Abstract Fifty waste cooking oils (WCOs) were transesterified with methanol (1:8 WCO:methanol molar ratio) at 60 °C for 60 min using NaOH as catalyst (1% wt.). Fatty acid methyl ester (FAME) composition of the resulting biodiesels was analysed by gas chromatography, and near infrared (NIR) spectra of these biodiesels and those of the starting WCOs were acquired. Biodiesel cetane number was then calculated from both FAME composition and from biodiesel NIR spectra, this last technique using the former one as reference data. Because of transesterification does not modify fatty acid distribution of the starting WCO, and the similarity between biodiesel and WCO NIR spectra, biodiesel cetane number was successfully predicted from WCO NIR spectra, achieving RPD (ratio of performance to deviation) of 3.83. Therefore, biodiesel cetane number (and, as consequence, any other biodiesel property related to FAME composition) can be predicted by NIR spectroscopy before performing the transesterification reaction, which allows beforehand selecting the most suitable substrates for biodiesel production.

中文翻译：

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使用近红外光谱预测酯交换反应前废食用油衍生生物柴油的十六烷值

摘要 将 50 种废食用油 (WCO) 与甲醇（WCO：甲醇摩尔比为 1:8）在 60 °C 下使用 NaOH 作为催化剂（1% wt.）进行酯交换反应 60 分钟。通过气相色谱分析所得生物柴油的脂肪酸甲酯 (FAME) 组成，并获得这些生物柴油和起始 WCO 的近红外 (NIR) 光谱。然后根据 FAME 成分和生物柴油 NIR 光谱计算生物柴油十六烷值，最后一种技术使用前一种作为参考数据。由于酯交换不会改变起始 WCO 的脂肪酸分布，并且生物柴油和 WCO NIR 光谱之间的相似性，从 WCO NIR 光谱成功预测了生物柴油的十六烷值，实现了 3.83 的 RPD（性能与偏差之比）。因此，生物柴油的十六烷值（和，