Comparative assessment of performance, emissions and combustion characteristics of tire pyrolysis oil-diesel and biodiesel-diesel blends in a common-rail direct injection engine

Alternative fuels have gained attention in diesel engines due to the depletion of fossil fuels, climate change, economic issues, population growth, and energy demand. So, the experimental study was conducted by using the tire pyrolysis oil (TPO), biodiesel and diesel blended fuel to compare the combustion, performance, and emission characteristics in the multi-cylinder high-pressure common-rail diesel engine. The results show that the cylinder pressure and heat release rate of all the tested fuels are comparable, especially at 3500 rpm. The torque, brake power, and brake thermal efficiency of P10 is greater than the B10 and diesel fuel due to its high calorific value and oxygen share. At 3000 rpm, the P10 shows the maximum brake thermal efficiency (BTE) of 27.9%, which is 2.2% and 3.3% higher than the B10 and diesel fuel, respectively. P10 indicates the 4% and 5.64% reduction in brake specific nitrogen oxides (BSNOx) emission at 3500 rpm relative to diesel and B10 fuel, respectively. Meanwhile, the highest reduction of 20.2% in smoke opacity was found using P10 compared to diesel fuel at the engine speed of 2000 rpm. Finally, it is concluded that the P10 is suitable as an alternative fuel for multi-cylinder diesel engine without any modification and in fact most of its combustion, performance and emission characteristics are outperformed the B10 fuel.