Advances in the transesterification of triglycerides to biodiesel using MgO–NaOH, MgO–KOH and MgO–CeO2 as solid basic catalysts

MgO–KOH, MgO–NaOH and MgO–CeO2 solid basic catalysts were prepared by the impregnation method. The catalysts were characterized by SEM, XRD, Raman and FTIR spectroscopies and evaluated for the trans-esterification of triglycerides in biodiesel. SEM analysis of the samples showed the formation of MgO nanoneedles. On the other hand, XRD patterns and Raman spectra confirm the presence of well crystallized structures. The identification of OH bonds by FTIR, lead us to propose the formation of strong basic sites. By means of FTIR-CO2 analysis it was found that the basic strength of the samples follows the order: MgO–KOH > MgO–NaOH > MgO–CeO2. The transesterification reaction was carried out at 60 °C using cooking oil and methanol in an oil:methanol proportion of 4:1. The results showed that the yield to biodiesel after 1 h of reaction was 44, 56, 78, and 100% for MgO and MgO–CeO2, MgO–NaOH and MgO–KOH, respectively. The results suggest the opening of new promising applications for these solids as strong basic catalysts.