The presence of free fatty acids interferes with the conversion of plant oils to biodiesel. Four strong and weak base resins were evaluated for the removal of free fatty acids (FFA) from oil. Amberlite FPA 51 showed the highest adsorption capacity of FFA. A resin concentration above 3% could enable a higher percentage FFA adsorption. The adsorption process fitted a pseudo-first-order kinetic model and achieved equilibrium in approximately 8 h. A full factorial design was used to optimize the resin and FFA concentrations at a fixed temperature (40 °C). A ratio of resin to fatty acid concentrations above 1.875 was sufficient for 70% adsorption and the amount adsorbed continued to increase with further added resin. A two-step washing of resin using hexane and ethanol recovered approximately 67.55% ± 4.05% of the initially added fatty acid. The resin that was used was regenerated with 5% NaOH and re-used for a minimum of three consecutive cycles. However, the adsorption capacity diminished to 75% of the initial cycle in cycles 2 and 3. Thus, the work presents a resin-based process for deacidification of oil to reduce fatty acid content of oil for biodiesel production. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd

中文翻译：

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响应面法引导使用树脂从油中吸附和回收游离脂肪酸

游离脂肪酸的存在会干扰植物油向生物柴油的转化。评估了四种强碱和弱碱树脂从油中去除游离脂肪酸 (FFA) 的能力。Amberlite FPA 51 显示出最高的 FFA 吸附能力。树脂浓度高于 3% 可以实现更高百分比的 FFA 吸附。吸附过程符合准一级动力学模型，并在大约 8 小时内达到平衡。全因子设计用于优化固定温度 (40 °C) 下的树脂和 FFA 浓度。树脂与脂肪酸浓度的比率高于 1.875 足以达到 70% 的吸附，并且吸附量随着进一步添加树脂而继续增加。使用己烷和乙醇对树脂进行的两步洗涤回收了最初添加的脂肪酸的大约 67.55% ± 4.05%。使用的树脂用 5% NaOH 再生并重复使用至少三个连续循环。然而，在循环 2 和 3 中，吸附能力降低到初始循环的 75%。因此，该工作提出了一种基于树脂的油脱酸工艺，以降低用于生产生物柴油的油中的脂肪酸含量。© 2021 化学工业协会和 John Wiley & Sons, Ltd