Herein, we present a process for recovering used locomotive engine oil using ultrasound-assisted extraction and sustainable organic solvents. We evaluated the quality of the oil recovered from used locomotive engine oil through ultrasound-assisted extraction or mechanical stirring. The extraction process involved the direct application of ultrasound (25 °C, 24 kHz, amplitude 20%) or mechanical stirring (225 rpm, 25 °C) to a mixture of used locomotive engine oil and alcoholic solvents (ethanol, propan-2-ol, 2-methlypropan-1-ol, and butan-1-ol) for 0.5, 1, and 5 min. With ultrasound (5 min), the yield of butan-1-ol was the highest (91.4 wt%), followed by that of 2-methylpropan-1-ol (79.4 wt%), propan-2-ol (12.1 wt%), and ethanol (3.6 wt%). With mechanical stirring (5 min), the yield of butan-1-ol was the highest (88.3 wt%), followed by that of 2-methylpropan-1-ol (59.8 wt%), propan-2-ol (9.54 wt%), and ethanol (2.3 wt%). The kinematic viscosities of the recovered oils extracted with 2-methylpropan-1-ol and butan-1-ol were 126.0 and 132.7 mm² s⁻¹, respectively, which were close to the kinematic viscosity of fresh locomotive engine oil (150.6 mm² s⁻¹). The recovered oil had decreased Ca, Cr, Fe, Mo, and Na concentrations. The proposed recovery is a promising approach for the support and intensification of used locomotive engine oil treatment.

在此，我们提出了一种使用超声波辅助萃取和可持续有机溶剂回收废机车发动机油的工艺。我们评估了通过超声波辅助萃取或机械搅拌从废机车发动机油中回收的油的质量。提取过程涉及直接对用过的机车发动机油和醇类溶剂（乙醇、2-丙烷）的混合物应用超声波（25°C，24 kHz，振幅 20%）或机械搅拌（225 rpm，25°C）。醇、2-甲基丙-1-醇和丁-1-醇) 0.5、1 和 5 分钟。超声处理（5 分钟）时，1-丁醇的产率最高（91.4 wt%），其次是 2-甲基丙-1-醇（79.4 wt%）、2-丙醇（12.1 wt%）。 ）和乙醇（3.6 wt%）。机械搅拌（5 min）时，1-丁醇的产率最高（88.3 wt%），其次是2-甲基丙-1-醇（59.8 wt%）、丙-​​2-醇（9.54 wt%）和乙醇（2.3 wt%）。用2-甲基丙-1-醇和丁-1-醇提取的回收油的运动粘度分别为126.0和132.7mm² s ^-1，接近新鲜机车发动机油的运动粘度（150.6 mm ² s ^-1）。回收的油降低了 Ca、Cr、Fe、Mo 和 Na 的浓度。所提出的回收是支持和强化废机车发动机油处理的一种有前途的方法。