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.

Graphical abstractVery high active solid basic catalysts for the transesterification of triglycerides (cooking oil) were obtained by impregnating MgO with KOH, NaOH and cerium nitrate.Figure optionsDownload full-size imageDownload high-quality image (224 K)Download as PowerPoint slideHighlights► The trans-esterification of cooking oil by biodiesel productions. ► The results showed yield to biodiesel after 1 h of reaction of 78 and 100% for MgO impregnated with NaOH and KOH. ► The MgO–NaOH, MgO–KOH showed the formation of strong of basic sites. ► SEM spectroscopy showed the formation of nanoneedles.