Experimental study on the production of diesel-like fuel from waste high density polyethylene via non-catalytic pyrolysis

Plastics have become an indispensable part of our daily life. Due to its non biodegradable nature it cannot be easily disposed off. Pyrolysis is a tertiary recycling method which can convert plastics into valuable petroleum resources. In this work, pyrolysis of waste high density polyethylene (HDPE) plastic was carried out in a fixed bed reactor heated for a final temperature of 500°C under a heating rate of 10°C/min. Direct pyrolysis led to wax production while a two step pyrolysis (setup 1) led to the production of 32.7% liquid and 65.3% gas. Thus a setup with reflux (setup 2) was designed and the liquid yield increased to 78.2%. The liquid fractions obtained were analyzed for composition using a gas chromatograph coupled to a Mass spectrometer and a flame ionization detector (GC-MS-FID). Specific diesel-like fuel production, as reported to HDPE mass, with setup 2 was estimated to be 2.3 times higher than setup 1 The physical properties of the pyrolytic oil (viscosity, density) were found to be lower than that of diesel fuel due to the presence of light compounds.