A highly active clay-based catalyst for the synthesis of fatty acid methyl ester from waste cooking palm oil

Local clay was prepared, characterized and used as catalyst for the synthesis of fatty acid methyl esters from waste cooking palm oil. Calcined raw clay at various temperatures was investigated and showed good activity for transesterification reaction when samples were treated at 830 °C for 4 h. The effects of parameters affecting the catalytic reaction, methanol to oil ratio, catalyst loading and reaction temperature in the range of 150–170 °C were investigated at fixed reaction time of 5 h. The obtained data showed that at methanol/oil ratio of 15:1, catalyst loading of 3.5 wt% and reaction temperature of 150 °C, the FAME content from the process was 96%. The catalyst is easily prepared and handled, avoiding the use of expensive rare earth metals in biodiesel production, easily separated from the reaction medium and could be reused up to three cycles.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (93 K)Download as PowerPoint slideHighlights► Heterogeneous catalytic reaction with clay and waste cooking palm oil was applied to synthesis methyl esters. ► A thermally treated clay catalyst showed high activity to methyl esters. ► Simple preparation, characterization, and reusability of clay heterogeneous catalyst. ► Catalytic transesterification employed converted waste resources to useful product. ► The recovered catalyst was used in successive reactions with nearly stable conversions.