Research at NIT-C shows that plastic can be broken down to release cooking gas, writes BIJU GOVIND.

Can the human ingenuity that invented plastic work to break down this necessary evil, indispensable to modern man, into useful, biodegradable bits? As plastic waste becomes a vexing problem across the State, it is an ideal worth pursuing.

Cities, towns and villages in the State generate a massive amount of plastic waste, a menace that has reached gargantuan proportions. Studies reveal that an urban resident generates 350 grams to 1,000 grams of solid waste a day. Plastics form a significant share of this refuse. Recycling is one way to reduce the burden.

Three months ago, the Kozhikode City Corporation started a plastic recycling unit on the West Hill Industrial Estate. The plant has a recycling capacity of 800-1,000 kilograms of plastic waste a day. But the garbage menace persists in the city.

The contractors of the plant insist that the plastic waste they get should be clean for processing. But people continue the same old method of dumping soiled carry bags and other plastic debris together.

Besides, the Kudumbasree volunteers engaged in door-to-door collection refuse to collect plastic waste from households. Some residents’ associations manage to do so once in three months.

In the same city, research at the National Institute of Technology, Calicut, (NIT-C) offers hope that plastics can indeed be broken down to release useful energy. Lisa Sreejith, Associate Professor, Department of Chemistry of the institute, has developed a technology to convert plastic into cooking gas.

The technology she developed along with N. Sitaraman, also of the Chemistry Department, of converting plastics into cooking gas is done completely without any segregation and sorting. Trials carried out showed that no poisonous gases are released into the atmosphere. If properly managed, the technology can give rise to a profitable, eco-friendly solution for energy production from assorted plastic waste.

She says that only polythene carry bags are processed at the recycling plant in Kozhikode.

The plant is not getting plastics due to the non-responsive attitude of the people. Not plastics can be recycled. The rejects include PVC, nicknamed plastic poison, and charring plastics such as toffee wrappers and biscuit packs.

Dr. Sreejith says the trials of her technology 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.

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. “It is calculated based on the experimental results that cooking gas equivalent to 3.4 cylinders can be obtained from a tonne of clean plastic,” she says.

Not biodegradable

Plastics in general are non-biodegradable and will remain as such for many thousand 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.

In 1994, a study commissioned by the Kerala Urban Development Project found out that the per capita solid-waste generation in the Kozhikode Corporation limits stood at 203 grams a day. The population then was 4.19 lakh.

It is estimated that the figure would have doubled now, considering the consumption pattern of higher standards of living. Consequently, the use of plastics in everyday life has increased. Now the population of the city is over 6.5 lakh after the merger of the grama panchayats of Beypore, Cheruvannur-Nallalam and Beypore with the Corporation.

Plastics form a major portion of the physical composition of solid waste in cities. Plastic waste make up 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.

People are forced to come out to the streets in protest against the garbage menace, though the State government and the civic bodies are making efforts to solve the problem.

Trials have been successful in disintegration of all kind of cleaned and dry plastic.


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  • A gas plant requires Rs. 2.5 crore of funds initially



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  • It requires a centralised processing mechanism