Date: Sun, 6 Mar 2005 18:05:32 -0500
Reply-To: Marc Perdue <marcperdue@ADELPHIA.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Marc Perdue <marcperdue@ADELPHIA.NET>
Subject: Another long diatribe, was Re: gas prices- a canadian perspective
In-Reply-To: <393ea1307725a2c275015ed66e7ed6c6@knology.net>
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Jim Felder wrote:
> I am all for paying farmers for fuel rather than mid-east royal
> families, but I've seen studies--don't know if they're legit or
> not--that show that the energy benefit from the ethanol is less than
> the energy used to produce it.
>
Comparing only ENERGY benefits and costs is inappropriate when looking
at ethanol production. Ethanol is not the only product produced. For
every bushel of corn that you process to make ethanol, you get 2.5
gallons of 190 proof ethanol. (I'm not even getting into the fact that
you CAN'T use 190 proof ethanol in gasoline; it has to be 200 proof and
that's a whole 'nother process.) If you were to total up the energy
used to produce that 2.5 gallons of fuel, you would find that, yes, it
took more energy to produce it than you get from burning it. HOWEVER,
when you process the corn, you break down the complex starches into
sugar, then the yeast eats the sugar and produces ethanol and CO2.
Obviously you remove and sell the ethanol, but you can do the same with
the CO2 and use it for any number of things from making dry ice to
growing plants. Big fat hairy deal, right? But wait, there's more.
When you run the beer (fermented mash) through the distillation column,
you get 190 proof ethanol off the top and the rest comes out the bottom
and is called, appropriately enough, "bottoms". The bottoms is a high
protein feed that is much easier for cattle to digest than straight
corn. You have thus added value to the feedstock that you started with
and that can be sold, as feed, for more than the cost of the original
bushel of corn.
There are other ways that you can create synergistic relationships
between farmers and ethanol producers as well. At the plant that I ran
in Madison, VA, we were located on a farm where the farmer raised beef
cattle and had a custom lime-hauling business. Being as our plant was
close to the feed lot, we built a system wherein the farmer would clean
off the feed lot and shovel the manure into a mixing tank that we had
buried in the ground. We would add waste liquids from the distillation
process, mix that in with the manure and then pump it into another
underground tank. In that tank, an anaerobic environment, the manure
was broken down over a 22-day period and gave off methane gas. The gas
initially had a high CO2 content, 40 %, and would not burn, so we ran
the gas through a device that we built (my idea) filled with lime water
(lime from the lime-hauling business). The lime water stripped out the
CO2 (remember that experiment in high school chemistry class?), and
brought it down to 5%. As a test, we brought out one of the burners
from our steam boiler and hooked up a line from the methane digester.
We fired it up at sunset one night and had the most beautiful 10 foot
blue flame coming out of there! We re-installed the burner and burned
the methane to make steam to cook the corn. The residual material
coming out of the second underground tank was a high nitrogen
fertilizer, in liquid state, that could be sprayed on fields with the
farmer's liquid spraying equipment. We thereby took a fairly unusable
waste product (in its existing form) and created energy to process the
corn (and other materials) and reduced our energy costs considerably as
well as creating a new product, high-nitrogen fertilizer, that could be
sold in the local market.
It's also possible to use feedstock materials other than corn to reduce
the costs of production. At various times we were using Brewex, liquid
waste from the Anheuser-Busch plant in Williamsburg, and government
stocks of milo that had gone bad and were no longer usable as food, to
produce ethanol.
> Vegetable diesel might do better. Besides, the carbon load it puts into
> the air came from last year's crop, so there's no net co2 gain unlike
> petro fuel which loads the atmosphere with carbon from long ago that
> otherwise wouldn't be there.
>
> Jim
>
Regarding the carbon cycle, there's no net gain to the atmospheric
carbon cycle, but the carbon in the entire system remains constant. It
is true, however, that the carbons in petroleum would likely remain
locked up in the ground if we weren't burning it and it wouldn't be
filling the air with greenhouse gases. The more important questions
might revolve around the form that the carbon takes once the fuel is
burned. Is it released as carbon monoxide or carbon dioxide? What is
the impact that these have on the environment? How easily can our
ecosystems handle the excess material that we're putting into the
environment and so on. There are so many questions regarding these
types of impacts and we have so limited an understanding of the actual
effects that they have, both in the short-term and in the long-term,
that it's really difficult to predict what the outcomes might be of
burning one type of fuel over another. Given that this is the only
planet that we have to live on at this point in time, it would seem that
we should be way more cautious and respectful in how we treat it. It is
our home, after all.
Well, I guess I couldn't stay off my soapbox after all. My apologies to
those who are not interested in all this
only-tangentially-Vanagon-related material.
Marc Perdue
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