Rudra Environmental Solution’s Plant
The technology of converting plastic back into its base of crude oil has been developing over the years. Here’s a look at its various forms being implemented across the country.
It was on a trip to a wildlife sanctuary that they first noticed how ubiquitous plastic had become, having made its way into a region where it was supposedly banned. “We were appalled and thought someone must do something. We usually think it is someone else’s problem, especially when it comes to garbage,” recalls Pune-based Medha Tadpatrikar, the co-founder-executive director of Rudra Environmental Solutions, which is collaborating with the Maharashtra Government to help eliminate its plastic waste.
Medha employs the Thermo Catalytic Depolymerisation process in a patented, custom-designed plant, to convert plastic into high-grade fuel, called polyfuel. “I have a Ph.D in management and my husband has a background in finance. We had no idea how to build a larger machine, but we managed to build one, modelled on the pressure cooker.”
They failed to account for the resultant gases the first time, so they scrapped the model and built another that could incorporate the gases from the exhaust to fuel the heating process. These largely comprise methane, propane, butane and the like, and trace amounts of sulphur oxide (SOX) and nitrogen oxide (NOX). It took them three years to do it. This time they were able to build a plant, and they began collecting waste.
Most of the fuel generated is used in industrial equipment such as generators, furnaces, burners, and boilers. “We are also connected to over 60 villages, who often burn wood or plastic to heat water for bathing. The fuel works as a cost-effective, less-polluting alternative to kerosene. Polyfuel is cheaper, at ₹36-38 per litre, and has a higher Calorific Value, which means more heat is generated and it lasts longer. We also work with residential societies, schools, and offices to create awareness about plastic and the importance of source segregation.”
Medha points out that nothing goes to waste. “We can generate anywhere between 50 and 70 litres of fuel from 100 kg of plastic. Nearly 22% of the residue comprises gases, which are used to fuel the plant. The remaining residue of 5% can be used to create tar roads, to make them more durable.” The plant can recycle almost every kind of plastic (except PVC), from biscuit wrappers to multi-layered packaging, and toothpaste containers. At the moment, however, she says it is not possible to meet the demands of vehicular fuel through this technology. “The demand for such fuel is very high because industries require large amounts of fuel.” They are currently running the third generation plant, and operate two plants based in Pune, with a workforce of seven. “The only kind of plastic we can’t recycle in the present set-up is PVC, since it releases chlorine, which is an unstable gas. Recycling PVC would involve setting up a more controlled environment. However, there isn’t much PVC in our waste.
The potential for this technology, she says, is enormous. “If you look at the numbers, in the last few decades, the world has generated over eight billion metric tonnes of plastic, almost 80 to 90% of which is in the oceans, rivers or landfills. Only 9% of the world’s plastic is recycled, even as the price of petrol is rising. This could be the next fuel: it is more cost-effective and less polluting. The emission of sulphur, for instance, is less than the norm of 17 ppm.”
“At present, we are collecting over 25 tonnes of plastic in a month and we have been doing this for four years. We have also given 50 tonnes of plastic to the Pune Corporation for road-laying. We have two more coming up in Pune, one is being installed in the Pune Corporation, one in Bengal and another one, in Telangana.” The technology could also help reduce the size of landfills by using up the plastic that has remained, after the degradation of the other kinds of waste.
“We are now trying to perfect the process and see if an unskilled worker can run the plant. We also need to create more awareness about segregating plastic. In India, we usually dispose of our wet waste in a plastic bag, which makes the waste useless. It then becomes more expensive to segregate at the time of recycling.”
Medha says her life has been taken over by the plant. “I love it when people start segregating and notice plastic everywhere. It has always been there; what has changed is the way they look at it. That’s what we want.”
“Banning of plastic is just a step in the right direction to save our environment. But that is not the ultimate solution. We need to find a safe and sturdy alternative to plastic. We also need a strong and powerful brand ambassador for plastic waste segregation,” says Vidya Amarnath, of Paterson Energy, Chennai.
Bringing back plastic in the most useful form is one of the ideas she thinks will go a long way in protecting the environment and thereby avoid landfills. The company, which is a circular economy startup, was launched in 2016. A waste-to-energy solution is the focus, where they recycle plastic waste into quality plastic oil using a continuous type thermochemical depolymerisation technology. The company’s yard, which is situated in Sriperumbudur, has the capacity to process three to 20 tonnes of plastic waste per day. “The Government ordinance says that anyone who generates/manufactures plastic or produces plastic waste should take up the responsibility of mitigating at least 50% of the waste,” informs Vidya. The company works in tandem with the state government and deals with industrial manufacturers of plastic products who generate tonnes of waste.
However, they do not process PET bottles and PVC. “Pet bottles have their own resale value in the market, so we don’t take it into consideration. And PVC has a chloride component and this does not suit our technology which is affluent-free and pollution-free,” says Balachandran V, chief commercial officer, Paterson. “Ours is a kind of social initiative to save our environment and this is where we wanted to make a difference. Plastic is not the enemy, but the real hazard is the manner in which we segregate and dispose plastic,” Vidya says.At the yard, tonnes of waste plastic are cleaned and shredded, and then it is fed into the reactor vessel through air lock valve and heated under controlled conditions without oxygen. The reactor is heated initially by burners using furnace oil. Later, the gas produced during the process is reused to heat the reactors. Carbon black in powder form, which is generated during this pyrolysis process, is sold to companies that require it. The yield from the plastic waste is 40 to 50% for homogeneity plastic. This fuel oil or furnace oil or pyro oil is widely used in industries and also in laying roads. While the cost of production is approximately about ₹25, the fuel is sold at a cost of approximately ₹40 in the market.
“Pyro oil can be used as furnace oil, to run generators and any process that requires heating. It is an efficient fuel for factories. As it has low residue, it is safe for the environment,” says Balachandran V, chief commercial officer, Paterson.
There are three different business models that Paterson has adopted. While the first model is where industrial plastic waste is processed and converted into fuel oil at the yard, the second model is where they work with the government, and set up plants for Thermochemical Depolymerisation where it is required. The company also sets up plants on site for industries which prefer to have them in-house, which is their third model.
Does the company believe in up-cycling? “I don’t think up-cycling is a holistic solution, as it simply brings back plastic in some other form or just extends the life of the plastic product,” she explains. “But what we do is visit various educational institutions on a regular basis to spread awareness about plastic waste segregation among the youth. They are the ones who can steer our nation in the right direction and we teach them that sensible disposal of plastic is valuable to our country,” says Vidya.
Hydroxy Systems Pvt Ltd, Hyderabad
Satish Kumar, founder, Hydroxy Systems Pvt Ltd, says he can turn ‘dead’ waste plastic or end-of-life plastic into three kinds of fuel at the same time: diesel, petrol, and kerosene. “When plastic is depolymerised, it turns into short-chain molecules, from which we derive synthetic diesel and petrol. Our process of extraction can be termed atmospheric-pressure depolymerisation. The fuels derived from this process are ‘green fuels’, as defined by law. They are also called as RDF oils (refuse-derived fuel),” says 48-year-old Satish, who graduated with a mechanical engineering degree from Andhra University and has been conducting research in alternative fuels also. The technology is up for evaluation by the Pollution Control Board (PCB).
Our code of editorial values
Printable version | May 26, 2022 11:02:00 pm | https://www.thehindu.com/sci-tech/energy-and-environment/plastic-surgery/article25604517.ece