Ethanol: How the Fuel is Produced, Growing Corn and Other Feedstocks, and More
by Collin Dunn, Corvallis, OR, USA on 07.26.07
Ed. note: This post, about ethanol is now the third post (read about biodiesel and compost to catch up) in the Green Basics series of posts that TreeHugger is writing to provide basic information about important ideas, materials and technologies for new greenies (or those who just need a quick refresher). Read on and stay tuned!
Ethanol as fuel
Ethanol is also known as ethyl alcohol, the same kind of alcohol you shake with vermouth and serve with some olives. Used as a fuel, it is often added to gasoline (notated much the same as biodiesel: E10 means 10% ethanol; E85 means 85% ethanol, and so on). Most gasoline-burning car engines on the road today will operate on E10 without modification, and most of the ethanol produced in the world today is "bio-ethanol," or ethanol derived from the starch or sugar in a wide variety of common crops, or feedstocks. Most commonly, ethanol is made by fermenting sugar with yeast (just as drinking alcohol is), distilling it to remove most or all of the water and then usually denaturing it (this steps isn't required to make fuel), altering it so that more than a swig will land you in the hospital. So don't drink it.
What is ethanol?
Compared with conventional unleaded gasoline, ethanol is a particulate-free burning fuel source that combusts cleanly with oxygen to form carbon dioxide and water. Use of ethanol, produced from current methods, emits a similar net amount of carbon dioxide but less carbon monoxide than gasoline.
Ethanol: who's making it
Brazil and the United States accounted for 90 percent of all ethanol production. Also, it should be noted that the United States, now producing at a rate of about 4.6 billion U.S. gallons per year, is widely considered the world’s largest ethanol producer.
Corn ethanol
Of the feedstocks in wide use today, corn is the most popular in the US, and this makes it a very contentious subject. In the US, corn is widely grown, heavily subsidized and (often) heavily fertilized and sprayed with pesticides; the latter two are very unhealthy and energy-intensive (many of the fertilizers are petroleum-based). One bushel of corn (about 35 liters) nets about 2.8 gallons (10 liters) of fuel -- that translates to between 330 - 420 gallons per acre, leaving about 18 pounds of by-products known as distillers dried grains with solubles (DDGS), which can be used as feed for livestock. Ethanol produced from corn offers roughly a 10% - 20% reduction in greenhouse gas emissions when compared to gasoline.
Ethanol and fuel prices
Because ethanol contains approximately 34% less energy per unit volume than gasoline, burning it results in a 34% reduction in miles per US gallon; that is to say, if your car gets 30 mpg and you switch to pure ethanol (that'd be E100), you'd likely get about 20 miles per gallon. Further, because corn-derived ethanol requires so much of the crop, the growth of this as a fuel source has wide-ranging agricultural implications, from the price of corn (which has risen by 50% in Mexico) to the substantial amount of land required to grow the crop. Additionally, prices for U.S. corn-based products, including animal feed, also rise. This translates to higher prices for animal products like chicken, beef, and cheese; for example, June 2007 cheese prices rose to $2 per pound on average, increasing 65% over the same period in 2006.
Ethanol in Brazil: all about sugar cane
In warmer climes, different feedstocks with different energy yields are used. In Brazil, sugar cane is the crop of choice (pictured above), and it provides about 18 percent of the country's automotive fuel. Sugar cane produces nearly double the yield per acre of corn (between 570 - 700), and offers a reduction of 87% - 96% in greenhouse gas emissions when compared to gasoline. Almost 50% of Brazilian cars on the road today are able to use 100% ethanol as fuel, that includes ethanol-only engines and flex fuel engines.
Ethanol's advantages and disadvantages
Proponents of the fuel argue that it's an important step away from petroleum, and offers to help increase national security because it can be produced locally. Ethanol's detractors point to blends above E10's incompatibility with many gasoline engines, and some signs of increased wear and tear on some internal parts, especially rubber hoses and gaskets. Further, whether the energy balance of ethanol -- whether the fuel contains more energy than was used to produce it -- is positive or negative is debatable, as is whether or not the land used to grow the crop was obtained by, say, chopping down a rainforest, in which case the ethanol produced is just as unenvironmentally-friendly as fossil fuel due to the carbon released by the dead plants.
Switchgrass and other sources of cellulosic ethanol
Moving forward, cellulosic ethanol has the potential to make ethanol a much more energy-efficient fuel, with yields that about double what the starch-based processes yield today. Because every plant contains cellulose, a huge variety of feedstocks -- some that would otherwise be wasted, like corncobs, straw or sawdust -- could be used. Switchgrass (pictured at left) is one such feedstock, and was thrust into the energy spotlight when it was mentioned in President Bush's 2006 State of the Union address. It grows eight or nine feet tall and is native to the US. Generally, it's very hearty and will grow in nearly any climatic variation, from the Gulf Coast into Canada. As a crop, it has a very high yield per acre (five to tens tons) with little use of pesticides, and a low production cost, which are two keys for economical production of alternative fuels. However, until very recently, the cost for producing cellulosic ethanol has been prohibitive, and the process has yet to hit mainstream ethanol production.
More ethanol information
For further reading and information, click Wikipedia's ethanol and ethanol fuel entries, and check the American Coalition for Ethanol and the US Department of Energy's Energy Efficiency and Renewable Energy Alternative Fuels Data Center entry for ethanol.
More ethanol reading in TreeHugger
Here at TreeHugger, it's been a hot topic of discussion; we've covered rice-based ethanol, noted that America is drunk on the stuff, checked out a car conversion kit and pondered the life cycle impacts of both ethanol and biodiesel. We even got the Car Talk guys to weigh in on the efficiency debate.
Distill more green goodness with our Green Basics column, which appears regularly here at TreeHugger.
Is the 10-20% GHG reduction from ethanol compared to gasoline calculated per volume, or per distance driven? If it's by volume, then you are producing more GHG than gasoline if it takes you 34% more ethanol to drive the same distance as gasoline. I sincerely hope it's per distance driven, but it's still a bad investment, in my opinion, from all the other costs involved in corn production and sacrifices made for corn production. Isn't there an LCA for ethanol and gasoline by now?
After all,reducing green gase emission by adding ethanol to the gasoline is not a bad alternative for preventing climate change.Now the key is to develop new technology to manufacture less energy-consuming or electric automobile involving fewer energy-transforming steps as much as possible to save energy .
Envirostats, you rightly point out that a 10-20% reduction in GHG emissions paired with a 1/3 reduction in MPG would make corn-based ethanol quite MORE carbon intensive than simply using old fashioned gasoline. The post above has it's numbers correct, but the implications of these numbers deserves some elaboration.
Treehugger's evaluation here may in fact give corn-based ethanol too much credit if they do not take into account the natural gas-based nitrogen fertilizers, petrochemical-based pesticides, and all of the diesel fuel that goes into the crop production, transportation, and distilling process.
Cornell's David Pimentel, who chaired a U.S. Department of Energy panel that investigated the energetics of ethanol production several years ago, subsequently conducted a detailed analysis of the corn-to-car fuel process.
His report (http://www.unisci.com/stories/20013/0813012.htm) summarizes; "Adding up the energy costs of corn production and its conversion to ethanol, on average 131,000 BTUs are needed to make 1 gallon of ethanol. One gallon of ethanol has an energy value of only 77,000 BTU."
This is a 41 percent net loss of energy!
It should be noted that the specific circumstances of corn-based ethanol production vary widely, thus so do the numbers with regards to energy input v output. But they nearly always come out negative when you consider the fossil-fuel consumption over the entire chain of production.
The VERY IMPORTANT IMPLICATION of this net energy loss scenario goes beyond the GHG emission story. How do we hope to continue corn-based ethanol production (fossil-fuel intensive AND a net energy loser) once the requisite oil and natural gas inputs become an increasingly scarce and expensive commodity? And WHY would we even want to do this now, given the fact that we put in far more energy than we can hope to get out?
(The whole situation is completely asinine from an energetics perspective, but makes perfect sense from an agro-politics standpoint - given the government's long-standing policy of (and substantial financial interest in) heavily subsidizing the corn industry, it makes sense that they would be corn-based ethanol's loudest supporters. Ah ha!)
If we give a careful look to the energetics of other types of biofuels, particularly sugar or grass based (cellulosic), we see a far greater potential in terms of net energy gains. Let's focus on these, and stop investing energy and hopes in unsustainable, untenable corn-based ethanol.
Before anyone should get too hyped up on the benefits of ethanol, just mosey down to
http://www.worldpress.org/print_article.cfm?article_id=2994&dont;=yes
and get a real shock.
adrianakau2aol.com
Yes, the Brazilian example does not include the energetic input of cheap labor and the human cost of the exploitation of that labor as described in the link above.
I believe we in the environmental movement have rushed to support biofuels before we understood the energetics and economics of using plants to generate fuel. Biofuels need to be eco-certified otherwise they are not really sustainable at all. You wouldn't support an explosive increase of all kinds of farming, be it either modern industrial or cheap-labor driven plantations, would you? No..you'd support organic agriculture which is eco-certified.
Similarly with biofuels, you are monkeying with the food system and eco-systems all at once, so you want to make sure that it serves human intentions not just sit on your hands and wait for agribusiness or the big fuel companies who are now involved to work it out for you...
I think that you are giving up on biofuels too early. Don't let Big Oil's smear campaign sway you from what is important!
" Pimentel's estimate for converting ethanol is about 7,000 Btu/gal higher because it includes energy for steel, cement, and other materials used to construct the ethanol plant, components not included in most other studies."
http://www.usda.gov/oce/reports/energy/aer-814.pdf
hi i have heard that a basic car (or avrige car on the road today) can have some minor (and cheep) ajestments made to it to handle E50 /i this true ? also isn't in most states a goallon of ethinal about a dollar cheaper than gasoline ? / in addthion i have heard that a car can be designed (new car not normal one ) to preform 30% better on ethinal than on unlead gasoline , that can translate to 30% more power or fuel economy depending on how the car is set to handle it . the reason for this is because it is using a hire octane
also if i am wrong plz let me know at my email address which is foxfauxfree@yahoo.com
You talk about corn like it is the only way to make ethanol cheap. What about all the un-used sugar cane fields in Hawaii? Sugar cane has been use by Brazil to make ethanol for 20 years. Hawaii has all but stopped growing sugar cane. It looks like they could use there sugar cane fields to make ethanol and improve there economy. In the rest of the US, why, has no one tried to use sugar beets to make ethanol? And instead of using coal or gas to fire the stills why not use ethanol and solar to fire them? Every problem has a green answer. I think the reason this study is skewed is because the oil companies want ethanol to look bad. I am not buying this load of BS. Ethanol is greener than Gasoline and always will be. It also is not supporting countries who are trying to kill us. Wake up people!! Big oil wants your money!! They want you to keep this stupid war going so they can get the oil to sell to us for a very high price. They want us to let them continue to charge more for gasoline than it cost t make ethanol. There are people right now making there own ethanol out of potatoes for there own use. They claim they can make it a lot cheaper than $2.00 a gallon some have told me they can make it for less than 1 dollar per gallon. The oil companies are ripping us off and they are trying to get us to believe that oil is the only answer. Forget the ecology for a minute think of the cost to every one of us who are paying the gasoline bill, not to mention the diesel that brings or groceries to us. The oil companies want to sell the last drop of oil to us to get as rich as they can. Even Pres Bush is an Oil Man he is on there side!!
I can not buy E85 in my neighborhood! And if I could all the cars that can run on it are sent to Brazil. Wake up people! We are being fed a line of pure bull! It is time the people tell it like it is.
Victor Ritchie a non oil man!
You talk about corn like it is the only way to make cheap ethanol. What about all the unused sugar cane fields in Hawaii? Sugar cane has been use by Brazil to make ethanol for 20 years. Hawaii has all but stopped growing sugar cane. It looks like they could use there sugar cane fields to make ethanol and improve there economy. In the rest of the US, why, has no one tried to use sugar beets to make ethanol? And instead of using coal or gas to fire the stills why not use ethanol and solar to fire them? Every problem has a green answer. I think the reason this study is skewed is because the oil companies want ethanol to look bad. I am not buying this load of BS. Ethanol is greener than Gasoline and always will be. It also is not supporting countries who are trying to kill us. Wake up people!! Big oil wants your money!! They want you to keep this stupid war going so they can get the oil to sell to us for a very high price. They want us to let them continue to charge more for gasoline than it cost t make ethanol. There are people right now making there own ethanol out of potatoes for there own use. They claim they can make it a lot cheaper than $2.00 a gallon some have told me they can make it for less than 1 dollar per gallon. The oil companies are ripping us off and they are trying to get us to believe that oil is the only answer. Forget the ecology for a minute think of the cost to every one of us who are paying the gasoline bill, not to mention the diesel that brings or groceries to us. The oil companies want to sell the last drop of oil to us to get as rich as they can. Even Pres Bush is an Oil Man he is on there side!!
I can not buy E85 in my neighborhood! And if I could all the cars that can run on it are sent to Brazil. Wake up people! We are being fed a line of pure bull! It is time the people tell it like it is.
Victor Ritchie a non oil man!
Why is ethanol so heavily subsidized by our government when it creates more problems than it solves?
Richard T. Steubi, contributing writer of Cleantech blog and the BP Fellow for Energy and Environmental Advancement wrote that
"Last year, government spent more than $8 billion of your tax dollars to achieve the following results:
�?� Dramatically increase the emissions of carbon dioxide and other greenhouse gases into the atmosphere
�?� Accelerate the destruction of the Amazon rain-forest
�?� Raise the price of milk, bread, beef and other grain-dependent products by more than 20%
�?� Increase world hunger
Natural gas, on the other hand, has no adverse effect on global food prices and it's cheaper than both ethanol and gasoline (In Los Angeles one chain was charging $2.55 for the natural-gas equivalent of a gallon of gasoline.)
Natural gas is plentiful. Reserves point to at least a 60-year supply, according to the Natural Gas Supply Association. Lastly, natural gas is more environmentally friendly than ethanol.
As the nation’s best kept secret, natural gas offers fewer emissions and larger savings at the pump. It ought to be included in more discussions as a viable alternative energy source.
Why is ethanol so heavily subsidized by our government when it creates more problems than it solves?
Richard T. Steubi, contributing writer of Cleantech blog and the BP Fellow for Energy and Environmental Advancement wrote that
Last year, government spent more than $8 billion of your tax dollars to achieve the following results:
�?� Dramatically increase the emissions of carbon dioxide and other greenhouse gases into the atmosphere
�?� Accelerate the destruction of the Amazon rainforest
�?� Raise the price of milk, bread, beef and other grain-dependent products by more than 20%
�?� Increase world hunger
Natural gas, on the other hand, has no adverse effect on global food prices and it's cheaper than both ethanol and gasoline (In Los Angeles one chain was charging $2.55 for the natural-gas equivalent of a gallon of gasoline.)
Natural gas is plentiful. Reserves point to at least a 60-year supply, according to the Natural Gas Supply Association. Lastly, natural gas is more environmentally friendly than ethanol.
As the nation’s best kept secret, natural gas offers fewer emissions and larger savings at the pump. It ought to be included in more discussions as a viable alternative energy source.
When will they start calling cellulosic ethanol "cellthanol"?
Does everyone realize that no matter what crop is chosen as a feedstock for fuel, the prices of that crop will increase because of supply and demand.
Okay where to begin?
Well I am against ethanol for many reasons:
1) It has been proven that ethanol can match or exceed the crbon dioxide emissions that gasoline produce. Which is more green house gases and that is what we're trying to prevent right.
2) The amount of land needed to take ethanol as a serious alterative for gasoline is such a large amount that it would distrupt and distroy natural ecosystems where ever we tried to make room for more ethanol producing crops such as corn. The water needed to produce this much corn would be the opposite or water conservation, and the amount of pestisides that would be used would be counter productive in the green movement because it is poison to us and our planet.
3)There are starving people all around the world and we are going to use natural resources that people need and at the same time make a ridiculous price increase for any products that use corn. That means any products that use corn starches, corn syrup, live stock such as chickens, turkeys, cows, pork, eggs, milk, ect.
Why don't we leave the oil for lubricating our windmills, ethanol for making drinks, so that we can eat the food we grow instead of burning it needlessly. Eventually all get electric cars that run off of clean energy such as solar and wind.
Ethanol represent a shortsightedness that plagued this country. It is by any stretch not a solution nor a revolution. You still burn it in a regular automobile engine and still produced CO2. The fact that there are so many arguments for or against ethanol showed its ambiguous benefits. In exchange for big oil, you get big corn. History has shown that large scale cash agriculture hurts the land, profits usually comes before good practices. Huge amount of resources have to be expended on infrastructure just to produce the same old thing, an uninspiring hydrocarbon fuel. This ethanol fad has nothing to do with cleaner energy. The lack of innovation in energy solution only showed the world Americans desire to perpetuate a wasteful, ignorant lifestyle without paying the price. Why not go for a full electric cars or hydrogen energy carrier and closed the energy loop by generating electricity from clean and/or renewable sources. It is no excuse saying that electric or hydrogen cars are still too far off. Socially and politically it is simply a lack of will to initiate a painful albeit more complete and far reaching solution. Saying that ethanol is a temporary solution is a lie, it is a permanent solution. How else can anyone explain the gov policies that seek to replace gas with ethanol so completely?
Okay people here we go here are a few ways to solve the problems.
First Ethanol is not a fuel I don’t care what you make it form.
If you want to use alcohol fuel then use butanol. The only problem I see with it is that the production numbers are not as high as yuckanol yet. This is only because the money isn’t going to the right places. Then once we get that problem fixed we can go teach Brazil how to make the better fuel. MPG goes up demand goes down supply goes up price goes down. Simple enough right? Or we can just take all the money, which goes to yuckanol production; the automakers are wasting on flex fuel vehicle production and advertising them, all the money that goes to pay the lobbyists, and all the money spent on everything else that goes into arguing whether yuckanol is good or not, and spend it on getting the bio crude of LS9 and the algae bio crude into mass production. The money is the problem and if we all don’t do something about it fast then it doesn’t really matter if the planet bakes or not because none of us will have any money to live any lifestyle that we have been so privileged to have so far due to the cheap oil we had for so long. The computer you are reading this on is largely made of plastic, that comes from oil. The energy the computer uses is largely produced from coal or natural gas.
What about the carbon cycle? The biggest benefit of using bio-based fuels is that any carbon emitted as a by product was taken out of the environment first, and more importantly, taken out of the environment in our lifetimes. The net effect being practically zero added carbon to the cycle. One of the biggest problems with fossil fuels is that carbon that was sequestered millions of years ago is being reintroduced to the environment - possibly what caused the dinosaurs to die off in the first place. What ethanol and other biofuels offer is sustainability.
Two more points:
1. Why no mention of hemp based biofuel?
2. Why is "biofuel" coming up as a misspelled word?
one word for all the worlds fuel/food/paper/plastic and just about every other important resource for the world:
hemp.
if we all started riding our bikes, and boycotting the fuel/oil industry and just basically stopped buying these horrible wares then the times would change as noone would be making money off these terrible earthkilling products.
it has been proven by the United States Agriculture department that an acre of hemp produces four to ten times more paper than 4 acres of trees, and seeing as how within every 3 months you could harvest/replant a new crop, it is way more beneficial than having to wait a good 30 years to get those trees back.