Re: Biofuels will just use up our oil even faster
- From: Evan <hpshstudent1@xxxxxxxxx>
- Date: Wed, 6 Feb 2008 08:26:39 -0800 (PST)
On Feb 6, 12:40 am, "Stephen Sprunk" <step...@xxxxxxxxxx> wrote:
Pimental's "research" has been widely and repeatedly discredited. Today,
ethanol production gives an output of ~1.7 times the input energy; there was
a recent announcement of some folks that've figured out how to improve that
nearly an order of magnitude by using bacteria instead of yeast. Biofuels
aren't great (only reducing consumption is), but they're not the evil that
certain biased "scientists" try making them out to be to appease their
oil-industry backers.
S
--
Stephen Sprunk "God does not play dice." --Albert Einstein
CCIE #3723 "God is an inveterate gambler, and He throws the
K5SSS dice at every possible opportunity." --Stephen Hawking"habshi" <hab...@xxxxxxxxx> wrote in message
news:47a4facf.6845953@xxxxxxxxxxxxxxxxx
It takes five watts of energy to make one of grain , and even
if used the stalk etc. you might get up to 3 watts.
By growing billions of barrels of biofuel , we will just use
up our remaining oil reserves even faster , and then all these fields
will become barren.
excerpt
http://feinstein.senate.gov/05speeches/ethanol-oped.htm
There's just one catch: According to scientists in New York
and California, it takes more energy to make ethanol than you get back
in fuel savings. More precisely, says David Pimentel of Cornell
University, it takes the equivalent of 1.29 gallons of gasoline to
produce enough ethanol to replace one gallon of gasoline at the pump.
Instead of making the nation more energy self-sufficient, ethanol
production actually increases our need for oil and gas imports,
Pimentel says
In a recent paper in the journal Natural Resources Research,
he calculates that it takes the energy equivalent of 271 gallons of
gasoline to grow a hectare (about 2.47 acres) of corn. Part of that
energy is for tractor fuel, but the biggest use is for manufacturing
nitrogen fertilizers, which are mandatory for high-yield corn-growing.
These fertilizers are made by heating natural gas under controlled
circumstances so that it reacts with nitrogen in the air. Not only
does it take heat to do this, but it uses up natural gas that could
have been burned as fuel. Pimentel estimates that in corn-growing,
nitrogen fertilizers alone use the equivalent of 80 gallons of
gasoline per hectare.
More energy is needed to turn the corn into fuel. Ethanol is produced
by grinding corn, mixing it with water, and fermenting it in a process
similar to that used to make beer or wine. The unprocessed product, in
fact, is a lot like beer: 8 percent alcohol and 92 percent water. Not
something that's going to burn in a car engine.
To make a usable fuel, all but 0.5 percent of the water must be
removed. This is done by a series of distillation and chemical
extractions that, according to Pimentel's calculations, use even more
energy than was used to grow the corn. And that doesn't count the
diesel fuel needed to ship corn to the ethanol plant or ethanol to the
pump. In theory, all of these energy costs should make ethanol
uneconomical to produce.
But it can be produced affordably, Pimentel says, because the
government is subsidizing its production to the tune of $3 billion per
year.
Tad Patzek, a chemical engineer at the University of California
Berkeley, who collaborated with Pimentel, calls the whole thing a
"politically driven initiative" by "confused people" who think it's
good for the country. But really, he says, it's equivalent to the
medieval alchemist's quest for the mythical Philosopher's Stone, which
could turn anything into gold. The only difference is that in this
case, the reward isn't gold, it's "pure, environmentally benign
energy" that could satisfy the greenest of environmentalists.
"We need a new liquid fuel," Pimentel adds, "but this isn't the one."
Outside the gates
Hosein Shapouri disagrees. An economist with the U.S. Department of
Agriculture, he too has spent years studying the amount of energy
needed to produce ethanol. His latest calculations, published in 2004,
conclude that for each gallon of gasoline invested (or its equivalent
in coal, electrical power, etc.), you get back the equivalent of 1.67
gallons of gasoline. That's up, he adds, from 1.36 gallons in 1996 and
1.24 gallons in 1991.
Shapouri charges that Pimentel's work is based on an outdated
understanding of how the industry works. "He doesn't see technology,"
Shapouri says. "Corn production is becoming more efficient, and
ethanol is, too."
Pimentel, on the other hand, charges Shapouri with overlooking
important steps in the farm-to-ethanol process. "The reason the USDA
comes up with positive returns and we do not," he says, "is that they
omit about half of the inputs."
One "input" that Shapouri has overlooked, Pimentel says, is the energy
used to make and maintain farm equipment. "Have you seen many farmers
raising corn by hand?" he asks. Shapouri "draws the boundary too close
to the gates of the ethanol plant," Patzek says. "His whole analysis
accentuates the last element of the chain, which is ethanol
production."
Patzek also says that Shapouri accidentally mixed up
ethanol-production statistics for corn with different amount of
moisture in it, so-called "wet" and "dry" corn. "That overestimates
the yield by 15 percent," he says.
Patzek thinks the U.S. needs a two-pronged approach, neither of which
involves ethanol. First, he says, we need more efficient cars.
Doubling the average car's fuel efficiency would cut gasoline needs in
half, while converting all of the nation's corn production into
ethanol would only satisfy 12 percent of current needs, he says.
Similarly, he says, we could reduce fuel needs by redesigning cities
to be livable, rather than "drive-in deserts."
Secondly, he says, we need to remember that corn is merely a natural
means of converting solar energy into chemical energy, and that it's
not really all that efficient at doing so. Solar cells are much more
efficient, and could be harnessed to make hydrogen fuel.
Rather than subsidizing ethanol production, Patzek says, we should
invest in research designed to make it possible to produce these cells
more efficiently. In the U.S., he predicts that people will eventually
realize that corn ethanol isn't efficient and will switch to a
succession of other crops, none of which will be much better. A much
bigger problem, he says, will come with efforts to supply the
developed world's fuel needs with "green" imports from developing
countries
--
Posted via a free Usenet account fromhttp://www.teranews.com
Many of these allegations appear to be true. Corn based ethanol is,
in my opinion, a horrid excuse for an alternative to oil and
gasoline. All figures of just growing and converting corn to ethanol
aside, ethanol doesn't match up with gasoline. Ethanol gets fewer mpg
and even in places where ethanol is cheaper per gallon than gasoline
is, it still costs more to travel the same distance because more
ethanol must be purchased.
However, this is corn based ethanol. The most promising vegetation is
algae. For instance, a 1-acre corn field can, over the course of a
year in optimal conditions, produce 600 gallons of oil. A 1-acre pond
of algae can, over the course of the year in optimal conditions,
produce 10,000 gallons of oil.
.
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