Conversion of Au(III)-polluted waste eggshell into functional CaO/Au nanocatalyst for biodiesel production

Developing an environmental-friendly and highly active catalyst in transesterification for biodiesel production is of great importance for a more economic biodisel process. Herein, we reported that waste eggshells were used to adsorb Au(III) in water and convert the Au(III)-polluted eggshells into the functional nanocatalyst-CaO/Au for the transesterification reaction between soybean oil and methanol to the preparation of biodiesel. By coupling of CaO and Au nanoparticles, CaO/Au nanoparticles showed superior catalytic activity for the transesterification reaction between soybean oil and methanol. An optimum performance was observed over CaO/Au nanocomposites in a methanol-oil molar ratio at 12 : 1 with catalyst content of 1.0 wt% at 70 degrees C for 3 h. Besides, the catalytic activity of CaO/Au nanocatalyst was almost unchanged after recycling for 5 times and the yield of biodiesel still kept at 88.9%. The proof-of concept study provided us a sustainable method for utilization of waste eggshells to remedy the metal ions-polluted wastewater and the synthesis of functional nanocomposite for biodiesel production, show great potential application of waste eggshell in adsorption and catalytic reactions. (c) 2020 Institute of Process Engineering, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

The use of waste eggshells to develop CaO/Au nanocatalyst for transesterification reaction between soybean oil and methanol showed superior catalytic activity and good recyclability.