Production of Glycerol-Free Biodiesel Using Pollen-Derived CaO Heterogeneous Catalyst

Rape pollen with fishnet-like network structure has been used as support in the construction of high dispersion CaO materials assigned to CaO(P) (“P” was symbol of the precipitation method). Effect of various preparation conditions such as calcination temperature was evaluated following the performance for no-glycerol biodiesel preparation. The relatively well activity was observed by yielding to no-glycerol biodiesel of 92.69% in the rapeseed 1/1/8 mixture of oil–methyl acetate–methanol at 65 °C for 3 h over 10 wt% of 1/1-CaO(P)-700 which is better than 80% over commercial CaO. In addition, the catalytic performance of reused catalyst was also investigated. TGA–DSC and BET studies showed that the catalyst has good thermal stability and high surface area with hierarchical microstructures with large and mesopores on the surface, respectively. Furthermore, hierarchical basicity has been also established which provided various active sites for the heterogeneous reaction.