Ethanol promising but can it deliver?
Ethanol:
Energy Panacea or
False Promise?
By Charles Q. Choi
April 18th, 2007
LIVESCIENCE.COM
(Links are in GREEN)
Now that experts
know how to convert prairie
grass and leftover lumber
into ethanol,
six biorefineries scheduled
for completion within five
years could help the
United States produce 130
million additional gallons
of the fuel per year.
Ethanol,
more commonly known as
drinking alcohol, is touted
by some as a viable
alternative fuel for vehicles.
Although its energy content
is roughly two-thirds that of
gasoline by volume,
ethanol is increasingly flowing
into gas tanks,
with some one out of every
eight gallons of gas sold in
the United States containing
8 to 10 percent ethanol.
Yet there is heated debate
among scientists as to whether
or not ethanol really is good
for the environment.
Studies hint,
for instance,
that ethanol might guzzle
more energy during its
manufacture than it provides,
and that it might
strain valuable water resources.
Recent findings also suggest
fuels high in ethanol
may pose an
than regular gasoline.
Corn ethanol and E85
Unlike gasoline,
ethanol is made renewably,
from plants,
which naturally soak up the
greenhouse gas carbon dioxide.
Ethanol production and
consumption might therefore
release less carbon dioxide
into the atmosphere than
gasoline use does.
In the United States,
ethanol is most often
made from corn.
Some 13 percent of the U.S.
corn crop was devoted to
making ethanol in 2004.
“There are certainly benefits
with ethanol if you’re a farmer
in terms of subsidies,”
said Stanford atmospheric
scientist Mark Jacobson.
E85,
a fuel blend of 85 percent
ethanol and 15 percent gasoline,
could power millions of
already on the roads and is
available at more than
1,000 service stations.
However,
the U.S. supply of ethanol
is small when compared
with gasoline.
The United States currently
uses roughly 140 billion
gallons of gasoline a year,
more than any other country.
In contrast, the country
produced roughly 4 billion
gallons of ethanol in 2004.
Most stations carrying E85
are in the Midwest, and the
fuel is rare and expensive in
the rest of country.
Although the six biorefineries
scheduled for completion by
2011 won’t by themselves add
great volumes to existing U.S.
ethanol production,
they are part of a strategy to
demonstrate that ethanol can
be generated more cost-effectively
from the hundreds of millions
of tons of cellulose in plant scrap
that would otherwise go
to waste.
“Those could show that you
can really bring the cost of
ethanol down,”
chemical engineer Bruce Dale
at Michigan State University
told LiveScience.
“I believe we’ll demonstrate
in less than five years that we
can make ethanol from cellulose
for in the neighborhood of
$1.20 a gallon.
Given that gas is now about
$3 a gallon lots of places,
I think people will fall all over
themselves trying to put
together supply chains to
make cellulosic ethanol.”
___ 
Energy for making it
Critical points of contention
over ethanol regard whether
or not creating it requires more
energy than consuming
it gives off.
Although a great deal of
energy that goes into ethanol
comes from the sun,
much human effort is also
required when it comes to
processing raw plant
material to make ethanol.
And there are the efforts
that go along with farming
and pesticide and
fertilizer use.
Research from applied economist
Jason Hill at the University of
Minnesota and his colleagues
found you do get more energy
from ethanol than you put in it,
some 25 percent more.
“So there is the benefit of
energy gain there,”
Hill said in a
telephone interview.
However, research by
chemical engineer Tad Patzek
at the University of California,
Berkeley and others finds
you get less energy from
ethanol than you put in it,
returning just 26 percent
of the energy invested into
making the fuel.
“Ethanol has this false
promise of satisfying our
transportation fuel needs,”
Patzek said.
Also, ethanol may not cut
down on carbon dioxide
emissions as much as hoped.
Energy expert Alexander Farrell
at the University of California,
Berkeley and his colleagues
found that replacing gasoline
with corn ethanol would
reduce a car’s total greenhouse
gas emissions by only
about 13 percent,
since creating ethanol in
itself produces a lot
of pollution.
Dale contended that cellulosic
ethanol could even cut total
greenhouse gas emissions
by 90 percent.
However,
Patzek suggested ethanol
manufacture and consumption
could release more greenhouse
gases into the air than
gasoline usage does.
“A problem I see is the
‘nirvana fuel syndrome,’
where there’s some fuel with
no problems,” Dale said.
“I would say instead,
‘What problems does this
fuel have compared
with others?’
I would say that ethanol as
a replacement for gasoline
is in almost every measurement
far superior to gasoline,
in terms of climate effects
and getting away from the
screw situation you have
geopolitically with oil.”
Patzek remained unconvinced.
“Not only can ethanol not
supply all of the nation’s
fuel demand, it can’t even
supply a small fraction of it,”
he said.
“That’s the bottom line.”
___________________________
Surprise:
Ethanol as Deadly
as Gasoline
For Now
By Charles Q. Choi
April 18th, 2007
LIVESCIENCE.COM
Fuels high in ethanol may pose an equal or greater risk to public health than regular gasoline, new findings suggest.
”Ethanol is being promoted as a clean and renewable fuel that will reduce global warming and air pollution,”
said Stanford University atmospheric scientist Mark Jacobson.
But he found the number of deaths and hospitalizations linked with respiratory ailments might increase if every vehicle in the United States used the latest automotive technology and ran on fuel containing high levels of ethanol.
The findings counter the environmentally friendly image of ethanol fuels.
Ethanol is made from corn and other plants, which naturally soak up carbon dioxide. Research suggests that ethanol production and consumption might therefore release less of this greenhouse gas into the atmosphere than gasoline use does.
Increase in ozone
Jacobson used 3-D atmospheric computer models to simulate air quality in the year 2020, when ethanol-fueled vehicles could become widely available in the United States.
”The chemicals that come out of a tailpipe are affected by a variety of factors, including chemical reactions, temperatures, sunlight, clouds, wind and precipitation,”
he explained.
”In addition, overall health effects depend on exposure to these airborne chemicals, which varies from region to region.”
Jacobson focused especially on Los Angeles, which is home to about 6 percent of the nation’s population and has historically had some of the most polluted airs in the United States and has been the testbed for nearly all U.S. air pollution regulations, making it ideal for a more detailed study, he explained.
He programmed the model to compare two future scenarios—one in which all the cars, trucks, motorcycles and other autos in the country are fueled by gasoline, and another in which vehicles are driven by E85, a popular blend of 85 percent ethanol and 15 percent gasoline.
”We found that E85 vehicles reduce atmospheric levels of two carcinogens, benzene and butadiene, but increase two others, formaldehyde and acetaldehyde,”
Jacobson said.
”As a result, cancer rates for E85 are likely to be similar to those for gasoline.
However, in some parts of the country, E85 significantly increased ozone, a prime ingredient of smog.”
.
_____
200 more deaths per year
Specifically, E85 would cause ozone levels to increase in Los Angeles and the northeastern United States but to decline in the southeast United States.
This is because of levels of airborne pollutants such as nitrogen oxides or volatile organic compounds such as formaldehyde vary in the air of each locale.
Emissions from E85 would therefore react chemically in different ways, creating ozone at some areas and destroying it in others.
Gasoline currently leads to roughly 10,000 premature deaths in the United States annually from ozone and particulate matter, Jacobson explained.
”In our study, E85 increased ozone-related mortalities in the United States by about 200 deaths per year compared to gasoline, with about 120 of those deaths occurring in Los Angeles,”
he said.
”These mortality rates represent an increase of about 4 percent in the U.S. and 9 percent in Los Angeles above the projected ozone-related death rates for gasoline-fueled vehicles in 2020.”
“We found that nationwide, E85 is likely to increase the annual number of asthma-related emergency room visits by 770 and the number of respiratory-related hospitalizations by 990,”
Jacobson said of his findings, detailed in the April 18 online edition of the journal Environmental Science & Technology.
”Los Angeles can expect 650 more hospitalizations in 2020, along with 1,200 additional asthma-related emergency visits.”
Combustion engine problem
These numbers might change if better ways to treat ethanol fuel emissions develop in the next 10 years, Jacobson said.
“But based on what we currently know, ethanol is at least as bad to public health as gasoline, and possibly worse,“
he told LiveScience.
“People might say that these aren’t huge increases in deaths we’re seeing here,”
he added.
“My response would be that I don’t think 10,000 deaths a year from gasoline is a good thing to begin with.
There are technologies we can use instead of any type of combustion engine that would result in no tailpipe deaths, such as battery-electric vehicles whose energy can come from wind or solar power.”
Atmospheric chemist Roger Atkinson at the University of California, Riverside noted,
“It’s been known for a long time that E85 is not the cleanest fuel in the world.”
He added that regulatory agencies such as the Environmental Protection Agency and the California Air Resources Board
“will have to keep on top of this issue to make sure things don’t go awry.
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