Optimization of technological conditions in synthesis biodiesel from waste oil with supercritical methanol

Supercritical methanol transesterification technology was used to produce biodiesel from waste oil The single factor experiment and the orthogonal experiment combination design were adopted to study the effects of molar ratio of methanol to waste oil,reaction pressure,the rate of rotation,reaction time,reaction temperature on biodiesel production rate.The results indicated the order of factors that influence the biodiesel production rate within the experimental range was as follows:reaction temperaturereaction pressurecatalyst dosagereaction timemole ratio of methanol to waste oil.The optimal technological parameters of oil transesterification from waste oil were determined as follows:reaction temperature 240℃,reaction pressure 10 MPa,catalyst dosage 0.06%,reaction time 6 min and mole ratio of methanol to waste oil 40/1,and under such conditions,the biodiesel production rate was 99.37%.