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03.08
The Future
of Biofuels
By George Zobrist
Henry Ford and Rudolph Diesel’s
initial efforts to fuel their fledgling
automobiles involved ethanol and peanut oil,
respectively. However, they soon discovered that
refined petroleum was a far more efficient
source for gasoline and diesel fuel.
Despite oil's dominance, before
and during WWII, biofuels were used as
alternative fuels — Germany used alcohol
fermented from potatoes mixed with gasoline, and
in Britain, grain alcohol was blended with
gasoline. In the years after the war, whenever a
“crimp” in the oil supply cropped up,
alternative fuels such as ethanol were proposed
— notably during the oil embargo of 1973 and
again with the supply shock of 1979. However, in 1986, oil prices dropped
dramatically and remained relatively level for a
decade, so alternative fuels were pushed to the
back burner.
Today, we seem to be in a
high-demand cycle. With the advent of
high-growth economies in China and India, the
demand for petroleum has skyrocketed. Rising oil
prices and the nation's dependence on oil from
an unstable region of the world has driven
alternative and renewable energy sources back
into the spotlight. In late December 2007, the
president signed into law the
Energy Independence
and Security Act, which, among its
numerous provisions, calls for a five-fold boost
to ethanol production, to 36 billion gallons, by
2022.
Improving ethanol's prospects
for mainstream development, methyl
tertiary-butyl ether (MTBE) — a suspected
cancer-producing agent — has been banned as a
fuel additive, making way for ethanol as the
additive of choice.
Brazil: Biofuel Superpower
Brazil’s love affair with
ethanol began in the 1920s and continues today
as a model biofuel economy. In the late 1960s
and early 1970s, the country was importing most
of its oil from foreign sources. After the oil
crisis of 1973 ended a period of unprecedented
growth in the Brazilian economy, President
Ernesto Geisel decided to “wean” Brazil off of
imported oil by launching a nationwide,
government-funded program to reduce the number
of domestic automobiles that utilized fossil
fuels, in favor of vehicles that could run on
ethanol or a combination of the two. Like the
United States, Brazil's automobile industry
began producing cars that could run on
fossil-fuel-based fuel or ethanol, separately or
in combination.
Sugar cane yields 600
gallons/acre more than corn when converted to
ethanol, so Brazil ramped up its production of
sugar cane to satisfy its burgeoning thirst for
the alternative fuel. Today, Brazil's sugar cane
industry is the largest in the world — in both
production and export tonnage.
Because the price of ethanol is
considerably cheaper than gasoline, very few
Brazilians use gasoline. Today, thanks to its
ethanol program (Brazil and the United States
account for nearly 90 percent of the world's
ethanol production) and its domestic oil
sources, Brazil enjoys complete oil self
sufficiency.
Ethanol — Where Does It Come
From?
There are numerous sources for
ethanol: corn, soybeans, sugar cane, cellulose
(grasses, wood chips), butanol (a direct
replacement for gasoline, no modification to the
engine required — produced from fermentation of
acetone, butanol and ethanol and can be
distributed over the existing infrastructure),
and algae to mention a few. Ethanol's energy
content is approximately 67 percent of gasoline,
while biodiesel is 86 percent of the energy
content of diesel obtained from petroleum.
According to biofuel critic, Dr. David Pimental,
Cornell University, “Biofuels are a total waste
and misleading us from getting at what we really
need to do: conservation. This is a threat, not
a service. Many people are seeing this as a
boondoggle.”
While corn based ethanol has
been stated to have an energy balance from
negative to positive over the years, the more
recent analyses come up with approximately
1:1.13 (fossil fuel input to energy in ethanol
output). Greenhouse gas emissions are considered
to be 22 percent less than gasoline. Although
this figure is sometimes disputed, since emission of
nitrous oxide is emitted, which can be even more
potent than carbon dioxide. When comparing
energy equivalence (i.e., miles/gallon) at a
present cost of $3.03 gallon of gasoline, and
$2.62 for a gallon of ethanol (E85), it would
take $ 3.71 of ethanol to get the equivalent
mpg.
Sugar cane is much more
efficient, mainly since it is already at least
20 percent sugar, while corn must be processed
to obtain its sugar content. The energy balance
for sugar cane is 1:8 and has 56 percent less
greenhouse gas emissions.
Cellulosic ethanol is obtained
from agricultural residues, solid waste, pulp,
forestry waste, prairie grasses (switch grass)
to name just a few sources. Depending upon
the production method, the energy balance is
between 1:2 and 1:36, with 91 percent less
greenhouse gas emissions. The major problem at
present is that an efficient way to turn the
cellulose plant into ethanol is needed. Abengoa
Bioenergy, among other companies, is diligently
working on techniques to produce cellulose efficiently.
The energy bill requires that 36 billion
gallons of ethanol be produced, and 21 billion
gallons of this is to be derived from cellulose
by 2022. There is an experimental plant in York,
Nebraska, that produces about 3,000 gallons of ethanol
a day from 1.5 tons of cellulosic material.
Another major obstacle, though, is that
cellulosic ethanol is
approximately twice as expensive to produce as
starch based ethanol (i.e., from corn, soybeans etc).
A promising development is obtaining
ethanol from algae, which does not harm the
environment and it grows in wastewater, or sea
water requiring nothing more than sunlight and
carbon dioxide. Theoretically, algae can produce
5,000 gallons of biofuel each year per acre,
compared to 300 gallons from an acre of corn,
and soybeans around 60 gallons per acre. Again the
biggest problem is reducing the cost.
One of the major concerns is that
starch-based ethanol production could strain the nation’s
water and food supply. Kevin Book, an analyst with Friedman, Billings,
Ramsey Group Inc., said, “Our love affair with
ethanol has finally ended because we’ve taken
off the makeup and realized that, lo and behold
it’s actually a fuel.” According to a study by
the National Research Council, in Washington,
D.C., the water needed to grow
the corn, process the fuel and dispose the waste
at a small ethanol plant is roughly equal to the
water needs of a town of about 10,000. However, the report also
states that if there is judicious location of
the plants and also where the corn for ethanol
is grown, water consumption may be minimized. Ethanol plants
now require about four gallons of water to
produce a single gallon of ethanol. T. Boone
Pickens has purchased 400,000 acres of water
rights in the Texas panhandle — there must be
money in drilling for scarce water.
Since the production of ethanol
from a starch-based source presents a disruption to
the fuel supply, one has to be concerned with
the impact on food production. In early 2007, stories
of food riots in
Mexico were related to the rising price of corn used for
tortillas. And Heineken also experienced reduced profits for Heineken
when the area used to grow
barley was reduced, driving up the the cost
of barley. According to Jean Ziegler, the U.N. Special Rapporteur on Food,
the effects on the
world's populace (especially the poor) from
transforming starch-based crops into biofuels
are “absolutely catastrophic.” Ziegler calls for
a five-year moratorium on biofuel production
while their impact upon the food chain is
investigated.
Another major hurdle for ethanol is
the nationwide distribution from the ethanol
plant (at present mainly in the Midwest) to the
point of usage. Ethanol isn’t shipped in
existing pipelines because its high oxygen
content makes it very corrosive, and it also
absorbs water and impurities. The research being
done by the pipeline industry is still in its
infancy. Brazil has shipped ethanol over
pipelines successfully — but, in the United
States, an
infrastructure has to be in place before there
is enough volume to pay for it, according to an
article in the St. Louis Post Dispatch by
James McPherson (17 November 2007).
Even the Sheikhs have begun to
be aware of declining petroleum resources and
have invested $250 million in a renewable
energy initiative.
One day, we may witness a return
to the late 18th and early 19th century, when
America’s transportation system was fueled by
biomass — 30 million horses and mules —
according to Ken Vogel, U.S Department of
Agriculture. The millions of acres used to fuel
this transportation system could be converted to
prairie grass for the fueling of our present day
transportation system, without disruption of our
food supply.
Material for this article was
“gleaned” from some of the following Web sites
and various newspapers, especially the Wall
Street Journal, and the National
Geographic magazine (October 2007):
Dr. George W. Zobrist is
professor emeritus at the University of
Missouri-Rolla, Department of Computer Science,
IEEE-USA's Member Activities editor, and former
editor of IEEE Potentials. Comments may
be submitted to
todaysengineer@ieee.org. Opinions expressed
are the author's.
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