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Wednesday, August 26, 2009

Guess how much of an old car gets recycled?

Professor of environmental and automotive engineering Edwin Tam, engineer Susan Sawyer-Beaulieu and PhD candidate Noor-A-Faiza Barsha are part of a national research project working to increase the amount of recyclable materials in vehicles by using a cradle-to-grave approach.

Currently, about 80 per cent of a vehicle's parts are recycled. Breaking down the various plastic components remains a challenge because different polymers are bonded together during the manufacturing process.

By looking at how parts are designed, fabricated, removed and recycled, Tam and his team hope to learn how vehicle disposal can be enhanced.

"Since a high percentage of a vehicle can be recycled, people often assume the process is similar to their home's blue box, where materials are from much simpler products that are often distinct from one another," Tam said. "This isn't necessarily the case with complex things like cars.

"The recycling process is very intensive and depends upon many factors."

His team's goal is to look at a vehicle's end-of-life and capture as much of that vehicle as possible.

"By and large the salvage industry does a very good job as a whole, and the more commercially viable we can make the process, the better they will do in the future," Sawyer-Beaulieu said.

In fact, between what is currently recycled and what is salvaged for reuse and re-manufacturing, the amount of material in a vehicle that is either reused or recycled is closer to 90 per cent already.

But there are still ways to improve.

Barsha, who graduated this past spring with a master's degree in environmental engineering, recently completed an award-winning paper looking at breaking down and separating different types of plastics used in the auto manufacturing process to make them easier to recycle. Such a process would make recycling easier and more commercially viable.

"Currently, the plastic is shredded and landfilled," said Barsha, who proposes pre-treating the plastics to make it easier to separate them. "Fuel-efficient vehicles means more lightweighting and that generally means more use of lighter materials such as plastics. Liberating these materials during recycling will require selective and intelligent methods.

Producing vehicles that are more easily recyclable may not add more cost to the manufacturing process, Tam said, because "you might be adding a design step in the process but not necessarily a manufacturing step.

"Instead of using rivets and glue to hold parts together, you might use clips which could be more easily separated."

While many decisions are based on economic factors, today's society places an ever increasing value on environmental and social factors.

Currently, when a vehicle arrives at a recycler, it's quickly assessed to determine its worth.

It's then either recycled for parts or sent to a shredder where it's ground up into piles of rubber, steel, aluminum and other materials, not all of which are recyclable.

The leftovers are usually plastics, glass, rubber, textiles, ceramics and carpeting that are difficult to recycle.

Using a process called life cycle assessment, Tam and his team hope to determine how to deal with these leftovers in a more environmentally friendly manner.

"Salvage companies remove the high-value parts and the rest is sent for shredding," Sawyer-Beaulieu said. "If you can reduce the amount of shredder residue that dismantlers and salvage companies have to deal with, it becomes commercially viable for them to do so."

Tam said the conceptual goal is to recycle 100 per cent of every vehicle but practically "that's neither possible nor commercially viable.

"But we still believe there is more we can do to reduce the impact scrap vehicles have on the environment."

http://www.calgaryherald.com/technology/Guess+much+gets+recycled/1905031/story.html

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