存在残留反应物。酯化过程后对催化剂的进一步检查显示，平均吸收孔径为341.41 Å，BET表面积约为41.68 m/g。尽管催化剂有轻微的物理变化，但HCR技术提供了一种可行的FFA还原工艺，可以提高生物柴油的生产效率。此外，本研究中实现的优化条件有助于推进生物柴油生产工艺，并提供了所用催化剂性能的见解。
