On Fri, 20 Apr 2007 11:29:13 -0500, "Wolfgang" wrote:


"Tim Lysyk" wrote in message
news:bXTVh.9156$VF5.1555@edtnps82...
Recently, we had a thread about ethanol and its environmental effects.
There was a study recently commissioned in Alberta to look at biofuels.
This included the environmental impact of ethanol use and production. The
executive summary is at http://www.aia.ab.ca/policy/ and the full text is
at

http://www.aia.ab.ca/policy/thebiofuelsfrenzy.pdf

in case there is still some interest.

Lots of interest here.

The picture painted at the above links appears rather bleak. But then, the
prospects for continued reliance on a diminishing supply of fossils fuels is
even more so.

There is, of course, much too much information in that report to do justice
to in a discussion here.......particularly given the inevitable fate of such
discussions. But there is one thing I'd like to touch on because I think it
typifies a fundamental problem with ALL such discussions (and has already
been mentioned here).

At the end of issue # 10, I find the following statement: "...production of
one litre of ethanol requires between 4 and 8 litres of water. Most of this
water must come from underground sources and this could reduce water tables
in the aquifer."

It doesn't take much of a chemist to understand that a liter of ethanol does
not result from the conversion of 4 liters of water, let alone 8. In fact,
I don't know exactly how much water is actually consumed in the process of
fermentation but I'd bet a shiny new nickel that it is less than 1 liter per
liter of finished product. Much of the rest of the 4-8 liters is
essentially the vehicle for a culture medium which remains at the end of the
fermentation. Allowing some loss for sloppy distillation and cooling
practices, MOST of the 4-8 liters SHOULD still remain at the end of the
entire process as useable water. In places where sufficient bodies of
surface water in the form of streams or lakes are available, the bulk of
that water is (typically) eventually returned to the source, albeit all too
often heated or otherwise polluted. In places where the source is an
underground aquifer the losses are huge, NOT because the water is consumed,
but because most of it is ejected into a convenient nearby lake, stream,
evaporation pond, or ditch. Finding ways of eliminating waste by the
careless and indifferent disposal of a mostly reusable (and valuable)
resource shouldn't present insurmountable or prohibitively expensive
engineering challenges.

What's important here is that the casual....or careless....reader can easily
be mislead into believing one thing, either unintentionally when certain
assumptions (perhaps taken for granted by specialists) are not clearly
spelled out, or deliberately if the ax to be ground requires certain special
secret lubricants, when the truth is something else entirely.

Incidentally, industrial scale fermentation, distillation, packaging and
distribution of ethanol will require the consumption of a good deal of
electricity, and the vast majority of the raw materials used for biofuel
production in the U.S. and Canada are grown in enormous open fields.....with
nothing to impede the sometimes ferocious winds which sweep across the great
plains of North America. Things that make you go "hm......."

Wolfgang


Is it possible the quoted water requirements include growing the raw grain?

/daytripper (that's how I read it, but I could be wrong...)