June
2007
Biofuel:
A Burden on the Food Supply?
By Valerie Yeager
Today’s Dietitian
Vol. 9 No. 6 P. 42
Renewable energy may lessen U.S. reliance
on foreign oil, but does developing biomass threaten sustainable
agriculture?
Having recently moved to a new city, I’m
naturally excited for the fresh experiences accompanying my
relocation—the bright lights, endless dining possibilities,
and world-class museums. The energy is tangible. Nevertheless,
I’m perhaps most excited about one thing in particular:
public transportation. No longer will I be standing at the fuel
pump, watching the numbers skyrocket as I fill my gas-guzzling
tank.
Even so, I still feel a twinge of horror every
time I pass a gas station. Will the prices ever drop considerably?
It’s unlikely, but the increasing popularity of biofuels
such as biodiesel and ethanol—quickly gaining momentum
as an unconventional substitute—will certainly help.
Biofuels are often applauded in the media as
the magical solution to the energy crisis, replacing petroleum
as the driver of our economy. But one can’t help but wonder:
How will transforming products derived from popular crops such
as corn and soybeans into fuel affect the food supply?
Seeking a Solution
At this point in the 21st century, the United States is faced
with two critically important energy problems: our dependence
on foreign oil and the climate-disrupting greenhouse effect.
The United States imports 70% of its oil, and Al Gore’s
An Inconvenient Truth demonstrates just how serious the climate
issues are becoming. The world’s oil demand is continually
growing while supplies are continually shrinking, leaving the
political and economic stability of our nation and its environment
at risk.
According to Dick Auld, PhD, of the department
of plant and soil science at Texas Tech University, approximately
96% of the energy sources in the United States come from nonrenewable
sources, such as the following:
• coal: 23%;
• petroleum: 40%;
• natural gas: 25%; and
• nuclear: 8%.
These nonrenewable resources will eventually
run out, significantly impacting future generations if sustainable,
renewable resources are not developed as a primary source of
fuel. Unfortunately, there is no easy solution, especially when
less than 4% of U.S. energy is currently produced from renewable
sources such as solar, wind, geothermal, hydroelectric, and
biomass (plant-derived material). Of these, biomass is making
the most significant impact.
Ethanol and Biodiesel
Corn muffins. Corn flakes. Corn fuel?
The largest U.S. renewable energy source each
year since 2000, biomass provides the only renewable alternative
for liquid transportation fuel in the form of ethanol and biodiesel.
Corn and soybeans are among the most popular sources of biomass
used to develop fuel.
Mostly developed from sugar and starch crops,
ethanol is a type of alcohol made by fermenting plant material.
It burns much more cleanly than pure gasoline, so it releases
far lower emissions. It can be combined with gasoline in any
concentration up to pure ethanol. Worldwide automotive ethanol
capabilities vary widely, and most spark-ignited gasoline-style
engines operate well with mixtures of 10% ethanol.
Meanwhile, biodiesel is a fuel designed for
diesel engines that is produced by blending petroleum diesel
with refined vegetable oil. The blend most often available for
consumers is 20% biodiesel, referred to as B20. Like ethanol,
biodiesel releases significantly lower emissions than pure petroleum
diesel.
To the surprise of many, biofuels aren’t
exactly a new concept. In 1892, the first diesel engine was
designed to run on peanut oil, and in 1908, the Ford Model T
was designed to run on ethanol.
Only since the 1990s, however, have biofuels
become more readily available to consumers. Demand for biofuels,
by farmers and trucking companies in particular, is growing.
Even tractor-maker John Deere is jumping on the bandwagon by
shipping tractors and combines from its factories with biodiesel
in the tanks. The price is roughly the same as pure petroleum
diesel and even began selling at 4 cents per gallon less at
some outlets during summer 2006.
The basic processes for converting biomass to
biofuel are well-known and used commercially today. Two key
reactions must occur to convert biomass to ethanol: hydrolysis
and fermentation.1
Hydrolysis is the chemical reaction that converts
the complex polysaccharides in the raw feedstock to simple sugars.
In the biomass-to-ethanol process, acids and enzymes are used
to catalyze this reaction. Fermentation is a series of chemical
reactions that convert sugars to ethanol. The fermentation reaction
is caused by yeast or bacteria, which feeds on the sugars. Ethanol
and carbon dioxide are produced as the sugar is consumed.1
Problems on the Horizon
Food Supply
A concern not only to nutritionists and dietitians but also
to biologists, environmental engineers, and farmers is food
supply. Are the industrial methods currently used to produce
crops popular for both food and fuel sustainable? According
to Angie Tagtow, MS, RD, LD, an environmental nutrition consultant
and immediate past chair of the Hunger and Environmental Nutrition
Dietetic Practice Group of the American Dietetic Association,
the answer is a resounding “no” for the following
reasons:
• the high input costs, such as land prices,
machinery, seed, herbicides and pesticides, fertilizer, storage,
and transportation;
• the environmental insults from aggressive
farming techniques, such as soil depletion and erosion, as well
as pesticide and fertilizer runoff resulting in polluted waterways
and contaminated water supplies; and
• the amount of energy it takes to grow,
harvest, and transport these crops to fuel refineries outweighing
the amount of energy generated from the fuel itself.
According to Tagtow, farmers in the Midwest
are devoting more land to corn production, “further perpetuating
a monocropping system, decreasing biodiversity, and further
destroying the resilience of the soil and waterways.”
Although these changes may not be immediate, the results will
eventually make staggering transformations in the way people
eat. “Agriculture is the foundation of the food system,
and the subsidized agricultural products have influenced what
we eat and the nutrition and health of our society. When monocrops
are the norm and diversity dwindles, this is directly reflected
in our diets,” she adds.
Finding a suitable, renewable source of fuel
is clearly crucial, but at what price? As more crops are grown
for ethanol production, the price of those crops will fluctuate.
“As the demand for corn increases, I anticipate the price
of corn will increase. As the price of corn increases, we will
experience an increase in food costs and particularly with beef,
dairy, pork, poultry, and eggs (livestock that rely on corn
for feed). The price of food will be greatly affected if the
price of petroleum and corn increases simultaneously,”
says Tagtow.
“This is especially critical to low-income
families who already devote 30% to 40% of their household income
to food and will greatly impact the budgets of federal food
and nutrition assistance programs, such as the Special Supplemental
Nutrition Program for Women, Infants, and Children; Food Stamps;
and School Feeding Programs,” she continues.
Genetic Engineering
Genetically engineering crops to ensure sustainability for both
the fuel and food supply is an option, but it may wreak havoc
on the ecosystem. Techniques such as accelerated domestication
make for more efficient energy crops, but the genetic modification
of these plants could take an invasive turn. One proposed biofuel
crop, Miscanthus, can grow up to 8 feet in six weeks, acting
essentially like a plant on steroids and overtaking surrounding
crops that act as food sources for wildlife.
Also, genetically engineering a crop may alter
its genes in ways other than just growth. “Some of the
genes being engineered into corn to make it a better source
of ethanol aren’t genes we want in the food chain. And
without confinement, such as plant sterility, those genes could
find their way into the corn that we eat,” says Albert
Kausch, PhD, a plant geneticist at the University of Rhode Island.
Overall, while genetic manipulation may be a quick fix to retain
sustainability, the long-term effects could be disastrous.
The Future of
Biofuel
Although it won’t entirely solve the problem, including
more diversity in the biomass converted to fuel will help. Luckily,
it is becoming more popular in research and technique for alternative
sources beyond corn and soybeans to be used as biofuel sources.
Among these emerging fuel sources are corn stovers and wheat
stalks, fast-growing trees such as poplar and willow, and several
perennial energy crops such as switchgrass. Switchgrass, a native
plant of the tall grass prairies, grows up to 12 feet tall in
one season and produces as many as 10 tons of plant material
in one acre without genetic modification.
After all, corn and soybeans alone aren’t
enough to make a dent in the nation’s dependence on oil.
Researchers have estimated that the United States has a sustainable
supply of roughly 1.4 billion tons of biomass each year that
could be used specifically for the production of liquid fuels,
which, using conventional methods, would provide only 30% of
the fuel required for the nation’s annual transportation
needs.2
Another helpful route is the increasing popularity
of new techniques in the way biomass is converted to biofuel.
Ethanol is currently developed using only the corn kernels because
that is the only part of the ear containing the sugars that
can be fermented and distilled to make ethanol. But corn stalks
and husks—largely considered waste—may be more useful
in biofuel production as advancements continually emerge.
Corn stalks and husks are made of cellulose,
a polymer that is comprised of many sugar molecules strung together.
If cellulose is treated with an appropriate catalyst—an
enzyme capable of breaking it down into the sugars from which
it is formed—these sugars can then be fermented and distilled
to form alcohol. This change would make the corn-to-ethanol
process far more efficient, allowing the corn kernels to continue
to be used as food, avoiding the steep increase in agricultural
prices that would occur if corn became a fuel supply source.
The conversion of corn husks and stalks to ethanol
is only one example of the potential to efficiently convert
cellulose into biofuels. Cellulose is the most abundant organic
chemical that exists and trees, leaves, grass, and virtually
all plant materials contain large amounts of it. Converting
cellulosic biomass to ethanol is currently too expensive for
use on a commercial scale, but that will hopefully change as
new advancements materialize.
The Biofuels Innovation
Program
In February, the National Wildlife Federation unveiled a proposal—the
Biofuels Innovation Program—for the 2007 Farm Bill Energy
Title to help farmers switch to growing a new generation of
biofuel crops. The proposal promotes the production of biofuels
and biomass through the following:
• encouraging production of dedicated
perennial energy crop feedstocks in a sustainable manner that
protects the nation’s soil, air, water, and wildlife;
and
• providing financial and technical assistance for owners
and operators to produce dedicated bioenergy perennial crops
and crop mixes of suitable quality and in sufficient quantities
to support and/or induce development and expansion of the use
of the crop for the following:
- biofuels;
-
- power or heat generation to supplement or replace non–bio-based
energy sources; and
- bio-based products to supplement or replace
non–bio-based products.3
Essentially, the plan would enroll up to 5 million
acres of land to promote the sustainable production of next
generation biomass energy, such as switchgrass for ethanol and
jojoba for biodiesel. Taking into account the concerns of invasive
biologists, the plants used must be perennials native to the
United States and not have the potential to become invasive.
The proposal also considers Tagtow’s concerns
regarding the amount of energy it takes to transport crops to
fuel refineries. For a facility that uses biomass to be economically
viable, the biomass it utilizes must be grown within a relatively
concentrated area to ensure manageable transportation costs.
Most experts describe this area as being within a 50- to 70-mile
radius of the facility. The Biofuels Innovation Program addresses
this issue by requiring groups of landowners to come together
to apply for funding as a project rather than as individual
landowners. This way, crops are being transported from several
farms in a local area rather than just one. Participants must
collectively submit a written Bioenergy Project proposal to
the secretary of the U.S. Department of Agriculture that includes
the number of owners and operators participating; number of
acres proposed for enrollment in the program; type and diversity
of eligible crops to be grown; probability that the bioenergy
crops proposed to be grown under this program will be utilized
for the purposes of the program; and potential for positive
economic impact on the local community.3
Conclusion
Our society is heavily reliant on several nonrenewable energy
sources, such as petroleum, coal, and uranium, and biofuels
alone will not be able to replace these sources and meet our
present high-energy needs. “We must look to true renewable
and sustainable energy sources such as solar, wind, and hydropower.
These are true renewable and sustainable energy sources because
they do not require continual inputs or degrade the environment
and can be maintained now and for future generations. Using
these renewable energy sources will decrease the competition
with our food supply,” says Tagtow.
Tagtow urges dietitians to take an “active
role with energy conservation and advocating for agriculture
policy that supports a diet aligned with the Dietary Guidelines
for Americans. Dietitians need to engage in critical thinking
about how food is produced, processed, purchased, and consumed
and how influences on our food system impact the availability,
accessibility, quantity, safety, and nutritional profiles of
foods needed for a healthy diet.”
Although the future energy crisis is unlikely
to be solved by biofuels alone, they are likely to make a substantial
impact on our energy future, as well as the future dietary habits
of Americans. Adds Tagtow, “If future fuel resources rely
on food sources, dietitians must be engaged in this dialogue.”
— Valerie Yeager is an editor and
freelance writer based in Philadelphia.
References
1. U.S. Department of Energy — Energy
Efficiency and Renewable Energy Biomass Program. “ABCs
of Biofuels.” Available here.
Accessed March 29, 2007.
2. Purdue University. “New Biofuels Process
Promises to Meet All U.S. Transportation Needs.” March
14, 2007. Available here.
3. Biofuels Innovation Program. “A Proposal
for the 2007 Farm Bill Energy Title.” Available here.
Accessed March 29, 2007.
