Plastic waste- a burgeoning issue
Plastics have become indispensable to human beings over the course of the last few decades, largely due to their utility value and cheap, easy availability. We are indeed so dependent that, in spite of the fact that they have been classified as environmentally hazardous material by the UN, the production of plastic is being ramped up in India. There are close to 60 million tons of waste being generated in India every year out of which close to 5% or 3 million tons is plastic waste alone. Only 6% of this makes its way to landfills while 8% gets picked up by rag pickers. So there is a huge potential for any technique that can aid in plastic disposal and thus reduce air pollution (from incineration of waste), water pollution (landfill) and various health risks that arise from improper disposal.
Why are plastics harmful to the environment?
Plastics initially came into the picture to replace metal, wood and paper for a whole host of purposes. They were then modified structurally to make them non-degradable, resistant to heat, stress, chemicals etc. Not only did this make them stronger, but it also made them environmentally dangerous. But the issues concerning plastics are all largely due to unawareness among the public regarding plastic waste and their disposal. For example, the mishandling of waste, burning it in the open atmosphere causes a lot of health problems for living beings. Simply put, if disposed properly, plastic is not only pretty harmless but also very helpful and can be harnessed for energy. Polyethylene and Polypropylene which form a significant percentage of plastic waste have higher calorific values than coal which is the primary fuel for electricity in India currently.
A possible solution to the plastic waste issue is to convert them into fuel, which not only addresses the fuel shortage problem that the world is currently facing but also increases the market value of the concern. This is accomplished by using a process called Pyrolysis.
The waste plastic, most of which falls under one of PP (poly propylene), PE (poly ethylene) or PS (poly styrene) is collected by the rag pickers or by local dealers at a reasonable cost and shredded. This waste can then, be turned into fuel oil using pyrolysis under controlled conditions. It is possible to achieve a conversion rate of 80% with the technology. The final product obtained is very similar to crude oil and can be purified to various fractions using distillation columns.
A bird’s eye view of what happens in the Pyrolysis process is shown below:
There is a lot of research that is being carried out on this front both on the national and international level. Some notable technology leaders (in India & abroad) in this field are Harita NTI Ltd (India, http://www.polymerenergy.com/contact), Samki Group (India, http://www.samkigroup.in/sample/index.html), Blest (Japan, http://www.blest.co.jp/), Splainex (Netherlands ,http://www.splainex.com/) etc.
The plastic-to-fuel industry, in India, is riddled with problems and survival is completely dependent on how these issues are overcome. Some of the problems are highlighted below:
- Organized collection of plastic waste is one of the biggest hurdles facing the industry. Waste is not segregated at the source which means all the plastic waste needs to first be separated from the other forms of waste and then, aggregated at a common location to which it will have to be transported. Thus the need for labor and transportation.
- Indiscriminate disposal will lead to contamination of ground water and land whereas if properly disposed, not only can these problems be avoided but plastic waste can also play a part in overcoming the fuel problems currently plaguing society. Non-segregated collection of waste will lead to contamination of “clean” waste.
- There is no awareness among the general public when it comes to proper disposal of plastic waste. If this can be remedied, it makes plastic waste collection and aggregation a lot easier.
- There is very little support from the government in matters relating to plastic waste. There are little or no incentives/promotions for recycling and for using fuel obtained from plastic waste.
If all this is remedied, plastics will maybe start contributing significantly to our fuel mix and perhaps then, we will be able to say “Say yes to plastic”.