Bio-based solutions for diesel engines: Investigating the effects of propolis additive and ethanol on performance and emissions

Abstract

This study aimed to investigate the impact of the addition of ethanol and propolis into diesel fuel on the performance of a single-cylinder diesel engine, as well as the resulting exhaust emissions. To determine this, experiments were carried out with various fuel blends, including 100 % diesel, 95 % diesel blended with 5 % ethanol, 90 % diesel blended with 10 % ethanol, 95 % diesel blended with 5 % ethanol and propolis, and 90 % diesel blended with 10 % ethanol and propolis. The constituents of the propolis extract were analyzed with the gas chromatography-mass spectrometry technique. The experiments were carried out at a speed of 3000 RPM under various engine load situations, including unloaded and load conditions of 1.6, 3.2, 4.8, 6.4, 7.9, 9.5, and 11.1 N-meters. During the experimental trials, various parameters were measured, including the exhaust gas temperature, fuel line pressure, fuel consumption, exhaust emission, and in-cylinder pressure. Based on the collected data, the following parameters were evaluated: heat release rate; in-cylinder pressure; maximum pressure rise rate; cumulative heat release; exhaust gas temperature; brake-specific fuel consumption; thermal efficiency; and O2, CO, CO2, HC, NOx, and PM emissions. Overall, the inclusion of propolis in diesel fuel was observed to decrease various key parameters, namely, the maximum pressure rise rate, cumulative heat release, thermal efficiency, heat release rate, and maximum in-cylinder pressure. Carbon monoxide, hydrocarbon, and particulate matter emissions decreased, but carbon dioxide emissions underwent an increase. The addition of propolis resulted in an increase in brake-specific fuel consumption.