Experimental Analysis on the Performance and Emission Characteristics of Direct Injection Diesel Engine Fuelled with Chlorophyta Algae Oil Biodiesel Blends

Chlorophyta algae, also known as green algae, are rich in oils suitable for biodiesel production. They grow quickly using minimal resources and can be cultivated on non-arable land. The extracted oils can be converted into biofuels that improve engine performance and reduce emissions. This makes Chlorophyta algae a sustainable and eco-friendly alternative to fossil fuels. This study presents an experimental investigation into the performance and emission characteristics of Chlorophyta algae oil biodiesel blends (A20 and A30) compared to conventional diesel (D100) in a direct injection (DI) diesel engine. The analysis reveals a notable enhancement in brake thermal efficiency (BTE), with A20 showing a 2.5% improvement and A30 demonstrating a 1.2% increase, attributed to enhanced combustion kinetics. Furthermore, brake specific fuel consumption (SFC) decreases by 4.1% and 6.8% for A20 and A30, respectively. Emission analysis indicates significant reductions in carbon monoxide (CO) emissions 18.3% for A20 and 25.7% for A30 primarily due to more complete combustion facilitated by the oxygen-rich nature of the biodiesel blends. However, carbon dioxide (CO₂) emissions increase slightly, by 5.2% for A20 and 7.9% for A30, reflecting improved carbon oxidation. Nitrogen oxide (NOx) emissions exhibit an upward trend, rising by 10.6% for A20 and 14.4% for A30, likely due to higher combustion temperatures associated with biodiesel use. Additionally, smoke opacity shows a notable decline 21.5% for A20 and 30.8% for A30 highlighting the potential of these blends in reducing soot formation. Among the tested blends, A20 emerges as a balanced option, offering improvements in efficiency and emissions control. Meanwhile, A30 demonstrates superior performance in smoke emission reduction, albeit with some compromises in fuel economy and NOx emissions. Overall, the findings affirm the feasibility of Chlorophyta algae biodiesel as a cleaner alternative to conventional diesel, with A30 standing out as a promising candidate for practical diesel engine applications.