When calcium oxide is employed for transesterification of vegetable oil at reflux of methanol calcium oxide is turned into calcium glyceroxide by combining with glycerol of the by-product As well as calcium oxide calcium glyceroxide seemed to catalyze the vegetable oil transesterification In the present paper the solid base catalysis of calcium glyceroxide was investigated by IR spectroscopy using methanol as the molecular probe The measured spectra indicated that calcium glyceroxide was, combined with methanol at the temperature of 333 K Chemical composition of the produced calcium compound was estimated at CH3O-Ca-O(OH)(2)C3H5 The IR spectrum of the calcium alkoxide indicated that hydrogen bond was formed among the glyceroxyl OH groups and methanol Data from the soybean oil transesterification which was carried out at 298 K elucidated that the calcium alkoxide functioned as the solid base catalyst At the same reaction temperature calcium glyceroxide did riot interact chemically with methanol and sent out only the homogeneous catalysis (C) 2010 Elsevier B V All rights reserved