Pyrolysis of Waste Plastic into Fuel

Project Abstract / Summary : Abstract

Pyrolysis and catalytic conversion of plastic is a superior method of reusing the waste. The distillate product is an excellent fuel and makes thermo fuel one of the best, economically feasible and environmentally sensitive recycling systems in the world today.

Pyrolysis is a process of thermal degradation in the absence of oxygen. Plastic waste is continuously treated in a cylindrical chamber and the pyrolytic gases condensed in a specially designed condenser system to yield a hydrocarbon distillate comprising straight and branched chain aliphatics, cyclic aliphatics and aromatic hydrocarbons. The resulting mixture is essentially equivalent to petroleum distillate. The plastic is pyrolised at 370°C- 420°C and the pyrolysis gases are condensed through a distillation tower to produce the distillate.

Approximately 950ml of oil can be recovered from 1kg of plastics such as Polyolefin including Polyethylene (PE) and polypropylene (PP), or polystyrene (PS). Although not suitable, the process can nevertheless tolerate small quantities of plastics containing heteroatoms. Heteroatoms are atoms other than carbon and hydrogen such as chlorine, sulphur and nitrogen. Since heteroatoms are heavier than the light elements such as carbon and hydrogen these increase the density of the plastic. This can be used as a guide to which plastics are suitable for Thermo Fuel

Pyrolysis is a process of thermal degradation in the absence of oxygen. Plastic waste is continuously treated in a cylindrical chamber and the pyrolytic gases condensed in a specially designed condenser system to yield a hydrocarbon distillate comprising straight and branched chain aliphatics, cyclic aliphatics and aromatic hydrocarbons. The resulting mixture is essentially equivalent to petroleum distillate. The plastic is pyrolised at 370ºC- 420ºC and the pyrolysis gases are condensed through a distillation tower to produce the distillate.

The essential step in the pyrolysis of plastics involves:
1. Purging oxygen from pyrolysis chamber.
2. Evenly heating the plastic to a narrow temperature range without excessive temperature variations.
3. Pyrolising the plastics.
4. Catalytic conversion of the gases to specific carbon chain lengths.
5. Managing the carbonaceous char by-product before it acts as a thermal insulator and lowers the heat transfer to the plastic.
6. Careful condensation and fractionation of the pyrolysis vapours to produce fuels of excellent quality and consistency.
7. Removal of sulphurs and residual contaminants.

Why did you choose to work on this project topic : In developing countries waste plastics posing problems to the environment and human health due to the lack of environmentally sound disposal practices
These practices ignore the fact that waste plastics can represent a great potential for resource conservation as this waste can be converted into a valuable resource.

1. In this scenario, our project aims to solve the twin problem of environment pollution due to plastic and the need for an alternative fuel source.
2. The main aim of our project is to find a solution to the mountings problem of plastic disposal, for which the plastic are converted to use-able fuel.
3. This is like cashing on the pollution itself.
4. This project if implemented can turn the tides globally by providing a long term solution for these problems.

Project Category : Mechanical / Automobile / Aeronautical
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Institute/College Name: Government Engineering College, Barton Hill, Trivandrum
City: Thiruvananthapuram
State: Kerala
Participating Team From: Final Year