In this study, we conducted an efficient microwave-assisted transesterification process combining homogeneous and heterogeneous catalytic phases to produce biodiesel from waste soybean oil. A cylindrical quartz reactor packed with nanoparticles of Fe₃O₄ as a co-catalyst was applied to improve the reaction. The process was carried out with a methanol-to-oil molar ratio of 6:1, power of 560 W, and residence time of 30 s. The specifications of the biodiesel produced in this study were compared with two standards, i.e., ASTM D6751 and EN 14214. We found that the continuous conversion of waste soybean oil to methyl ester was approximately 95%. The biodiesel showed a higher flash point and a higher carbon residue content than that of both standards, and the viscosity (5.356 mm²/s) and density (898.1 kg/m³) were both at a high level. Compared to a conventional heating plate, the energy consumption was significantly reduced by nearly 93%. It is expected that these findings will provide useful information for green and sustainable processes for the regeneration and reuse of oil.

中文翻译：

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纳米Fe3O4微波催化从废豆油中连续生产生物柴油

在这项研究中，我们进行了有效的微波辅助酯交换工艺，结合了均相和非均相催化相，从废豆油生产生物柴油。使用填充有Fe ₃ O ₄纳米颗粒作为助催化剂的圆柱形石英反应器来改善反应。该过程在甲醇与油的摩尔比为6：1，功率为560 W，停留时间为30 s的条件下进行。将这项研究中生产的生物柴油的规格与两个标准（即ASTM D6751和EN 14214）进行了比较。我们发现，废豆油的连续转化率约为95％。该生物柴油的闪点和碳残留量均高于两个标准品，且粘度（5.356 mm ²/ s）和密度（898.1 kg / m ³）都处于较高水平。与传统的加热板相比，能耗显着降低了近93％。预期这些发现将为石油的再生和再利用的绿色和可持续过程提供有用的信息。