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Let’s talk plastic

TV Jayan | Updated on November 01, 2019 Published on November 01, 2019

Drowning in plastic: The world has produced 8.3 billion tonnes of the synthetic material since the 1950s   -  ISTOCK.COM

The bad news first: There is too much plastic in the world. The good news is that scientists, both in India and abroad, are working on giving us ecofriendly alternatives

In all likelihood, Sarthak Gupta will get it right. And if — and when — he does so, it will mark a new beginning. Not just for the outfit that he founded a year ago with his friend Mohammed Shahid Jamal, but for the country — and people at large.

A mechanical engineer by training, Gupta (27) dreams of chipping away at a serious environmental problem that stares India and the rest of the world in the face: The ever-growing burden of plastic waste.

In August 2018, Gupta, who briefly worked with the Indian IT giant Infosys as an analyst, and Jamal, a nanotechnologist, incubated a startup — InvoViron Industries — supported by the Startup Incubation and Innovation Centre at the Indian Institute of Technology (IIT) Kanpur. The engineers, both from the industrial city of Kanpur, funded their venture partly with the money given by their parents and their own meagre savings.

Their plan is an ambitious one, no doubt. They want to tap a new source for producing a kind of plastic that, unlike the usual fossil fuel-derived variants, would degrade in soil in no time. In comparison, synthetic plastics, which are currently used in making a wide range of products from carry bags and straws to the insides of an aircraft or an automobile, take hundreds of years before they begin to disintegrate.

According to the United Nations, the world has produced 8.3 billion tonnes of plastic since the 1950s. Of this, only 9 per cent of plastic waste was recycled, while another 12 per cent was incinerated. The rest — around 80 per cent — has accumulated in landfills, dumps or the natural environment. Burning plastics is not a safe way to get rid of it as it leads to the production of environmentally harmful toxins that can increase the risk of heart diseases, aggravate respiratory ailments, damage organs such as kidney and liver and even affect the reproductive and development system in young people.

What, then, is the way out? As mounds of plastic build up after Diwali — think of all those coloured wrappings — the time has come to seriously look at alternatives. Even now, despite increasing awareness, the total production of plastics is about 350 million tonnes in a year in the world, which is more or less equal to the weight of the entire human population. According to PlastIndia Foundation, an industry conglomeration of associations and institutions that deal in plastic, the use of plastics in India in 2019-20 is expected to be around 20 million tonnes and the market is growing at a rate of 9 per cent per annum.

Plastic, it must be said, is one of the most versatile materials ever known to humankind. It is there in almost every item that people use in their daily lives — from cell phones and television sets to cars and computers, from toys to shampoo bottles. But its production and use have precipitated a huge problem.

Tall order: A file image of a giant bottle made with plastic waste in central Delhi - Shanker Chakravarty   -  The Hindu

 

First, most plastics that we know today are produced from petroleum and they have a huge carbon footprint. According to a study by researchers from the University of California Santa Barbara published in April this year, plastic led to 1.8 billion tonnes of carbon dioxide emissions in 2015. It is said that if the world uses 1 tonne less plastic, the savings would be humongous: 5,774 units of electricity, 3,114 litres of oil and over 3,000 litres of water.

There is more to it. Apart from contributing to the mounting climate change crisis — floods, heatwaves, severe cold spells, melting glaciers et al — there are other serious issues around the disposal of plastics. On an average, we use a plastic carry bag for 12 minutes before it is disposed of, but it can take nearly 500 years to break down in the environment. While it is still there, it chokes to death not just animals on land, but also puts the more vulnerable marine organisms at peril.

While a foamed plastic takes 50 years to degrade, 200 years would be gone by before plastic straws and nappies disintegrate. Plastic bottles, on other hand, can take 450 years and a fishing line almost 600 years!

Looking for solutions

There is, of course, an increasing realisation that the problem of plastic pollution needs to be tackled before it wears the entire planet down. It is also clear that the problem being multi-pronged, multiple solutions need to be found to address it.

That is why the IIT Kanpur-incubated InvoViron’s efforts are important. The feedstock that Gupta and Jamal have zeroed in on is not fossil fuel, but a waste material that is abundantly available. Besides, the kind of plastic that they are making will break down in the soil. “The plastic that we are making can start degrading within a week,” says Gupta.

He is not ready to disclose the nature of the feedstock used by the outfit as the founders have not applied for intellectual property yet. But he reveals that it is a sort of protein waste, a substantial part of which currently lands up in landfills. According to the latest estimate, India alone produces 350 million tonnes of this waste — significantly as much as the plastic production of the entire world.

“I can assure you that it is so vastly available in the country that it can take care of most of our need for plastics,” states a confident Gupta. At InvoViron, they have already made plastic sheets which are 3-mm thick using this and have shown that they can be moulded into different products. Their plan is to initially set up a plant of 10,000 tonnes capacity at a place where feedstock is abundantly available.

“We are already in talks with investors,” he says.

About 1,500 km away from Kanpur, Vimal Katiyar, a professor of chemical engineering at IIT Guhawati, is toying with multiple ideas to deal with the plastic problem. One of them is turning agro-waste material abundantly available in the country into biodegradable plastic.

“The problem with conventional plastics is that the polymers have extremely strong carbon-carbon (chemically speaking, one carbon atom sticking together with another carbon through a chemical bonding) chemical bonds, which most microbes find difficult to break. As a result, these tiny organisms cannot use them as food,” says Katiyar, who heads the Centre of Excellence for Sustainable Polymers at IIT Guhawati.

Plastics are basically made up of a long chain of molecules (polymers) containing repeated units of carbon atoms. The chemical bonds that hold these molecules together are so strong that Nature does not have the power to take them apart. While there are numerous types of plastic materials, the most commonly used ones are polyethylene (PE), polypropylene (PP), PET, polyvinyl chloride (PVC) and polystyrene (PS).

Artificial cover: Polystyrene is used in packaging material and F&B containers   -  Reuters

 

The trouble, however, is they cannot be recycled together. Besides, world over there are no mandatory declaration laws for plastics and the additives they contain, and producers keep the composition of materials secret, making it difficult for consumers to tell harmful products from harmless ones.

For instance, in 2016-17, India produced 4.76 million tonnes of PE, 4.97 million tonnes of PP, 2.07 million tonnes of PET, 1.44 million tonnes of PVC and 0.6 million tonnes of PS.

“All these synthetic plastic materials take a very long time to degrade,” Katiyar says.

Scientists sought to see if polymers being broken down to monomers would be a solution. It wasn’t. In fact, after the researchers found a way to break many of these polymers by introducing a salt of iron or manganese, they found that the process led to further complications. When these polymers were broken down to monomers, the number of tiny monomers in the soil increased several fold, adding to the menace of microplastics. They are so tiny that they can be airborne or be present in water, triggering health complications. Scientists studying Arctic ice recently found that a good part of ice floes found there contain higher concentration of microplastics than elsewhere.

“Some time ago, scientists also realised that polymer materials that can have aliphatic carbon bonds rather than stronger aromatic bonds could be a better alternative. Carbon atoms typically form two types of compounds in nature — aliphatic and aromatic. While aromatic carbon bonds are difficult to crack, aliphatic bonds are more amenable to microorganisms,” observes Katiyar.

Food or plastic

Polylactic acid (PLA) is one such plastic alternative. Usually made from the fermented starch of grains such as corn, PLA is a bioplastic that can be easily digested by microbes, making their degradation easy.

“But substituting plastic with PLA poses a moral question — should grains be used for feeding people who go hungry or for making plastics,” asks Anjanikumar Jyotiprasad Varma, former dean of school of chemical sciences at the Central University of Haryana (CUH) at Mahendragarh.

Still, the production of PLA is going up in the world. Natureworks, a US firm, is already producing 140,000 tonnes of PLA per year and it plans to soon ramp up its production to 200,000 tonnes per annum, Katiyar says.

According to Varma, the fact that better feedstock is not available is not the only difficulty in finding alternatives to different plastic materials. “The kind of research that has gone into developing additives — substances that are mixed with various plastic forms to bring about desired properties — in the last 70 years is voluminous. Scientists may have to double this work if new kinds of materials have to come into being,” Varma remarks.

Varma would know. He was heading the polymer chemistry division of the Pune-based National Chemical Laboratory (NCL), one of the flagship research institutes of the Council of Scientific and Industrial Research (CSIR), before he joined CUH. His team at NCL has developed a process to produce plastic alternative materials from sugarcane bagasse, a waste material of sugar mills. The technology, developed almost a decade ago, was awarded the CSIR Technology Prize several years ago.

Even for Katiyar, agricultural waste is a promising raw material when it comes to developing biodegradable plastic. His Centre of Excellence at IIT Guhawati recently received funding of ₹4 crore from the State-owned Numaligarh Refinery for using bamboo waste products, abundantly available in Assam, among other things for making bioplastics.

“It is time that we made handsome investments in technologies for finding alternatives to plastics. Many big corporations in the world such as Mitsubishi and BASF are finding new materials for plastics. We have the capabilities to carry out such research indigenously,” Katiyar says.

It is not that the scientific community is unperturbed by the environmental problems posed by plastic. A large number of scientific groups around the world are trying out diverse strategies to deal with the menace. Scientists working for industrial firms have already found a way to use bacteria to synthesise certain polymers such as poly hydroxybuterate, which are biodegradable and used for medical applications widely. While some groups are trying to develop greener versions of plastics, others are working to find better ways to recycle them. There are also others who are trying to identify — or even genetically engineer — microbes that can break down different plastics. Significantly, a research team led by Richa Priyadarshini of the Department of Life Sciences at Shiv Nadar University, on the outskirts of Delhi, stumbled upon two bacterial strains that have the potential to decompose ‘polystyrene’ — a key component in single-use plastic (SUP) items such as disposable cups, cutlery, toys, packaging materials and so on. The team discovered them while mapping microbial biodiversity of a wetland on the campus.

Katiyar’s centre is a member of a global alliance of research institutions that work on sustainable plastics. Formed by researchers from 12 countries including the US and Japan, the Association for Sustainable Polymers allows member research groups to have access to novel processes being developed by other groups of the alliance.

According to the scientists, the price of alternative materials will come down only when there is an economy of scale. PLA, for instance, currently costs around $2 a kg, but it is still twice the price of commonly used plastic. But, if you take into account the environmental cost of conventional plastics, many alternative polymers are already cost-competitive or on the way to becoming cost-competitive, Katiyar points out.

Gupta, for instance, is confident that they would be able to sell their plastic ingots for $2.5 a kg once they set up the plant. A similar material, if imported, can cost around $4 a kg, he says.

Chandra Mohan, a Delhi-based environmentalist, says it is important to know plastics has a big role in modern-day living. “It is next to impossible to replace all plastics that are used currently and, in many cases, the environmental impact of such replacement can be huge. For example, PVC pipes used for applications like plumbing and water supply. If they were to be replaced with steel, aluminium or copper, the mining would have to be increased to completely unsustainable levels,” he says.

According to him, India needs a four-pronged strategy to deal with the existing problem of plastics. First, identify those single use plastic products that can be done away with mostly, if not completely, such as carry bags, disposable cutlery and straws. Second, identify those that can be brought under a buyback scheme. PET bottles, milk pouches and used food packaging materials and plastic bottles used for toiletries fall under this. In the case of such plastic products that cannot be recovered directly from customers, such as shampoo sachets or multi-layered plastics for packing snacks, producers making these products should work closely with local authorities to ensure their recovery from the environment and recycle accordingly. Fourth, exempt those plastic products having longer service life or those whose replacement itself will add to environmental issues.

While a solution to the problem of plastic is still far away, many governments around the world have been successful in creating awareness about the problem. It is a beginning. And one that seeks to counter the end.

Know your plastic
  • Polyethylene (PE)

PE is the most widely produced plastic, and comes in a number of different forms, including high-density polyethylene (HDPE) and low-density polyethylene (LDPE). It is used in carry bags, bottles, films, pipes and toys.

Carry over: The ubiquitous grocery bag is made with polyethylene - M Periasamy   -  The Hindu

 

  • Polypropylene (PP)

PP is particularly resistant to heat, physical damage and corrosion. It is commonly used in food containers, carpets and rugs, ropes, furniture and pipes. It is also used to make items of medical and laboratory use.

  • Polyethylene terephthalate (PET)

PET is a lightweight polymer and comes in forms of varying rigidity. It is commonly used for making drink bottles and also for making clothing fibres (polyester). It is also used in ready-to-eat meal packaging and tapes.

  • Polyvinyl chloride (PVC)

PVC comes in both rigid and flexible forms. In its rigid form, it can be used for making window and door frames, pipes and bank cards. By adding certain additives, a more flexible form of PVC can be obtained, which is used in electric cable insulation and as a substitute for rubber.

  • Polystyrene (PS)

In its solid form, it is used to make plastic cutlery, CD cases and disposable razors. As foam, it is also used in packaging materials, building insulation and containers for food and beverages.

Published on November 01, 2019
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