Evaluating The Potential of Waste Fry Oil Biodiesel Blends for Sustainable Diesel Engine Performance and Emission Reduction

The increasing global energy demand, environmental concerns, and waste volume necessitate solutions integrating waste management with renewable energy production. One approach within the circular economy framework is converting waste cooking oil (WCO) into biodiesel. This study investigates utilizing WCO to produce biodiesel, transforming waste into an energy resource. The biodiesel was blended with diesel (B60 and B80) and tested for engine performance and emissions on a compression ignition engine. Three types of waste oils were obtained from food outlets: O1 (university cafeteria), O2 (university hostel mess), and O3 (households). The biodiesel exhibited promising characteristics, including a calorific value of 34– 36 MJ/kg and kinematic viscosity between 30– 34 mm ² /s, suitable for engine applications. The biodiesel blend demonstrated increased Brake Specific Fuel Consumption (BSFC) with higher engine speeds while reducing Brake Thermal Efficiency (BTE), likely due to biodiesel's higher viscosity (33 mm ² /s for mixed oil). Additionally, CO 2 emissions were higher for biodiesel blends compared to neat diesel, influenced by heating value and density, with biodiesel from mixed oil showing a calorific value of 37 MJ/kg and relative density of 898 kg/m ³ . The study yielded approximately 5.7– 5.9 liters of biodiesel per day from around 6 liters of waste oil, demonstrating efficient conversion. Furthermore, glycerol (450– 600 liters/day) was utilized by local cosmetic industries, supporting a circular economy. Despite challenges related to increased CO 2 emissions and fuel consumption, the study highlights that converting waste frying oil into biodiesel addresses waste disposal and contributes to sustainable energy production, supporting a circular bioeconomy.