1,000 Gallons Water Per 1 Gallon Ethanol – How Green is That?
Water conservation has always been a hot button for aid organizations and environmentalists, and with a world wide lack of drinking water, and third world countries getting involved in the growing bio-economy, I think it’s time to look behind the curtain of the fuel movement that calls itself “green.”
Most of us are familiar with the “food vs. fuel” controversy that’s been making news, but in addition to this, one of the things that many people are taking a good hard look at, is water sustainability in reference to this corn ethanol fuel.
If we look at the raw data, it becomes apparent that it takes 1 bushel of corn to make 2.5 gallons of ethanol. Now that doesn’t seem so bad, until you ask yourself, “How much water does it take to grow that bushel of corn?”
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Let’s look at some more raw data. Did you know that it takes 2,500 gallons of water to produce that one bushel of corn? That’s a lot of water for 2 and half gallons of Ethanol. Let’s take this thinking a step further. If it takes 2,500 gallons of water to create 2.5 gallons of ethanol, then it takes 20,000 gallons of water, to make 20 gallons of Ethanol.
Think of it like this, the average firetruck holds up to 1,000 gallons of water. Now imagine 20 firetrucks lined up side by side, that’s how much water it takes to make 20 gallons of Ethanol.
I realize that not all of the water that’s needed to grow corn, is fed to the crop through irrigation. In the United States, about 15 percent of a crops total water usage comes from irrigation. But the United States is not the only country that’s growing corn for ethanol. In the growing bio-economy, many smaller (and less water laden countries) are jumping on the corn bandwagon, and some of these countries don’t have the average yearly rainfall, or depth of top-soil that the United States has.
The best source of any type of renewable fuel, should be as environmentally friendly as possible, and until other technologies become available, I for one, will keeping my eye out for other options.
Photo courtesy of SouthernPixel via Creative Commons License.
Source: Domestic Fuel
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October 16th, 2008 at 3:14 pm
Since I’m in a corn-growing region…I might inform you that most of this 2,500 gallons of water to grow 1 bushel of corn comes free from the sky in the occasional events we call “rain.”
October 16th, 2008 at 3:18 pm
Doesn’t it seem likely that the majority if that water is absorbed by the ground and not the corn? It would then filter it’s way back to an aquifer or possibly even be evaporated. I highly doubt a bushel of corn sucks up 2500 gallons. Another point of interest would be how ethanol is derived from the corn. If they press the corn to make some sort of corn mash then a lot of that water would be regained at that point.
October 16th, 2008 at 4:03 pm
Bill,
you are absolutely correct. Most corn grown in the United States gets 85% of its water from the ground and rain, and 15% from irrigation. So if we take into account only irrigated water, were looking 150 to 1 instead of 1000 to 1. That’s still a lot of water.
But not all of the corn being grown is in the corn belt, (or even in this country) where rain is plentiful and top soil is deep. (Interesting Article in this months National Geographic on world soils)
More and more corn is being grown in area’s of the world where far more than 15% of a corns water consumption, is being “fed” to the corn.
Thanks for you’re comment.
October 16th, 2008 at 4:38 pm
It’s sad that you are positing such an ignorant argument, because a certain number of people will believe it fully makes a case against ethanol.
The 2500 gallons of water are not ‘consumed,’ but returned to the earth. They are not gone forever, not lost, not contaminated.
There is certainly a case to be made comparing ethanol to other alternative fuel sources, but bad science does not a solid case make.
October 16th, 2008 at 4:43 pm
The water never ‘goes away’, it either comes back as rain, through evaporation, or is pumped back out of the ground, or falls as natural rain in the first place.
Corn ethanol is the most inefficient source of ethanol; although it’s becoming more efficient very quickly, it will not remain the source of ethanol in this country.
SO GET OVER IT! Also, expect to see much less criticzim of corn ethanol once Barack Obama is president. (Obama is pro-ethanol)
October 17th, 2008 at 1:24 am
Who cares?
October 17th, 2008 at 3:41 am
I work at an ethanol plant and in production we typically average 3-5 gallons of water per gallon ethanol produced. About half of that is make-up for utilities.
And be careful when using a term like inefficient. You can make ethanol very “efficiently” but you would be sacraficing rate in the process. There will be plenty of warts with cellulose. For example, thing about the logistics of moving stover or switchgrass vs a nice packed corn truck.
October 17th, 2008 at 7:03 am
Forget how inefficient the manufacture of ethanol from corn is. Ethanol is a very inefficient fuel to use for motor vehicles. To cover the same distance as 8 gallons of ethanol, you would use only about 5 gallons of gasoline and less than 4 gallons of diesel fuel.
Ethanol is a bad idea for motor car power. With luck we won’t have to worry about Obama pushing Ethanol from the oval office. He will just go back to being the most liberal senator in existence.
October 17th, 2008 at 1:04 pm
Corn ethanol is grown and processed in a few months while petroleum has sat underground reacting for millions of years or whatever your fancy is. Of course gas is going to have more energy. Still, it has about 93% of the BTU value of gasoline. The big difference is that you are driving a car that has been developed to run primarily on gasoline for nearly 100 years. Putting it in that motor will work but its not apples to apples.
October 17th, 2008 at 2:00 pm
I work in Communications for General Motors and the water issue around ethanol production is one of those that ethanol haters keep raising to help make it the Big Lie – say it enough and people automatically think it is true. Heartening to read here that posts before this one corrected the 2,500:1 premise. Here’s something else to keep in mind: Next-generation carbon-based ethanol from Coskata (a company with which GM has a strategic alliance) uses less than a gallon of water to produce a gallon of ethanol. The bioreactors in the Coskata system produce 99.7 percent fuel-grade ethanol and a little water. Most of the water used is recycled in the process. Don’t take my word for it. Argonne National Laboratory checked and verified this.
October 17th, 2008 at 4:03 pm
Misidentifed verification of process water use at Coskata. That was verified by Parsons Engineering. Argonne vouched for two other key elements – 7.7 times more energy created than used in making Coskata’s ethanol and Greenhouse Gas reductions of up to 96 percent (vs. gasoline) depending on the feedstock used.
October 17th, 2008 at 4:43 pm
What is this article, A joke?
Excluding the fact that 2.5 gallons of hooch per bushel of corn is outdated 1970s technology, we still get much more than Ethanol from a bushel of corn.
In addition to the Ethanol, Bio-Diesel and Methane or Syngas we get massive quantities of human food, Pharmaceuticals, industrial chemicals and animal feeds as corn derived coproducts, often more than we have markets for.
Food is especialy problematic. We can not market anywhere near as much corn based people food as we can grow and produce as a coproduct of the hundreds of other corn based products.
Here is the list of products coming out of Iowa Corn Processing Center in Eddyville Iowa; High Fructose Corn Syrup, Corn Syrup, Dextrose, Crude Corn Oil, Corn Gluten Meal, Sweet Bran®, Dry Sweetners, Acidulants, Citric Acid, Anhydrous Citric Acid, Liquid Citric Acid, Sodium Citrate, Potassium Citrate, Itaconic Acid, Natural Vitamin E, D-Alpha Tocopheryl Acetate, Mixed Tocopherols, Phytosterols, FFA, Citrous Salt, CO2, Monosodium Glutamate, Threonine and Cyclodextrins, bio-diesel, Ethanol.
In modern corn processing plants, corn is processed, like many other commodities including petroleum, for best uses. Just as gasoline is only one of many petroleum products, so Ethanol is only one of many value added products derived from corn.
This babble about water usage is simply a red herring. If we actualy used up water the earth would have gone bone dry long ago. All water is endlessly recycled. In fact it evaporates endlessly from plants, soil and the ocean and falls again as rain.
Rain distribution; rain forests and deserts, come and go, but the water is always on earth somewhere and is constantly being naturally repurified and redistibuted.
What is true is that with both water and petroleum, we are using up the easy to reach ancient underground pools and aquifiers. Not the first time, or the hundredth time that has happened. Lots of ancient cities are now burried under desert sands.
In the future we will be using solar, wind, wave, ocean current and tidal power to desalinate trillions of gallons of ocean water and send it thru pipelines all over the world. That has already started in a few places and then even natures spotty water redistribution will be conquered and controlled by man.
larry
October 21st, 2008 at 5:15 pm
To ChuckL,
I respectfully disagree with your assessment of the efficiency of ethanol (E85). The inefficiency you cite is a result of the engines on the road today not being set up for ethanol useage. E85 requires a compression ratio of approx. 13.0 to 1. Most cars and trucks barely break 9.0 to 1, if they do that. Even my high performance Mach 1 only has 10.0 to 1. It isn’t difficult to gat the ratios E85 requires. Far less expesive and complicated than CNG conversion.
Drag racers have been using alcohol blends for decades and the Indy Racing League mandated E85 useage, exclusively. NASCAR is under pressure to do the same. The first internal combustion engines were powered by ethanol, the same fuel Henry Ford used in his first cars, like the original Model T’s.
Corn is the least efficient fermentation stock. Sugar cane, sugar beets and best of all, Jerusalem Artichokes are far better, don’t require the amount of water to grow and refine and are not food commodities that threaten the world’s food supply.
E85 is an excellent “bridge” fuel, until more efficient alternatives come on line. No drilling required and no supertankers to belch out pollution along the world’s coastlines or to be fought over.
November 14th, 2008 at 10:14 pm
http://www.swhydro.arizona.edu/archive/V6_N5/feature4.pdf has slightly different statistics than you are pulling out of your arse
96% of corn used for ethanol production is not irrigated
and then in the conversion to ethanol a ratio of 4:1 or 3:1 water per ethanol
Sure ethanol isn’t a solution for our energy needs, but you sir need to put down the crack pipe
December 7th, 2008 at 5:23 pm
Adam, corn is going to be raised one way or another, people used irragation long before ethanol.
March 29th, 2009 at 1:38 am
liars figure and figures lie on both sides of this silly “ethanol” issue. Fact – energy can nether be created or destroyed, meaning: rearrange the molecules however you like, rename them to your own phycological delight and the end of it all human non-intrinisic motion requires energy inputs and they all come from the same place – da sun. Ethanol for cars? the question should be – why cars? Ethanol renewable? – that too is a poor argument – why do farmers carry crop insurance? because when wind and hail damage their corn crop they CAN’T get it back – renew it – its gone. with each crop the anhydrous and all the diesel used to plow, till, spray, truck and store the stuff is consumed – not renewable.