Reducing NOx emissions in biodiesel-powered LHR engines using an antioxidant additive: a methodological approach

Abstract

This study examined the effects of various biodiesel blends with an antioxidant additive on the performance and emissions of a 5.2 kW diesel engine, coated with lanthanum oxide to enhance its performance. The aim was to identify the optimal blend and proportion of biodiesel and antioxidant that could reduce NOx emissions while maintaining or improving engine performance. Experiments were conducted on low heat rejection and conventional engines, using different blends of AME, WCOME, and JME with different proportions of L-ascorbic acid and LA. Results showed that a 20% biodiesel blend with 200 mg of LA additive performed best in a low heat rejection engine, with a 15.8%, 10.4%, and 9.3% reduction in HC, CO, and smoke emissions, respectively, compared to diesel. The NOx emissions increased by 13.7% with biodiesel blends, but AME20 exhibited the lowest increase of only 2.1%. Additionally, AME20 showed the highest brake thermal efficiency (BTE) of 30.3% and the lowest HC, CO, and smoke emissions among all the blends. Further experiments revealed that adding LA200 mg to a 20% blend of biodiesel in a low heat rejection engine resulted in even more significant improvements.