The utilization of Harmota olive oil to produce a sustainable biofuel

• Olive pomace was used as a sustainable feedstock for biodiesel production. • A 91% biodiesel yield was achieved through process optimization. • Biodiesel showed reduced emissions, supporting climate goals. • The fuel met ASTM standards, ensuring engine compatibility. Biodiesel may be considered a renewable and clean energy source that can contribute to reducing global greenhouse emissions and global warming phenomena. Biodiesel possesses several advantages over traditional petroleum diesel fuel, such as fewer greenhouse gas emissions and environmentally friendly fuel. The local olive oil factories dispose of the olive pomace, a non-edible by-product stream from the production process, with low production costs. Olive oil and pomace oil can be considered appropriate feedstock supporting biodiesel production worldwide. In this study, biodiesel was produced from a local olive oil sample sourced from Harmota olive oil in the Koya district of Iraqi Kurdistan. The produced biodiesel was also examined by several laboratory tests, such as density and cetane value, and the results were compared well with ASTM D6751 standards. The transesterification process utilized potassium hydroxide (KOH) as a catalyst, with varying methanol-to-oil molar ratios. The optimal conditions were identified as a 7:1 methanol-to-oil ratio and 0.5 grams of KOH, achieving a high biodiesel yield of approximately 91%. The resulting biodiesel demonstrated key fuel properties—density (879 kg/m³), viscosity (5.125 mm²/s), cetane number (64), and flash point (165°C)—which are all within the ASTM D6751 biodiesel standard limits. Furthermore, this study shows the intriguing possibilities of using Harmota olive oil and its by-product, olive pomace oil, as a sustainable and effective feedstock. But it goes beyond that: guaranteeing high-quality biodiesel that is both affordable and environmentally benign depends on process optimization.