Print

Print


The response that your question has generated is simply 
fantastic!
 I agree with Jason in that we should discuss this issue in the 
flesh.

But for now, I have a simple, but by no means an all-encompassing, 
answer:

First of all, the term biofuels involves many different types of 
fuels
-biodiesel, bioethanol, biogas, biomass... etc.
I will address biodiesel, which could have a significant impact on 
the amount of petroleum
used in transportation, personal and commercial.
Biodiesel can be used as a diesel fuel substitute in any existing 
diesel engine with minor (or no) modifications
(usually fuel pumps and fuel lines need to be replaced on older 
engines).
And apart from reducing a myriad of air pollutants- CO, Sulfur 
oxides, volatile organic compounds, unburnt hydrocarbons, etc.-
biodiesel increases engine efficiency and longevity by increasing 
the lubricity of the internal engine compnents.

But to get to the meat of your question:
In a life cycle analysis of Biodiesel vs. Petroleum diesel in an 
urban bus,
"Petroleum diesel generates roughly five times as much wastewater 
flow as biodiesel."
(pg. 24 of Overview of Biodiesel and Petroleum Diesel Life Cycles- 
http://www.nrel.gov/docs/legosti/fy98/24772.pdf )

So even though biodiesel does use water in signifiant amounts, the 
amount of water used in the extraction of crude oil make petroleum 
diesel far more water intensive.  Also you have think of how these 
waters are used, what they are contaminated with, and how they are 
treated. Most of these questions are highly variable and I admit 
that I do not know the answers, especially in crude oil 
extraction. However, the wash water produced in biodiesel 
manufacturing is dilutly contaminated with soap, methanol, and 
excess potassium hydroxide (in very small amounts) mostly 
envronmentally benign. Water waste in traditional soybean 
production is contaminated with agricultural chemicals: 
pesticides, herbicides, and fertilizers, which could- ideally- be 
eliminated with changes to more holistic agricultural practices.

Hope this illuminates some on these critical subjects.

cheers,
-Scott J. Edmundson

~Also check out this paper from the Proceedings of the National 
Academy of Sciences analyzing ethanol and biodiesel.
http://www.pnas.org.lp.hscl.ufl.edu/cgi/content/full/103/30/11206




On Thu Dec 21 01:18:47 EST 2006, "MARTIN,ELIZABETH J" 
<[log in to unmask]> wrote:

> To anyone willing to address my question:
> 
> I was wondering if someone would mind directing me to some 
> information regarding the pros and cons of biofuel vs. petroleum 
> in terms of land use and water consumption.
> 
> While I fully agree that there is a dire need to reduce reliance 
> on petroleum and other non-renewable resources, I am concerned as 
> to how it balances out on the other end of the spectrum.  
> Currently over 1 billion people do not have access to safe 
> drinking water, resulting in millions deaths every year due to 
> unsafe and unsanitary water conditions.  The main problem is the 
> agricultural techniques used to produce crops such as corn, 
> wheat, soybeans, etc.  The largest problem is the net loss of 
> water and the destruction of land due to irrigation.  From what 
> I?ve been reading, it appears that the main alternatives to 
> petroleum lie in the use of these organic materials as potential 
> fuels.  So my main point is this, even if biofuels replace 
> petroleum and reduce green house gases and air pollution, won?t 
> the result be an even bigger problem due to water scarcity?  I 
> understand that no one can know if this will even be a problem, 
> but I can?t help but wondering if biofuels are the answer, or if 
> they are a catch 22.
> 
> I also have a slight problem with the burning of natural and 
> human wastes.  While this does eliminate the growing problem of 
> landfills and the release of methane gas into the atmosphere, 
> isn?t it still slightly retroactive because combustion of any 
> material releases carbon dioxide?
> 
> I'm terribly sorry if these questions seem ridiculous or 
> completely off base, but I'm having trouble finding answers.
> 
> Incase anyone was wondering where I got my information on water 
> scarcity:
> www.blueplanetproject.net
> 
> There is also a very informative article available at:
> http://www.qmw.ac.uk/~ugte133/courses/environs/cuttings/water/
> Click running.pdf
> 
> Thanks.
> Liz
> --
> MARTIN,ELIZABETH J
> 
> 



--
SCOTT JAMES EDMUNDSON