Weight Watching Materials for Cars – Recyclable

July 22, 2008 – Vol.13 No.18

WEIGHT WATCHING MATERIALS FOR CARS – RECYCLABLE.

Cars and trucks need to go on a diet. Without resorting to plug-in hybrid, battery electric or fuel cell technologies, vehicles could be considerably more fuel efficient by weighing less. As the equation says, for every 10-percent in weight reduction there’s an 8-percent increase in fuel economy.

The car companies know this, of course, and to some extent have been working for decades to slim down. Plastic and aluminum parts are used extensively and are much lighter than steel. Slowly the industry has been adopting them piece by piece, but at their core cars and trucks are still made of steel.

Would the auto industry move away from steel if they could easily do it? Certainly: If the right material came along. But it’s not a simple decision to make. It’s not just a material. It’s what the material must accomplish.

Parts made from any new material must be to able to be manufactured quickly so as to fit into mass production schemes. Parts from the material have to be easily attached to one another. The material has to be low cost to keep vehicle costs reasonable. If used as a structural component in cars it has to help the vehicle comply with crash testing. It has to be recyclable at end of life. And increasingly, with global warming concerns, the material’s carbon footprint must be small. All together that’s why car manufacturers are slow to adopt and move away from steel.

So far the best choice is probably aluminum. It fits into neatly nearly all the above criteria with a few caveats. It is more expensive than steel, but at the end of life it has greater scrap value. (Junked aluminum cars would be very valuable.) Aluminum parts are not as easily attached to one another, yet not impossible. And aluminum has a high carbon footprint when made from ore, but it’s easily recycled using a tiny fraction (5 percent) of the energy needed to make it in the first place.

The other material option - and the gleam in many auto designer’s eye - is carbon fiber composites.

Carbon composites are strong, very light (about one fifth the weight of steel for the same strength). It’s fairly easy to attach composite parts to each other. But it’s still expensive (about 30 times the cost of steel). Much of that cost is related to the energy used to make the material and parts from it. Temperatures up to 3600 degrees are needed make carbon filaments: that’s a lot of energy. Later, molded composite parts must be cured in an oven for hours: more energy.

Yet surprisingly carbon fiber composites can be recycled. Carbon fiber composites have been used by the aircraft industry for a number of years. With that experience, at least some members of the industry are recognizing the value of recycled carbon fiber.

Boeing, which is building its 50-percent composite 787 Dreamliner, and Italian aircraft builder Alenia Aeronautica have joined forces to help establish Italy's first composite recycling facility. With partners Milled Carbon of the UK, Karborek of Italy and ENEA (Italian National Agency for new Technologies Energy and the Environment), Boeing and Alenia have signed a letter of intent to apply their expertise and work with academia to advance industry knowledge surrounding the recycling of composite airplane parts into reusable materials for manufacturing.

The companies, too, will help build a market for recycled carbon fiber. Potential uses would be in automotive, civil engineering, sporting goods and marine industries. (Think cars, trucks, bridges, light poles, tennis rackets, fishing poles, a wide array of boats and kayaks.)

The composite recycling facility – expected to be operational in 2009 - will be near the Alenia Aeronautica manufacturing center and use scrap from the facilty as feedstock. When fully operational, the center is expected to process an average of 1,000 metric tonnes (1,102 tons) of composite scrap annually and add approximately 75 jobs to the regional economy.

Boeing and Milled Carbon have been working together in a pilot industrial plant, to process cured and uncured composite parts on a continual feed that extracts high-quality carbon fibers.

ENEA has been working with Karborek to develop recycling process technologies for the recovery of carbon and glass fiber from composite materials. ENEA and Karborek each has separately developed prototypes of complementary technology.

Karborek and Milled Carbon will team-up on the building and operation of the composite recycling plant.

If carbon fiber composite airplane parts can be recycled so should car parts. Like light weight cars made of aluminum (of which there are already a few) carbon composite cars might be more expensive initially than steel cars, but better fuel economy combined with the value of the recycled material from a retired car could add up to full life cycle savings.

Links:

Boeing
http://www.boeing.com

Milled Carbon
http://www.milledcarbon.com

Karborek
http://www.karborek.it

Alenia Aeronautica
http://www.alenia-aeronautica.it

ENEA
http://www.enea.it/com/ingl/default.htm

--- Thank Carbon for Air Cars.