The Mechanical Engineering Department of Annamalai University has evolved a technique to convert waste plastics into petroleum products.
It has already set up a unit on the university campus that can produce 50 litres of the petroleum products in two hours.
“It is a clean and cost-effective technology that can effectively address the problem of disposal of mounting plastic waste,” said C.G. Saravanan, professor, Mechanical Engineering Department.
The project has been funded to the tune of Rs. 55 lakh by the Union Ministry of Environment and Forests, and has come to fruition after three years’ endeavour. It is an interdisciplinary achievement as M. Gopalkrishnan, professor, Department of Chemistry, has provided the critical input to crack the raw materials - plastic pellets.
Mr. Saravanan told The Hindu that plastic pellets were being obtained from discarded plastic materials such as milk and water sachets, pet bottles, containers of carbonated drinks, plastic chairs, etc.
With the help of heavy capacity crusher, the plastic articles are shredded into pellets and fed into the melter whose temperature could be controlled through a panel. Mr. Saravanan further said that in breaking the pellets, fly ash was being used as a catalyst.
Flyash obtained from the Neyveli Lignite Corporation had been found ideal as it had all the required properties such as silica – 60 per cent, alumina – 13 per cent and iron – 15 per cent.
However, for the inert flyash to act as a catalyst it ought to be initially activated and the formula for the same had been kept a closely-guarded secret. Mr. Saravanan further said that with the catalyst it would take two hours to get 50 litres of fuel and without catalyst, 9 hours .
Temperature variance would determine the kind of output. For instance, petrol could be obtained at 100 degree Celsius and diesel, 150 degree Celsius. Gas would be a by-product that could be utilised for cooking purposes.
Mr. Saravanan also said that the fuel obtained from the unit was being used for running generator sets in the engineering faculty. He also demonstrated the use of the fuel in a motorcycle.
As the fuel thus obtained had low sulphur content, high cetane number and high calorific value, it would help in smooth functioning of engines. Production cost of diesel worked out to Rs. 25 a litre and that of petrol, Rs. 30 a litre. He said that the unit does not emit harmful gases or any odour.
Mr. Gopalakrishnan said that examination of residue from the unit was found to be free from any harmful effect, and even the small quantity of left-over substance could be profitably re-cycled.
University Administrator Shiv Das Meena suggested that patent could be obtained for the fuel unit and efforts should be made to disseminate knowledge about the technology.
Director (Clean energy) of Union Ministry of Environment and Forests M. Salahuddin congratulated the professors and their teams.
