Wednesday, May 23, 2007

Carbon Footprint: Recycle Aluminum

I have heard several times that recycling one aluminum soda can conserves as much energy as it takes to power a television for one hour. Of this, I am skeptical. The requirement I impose on myself whenever I assume the mantle of skeptic is that I am willing to look for an answer - not just question a statement! Here is what I have found:

It turns out that recycling containers uses less energy than it takes to make them from brand new, raw material. For metals, this is linked to the immense energy consumption involved in mining ore and refining it for materials. For plastics, it is connected to the petroleum refinement and subsequent polymerization processes - remember that plastics come from oil!

There is a nice list of facts at the Recycling Revolution site about aluminum recycling. There I learned all sorts of tidbits about can consumption. Evidently, one can there uses the equivalent of 3 hours of television. Maybe TV's are more energy efficient these days... I doubt it is harder to pull aluminum out of bauxite ore. Evidently it takes A LOT of energy (and CO2 emission) to make aluminum. According to another source at Blogcritics magazine,
recycled aluminum uses only 5 percent of the energy needed to process "fresh" aluminum and is virtually waste-free.
So there you have it, there is some credibility linking can recycling to television hours. If you want to really reduce your carbon footprint, recycle your cans and don't watch the television...


Anonymous said...

Actually from a geological perspective, due to the finite (fixed) amount of ore deposits on the planet we might expect that over time, as the choicest ore deposits are depleted, less-economical ore deposits would need to be mined and used (with higher energy costs). Futurists expect that our landfills may be dug up and "mined" someday for just this reason.

But actually I do suspect the calculation was adjusted in this decade by that ratio because the new LCD TVs do use about 1/3 the electricity of the old CRT televisions.

Anonymous said...

Aluminum is resists conducting heat and its melting point is so high, so to extract it from rock (bauxite) by melting requires sustained 2000 degree heat for hours, which is why recycling it saves immense amounts of energy. In fact, Brazil during their electricity crisis in 2000 banned aluminum smelting, they found the available electricity in the nation DOUBLED.

george.w said...

Aluminum is actually a good thermal conductor; the high energy cost of refining it from ore lies in its reactive nature. It bonds ferociously (often used in explosives) and separates reluctantly.

Mary said...

Aluminum is a great resource. I think it makes sense that we recycle it as much as we can.