Three component mixtures of canola oil, dimethyl carbonate, and methanol, catalyzed by suspended calcium oxide (CaO) particles, produced a biodiesel that required little further processing. Only the catalyst particles needed to be recovered and reused. Substrates for the CaO were laboratory-grade acetate, hydroxide, oxalate, and carbonate compounds of calcium heated to temperatures >= 850 degrees C at which calcination is complete. The catalyst substrate and conversion process determined the effectiveness of the catalyst for high product yields. CaO derived from calcium carbonate exhibited morphological characteristics that included larger contact surface areas, and thus more reactive sites, compared to the other precursors. Moreover, with only 0.17 mu g/g (0.017 %) free glycerol present in the produced biodiesel, the biodiesel can be used directly without further treatment.