Conversion of Waste Polypropylene Plastic into Fuel

Plastic is made from wide range of synthetic or semi-synthetic organic compounds that are malleable and so can be molded into solid objects. The yearly use of plastics in Bangladesh has grown to 12,00,000 metric tons in 2018. A part of it is recycled but Bangladesh still generates 8,00,000 tons of plastic wastes every year. Disposal of plastic is of great environmental concern now-a-days, as it seizes centuries to decompose if left at its own. Conversion of waste plastic to fuel oil mitigates both plastic pollution problem and fuel crisis. This study focuses on the thermal degradation of polypropylene plastic wastes by pyrolysis process without any catalyst to produce fuel oil. A small scale batch type set up was built to perform thermal degradation of plastic. Polypropylene plastic wastes were cleaned, shredded and pyrolysed from 300-400 degrees C for 60 minutes in this setup. The yield products were liquid fuel oil, gas and black solid plastic residue. These pyrolysed products were collected and characterized by different experimental and analytical methods. The conversion efficiency of oil achieved by the set up was 78% by mass. 73% plastic waste volume reduction was obtained by converting it into fuel oil from solid waste. Equivalent energy output calculated from measured heating value of pyrolytic oil which was obtained from 60 minutes pyrolysis was 12.8MJ/kg. Properties of the fuel oil produced such as - calorific value, viscosity, density, flash point and water content were measured and all of these properties were found to be very close to that of diesel and octane.The products obtained have potential values for further use as fuel oil, lubricating oil, diesel supplement etc which may provide solution as alternative energy resource.