Optimization of biodiesel production from coconut testa

Biodiesel is a renewable fuel in global demand to replace fossil fuels. To meet rising biodiesel demand, the production process must use a variety of biomass. Coconut testa is a significant source of biomass waste globally. Coconut testa's high lipid content makes it a good biodiesel source material. Thus, using transesterification to make biodiesel from coconut testa may improve production efficiency. This study aims to determine the most effective solvent for extracting oil from coconut testa based on the percentage of oil yield. This study utilises two solvents, hexane and ethanol, for the extraction of oil from coconut testa. Hexane is the most effective solvent, resulting in an oil yield of 71.4%. Subsequently, the extracted oil will be utilised for the manufacturing of biodiesel by a transesterification reaction. The composition of extracted oil is evaluated to determine the concentration of free fatty acids (FFA) present. The presence of high amounts of free fatty acids is a desirable trait in biomass to produce biodiesel. The acid value of the oil recovered from coconut testa was found to be below 0.8 mg KOH/g, which is in complying with the American Society for Testing and Materials (ASTM) requirement for acid value. The FFA percentage can be represented in relation to the proportions of palmitic acid, lauric acid, and oleic acid, which account for 28%, 22%, and 31% respectively. The process optimisation of oil extracted from coconut testa for biodiesel synthesis indicates that a temperature of 40.00 ⁰C and a 0.975 g alkaline catalyst have resulted in a 23.40% oil yield. This study demonstrates that coconut testa, a plentiful biomass resource in Malaysia, has the potential to be utilised for the production of important products such as biodiesel. • The result revealed high oil yield (71.4%) was produced by using Hexane as a solvent • Acid value below 0.8 mg KOH/g complying American Society for Testing and Materials (ASTM) requirement • The optimal conditions for biodiesel production were found to be a reaction temperature of 40.00°C and catalyst loading of 0.975 g, resulting in a biodiesel yield of 23.40% • The free fatty acids (FFA) consisted of 31% oleic acid, 28% palmitic acid, and 22% lauric acid, indicating a good quality for biodiesel production • Response Surface Methodology (RSM) was used to optimize the biodiesel production process, confirming that catalyst loading had a significant effect on yield, while reaction temperature did not significantly impact the results.