Ultrasonic-assisted alkali-catalyzed preparation of biodiesel from swill-cooked dirty oil was studied. The influences of temperature, catalyst dosage, mass ratio of methanol to oil on biodiesel conversion rate were studied by response surface methodology(RSM). The optimal preparation conditions were as follows: ultrasonic power 50 W, ultrasonic frequency 28 Hz, temperature 62.47℃, catalyst dosage 0.98%, reaction time 30 min, mass ratio of methanol to oil 7∶1. Under the optimal conditions, biodiesel conversion rate was 90.26%. |