Is ethanol better for the environment than gas?

Jun 23, 2010 By E/The Environmental Magazine

Dear EarthTalk: Where does ethanol as an automobile fuel fit into the alternative energy mix? Is it better for the environment than gasoline? (Donna Allgaier-Lamberti; Pullman, Mich.)

Ethanol -- a derived from corn and other -- is already playing a major role in helping to reduce emissions from many of the traditional gasoline-powered cars on the road today. According to the U.S. Department of Energy, nearly half of all the gasoline sold in the U.S. contains up to 10 percent ethanol, which not only boosts octane but also helps meet federally mandated air quality requirements. By promoting more complete fuel combustion, this small amount of ethanol mixed into gasoline reduces exhaust emissions of carbon monoxide -- a regulated pollutant linked to smog, , global warming and other environmental problems -- by as much as 30 percent compared with pure gasoline.

Also, a growing number of so-called "flex-fuel" vehicles now available can run on either straight unleaded gasoline or so-called E85, a mix of 85 percent ethanol and 15 percent gasoline. Ethanol proponents underscore emissions savings, cost stability (ethanol is distilled from domestically grown corn) and reduced reliance on (foreign) oil as benefits of more drivers filling up their tanks with E85 instead of gas.

But even though some eight million flex-fuel vehicles are now on U.S. roads, most of them are not near convenient ethanol refilling stations and are therefore mostly running on regular . (The U.S. Department of Energy website has a map-based listing of E85 refueling stations across the country -- most are in the Midwest's ".") So while the capacity and perhaps demand for a cleaner burning fuel is there, supplies have not kept pace -- some say because the federal government has subsidized ethanol producers only and not the distributors and retailers who get the product to customers.

But this may change. In May 2009 President Obama signed a Presidential Directive to advance research into biofuels like ethanol and expand their use. The resulting Biofuels Interagency Working Group is developing a plan to increase flex fuel vehicle use by making E85 and other biofuels more available.

While many environmental advocates view increasing ethanol use as a promising development (if drivers would actually fill up with it), others are not so sure. Cornell agriculture professor David Pimentel argues that producing ethanol actually creates a net energy loss. His research shows that a gallon of ethanol contains 77,000 BTUs of energy for engines to burn but requires 131,000 BTUs to process into usable fuel, not including additional BTUs burned from fossil fuel sources to power the farm equipment to grow the corn, and the barges, trains and trucks used to transport it to refineries and ultimately fueling stations.

Pimentel also says that powering a car for a single year on ethanol would require 11 acres of corn, which could alternatively feed at least seven people. If we step up our use of and begin putting our farmers' yields into gas tanks instead of on dinner tables, we could see a shortage of domestically grown food and higher prices at the grocery store. To address this problem, biofuels producers are researching alternative non-food feedstocks such as algae, corn stalks, wood chips and switchgrass, though they would still make use of arable land that could grow food for human consumption.

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merlinson
5 / 5 (2) Jun 23, 2010
*Sigh* Isn't it amazing that Pimentel is always the guy who's 'science' gets quoted in so many of these articles. (The scientific consensus does not agree with his conclusions and his methods are generally criticized.) But he does have connections with the American Petroleum Institute. I'm sorry to sound so cynical, but it is so depressingly familiar. See, for example:
http://journeytof...rgy.html
gunslingor1
5 / 5 (1) Jun 23, 2010
"According to the U.S. Department of Energy, nearly half of all the gasoline sold in the U.S. contains up to 10 percent ethanol"
-NEARLY half and UPTO 10% are the key terms. very misleading; actually far less than 1% of fuel is ethanol.

Also, a growing number of so-called "flex-fuel" vehicles now available can run on either straight unleaded gasoline or so-called E85, a mix of 85 percent ethanol and 15 percent gasoline.
-This is good, but there are no fueling stations so it's pointless and these cars burn more gasoline than non-flex cars, they weren't designed for gas; so we are actually polluting more as a result of these cars.

His research shows that a gallon of ethanol contains 77,000 BTUs of energy for engines to burn but requires 131,000 BTUs to process into usable fuel.
-how about a comparison with fossil? this value alone means nothing.

-you can make ethanol out of any organic matter, but its just a temporary method that fits with existing infrastuture.
merlinson
5 / 5 (3) Jun 23, 2010
I'm one of the lucky few with an ethanol station a few miles from my home. I believe that the only real difference in a flex-fuel vehicle is the oxygen sensor in the input fuel line (both have exhaust sensors) and the software in the ECU to take that info into account. I put a conversion kit in my 2006 scion which has a pot to adjust the magnitude of an extra pulse to the fuel injectors. With the pot set to about quarter-scale, I'm getting about 10% less mpg on e85 with excellent performance. But e85 is $2.10 and premium is $2.95 so I'm actually coming out ahead at the moment. (I'm also beating regular gas, but e85 is 105 octane.) With the pot at 50%, I get about 20% less mpg. If I am away from home base for a while, I can just set the pot to zero and get my normal mpg on regular. I think the value of the fuel line sensor is to set that pot for me automatically, so I don't think there is really that much of a design difference.
jerryd
3 / 5 (2) Jun 23, 2010
Pimental is a liar bought and paid for by big oil.

What he doesn't mention is the yellow corn used is not human food. But after making ethanol it is a much higher quality food for either humans or cattle. So in reality, little food is lost in making ethanol. He also uses very old data, now ethanol uses far less energy.

But not only do you get ethanol from the corn used but also the dried mash sell for almost what the corn was bought for plus there is corn oil, stalks, cobs that can be used as food, fuel, bedding, methane production after being used for bedding, ect. So all the energy input must be divided by all these products which Pimental leaves out.

Since ethanol makes up 6% of US gasoline supply something in the article's numbers is wrong too.

I have no stake in ethanol as I'm an EV person and mine gets 600mpg equivalent. But it Pi--es me off see such lies by big oil still being spread.
Choice
5 / 5 (1) Jun 25, 2010
So, the issues have been spotted and the pros and cons mentioned, but where is the answer to the question. Is it better or not? The answer depends on what aspect of the environment you are looking at or in other words what are the boundaries of the comparison. Here is an example of one study using only one type of ethanol crop:
www.nrel.gov/docs...1792.pdf

This hyperlink will take you to a list of articles using other boundaries:
http://politicale...t=Search