First we pretended they didn’t exist, then we thought of dumping them, followed by the thought of burning them. But none of this has helped us to get rid of plastic bags, PET bottles, food wrappers, and more. The question is, how do you get rid of the enormous quantity of plastic waste continuously collecting in your home?
A Pune-based organisation has the answer — its technology converts plastic waste into useful poly-fuel and the sludge-rich polymer is reused with bitumen to make roads. In this way, 100 per cent of the plastic waste is recycled with no emissions and no harm to the environment. Here’s how.
Rudra Environmental Solution (India) Ltd has been successful in getting rid of non-degradable polymer waste via the Pyrolysis process, that is, the decomposition of condensed substances by heating, and generating poly fuel from the plastic waste. The company collects plastic waste such as bottles, bags, food pouches, wrappers, cable covers, etc., from different houses around the city once every fortnight, and recycles it into fuel, gas and sludge. At present, the collection happens from almost 5,200 households, hotels and industries. In fact, the company has a goal to reach 10,000 households in Pune by the end of 2016.
How the plant functions
Established in July 2009, the ISO 9001-2008 certified Indian company has done research in converting waste plastic into fuel and currently runs three plants to generate fuel from waste.
Meanwhile, the company’s technology has a distinct advantage. One of them is self-sufficiency for fuel consumption (typically for industrial/commercial) fuel requirement. Also, the plant through which company does the Pyrolysis process, does not require segregation of various types of plastic. Importantly, the plant can be operated up to 50 per cent turndown with the eco-friendly process and no harmful gases/effluents are produced.
The plant developed by Rudra can process up to 1 tonne per day. The plastic fuel generated has a calorific value of 10,400 to 10,800 KJ/kg and can be effectively used to run tractors, diesel electricity plants, boilers, stoves, agri-pumps, etc. The company has four kinds of machines, based on batch loading capacity. The plants can take up from anywhere between 300 kg to 2 tonnes of plastic waste for each cycle of the process. In fact, its ‘Pro 34’ machine can consume 15 to 20 tonnes of plastic in a single day. For every kilogram of plastic, the company generates around 40 to 45 litres of fuel.
Since the sludge is rich in polymer, the company claims the same can be reused with bitumen to make roads. Rudra gives the sludge to local builders who use it for the construction of internal roads within housing societies.
As far as feasibility of employing this technology in other cities is concerned, according to the company, such plants can be started anywhere in the world and all it needs is a mere one ground of vacant land. It can also be installed in villages, taluks, etc. More than decomposing non-degradable plastic, it provides employment to many. The investment is also minimal.
Accepted plastic waste:
- Milk bags/oil bags, food bags, yogurt containers/plastic glasses
- Cooking oil canisters, laminated tubes (toothpaste, medicines)
- Carry bags (all micron thickness), blister packing, bubble wraps
- PET bottles (mineral water, soft drinks, toilet cleaning material)
- Shampoo/powder bottles/empty sachets
- Detergent bags
- Food item bags, wrappers
- Plastic flowers, buckets, toys, plastic covers, table mats, shower curtains, cassette covers, and CD covers.
The plant operates on a batch processing system. Waste plastic is unloaded at site and shredded to a smaller size, which is better for handling & processing. The weighed plastic is transferred to the reactor, which is specially designed to handle polymers also. A suitable catalyst is added to the reactor. The feedstock is heated under controlled and even temperature through hot air. The reactor operates at high temperature and in absence of air. The process of liquefaction and in turn vaporisation of solid waste plastic occurs in a temperature range of 370°C to 430°C in the absence of oxygen.
These vapours are carefully transferred to a condensing system where the final liquefied plastic fuel is recovered from the vapours. The condensation is achieved by circulating cooling water. Along with the oil, the process also gets some amount of uncondensed gases, which is used for heating the air. The non-condensable gases (like chlorine) are then passed through a scrubber for removal. After scrubber, the fuel gas is compressed and stored for further utilisation.
For heating, the air HSD, uncondensed gases and process liquid fuel are used. The necessary controls/safety measures have been incorporated into the system. A centralised control panel is provided for the entire operation of the plant.