Green chemistry metrics application to biodiesel production from waste vegetable oil

Biodiesel is a promising alternative fuel to diesel; it is produced by the transesterification reaction of fatty acids present in plant oil using basic catalytic reaction. The use of frying oil as a feedstock of the transesterification reduces the raw material cost and eliminates an important waste. In addition to the renewable nature of the alternative fuel, the process of its production must be as environmentally friendly as possible.Therefore, the aim of this work is to estimate the green chemistry balance of a transesterification reaction of waste frying soybean oil collected from university restaurants, using methanol and KOH as a catalyst.Indeed, the green chemistry metrics measuring aspects of a chemical reaction, in relation to the principles of green chemistry are calculated. Carbon efficiency, atom economy, environmental factor, reaction mass efficiency, material recovery parameter, toxicity and stoechiometric factor are calculated, and the green chemistry balance of the reaction is estimated as 64.44%. Recycling the recovered excess methanol and the wash water improves this balance by 18.35%.