► The industrial eggshell wastes as heterogeneous biodiesel production catalysts. ► Microwave-assisted biodiesel production. ► The strong base site with average basic site density of 194 μmol m−2. ► Above 96%FAME can be produced within 10 min in microwave process catalyzed by the eggshell-derived catalysts. ► The catalyst is reusable for at least 5 cycles.