In the presence of acetone as the co-solvent, eggshell-derived catalyst was used as a heterogeneous catalyst for biodiesel production. The fatty acid methyl ester yield of 93% was obtained from jatropha oil at 1: 1 (acetone/oil) weight ratio, 9: 1 (methanol/oil) molar ratio, 7 wt% catalyst, and 2 h reaction time at 65 degrees C. Compared with the reaction without co-solvent, the reaction time was greatly reduced by co-solvent technology. Furthermore, the presence of acetone had a positive effect on the separation of fatty acid methyl ester from glycerin. Excessive amounts of methanol and acetone could be recovered by heating under negative pressure, and used for the next experiment.