Emission characteristics of a compression ignition engine using biodiesel and clove oil antioxidant blends

The growing environmental concerns associated with fossil fuel combustion have intensified the search for sustainable alternatives, particularly in the transportation sector. Biodiesel, derived from renewable biological sources, offers a promising substitute for conventional diesel due to its potential to reduce greenhouse gas and particulate emissions. However, its use in compression ignition (CI) engines presents challenges, including oxidative instability and inconsistent performance. This study investigates the impact of biodiesel blends, with and without antioxidant additives, on engine emissions in a single-cylinder CI engine. Three fuel types were evaluated: pure diesel (D100), a biodiesel blend (B30: 70 % diesel, 30 % biodiesel), and a modified blend incorporating 3 % clove oil antioxidant (D67+B30+3Cl). Emissions of particulate matter (PM), carbon monoxide (CO), carbon dioxide (CO2), and noise levels were measured under controlled operating conditions. The results reveal a 14.6 % reduction in PM emissions with B30 compared to D100, and a further 28.1 % reduction with the clove oil-enhanced blend. Additional decreases in CO, CO2, and noise emissions were also recorded, highlighting the benefits of antioxidant-enriched biodiesel in enhancing combustion efficiency. These findings underscore the potential of biodiesel-antioxidant blends to improve environmental performance while suggesting directions for future research in fuel stability and long-term engine compatibility.