A recycling story- From automobile tyres to road laying

In this next article under the 'Sustainable Consumption Series', the author writes about the problem of waste car tyres and a few ways in which tyre waste could be recycled to effective use.

Ralph Waldo Emerson, the famous American philosopher once said ‘The civilized man has built a coach, but has lost the use of his feet’ and several decades after his demise, his worst fears have come true. Motorised vehicles are now the single biggest source of atmospheric pollution contributing an estimated 14% [1] of the World’s CO2 emissions from fossil fuel burning.

On one hand whereas the places are now well connected with vehicles that can ferry people from one place to another at mind-blowing speeds, on the other hand, the amount of fuel these motors guzzle each year is rising at alarming pace. Fast paced lifestyle allows the modern man to stay in townships away from the din of the business district which allows him to save on money paid in form of heavy housing rentals and at the same time he can commute to his workplace in the comfort of his car within feasible time frames. But the price the environment has to pay for the comfort of man is detrimental to mankind and the damage is irreversible.

There are approximately 600 million passenger cars worldwide, roughly one car per eleven people [2]. Car manufacturers across the globe have been continually improving the technology to cut down on the carbon emissions either by making hybrid models, fuel cell technology or by introducing catalytic converters which keep the air-to-fuel ratio very close to the stoichiometric point. These technologies do help to reduce the pollutants that the gasoline burn releases into the atmosphere but what they don’t control is the damage that is caused to the environment during the manufacturing and disposal of these vehicles. Let’s take a look at the process wise breakup of pollutants getting released in the environment during the manufacturing to the disposal of ONE car:

- Extracting Raw Materials for a single car leads to generation of 26.5 tonnes of waste and 922 cubic metres of polluted air Transporting Raw Materials for the car entails use of 12 litres of crude oil in the ocean and generation of 425 million cubic metres of polluted air
- Producing the Car leads to 1.5 tonnes of waste and 74 million cubic metres of polluted air
- Driving a typical Car through its lifetime generates 18.4 kilos of abrasive waste and 1,016 million cubic metres of polluted air
- Disposal of the Car leads to 102 million cubic metres of polluted air [1]

So while every car manufacturer is making a beeline to be branded as eco-friendly and is seemingly concerned with technology that reduces the ‘carbon footprint’, what they don’t address is the damage done during the manufacture and disposal phases. When a car is disposed, most of the parts are recycled or sold in the second-hand market, but the tire is amongst those parts which face difficulty in finding a suitable use for itself.

In India the number of vehicles hitting the road is increasing everyday and so is the number of tyres and hence there is a huge business opportunity that exists in recycling them. With more than 33 million vehicles added to the Indian roads from 2007 to 2010, about 80 million tyres have hit the roads – these include two, three, four and six wheelers, and pose a potential threat to the environment [6]

A typical car tyre contains 24-28% of Carbon black, 40-48% of natural rubber and 36-24% of synthetic rubber including Styrene Butadiene Rubbers (SBR) and Butyl Rubber (BR), which are all ingredients used for tyre manufacturing. Currently India produces 90,000 MT of reclaimed rubber, which is sold at Rs 25-30/kg but does not produce Carbon black, Butyl Rubber and oil from used tyres.

Tyre recycling is a 40 year old industry in India with 15-25 players in the field as compared to 36 tyre manufacturers. The major players in this space are Gujarat Reclaim, ELGI Group, Balaji Group, Rishiroop and Swani with Gujarat Reclaim being the oldest player with an annual turnover of over Rs 15 crore and a production of 20 TPD (Tonnes per day) of reclaim rubber. India is currently the second largest reclaim rubber producer after China and there is a potential for a 50-100% growth with the right initiatives from the Government – this growth represents a mammoth potential increase of 1.13 billion INR in the industry [6]

Worldwide more than 981 million tires are thrown away each year [3] and even less than 7% are recycled, 11% are burned for fuel, and 5% are exported. The remaining 77% are sent to landfills, stockpiled, or illegally dumped. That’s almost 765 million old tires a year wasted across the world!

People in the auto recycling industry have known this for years but nothing major has been done so far to address it. The major applications of the End-of-Life (EOL) tyres are:

• As fuel in cement kilns
• As filler in sports and playground surfaces
• As a blend for road surfacing
• Reclaim and crumb rubber for use in rubber industry

There is one particular use for these old tyres that addresses the problem of effective recycling as well reduces the challenge of maintaining roads to some extent. Rubberised Asphalt Concrete (RAC) is one such use that kills two birds with one stone; it makes for better roads, roads that need less work later on, and it’s easy to make from EOL tyre. The dumped tires are shred into “crumb rubber”, then melt and mixed with asphalt to produce RAC, which when used for laying roads works extremely well because of the following reasons:
• Using RAC reduces road noise by as much as 85%

• A 2 inch layer overlay of RAC can save  approximately 20Lacs INR lane-mile compared to using 4 inches of conventional asphalt in the same application

• An overlay of RAC prevent cracks in underlying pavements from reflecting through to the surface of the new paving

• RAC retains its original colour better than conventional asphalt and markings remain more visible

• Using RAC saves on maintenance costs and a properly designed application can enable 50% more use than standard asphalt

• RAC provides better traction and can reduce traffic accidents in poor weather [4]

RAC has a proven track record as an effective polymer modifier for bitumen in road construction and has been extensively used within UK, EU, and USA over the past 40-50 years but there are certain limitations. It is less effective in very cold environments. Additionally it may appear as expensive initially though it saves money in the long term. While RAC may not be the end-result for each scrap tyre it certainly presents itself as a credible and serious option to save the planet from being inundated by these pollutants.

So why hasn’t RAC delivered on its promise?
Fundamentally continued use of Rubber is under threat from synthetic polymers who have invested heavily in the development, promotion and marketing of often less environmentally friendly and more expensive alternatives. So are we faced with a situation where the government’s monopoly over the road infrastructure is being exploited by a few politicians and supplier companies closely engaged with them to ignore the techno-environmental merits of these progressive technologies?

The author Sandeep Roy is a Associate at cKinetics, a sustainability consulting firm.

[1]- http://www.worldcarfree.net
[2]- http://en.wikipedia.org/wiki/Automobile
[3]- http://www.gujaratreclaim.com
[4]- http://www.ridelust.com
[5]- http://www.vkrt.org/admin/upload/20041209R.pdf
[6]- http://www.dare.co.in/opportunities/

Image(s) Courtesy:
Mykl Roventine
Alex Graves

Author: Sandeep Roy