Synergism and production of hydrocarbon-rich fuel from mixed-feedstock through co-pyrolysis of LDPE and PP: An assessment of fuel properties, engine performance, and gas emission

This investigation reports the conversion of waste plastic materials to hydrocarbon-based fuel as an alternative source of energy with a detailed study of fuel properties and CI engine performance including an analysis of gas emission. Low-density polyethylene and polypropylene have been used for the production of hydrocarbon-based pyrolysis oil or pyro-oil. The properties of pyro-oil have been determined using different ASTM methods and analytical techniques such as GC-MS, 1H and 13C NMR, FTIR, CHNS analysis, etc. The fuel properties of the pyrolysis oil were more or less similar to that of commercial diesel. The results of mass spectroscopy and NMR confirmed the presence of hydrocarbons like paraffin, aromatic, cyclic olefins, and some lower hydrocarbons. The conversion rate of post consume waste plastic material was found to be 75-81 wt% in the form of liquid, 9-18 wt% fuel gases, and 2-10 wt% as a solid residue. As per the 1H NMR results, the percentage composition in liquid fuels was 9-11 % (v/v) aromatics, 17-26 % (v/v) olefins, and 65-71 % (v/v) paraffin with a degree of branching in the range of 0.84-3.94. The engine performance has been evaluated at different blending ratios using a four-stroke diesel engine. The emission results showed that blending of PO with diesel-31.34 % of CO emission could be reduced, while CO2 emission was found to be-3.55 % lower in PO blended fuel samples as compared to commercial diesel. On the other hand, the results showed that 10 % and 20 % blending of PO can reduce the un-burnt hydrocarbon release by-50.74 % and-21.8 % as compared to commercial diesel. The experimental results of performance and combustion revealed that blending of hydrocarbon-rich fuels produced from waste plastic material can reduce the overall fuel consumption as well as enhances the engine performance.