NIT Calicut claims to have a solution to our plastic problems
Can we, who invented plastic, learn to break down this necessary evil into useful, biodegradable bits? As plastic waste becomes a vexing problem, it is an idea worth pursuing.
Three months ago, the Kozhikode City Corporation started a plastic recycling unit on the West Hill Industrial Estate with a recycling capacity of 800-1,000 kg of plastic waste a day. But the garbage menace still persists. The contractors insist that the plastic waste they get should be cleaned for processing. But people continue the same old method of dumping soiled carry bags and other plastic debris together. The Kudumbasree volunteers who are engaged in door-to-door collection refuse to collect plastic waste. Some residents’ associations manage to do so once in three months.
However, there is hope. Research at the National Institute of Technology, Calicut, (NIT-C) says that plastics can indeed be broken down to release useful energy.
Lisa Sreejith, Associate Professor, Department of Chemistry of the institute, along with N. Sitaraman, has developed a technology to convert plastic into cooking gas without any segregation and sorting. Trials showed that no poisonous gases were released into the atmosphere. If properly managed, this technology can start a profitable, eco-friendly solution for energy production from plastic waste.
She says that only polythene carry bags are processed at the plant in Kozhikode. The plant is not getting plastics due to the attitude of the people. Not that plastics can be recycled. The rejects include PVC, nicknamed plastic poison, and charring plastics such as toffee wrappers and biscuit packs.
The trials have been successful in disintegration of all kind of cleaned and dry plastic, which include bottles, polyethylene carry bags, polystyrene (known as Thermocol), toffee and biscuit wrappers, PVC, melamine, rexine, toys, ropes, flex sheets and Bakelite, she adds.
However, a centralised processing mechanism is required for starting such a plant. For a 50-year plant for the Kozhikode Corporation, a sum of Rs 2.5 crore is needed as initial cost. This is for the space and machinery. “From the experiment, we derive that cooking gas equivalent to 3.4 cylinders can be obtained from a tonne of clean plastic,” she says.
Plastics in general are non-biodegradable and will remain for thousands of years. Only about five per cent of the plastics produced are recycled. While 10 per cent of it makes it to the ocean, about 50 per cent ends up in landfills. This is dangerous for the environment, Dr. Sreejith says.
Plastics form a major portion of the physical composition of solid waste in cities. Plastic waste makes up for over 15 per cent of the total garbage. The other types of solid waste found in cities are organic, paper, metal, rubber, sand, textile and glass.
Most towns and villages have no proper management and safe disposal systems for solid waste. Thus residents collect the waste in plastic carry bags and litter at public areas.
Most cities in the country are grappling with the problem of safe disposal of garbage, while developed countries have adopted recycling and composting. Now civic bodies are mooting steps to adopt technologies.