This paper presents a study about the deacidification of typical Amazonian oils, namely, patawa and pracaxi oils. The liquid–liquid extractions were carried out using three alcoholic solvents: anhydrous ethanol, azeotropic ethanol, and azeotropic isopropanol at 298.15 K and atmospheric pressure. Liquid–liquid equilibrium data for the oils + oleic acid + solvents systems were determined. The azeotropic ethanol was found to be the best extractant for removing free fatty acids (FFAs) since its use provided the highest selectivity values (from 62.98 to more 1.53 × 103), reasonable distribution coefficients (from 1.06 to 1.47), and reduced loss of neutral oil (oil concentrations lower than 1.49 wt% in the alcoholic phases). Moreover, the obtained experimental data were correlated using the nonrandom two-liquid (NRTL) and universal quasi chemical (UNIQUAC) activity coefficient models. The deviations between calculated and experimental values ranged from 0.39 to 1.22 and from 0.28 to 1.10 for the various studied systems using the UNIQUAC and the NRTL models, respectively. Such results indicate the positive perspective of using the liquid–liquid extraction technique for patawa and pracaxi oils refining and the feasibility of using ethanol as an FFA extractant.

中文翻译：

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Amazonian Pracaxi (Pentaclethra macroloba) 和 Patawa (Oenocarpus bataua) 油的脱酸：使用酒精溶剂进行液-液萃取的实验和建模

本文介绍了对典型亚马逊油类（即 patawa 和 pracaxi 油）的脱酸的研究。液-液萃取使用三种醇类溶剂进行：无水乙醇、共沸乙醇和共沸异丙醇，在 298.15 K 和大气压下进行。确定了油 + 油酸 + 溶剂系统的液-液平衡数据。发现共沸乙醇是去除游离脂肪酸 (FFA) 的最佳提取剂，因为它的使用提供了最高的选择性值（从 62.98 到更多的 1.53 × 103）、合理的分配系数（从 1.06 到 1.47），并减少了游离脂肪酸的损失。中性油（醇相中油浓度低于 1.49 wt%）。而且，使用非随机二液 (NRTL) 和通用准化学 (UNIQUAC) 活度系数模型将获得的实验数据关联起来。对于使用 UNIQUAC 和 NRTL 模型的各种研究系统，计算值和实验值之间的偏差范围分别为 0.39 到 1.22 和 0.28 到 1.10。这些结果表明，使用液-液萃取技术进行 patawa 和 pracaxi 油精炼的积极前景以及使用乙醇作为 FFA 萃取剂的可行性。