CaO supported on mesoporous silicas as basic catalysts for transesterification reactions

A new group of basic catalysts supported on mesoporous solids has been prepared with the aim of being used as heterogeneous catalysis in biodiesel production. These catalysts based on calcium oxide supported on porous silica (SBA-15, MCM-41 and fumed silica) have been characterized and evaluated in transesterification processes. They were characterized by DRX, XPS, SEM, FT-IR, CO2-TPD and N2 adsorption. The catalytic activity was evaluated in the transesterification of ethyl butyrate with methanol, and different reaction parameters were optimized by a factorial design response surface methodology. Thus, a sample containing 14 wt.% of CaO supported on SBA-15 was the most active, and, unlike commercial CaO, no lixiviation of the active phase was detected in the reaction medium. The transesterification activity of vegetable oils confirms the results obtained in the reaction of ethyl butyrate with methanol, reaching conversion as high as 95% with sunflower oil (after 5 h of reaction) and 65% (after 1 h) for castor oil.

Graphical abstractCaO supported on mesoporous SBA-15 silicas were prepared and characterized. The transesterification activity of vegetable oils confirms the results obtained with ethyl butyrate and methanol, reaching conversion as high as 95% with sunflower oil (5 h) and 65% (1 h) for castor oil. Moreover, unlike commercial CaO, no lixiviation of the active phase was detected.Figure optionsDownload full-size imageDownload as PowerPoint slide