Fuel’s
Gold - Ethanol
found @ http://feinstein.senate.gov/05speeches/ethanol-oped.htm
Most
people would agree that the United States needs a new source of
fuel: something renewable and nonpolluting with which to replace
gasoline ... something that could be produced right here at home.
Deep in America's heartland, a lot of people think they know the
answer: ethanol, a fuel made from fermented crops.
According to U.S. Department of Agriculture estimates, you can get
about 21/2 gallons of it from a bushel of corn. And an increasing
number of states are working to make an 85 percent ethanol fuel
called E85 available at gas stations at prices significantly below
that of regular gasoline ... even when you account for the fact
that ethanol provides only 62 percent of the mileage of
gasoline.
It sounds like a perfect, win-win solution for both the nation's
farm economy and its energy needs. According to the National Corn
Growers Association, ethanol production could make 1.4 billion
bushels of corn "disappear" in 2004 ... enough to replace more than
2 billion gallons of gasoline and provide a much-needed market for
farmers stricken with chronically low corn prices.
This would also be one of many small public scapegoats for the
coming artificially induced food shortage and economic
decline........
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.
Pimentel is an ecology professor who had been examining energy
usage in corn production since 1970. It may sound odd for an
ecologist to study agriculture, but it's not actually a big jump,
because ecologists have long been interested in energy flows in
natural systems. Pimentel sees his work merely as applying a
traditional way of thinking to a new arena.
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.
Shapouri, on the other hand, charges that Patzek and Pimentel
should be basing their study on USDA's corn-growing data, rather
than attempting to supplement the government statistics with
figures from other sources. "We used a USDA corn survey and also a
survey of ethanol plants," Shapouri told the National Corn Growers
Association in 2004. "Our data are crystal clear."
Patzek, on the other hand, sees no reason not to try to improve on
the USDA data. "They're not God," he says.
Rating the leftovers
But the most important dispute involves how to account for the fact
that fuel isn't the only product to come from an ethanol plant. The
leftovers from the fermentation process form dry distillers grain,
which can be used in food production. Because dry distillers grain
represents nearly 34 percent of the plant's output, Shapouri says
that 34 percent of the total energy cost should be credited to it.
That leaves only 66 percent to be charged against the
ethanol.
Pimentel agrees that a credit is appropriate but argues that
because soybean meal can be used for many of the same purposes, the
appropriate adjustment is for the amount of energy needed to grow
and produce soybean meal – vastly smaller than the amount needed
for growing corn and making dry distillers grain.
An additional problem is that corn is an environmentally unfriendly
crop. It contributes more to soil erosion than do other crops, says
Pimentel, and pesticides and the nitrates from nitrogen fertilizer
contaminate creeks, rivers and even the Gulf of Mexico.
These problems can be reduced by using other crops for ethanol,
such as grass or wood, or by making biodiesel from soybean oil or
sunflower oil. But grass and wood are difficult to process, and
oilseed crops have relatively low yields compared with corn.
Pimentel did his energy calculations with all four and found that
only soybeans fare better than corn (because they don't need
nitrogen fertilizer to grow). But even they require 1.27 times as
much energy to produce as they give back in biodiesel, he
says.
A fifth alternative, sugar cane, might be slightly better, he adds,
but it too depletes soils and increases erosion.
In his 1966 novel "The Moon Is a Harsh Mistress," science fiction
writer Robert A. Heinlein coined the slogan TANSTAAFL – short for
There Ain't No Such Thing as a Free Lunch. If there is any single
thing that the ethanol dispute reveals, it's that in the search for
alternative fuels, Heinlein's motto is depressingly correct.
Even Shapouri's figures show only a 67 percent return on the energy
investment needed for ethanol production. But many other forms of
energy suffer from the same problem, including drilling for oil and
mining coal, which require a lot of energy for drilling,
transportation and digging.
"That's the thing," he says in an echo of Heinlein. "If you want to
produce energy, you have to spend energy."
Pimentel thinks we'd get more return on our energy investment by
growing trees for woodstoves or other such uses. "Wood is an
extremely valuable resource," he says. "We already get 3 percent of
our energy from biomass – the same as we get from hydropower. But
that's thermal energy, not liquid fuel."
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.
"All this hoopla about corn ethanol is child's play compared with
the issue of biomass production in the tropics," he says. "The
issues with converting pristine, important ecosystems into
plantations will dwarf the problems we have with corn ethanol in
the U.S. We're encroaching on the basic environmental services of
the planet, and that's a lot more scary than polluting the
Mississippi Basin and Gulf of Mexico with nitrates."
Patzek would most likely agree with Heinlein's TANSTAAFL principle.
As he sees it, there's no such thing as a totally benign,
farm-grown energy source. "It's not that simple," he says sadly.
"It's anything but simple."
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