Calcium oxide as a promising heterogeneous catalyst for biodiesel production: Current state and perspectives

The present paper is an overview of the recent progress in the development of various CaO-based catalysts suitable for biodiesel production. The mechanism, kinetics and optimization of transesterification reaction over these catalysts are first considered. Then, the practical application of CaO-based catalysts is discussed with a special stress on leaching and reusability of these catalysts. Also, various continuous reactor systems currently in use for biodiesel production are appraised. In addition to it, purification of crude biodiesel and the ecological aspects of using CaO-based catalysts are considered. Finally, the potentials of CaO-based catalysts for heterogeneous catalysis for biodiesel production are emphasized to assess the future perspectives of their use. This review might help in selecting suitable CaO-based catalysts and the optimum reaction conditions for biodiesel production. (C) 2015 Elsevier Ltd. All rights reserved.