Effects of hydrogen and Ce2O3 nanoparticles in a diesel engine fueled with pyrolysis plastic oil

The current study examines the combination of pyrolysis oil, Ce2O3 nanoparticles, and hydrogen as a secondary fuel in conventional unmodified single cylinder direct ignition diesel engine. The main objective is to assess the performance, combustion, and emissions characteristics of a diesel engine fueled with pyrolysis oil. Hydrogen gas is injected into the diesel engine via the intake manifold at a constant rate of 30 L per minute throughout the study. The research also investigates the engine behavior when injected with different fractions of pyrolysis oil (10 % and 30 %) by continuously monitoring engine noise and vibration data. Use of pyrolysis oil reduces the thermal efficiency due to the presence of alkane and alkene compounds. To address this, nanoparticles was dispersed into the blends using ultrasonication at a frequency of 35 kHz. The inclusion of nanoparticles, along with hydrogen, enhances the oxygen concentration in the blends, promoting complete combustion. Additionally, the addition of Ce2O3 nanoparticles increases the latent heat of vaporization of the pyrolysis-based fuel blends, thereby slowing the evaporation process and reducing the overall combustion rate. The chemical structure of pyrolysis oil, characterized by double bonds, results in higher heat release rates and in-cylinder pressure compared to neat diesel irrespective of engine brake power. In terms of emissions, there is no evidence of a decrease in NOx, but a significant reduction in CO and HC emissions was noted due to presence of Ce2O3.