Effects of Pyrolysis Fuel Blend, Ethanol-Pentanol Additives, and Injection Pressure Variations on Diesel Engine Performance

Diesel engines have high thermal efficiency and produce substantial torque, making them widely used across various sectors. However, dependence on fossil fuels and increasing exhaust emissions have driven the need for the development of more environmentally friendly alternative fuels. One of the solutions being developed is the utilization of pyrolysis oil derived from plastic waste as an alternative fuel. Nevertheless, the use of pyrolysis oil still has limitations in combustion quality, thereby requiring the addition of additives. This study was conducted experimentally using a single-cylinder diesel engine operated at a constant speed of 1500 rpm under load variations of 1000, 1500, 2000, 2500 and 3000 W. The tested fuels included solar diesel fuel, a P20 blend (20% plastic waste pyrolysis oil and 80% diesel fuel), and P20 blends supplemented with ethanol and pentanol at specified proportions. The performance parameters evaluated were brake power, torque, Brake Thermal Efficiency (BTE), Specific Fuel Consumption (SFC), and smoke oppacity. The research findings showed that increasing the injection pressure from 180 to 210 bar improved engine performance and reduced emissions across all fuel blends. Diesel at 210 bar achieved the highest power (3.70 kW), torque (23.55 N·m), BTE (22.53%), and lowest SFC (0.38 kg/kWh). Among the pyrolysis oil blends, P20E10Pn10 at 210 bar demonstrated the best performance, with 3.60 kW power, 22.93 N·m torque, 21.67% BTE, and 0.39 kg/kWh SFC, while producing the lowest smoke opacity (3.50–18.67%). Thus, P20E10Pn10 at 210 bar was identified as the optimum condition, providing a favorable balance between engine performance and emission reduction.