CHENNAI : A team of students from IIT-Madras has developed a solar-powered mobile unit that converts non-recyclable plastic waste into fuel oil that is cheaper than diesel and can be used as a substitute in generators, industrial boilers, furnaces, diesel-powered engines and agricultural pumps. The technology, when scaled up into a full-fledged commercial product, can be the ideal solution for city corporations to manage plastic waste. This green technology — Plastic Pyrolysis — essentially breaks down polymer chain in plastic at 350-500 degree Celsius in the absence of oxygen to get the low density fuel oil.
The best thing about this technology is that even waste such as plastic bags, packaging material and other miscellaneous plastic stuff that are not normally picked up by ragpickers for recycling can be used as raw materials. These non-recyclable varieties are a real nightmare as they do not degrade, but clog drains, choke livestock and mar the environment. India generates about 5.6 million tonnes of plastic waste annually, of which 2.24 million tonnes remain uncollected. Chennai ranks second among all the cities with 429 tonnes of plastic waste being generated daily.
Research scholar G Divyapriya, who is part of the student team, said there are large-scale pyrolysis plants with a capacity of five tonnes per day. “There is one at Alandur, but these plants are not optimised due to low input of raw materials. Ours is a completely decentralised mechanism, where the vehicle can go to the corporation collection points once in a fortnight and process the waste. We are also working on different catalysts that can improve the yield of the fuel. One kilogram of plastic will give 0.9 litre of fuel oil. The primary objective of the plastic fuel mobile unit is waste management,” she said.
A couple of industries like Indian Oil Corporation have already shown interest in the technology.
Indumathi M Nambi, professor, Environmental and Water Resources Engineering Division, Department of Civil Engineering, IIT-M, said the mobile unit can cater to the waste management needs of big residential complexes and industries. This mode of plastic disposal can also come under CSR activity of the corporate sector.
Sriram Narasimhan, managing trustee of Samriddhi foundation and industrial mentor for the project, said the team has done a good job understanding the issues with the current largescale technology. “Finding a solution that is not bound by unavailability of raw material, catering to urban, semi-urban and rural needs is commendable. Compared to furnace oil, the plastic fuel is cheap and less polluting,” he said.
The team has won the Zero Carbon Challenge-2018 recently and looks to incubate with IIT Madras Research Park.