The Use of Untreated Waste Cooking Oil and Diesel Fuel Blends as IC Engine Fuels

In the present experimental investigation, untreated waste cooking oil (UWCO) was used as an alternative fuel for a diesel engine. The high viscosity of the UWCO was reduced by blending with ordinary diesel. The blends of varying proportions of UWCO and diesel were prepared, analyzed and compared with diesel fuel. Measurements of chemical and physical properties have indicated a good potential of using UWCO as an alternative diesel engine fuel. The results showed that blends containing 5 to 40% of UWCO in diesel yielded the properties closely matching that of diesel. The performance of the engine using blends of UWCO was evaluated in a four cylinder diesel engine and compared with the performance obtained with diesel. Significant improvement in the engine performance was observed. The results showed that the addition of 30% UWCO with diesel produced higher brake power with a reduction in exhaust emission such as CO2 and NOx. The specific fuel consumption and the exhaust temperature were increased due to decrease in viscosity of the UWCO. Acceptable thermal efficiencies of the engine were obtained with blends containing up to 30% volume of UWCO. From the properties and engine test result, it has been established that 10-30% of UWCO can be substituted for diesel without any engine modification.