An experimental investigation of biodiesel synthesis from waste canola oil using supercritical methanol

► Biodiesel is synthesized from waste canola oil using supercritical methanol. ► Biodiesel yield of 102% is achieved at 270 °C and 10 MPa for 45 min reaction time. ► Reaction time, temperature and their interaction are the most significant factors on the yield. ► Side reactions are confirmed by an increase in water content of reaction product. ► Oxygenated compounds and methyl esters are found in products of the side reactions.