Performance and emission insights of IC engines powered by Tunisian vegetable‐based biodiesel–diesel blends

Abstract

Abstract

Abstract The adoption of alternative fuels is increasingly regarded as a promising strategy to mitigate emissions from internal combustion engines. However, the influence of biodiesel feedstock choice on engine behavior remains insufficiently explored and warrants further investigation. This study aims to address this gap by examining and comparing the performance and emission responses of a single‐cylinder engine fueled with biodiesel blends derived from different vegetable feedstocks. A combined experimental and numerical approach was employed to assess the impact of four vegetable feedstocks cultivated in Tunisia, which are waste cooking oil, sunflower, almond, and avocado, on engine operation across varying loads (25–75%) and speeds (800–1600 rpm). Four B20 blends were prepared, each containing 20% biodiesel from one feedstock (B20W, B20S, B20AL, and B20AV), along with a fifth blend referred to as 5B20 consisting of equal portions of the four biodiesels (20% for each feedstock) mixed with diesel. The B20AL and B20AV blends exhibited significant reductions in CO, CO 2 , NOₓ, and HC emissions under diverse engine operating conditions, although this was accompanied by a decline in engine performance compared to B20W, B20S, and 5B20 blends. The results provide valuable insights into feedstock‐dependent biodiesel performance, offering guidance for optimizing fuel selection in next‐generation engine technologies and advancing cleaner, more efficient propulsion systems.