Transesterification of waste cooking palm oil by MnZr with supported alumina as a potential heterogeneous catalyst

•Developed the novel supported Mn3.5xZr0.5yAlxO3 catalyst activity towards transesterification of WCPO.•The prepared catalyst was characterized via its chemical and physical properties.•FAMEs were produced from cheap feed stock of waste cooking palm oil.•Reaction variables were studied for transesterification reaction.•High reusability potential of the catalyst was proved.

The transesterification of waste cooking palm oil (WCPO) with methanol into fatty acid methyl esters (FAMEs) was investigated using solid acidic mixed oxide catalysts Mn3.5xZr0.5yAlxO3 prepared via coprecipitation. The effects of reaction temperature, time, molar methanol-to-oil ratio, and catalyst loading were investigated. The stability of the catalytic activity was examined via leaching and reusability tests through five consecutive batch runs. The catalyst achieved a FAME content of more than 93%, and the optimal reaction conditions are as follows: reaction temperature of 150 °C, reaction time of 5 h, molar methanol-to-WCPO ratio of 14:1, and catalyst loading of 2.5 wt.%.