Production of biodiesel from brown grease under ultrasonic activation

Global climate changes and the necessity of reducing dependence on fossil fuels as a major energy source raise the need for development of alternative energy sources. Non-toxic biodegradable and renewable biodiesel can become a promising alternative.

The present study was aimed at developing a continuous process for biodiesel production from brown grease, i.e. cooking oil waste, which has a high free fatty acids content. Separation of the fatty fraction from other brown grease wastes components was performed by centrifugation of preheated brown grease. Conditions for effective esterification of fatty acids were chosen by means of thermal and ultrasonic activation under heterogenous catalysis using incorporation of catalysts into sol-gel matrices.

The results show that biodiesel can be produced under ultrasonic activation, instead of thermal activation. Application of heterogeneous catalysts opens prospects for development of biodiesel production in a continuous regime.