Abstract An experimental study of solid-liquid equilibrium of binary and ternary mixtures of ethyl laurate and ethyl palmitate, two ethyl esters frequently found in biodiesel, and decylbenzene, a representative aromatic compound present in conventional diesel, was carried out using differential scanning calorimetry (DSC). Such a study is of interest due to concerns about the economic and environmental sustainability of petroleum-based fuels, raising attention to alternative fuels, such as biodiesel. The binary mixture ethyl laurate + decylbenzene presents a eutectic point close to 255 K, whereas that of ethyl palmitate + decylbenzene is close to 258.8 K. The eutectic compositions, in decylbenzene mole fractions, are close to 0.80 and 0.97, respectively. Equilibrium data were modeled either considering that the liquid phase is an ideal mixture or using the UNIFAC-Dortmund and Flory-Huggins models for liquid-phase non-ideality. A simple eutectic behavior was observed for the binary system containing ethyl palmitate and decylbenzene, with an average deviation between calculated and experimental melting temperatures lower than 1.0 K. The binary mixture ethyl laurate + decylbenzene presents a more complex phase diagram, and the root mean-squared deviation is smaller than 2.3 K. Transitions of the binary system containing ethyl laurate and decylbenzene hardly influence the liquidus line of the ternary system. A good agreement was obtained between experimental and predicted data by using Flory-Huggins equation for liquid phase non-ideality and eutectic solid phase.

中文翻译：

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月桂酸乙酯、棕榈酸乙酯和癸基苯形成的二元和三元体系的固液平衡

摘要 使用差示扫描量热法 (DSC) 对月桂酸乙酯和棕榈酸乙酯（生物柴油中常见的两种乙酯）和癸基苯（常规柴油中存在的代表性芳香族化合物）的二元和三元混合物的固液平衡进行了实验研究。 ）。由于对石油基燃料的经济和环境可持续性的担忧，引起了对替代燃料（如生物柴油）的关注，因此这项研究很有趣。月桂酸乙酯 + 癸基苯二元混合物的共晶点接近 255 K，而棕榈酸乙酯 + 癸基苯的共晶点接近 258.8 K。以癸基苯摩尔分数计，共晶成分分别接近 0.80 和 0.97。平衡数据的建模要么考虑液相是理想的混合物，要么使用 UNIFAC-Dortmund 和 Flory-Huggins 模型用于液相非理想。观察到含有棕榈酸乙酯和癸基苯的二元体系的简单共晶行为，计算和实验熔融温度之间的平均偏差低于 1.0 K。月桂酸乙酯 + 癸基苯二元混合物呈现更复杂的相图，根均值为 -平方偏差小于2.3 K。含有月桂酸乙酯和癸基苯的二元体系的转变几乎不影响三元体系的液相线。对于液相非理想和共晶固相，使用 Flory-Huggins 方程在实验和预测数据之间获得了良好的一致性。