Alkali-catalyzed transesterification of waste cooking oil to prepare biodiesel by ultrasonication

摘要

Biodiesel is a renewable, biodegradable, and nontoxic fuel. At present, biodiesel is primarily produced in batch reactors in which the required energy is provided by heating accompanied by mechanical mixing. Alternatively, ultrasonic processing is an effective way to attain required mixing while providing the necessary activation energy. Biodiesel was synthesized by waste cooking oil using ultrasonication and alkali-acid catalysis method. Its structure was characterized by gas chromatograph, and the effects of various factors on transesterification rate were studied. The results show that a biodiesel yield in excess of 91% can be achieved in 30 min, at the 30Hz amplitude level, methanol/oil weight ratio of 1.3, 2% of alkaline, reaction temperature of 40-50°C.