Monday, July 16, 2012

You Can, But Should You?

Over the weekend I sat and did a fair bit of reading. We are now completely moved in to the new house, indeed with hand over the keys to the old apartment on Wednesday, and in between bouts of box emptying, tree limb sawing and other sundried tasks I caught up with my reading. I have a confession to make, I have neglected my reading lately, mainly because we have Netflix and streaming endless tv shows and films through our Wii was so easy that we watched inordinate amounts of stuff. In the new house we don't the luxury of essentially limitless broadband, so Netflix has gone by the by and I for one am enjoying reacquainting myself with the written word.

Among the beer related stuff I have been reading is a recent edition of Brew Your Own magazine with clone recipes of beers available in cans, including 21st Amendment's Bitter American (official beer of the TEA Party from what I hear). Cans are the big in thing at the moment, a couple of our local breweries having canning machines, Starr Hill and Blue Mountain, and canned beer from independent breweries is becoming ever more common. One part of the article that intrigued me was the description about how using cans is better for the environment than bottles. According the writer of the article the energy required to recycle aluminium cans is much less than to recycle glass, which may or may not be true, I really have no idea. One thing I do vaguely understand though is that making the aluminium to begin with is viciously destructive.

The starting point of aluminium production is the mining of bauxite, which is then heated with sodium hydroxide (caustic soda or lye) to create alumina, apparently this process alone creates 5 tons of caustic waste to produce the equivalent of 1 ton of cans. The alumina is then smelted to about 1800°F (980°C) to form aluminium itself using the Hall-Heroult process, which gives the aluminium a purity of 99%. According to some statistics I have seen, 5% of electricity usage in the USA is consumed in the process of making aluminium. You remember the 5 tons of waste that was mentioned earlier? It is known as "red mud" and is pretty much just dumped into holding ponds where it sits around doing nothing but taking up space. When there was a accidental release of red mud in Hungary in 2010 it "extinguised" all life in the Marcal river and 9 people died, as well as there being a large area of contamination. Even when these ponds of red mud are dry they are basically just dead zones, with agriculture and housing both impossible.

I think it is pretty clear that the production of aluminium is far from environmentally friendly and while glass is barely any better, it is obvious to me that the "environmentally friendly" claim for aluminium cans is misleading at best and spurious at worst.

3 comments:

  1. Presumably, though, you can offset some of the damage against recycled aluminium. Any idea what sort of percentage that is?

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  2. The key to the argument is the recycling. Melting down glass uses the same energy as making it in the first place. Recycling aluminium uses vastly less than purifying it from the ore. But these are solely energy matters. The waste materials are clearly not nature's friend.

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    Replies
    1. Surely re-using bottles - the normal system in Holland and Germany - is the most efficient?

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