On Thu, 4 Feb 2010, MIG wrote:

Recycling, with all the extra transportation, washing and other
processes, is of very dubious benefit, even it it's done properly.

Except for aluminium, which takes an awful amount of energy to make, but
much less to recycle. According to this interesting powerpoint file (in
which slide 10 is also good, about the lifecycle energy cost of a car):

http://ec.europa.eu/enterprise/polic...von_zengen.ppt

It takes 5% as much energy to recycle as to produce, and it looks like
production takes 10 kWh per kg, hang on, i've just googled a bit and it
seems 13.5 kWh/kg is the current figure, so for every 15 gram pop can you
recycle, you're saving almost 700 kJ. To put that in context, that's as
much energy as you'd expend spending an hour playing Wii tennis. Er, that
doesn't help, does it? Anyway, the word recycles enough aluminium to save
2.3 exajoules of energy a year, which at 0.43 kg CO2 per kWh (a number
which i found on a website) is 270 million tonnes. That sounds like a lot.

The economics for steel aren't as good, but they're still pretty good.

Other things, less so. I would love to see a proper analysis of the
resource benefits of recycling various kinds of material.

tom

--
drink beer and forget about gods. -- derslangerman