Waste oils are a very promising raw material in the biodiesel industry, which is why great efforts have focused on the removal of the free fatty acids (FFAs) present in this source, mainly through the esterification reaction. Many studies have evaluated the influence of different variables on the reaction conversion, such as temperature, catalyst concentration, and alcohol/oil ratio. However, it is still necessary to verify how the esterification is affected by higher water concentration. In this study, different acid‐catalyzed esterification reaction conditions with distinct water concentrations were tested experimentally, and a new rate expression was proposed. This newly obtained reaction kinetics was then used to undertake a complete analysis of the biodiesel production process from waste oil, evaluating the influence of higher water concentrations in the esterification, and including different optimizations and an economic evaluation. Concerning some of the process modifications, it was verified that the inclusion of three energy‐saving heat exchangers reduced utility costs by 40%. In contrast, the inclusion of an ethanol‐recycling distillation column reduced raw material costs by 40%. Different settings were also tested, varying the feed composition and the esterification reaction time and conditions, resulting in a payback period of less than 3 years in any evaluated scenario. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd

中文翻译：

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从脂肪酸获得酯的过程的模拟，优化和经济分析

废油是生物柴油行业中非常有前途的原材料，这就是为什么要进行大量努力以主要通过酯化反应来去除该来源中存在的游离脂肪酸（FFA）的原因。许多研究评估了不同变量对反应转化率的影响，例如温度，催化剂浓度和醇/油比。但是，仍然有必要验证较高的水浓度如何影响酯化反应。在这项研究中，通过实验测试了具有不同水浓度的不同酸催化的酯化反应条件，并提出了新的速率表达式。然后，将这种新获得的反应动力学用于对废油生产生物柴油的过程进行完整的分析，评估较高水浓度对酯化的影响，包括不同的优化和经济评估。关于某些工艺修改，已证实包括三个节能热交换器可将公用事业成本降低40％。相反，包含乙醇循环蒸馏塔可将原材料成本降低40％。还测试了不同的设置，改变了进料组成以及酯化反应的时间和条件，在任何评估的情况下，回收期均少于3年。©2021化学工业协会和John Wiley＆Sons，Ltd 事实证明，包含三个节能热交换器可将公用事业成本降低40％。相反，包含乙醇循环蒸馏塔可将原材料成本降低40％。还测试了不同的设置，改变了进料组成以及酯化反应的时间和条件，在任何评估的情况下，回收期均少于3年。©2021化学工业协会和John Wiley＆Sons，Ltd 事实证明，包含三个节能热交换器可将公用事业成本降低40％。相反，包含乙醇循环蒸馏塔可将原材料成本降低40％。还测试了不同的设置，改变了进料组成以及酯化反应的时间和条件，在任何评估的情况下，回收期均少于3年。©2021化学工业协会和John Wiley＆Sons，Ltd