Abstract
An experimental investigation was conducted to study the conversion of waste plastics and single polymers into high quality oils through the pyrolysis process at elevated temperatures that haven’t been investigated before. Furthermore, the utilisation of the produced pure oils in a diesel engine for power generation was explored, which is a novelty of this research. In addition, a longevity test was carried out in the diesel engine with a high blend of pyrolysis oil to diesel in order to understand the long-term effects of the oil in the engine performance characteristics and components. In order to improve the engine’s performance and increase the operational life of the engine, different approaches (such as the injection timing modification and fuel additive addition) were studied. Another novelty of this research is the investigation of the macroscopic spray characteristics of the plastics pyrolysis oil in a constant volume vessel. The effect of the pyrolysis temperature on the produced yields and oils quality was also explored for a mixture of plastics and different pure polymers (such as styrene butadiene, polyethylene terephthalate, ethylene-vinyl acetate, polyethylene and polypropylene) separately. An important finding of this research is that the pyrolysis of polyethylene terephthalate at high temperatures results in the production of only gas and char (no liquid) and pyrolysis plant failures. Finally, the best pyrolysis oil quality and diesel engine performance were acquired from the oil that was produced from the pyrolysis of low density polyethylene, while the rest of the oils produced from the pyrolysis of ethylene-vinyl acetate and polypropylene generated acceptable diesel engine performances.