With increasing automotive vehicles, disposal of waste automotive landfill engine oil (WALEO) is foremost challenge. Present work investigated synthesis of fatty acid methyl esters (FAMEs) from WALEO using first stage of orthophosphoric-catalyzed acid esterification followed by subsequent stage of potassium hydroxide-catalyzed alkaline transesterification using conventional and intensified microwave methods. Process parameters for study were molar ratio of oil–methanol, and catalyst concentration. The optimize parameters of acid esterification for reducing acid value from 33.72 to 1.71 mg of KOH/g of oil were catalyst concentration: 12% weight/weight, reaction temperature: 60 \(^\circ{\rm C} \) and molar ratio: 1:2 using conventional method. Nearly same results were obtained using microwave-assisted esterification but there was considerable decrease in process time requirement using intensified approach of microwave irradiations. Time required for processing was 210 and 30 min for conventional and microwave methods, respectively. Microwave accelerated the rate of reaction by 7.5 times. There was substantial decrease in energy requirement for esterification process and energy utilization was 14.2–26.4 mg/kJ for conventional and microwave methods, respectively. Transesterification of esterified oil were performed using microwave method. The optimized parameters for transesterification process were molar ratio: 1:6, catalyst concentration: 1% weight/weight, reaction time: 15 min and yield: 92.3%.

随着机动车辆的增加，废弃汽车垃圾填埋机油（WALEO）的处置是首要挑战。目前的工作研究了使用正磷酸催化的酸酯化反应的第一步从WALEO合成脂肪酸甲酯（FAME），随后使用常规的和增强的微波方法进行氢氧化钾催化的碱性酯交换反应的后续步骤。研究的工艺参数是油-甲醇的摩尔比和催化剂浓度。用于将酸值从33.72 KOH / g油降低至1.71 mg KOH / g的酯化反应的最佳参数是催化剂浓度：12％重量/重量，反应温度：60  \（^ \ circ {\ rm C} \）和摩尔比：使用常规方法为1：2。使用微波辅助酯化获得了几乎相同的结果，但是使用增强的微波辐照方法大大缩短了处理时间。传统方法和微波方法的处理时间分别为210和30分钟。微波将反应速率提高了7.5倍。常规方法和微波方法的酯化过程能量需求大幅降低，能量利用率分别为14.2-26.4 mg / kJ。酯化油的酯交换反应使用微波方法进行。酯交换反应的优化参数为：摩尔比：1：6，催化剂浓度：1％重量/重量，反应时间：15分钟，产率：92.3％。