Biomass to biofuel: Palm kernel shells as catalyst supports for enhanced biodiesel production

Abstract

The use of agricultural biomass fibers, specifically palm kernel shell (PKS), has significant potential to enhance biodiesel production. This approach overcomes economic barriers and contributes to sustainability by repurposing agricultural biomass. This study explores the effectiveness of PKS as a cost-effective and sustainable catalyst support. Palm kernel shell was chosen due to its high carbon content, low ash presence, and abundance as a byproduct in the palm oil industry, making it an economically viable and environmentally friendly option. In this study, an optimized activated carbon from PKS biomass was fabricated as catalyst support to enhance biodiesel production efficiency. Using response surface methodology (RSM), the PKS was impregnated with phosphoric acid and synthesized at various acid concentrations, impregnation times, and activation times to enhance porosity for catalytic support capabilities. The experimental design included a central composite design (CCD) to vary these factors systematically and determine their optimal levels. Scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET) analysis revealed significant development of porosity, affirming the efficient activation process. Energy dispersive X-ray (EDX) analysis confirmed phosphorus incorporation during activation, indicating the formation of an intricate pore structure. Fourier transform infrared (FTIR) spectroscopy highlighted the presence of functional groups pertinent to the biodiesel reaction process. The transesterification process employing PKS as a catalyst with different biobased feedstocks, such as waste frying oils from corn, palm, and sunflower, led to biodiesel yields of varying efficiencies. Notably, corn oil had the highest yield at 94.92%. This study highlights the potential of PKS as a biobased catalyst support and contributes to the broader biorefinery concept by integrating biomass utilization into renewable fuel production.