Sunday, November 9, 2008

Aluminum Can Recycling

Aluminum is made from bauxite ore and other natural resources. However, aluminum is the only material that is currently 100% recyclable, which means that, once the metal is made, it can be recycled indefinitely. The process of recycling aluminum uses only 5% of the energy that would be required to make the same amount of aluminum from virgin materials. Although some groups estimate the energy savings to be closer to 75-80% than the 95% that is so popularly quoted, they instead break down the savings by cost. In the 1980s, one ton of virgin aluminum ore was $1,933, while the same amount of recycled aluminum totaled a mere $313, which is a net savings of $1,620 per ton—still a significant amount.

Since most recycled aluminum is turned back into beverage containers, the EPA stresses that the materials must be source separated, clean, and dry so processors can “…generate only high-quality scrap. The recovered aluminum containers must be free from steel, lead, ferrous materials, bottle caps, plastics, glass, wood, dirt, grease, trash, and other foreign substances.” Once the aluminum is separated, it is condensed into 1,200-pound bales and shipped from the scrap yards to aluminum processing and manufacturing plants. After workers strip the outer decorations from the cans, the aluminum is shredded and fed into a melting furnace.

At this point, the recycled aluminum is mixed with virgin aluminum ore; the cans on store shelves today are made up of approxomately 40% post-consumer content. Once melted, the molten aluminum pours into ingots, or molds that cast the metal into large sheets (25 feet long and 20 inches thick) that are fed through large rollers, which reduce the thickness of the aluminum sheets all the way down to 1/100th of an inch—the thickness of a human hair! The metal sheets are then coiled and sent to can makers, who fashion the body and lids of the new cans, which then arrive at the bottling plants, ready to be filled and placed back on store shelves.

The entire process—from the moment a can is recycled to the time it arrives back on store shelves—takes only 60 days, which means that a recycled aluminum can could potentially be reused up to six times a year. The Aluminum Association estimates that recycling saves roughly 15 million gallons of crude oil annually, and it is doing its part to reduce the amount of aluminum that is wasted each year. One of the biggest changes made in the past 30 years is the amount of aluminum used to make each can. In 1972, cans weighed about three ounces each, but in 2006 this weight was reduced to a mere half-ounce per can. This means that 200 million fewer pounds of aluminum are used to create the 100 billion cans made each year.

The Aluminum Association has set a goal of a 75% recycling rate for aluminum cans, and strives to make aluminum recycling production a closed-loop process. The closed-loop recycling method all but eliminates the use of virgin materials by recycling and remanufacturing a used product into the same product, and the aluminum can is the perfect candidate for this type of recycling, as it can be recycled indefinitely. This method is already widely used in the iron and steel industries, and with great success. With the current recycling rate of aluminum hovering well below 50%, there is much room for improvement and also money to be made—the industry currently pays out $800 million dollars for recycled aluminum each year.

With so much potential for recycling aluminum, and the significant savings in cost and energy that would result, why isn’t the recycling rate already much higher than it is? Some of the problems can be chalked up to the “human factor”—recycling isn’t as convenient as it could be, selling scrap metal isn’t as profitable as it once was (thanks in part to inflation and to the reduced weight of aluminum cans—one pound of aluminum required more than 34 cans in 2006, up from a mere 22 cans in 1972), and the current curbside recycling programs aren’t capturing a satisfactory percentage of used beverage containers, as most of these drinks are consumed away from the home.

What, you might ask, are the other factors that hinder aluminum recycling in ths country? Stay tuned....

No comments: