1 BTU (of fossil energy) to produce 47 BTUs of Ethanol -(DAMN!!) - Scientific American.com

[JohnWxy]

http://www.sciam.com/article.cfm?chanID=sa003&articleID=0E20535DE00C6A84CCA2FF2DA9A6A402

From the Scientific American.com article:


"Langley also said his plants are more cost-efficient than competitors. A traditional ethanol plant requires about 1 British thermal unit (btu) to make 2 to 2.5 btus of ethanol, while Genesis will use 1 btu to make 46.67 btus of ethanol."


He is talking about 1 BTU of fossil energy here. It requires more than 1 BTU of total energy to produce 46.67 BTUs of ethanol but the renewable fuel has replaced all but 1 BTU of energy which is still energy form fossil fuel(probably electricity).


That's a 4667% return on fossil energy input. Pretty good!

Thanks to OmahaSteve for making us aware of this. I just wanted to give it a headline that would grab a bit more attention.

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x85077

[Ezlivin]

1. This is a great advance

I love the idea that the ethanol plant is closed-loop; it powers itself!

The only downside I can see from this is that it is reliant upon our love of meat. It appears that the success of this type of ethanol plant would be correlated to the success of its "feedstock" or in other words the continuance of large cattle operations.

But it's great that it's able to make use of all that manure!

[JohnWxy]

2. They are also developing ethanol plants that obtain thermal energy from burning corn stover and

other agricultural wastes.

[GliderGuider]

10. The problem is that it's not really a closed loop

The article is written to make it sound like that, but it's not. The corn used to make the ethanol has to be gown, and that requires external fuel inputs that aren't mentioned - see my analysis of the energy required to grow the corn further down the thread. This article is very carefully spun. In other words it's propaganda. Like any good propaganda it is built on a kernel of truth - the distillation will be done with no FF inputs. But that's pretty much where the truth stops and the messaging takes over.

[Ezlivin]

12. I've been accused of being a "doom and gloom" guy before....

when I've pointed out the obvious shortcomings of ethanol.

Thanks for your more careful analysis.

[The_Casual_Observer]

3. This is probably the future of energy. They will probably use nuclear

power to do the "refining" someday & then no fossil energy will be required at all, assuming that they use hydroelectric power to refine the nuclear fuel.

[IDemo]

8. Land has just been purchased in Idaho for this type of plant

Energy firm buys land for nuclear plant

Shannon Dininny
Associated Press
February 9, 2007

BOISE – An alternative energy company announced an agreement Thursday to buy 4,000 acres of remote land along the Snake River to build a proposed nuclear power plant.

Virginia-based Alternate Energy Holdings Inc. in December announced plans to build a 1,500-megawatt nuclear plant in southwestern Idaho. The company, created last year, also said it was considering the possibility of making the facility a co-generation nuclear and ethanol plant.

The company signed the land purchase agreement with a farmer on Feb. 1. The purchase price was about $20 million, Alternate Energy Holdings CEO Don Gillispie said. The agreement should be finalized by the end of March.

[phantom power]

4. There's something funny here.

An acre of corn yields about 350 gallons of ethanol. I don't know how many crops they're getting per year, but even assuming it's 3 crops of corn a year, that's over 22,000 acres to grow enough corn for 24 million gallons.

So their 2000 acre facility is *not* self-contained. It doesn't include the acreage use to grow corn. Bit of an oversight, there.

[phantom power]

6. Putting that into perspective...

we currently use about 400 million barrels of gasoline each day. Suppose we tried to generate the equivalent in ethanol. Then we would need 22000 acres * 400e6 * 365 / 24e6 = 140 million acres of corn cropland. In 1997, we used about 68 million acres to grow all our corn.

So, we would need to triple the current acreage allocated to corn, to grow the amount of ethanol equivalent to our current gasoline usage, and supply the corn we currently use for feed, grain, etc.

That's assuming 3 crops of corn per year. I'm pretty sure it's only 1 or two in reality, but maybe somebody can set me straight.

[Sal Minella]

7. It's ONE crop a year in northern Iowa -- plant in the spring, combine in the fall.

I also hear that the ethanol plants use tremendous amounts of water.

[JohnWxy]

35. The Oak Ridge National Laboratory determined that ethanol could supply about 1/3rd the fuel demand

for transportation. This is without significant changes to food production. This study was completed before other developments.

MIT engineers have designed an ICE which uses turbo charging along with direct injection of ethanol to achieve a 30% reduction in fuel consumption. This is done with a 5% proporttion of ethanol to a 95% proportion of gasoline being used. This means if all cars were to use this engine we could reduce total gasoline demand by 30% using an amount of ethanol which represented 5% of total fuel demand. IF we are producing 33% of the total fuel demand in ethanol - rmoving 5% for direct injection leaves still another 28% of the total fuel demand from ethanol. the 5% gains a 30% reduction in fuel consumption. To that you add the other 28% iof ethanol available for blending with gasoline and you get a 58% reduction in gasoline usage.

iowa state university has developed a process using ultrasound to boost alcohol production from corn by 30% that would raise the amount of ethanol being made from the same amount of grain (for corn ethanol). Of course, it's expected that cellulosic ethanol will become commercially viable in about 5 yrs. That will surpass corn based ethanol for alcohol production.


In 20 to 30 years fuels cells should be commercially viable and they will be the best bet for fully replacing gasoline.

But, until fuel cells come along, doing nothing to increase energy security and reduction of GHGs is not an option.

[GliderGuider]

40. They did not.

The report talks directly about about ethanol only in the context of grain-based ethanol. Cellulosic ethanol rates only one mention in a pullout. Otherwise they simply ignore the process for getting from biomass (the majority of the energy under cionsideration to liquid fuel. In the introduction they just talk about biomass R&D, and say they "envision" a 30% replacement by 2030. As there is no commercial cellulosic ethanol capability yet, this is an exercise in hoping and wishing.

MIT proved that a new engine design that uses a little bit of ethanol could reduce automotive gasoline consumption by 1/3.

Offering these two pieces as evidence that "ethanol will save us without impacting our food supply" is misleading at best

Producing food based ethanol should be considered a crime against humanity. IMNSHO.

[NNadir]

5. Unless of course, you count the cattle.

As usual, your ability to misinterpret what is being said is more spectacular than the ethanol future.

[GliderGuider]

9. Let's have some fun with numbers. You're numerate, right?

Let's assume we feed all those cattle on corn, and also use corn as the ethanol feedstock.

First, we grow the cattle feed:

To feed a cow you need about 15 lb of corn per day.
To feed 27,000 cattle for a year takes 15*27,000*365 = 148 million lb of corn.
At 56 lb/bushel that's 2.7 million bushels of corn.
At 115 bushels per acre, that requires 2,700,000/115 = 23,000 acres of corn.
Corn takes 140 gal/acre of fossil fuels, so growing the cattle feed takes 23,000*140 = 3.2 million gallons of fossil fuel.

Now we grow the corn for the ethanol:

To make 24 million gallons of ethanol we will need 24,000,000/2.5 = 9,600,000 bushels of corn.
At 115 bu/acre we require 9,600,000/115 = 83,500 acres of corn.
At 140 gal/acre we will need 83,500*140 = 11,700,000 gallons of fossil fuel.

Just growing enough corn for 24 million gallons of ethanol required the use of about 12 million gallons of fossil fuel, a ratio of 1:2, not 1:47.

The whole process needs 15 million gallons of fossil fuel for a full-process ratio of 1:1.6. Of course we also have to allow for all those yummy Big Macs we get at the end of the year too, so lets just say the cows came "for free", and only count the 12 million gallons of gas we needed to grow the corn.

What we are saving with this process is only the fossil fuel inputs to the distillation. Ethanol requires 33,000 BTU/gal for distillation, so we are saving 24,000,000*33,000 = 800 billion BTUs. Gasoline contains 115,000 BTU/gal, so we save save the equivalent of 7 million gallons of gasoline.

So in the final analysis 24 million gallons of ethanol production used 12 million gallons of fossil fuel instead of 19 million gallons. While that's nice, it's a reduction of the fossil fuel to ethanol ratio from 1:1.26 to 1:2. This is nowhere near an overall process ratio of 1:47 as this article so mendaciously implies. As Pimentel says, it's really important to choose your system boundaries correctly.

If you'll pardon the expression, the article is bullshit.

[Porcupine]

11. Nice smack down. Thanks.

Of course since we refuse to reflect on the transport and packaging costs of all that corn and all that cattle we neglet another drain on fossil fuels. Feed lot cattle production is never going to be carbon neutral.

We also ignore the carbon costs of manufacture of all the megatractors and the ethanol plant itself.

I wonder when the EROEI for the entire "rolling wharehouse", fossil-fueled economic culture will fall below unity. I suspect that date is in the very near future.

The French have proven their understanding of fossil fuel economics. They tax the hell out of gas and have the worlds best train systems. They tend to avoid military adventures whenever they can. We aren't that smart yet.

Nnadir is correct in that we could fuel our current economic culture on uranium/thorium breeder reactors but current military powers are not likely to let that happen. I also believe that the politics of nuclear power do not work in the US corporate culture that continues to put profits over serious planning for the future.

[4dsc]

13. isn't that 27,000 cattle per day??

If I am not mistaken, aren't these E3 proposals based upon 27,000 cattle per day?? So a little more multiplication is needed..

[GliderGuider]

14. No, it's the same 27,000 cattle, maintained in the feedlot for a year

You just feed them and the keep pooping. 60 pounds of bullshit per cow per day (presumably two thirds of that is water, and 20 lb. or so is organic matter from the food).

This is a nice example of one thing you can use the methane from feedlot dung for, but the salient point of the story is not the ethanol, it's the methane that comes out of the digesters. You can do anything you want with that, and boiling mash to make XOM brand moonshine is just one use.

I'm not sure what "27,000 cattle per day" would mean?

[4dsc]

18. more research needed

If I am not mistaken, the 27,000 number of cattle is an aveage per pay kept at a commercial feedlot. That 27000 is rotated for slaughter not kept there for eternity.. See where I'm going with this??

[GliderGuider]

20. No I don't, see actually.

If there are 27,000 cattle on a feedlot, what difference does it make if it's different cattle on different days? They have essentially the same feed requirements - cows are fungible...

[4dsc]

31. You are correct

what was I thinking.. Overall I believe 27000 is the daily average over the whole year.. Your calculations are correct..

[muriel_volestrangler]

15. I'm not quite sure what you mean

"cattle per day"? Do you mean 27,000 cattle are born, or are killed, per day? That sounds like an absolutely huge operation. The one described in the article is talking about a herd of 27,000 cattle, so you work out how much they eat per day, per year, and so on. GG's calculation looks OK on the face of it.

[jpak]

17. Grow the corn organically, use biogas for distillation and try again

:popcorn:

[phantom power]

19. I have a proposal: why don't *you* show us *your* numbers?

I showed you my numbers, other people showed you theirs. So weigh in: How many acres are we going to save by growing corn "organically?"

[GliderGuider]

21. While I'd like to see him do that too, we both know it ain't gonna happen.

For this discussion at least, it really doesn't matter. The point of the exercise is that the original article's apparent claim of achieving an a EROEI of 47:1 for corn ethanol was utterly and maliciously bogus. No amount of horse-drawn no-till corn cultivation will salvage that outrageous flimflammery.

Food-sourced biofuels are a travesty, no matter how much lipstick you try to make that pig wear.

[GliderGuider]

22. BTW - Kaufmann's "Investigations" is astounding.

It's going to take me a while to get through it, there's just so much there to think about.

I had an interesting chat with my father last night on the phone. He spent his professional life as a pure research molecular biochemist, and at the age of 82 hasn't lost an iota of his acuity. I read him snippets of Kaufmann's book, and he got very excited. It turns out he uses the theory that order and life arise spontaneously from self-catalyzing reactions in complex chemical systems as his main argument against the need for (existence of) God, but he'd never heard of Kaufmann before. He's a member of the Canadian Humanists, and has arranged for me to give my Peak Oil talk to his local chapter in September.

It's exhilarating (and a bit intimidating) to have an old man who's that far out on the front side of the curve at his age.

Thanks for the recommendation!

[phantom power]

23. Hey, maybe Kauffman stole it from your pops.

Anytime a good idea starts to get traction, somebody digs up a few people who actually had the same idea decades earlier, but were too far ahead of their time, or just didn't go anywhere with it for other reasons.

[jpak]

24. Organic agriculture produces the same crop yields as conventional agriculture

but uses 30-50% less energy and no fossil fuel-derived pesticides...

(take 30-50% off the fossil fuel input side of the equation)

http://www.sciencedaily.com/releases/2005/07/050714004407.htm

http://www.fibl.org/english/news/2002/2002-05-science/release.php

...and organic agricultural systems are FAR more drought resistant than conventional agriculture...(global warming and all)...

...and sequesters fossil fuel CO2 as soil organic matter as well...


http://72.14.209.104/search?q=cache:sQblTvF548gJ:dspace.library.cornell.edu/bitstream/1813/2101/1/pimentel_report_05-1.pdf+organic+conventional+agriculture+fossil+fuel&hl=en&ct=clnk&cd=6&gl=us

Using biogas derived from manure or biomass (wheat straw, corn stover) in closed loop ethanol systems eliminates the use of fossil fuels for distillation process heat.

Using biodiesel and/or ethanol in farm equipment - in combination with organic agriculture - would eliminate (or drastically reduce) fossil fuel inputs used to produce soy or corn for biofuels.

As stated in the OP, the energy efficiency of corn ethanol production is steadily improving through R&D and through improvements in crop drying (ambient forced air vs. propane) and milling (dry vs. wet).

There are also no technical reasons why low temperature solar air heating systems can't be used for crop drying or renewable electricity from PV or wind can't be used in biofuels production.

Renewable energy and organic agriculture will save the day down on the farm...and don't complain about organic farmers with yo' mouth full and yo' gas tank empty...

:evilgrin:

[phantom power]

25. I'm certainly interested in "organic" for improved sustainability and drought tolerance.

I mostly put "organic" in quotes because it is such an overloaded term, and I'm never quite sure which meaning is supposed to be in play.

But that aside, I still don't see organic farming methods as a convincing enabler for an ethanol economy. It's an improvement, but an improvement over a baseline that's just too terrible to start with.

I think organic methods may help keep ourselves fed in our water-poor and topsoil-poor future. At least I hope so.

[jpak]

27. Breaking - there isn't going to be an Ethanol Economy

There's going to be a Transportation Technology Mix Economy.

Biofuels - ethanol and biodiesel from a variety of sources (not just ethanol from corn) and biogas

Electric and plug-in electric hybrid vehicles (trains, buses, cars)

even *gasp* HYDROGEN FUEL CELL VEHICLES

and - unfortunately - coal liquefaction fuels (for the military).

It's not going to be "just one thing"...

[phantom power]

28. Sure, I get that we're going to diversify.

We're diversified now, it just so happens that most of the diversity stems from one fossil-fuel or another. Which is going to kill us.

What I'm attempting to do is figure out how much energy all the pieces are going to add up to. And then, compare that number to the amount of energy we currently use for various things.

It's one thing to wave our hands and say "hey, we can extract energy from lots of different sources." It's another to seriously consider how much energy it will really be. And even though I'm a big believer in the basic principle of technological progress, I think it's bogus and dangerous to base our energy predictions on technology we haven't industrialized yet, for instance cellulose ethanol, fuel cells and cheap PV.

The reason I am always poking you with a stick about numbers is that whenever I run the numbers, I come up with figures like 2% of our current energy usage here, 3% there, etc. So even when you add up a long-sounding list of energy sources, you end up with something like 20% of our current energy budget.

And that is what leads me to say things like "we really ought to build nuclear reactors, if we want to preserve a humane standard of living for 6.5 billion people"

[jpak]

29. The first commercial power reactor (Shippingport, 1957) was rated at only 60 MWe

It was puny and supplied less-than-fuck-all kWh to the US grid.

If the philosophy that "any viable energy technology has to be big - REAL BIG - from the Get Go and industrialized today" was valid, nuclear power would never have gone anywhere...(and it hasn't in the US since 1973).

and it's also bogus to base our energy future on Big Oil and Big Gas - just because they are Big doesn't mean they are desirable or sustainable.

We could just as well go Big Time to coal liquefaction too - right???

After all it's been "industrialized" in several countries already.

Cellulose ethanol, fuel cells, cheap PV are being "industrialized" as we speaks. The plants are under construction and the contracts have been signed.

I'm not worried about it at all...

:)

[4dsc]

32. The BB approach

YEs there will be many alternative fuels with no one taking the lead or being the silver bullet..

But either way, no amount of ALL alternatives will replace what we get from oil. Therefore there is still going to be a major paradism shift when people are required to use less oil, much less oil..

[GliderGuider]

33. Peak Oil has taught me a lot about the validity of the BB theory.

The BB theory of oil fields says it doesn't matter if the big fields deplete, we'll just drill into a whole bunch of little "BB fields" to replace them. Well, that isn't happening, for reasons that have much to do with geology and the statistics of bell curves. I strongly suspect that similar forces are at work in the larger field of energy substitution, making it extremely unlikely that the Big Kahuna of oil can be replaces by the hundred Tiny Kahunas of wind, solar, biofuels, biomass, biogas, run-of-river hydro etc. etc.

[GliderGuider]

26. Nobody's saying that organic farming is a bad idea.

Let's say Pimentel's number of 30% for fossil fuel reduction for organic corn growing is a reasonable estimate, and that the yield does not suffer. It's a given from this article that the distillation is being done by biogas (that was the real point of the article). So let's run the numbers again:

Producing the corn for the ethanol feedstock takes 12*.7 = 8.4 million gallons of fossil fuel. That's a ratio of 8.4:24 or 1:2.86. Still not very close to the 1:47 claimed by the original article.

Organic corn production is a good idea. Ethanol from corn is not a good idea. This article was propaganda.

[jpak]

30. Propaganda - No, Bad Reporting - Yes

It looks like someone forgot to mention that those input BTUs were fossil fuel BTUs.

The plant was designed to minimize inputs of fossil fuels - and it does...

[amandabeech]

45. The real difference between organic farming and commercial farming

is that organic farming makes much more of crop rotation. In organic, you might something like legumous pasture/hay, corn, rye or maybe wheat, soybeans or other dry beans. That's corn only one year in four, beans one year in four. Commercial farmers sometimes do corn indefinitely in the same field using heribicides and pesticides. Or they rotate with soybeans. Right now, wheat is gaining in price, but you can barely give rye away. Hay? In some areas of the country only.

Organic farming will give us grain and feed for livestock, just not nearly as much in the short run as commercial farming of one or two cash crops only.

[JohnWxy]

34. are YOU numerate? I don't want to devote too much time to this mumbo jumbo but here are some more

sensible numbers for corn yield (149-150 bu/acre) and gallons of fuel per acre: 64.
yield data are for 2006. MJ per Hectare from Shappouri.

Hate to spoil your fun but here are the calculations.

MJ / Hectare              18921
acres/ Hect               2.471
MJ / acre                   7657
MJ/L Gasoline               31.45
liters of gas per acre       243
liters / gal                   3.785
gals per acre          64.32574232


latest corn yield data(USDA)
bushels per acre          149


bushels per gal of fossil fuel:         2.3

You can check my numbers to see if I made any errors.

Now, the article is ONLY talking about the conversion costs of producing ethanol from corn. IT IS NOT talking about the costs to raise the corn on the farm.

My figures above start with the total MJ per Hectare from Shappouri's (USDA) study as reported in Farrell and Kammen's meta-analysis (Jan 2006, Science). Shappori's data for raising the corn and the costs for the ethanol plants operations show the farm inputs being about 26% of the total energy costs and conversion costs being about 74% of the total.

Of course farm processes are in for change in the future too. Biodiesel will be used more on farms in the future which will reduce the fossil fuel input on the farm too.

other developments which look good for the future are:

Iowa State University filed for commercial patent protection for a process which applied ultra-sound to the corn slurry before the fermentation stage. This process increased alcohol yield by 30%.

Carnegie Mellon Engineers looked at the ethanol production process and redesigned equipment to capture waste energy and recycle it and have achieved a 60% reduction in thermal energy inputs to the ethanol production process.

MIT engineers have developed a Direct Ethanol injection ICE which reduces gasoline consumption by 30% while using only 5% ethanol (!) and 95% gasoline. A company has been formed and they are working with Ford to bring this engine to mass production by 2011. (if every car on the road was powered with this engine we could reduce gasoline consumption by 30% using a supply of ethanol that was only 5% of the total fuel supply! Any additional ethanol, above the 5% could be blended with the gasoline to increase the reduction of gasoline consumption - by displacement of the gasoline itself.)

A study conducted in Iowa determined that farmers using soil testing before applying Nitrogen to their fields reduced their Nitrogen usage (a significant part of the GHG emissions in the agricultural phase) by 46% with only a 1% reduction in yields. This means that farmers using soil testing could reduce their nitrogen consumption by almost half! - without sacrificing yields!

And of course, cellulosic ethanol is expected to be commercially viable in about 5 yrs an it is far more productive than corn. It will take a while to build up the production of cellulosic ethanol so corn based ethanol will still be produced for some time. But fortunately, due to the innovations mentioned above, along with more and more closed loop plants being built, production of corn based ethanol will become even more efficient than it is now.

[GliderGuider]

36. Well, you've proven that changing the input assumptions will change the outputs.

However, this doesn't do much to support the devious claims of the original article.

Let's say that these numbers are correct. 150 bu/acre gives 375 gallons of ethanol. If it takes 64 gallons of gasoline to produce that amount, then you get 6 gallons of ethanol for each gallon of gasoline. Now ethanol has only 2/3 the energy content of gasoline, so you get 4 BTU of ethanol for every BTU of fossil fuel used.

1:4 still isn't the 1:47 claimed by the original article, which hid the production cost of the corn.

The issue really isn't whose numbers are correct. There's enough ambiguity in the assumptions and boundaries of the problem to allow any set of numbers to be gospel. What it comes down to is, do you think ethanol is a good idea? If it is then even low efficiencies can be accepted, while if it isn't then even high efficiencies must be rejected. I am convinced that ethanol is a Bad Idea, and that colours my arguments. You are convinced it's a Good Idea, and that likewise colours yours.

[JohnWxy]

38. You continue with the fraudulent practice of ignoring coproduct credits - an approach which

attempts to deny reality.

Everybody knows when producing ethanol Dry Distillers Grains and Solubles are also made which are sold as cattle feed supplement to farmers. A portion of the energy which goes into making ethanol also goes into the DDGS product. Pimentel & Patzek have widely been ridiculed for not recognizing any energy inputs to DDGS. Pimentel (also Patzek) has no credibility among legitimate researchaers of energy yield of ethanol (and other alternative fuels). Farrell and Kammen (University of California - Berkeley) in their study published in the journal Science (Jan 2006) noted that both Patzek and Pimentel included data which was out of date or or so poorly documented that it could not be evaluated as to it's quality. NOt including coproduct credits invalidates Patzek and Pimentel's so-called studies.

I'll address the coproduct credit issue in another response to your post where you perform some more lengthy and erroneous calculations (above).

[GliderGuider]

39. This thread isn't about the overrall EROEI of ethanol.

This thread sprang from the apparent claim in the original post that 1 BTU of fossil fuel input could produce 47 BTU of ethanol output. Whether or not DDG is factored in will not make a a significant difference in determining whether that claim is valid or misleading. They left out the production of corn in its entirety, and that makes the OP undeserving of further consideration. The inclusion of co-product credits may be a valid subject for discussion, but that's not the context of this thread.

Frankly, my objections to ethanol go far beyond the question of net energy. I believe biofuels in general are a dead end, and food-sourced biofuels in particular border on criminal practice. The reasons I feel that way are here. It doesn't matter what you feed the cows and whether you count DDGs or not. Corn ethanol is both morally and technically indefensible.

[Javaman]

37. Thank you for that analysis...

I'm gathering research for a project and this will come in mighty Handy.

also to dove tail into what your were saying.

nothing was ever mentioned in the article regarding the methane output by these same cattle.

I like meat as much as the next person but the continuation of raising cattle in such large numbers is part of the problem concerning global warming.

[JohnWxy]

41. I decided to take a closer look at these rediculous calculations when I discovered so many erroneous

calculations and assumed (made up?) values.

FIRST: you calculated the cost of raising corn to feed the cattle. This has nothing to do with the cost of producing the ethanol. The cattle would be there and be fed corn (or some other grain) regardless of any demand for ethanol. Farmers have been raising dairy cattle and cattle for beef since long before there was a need for corn for ethanol. Including this calculation is entirely erroneous.


YOU state: "to make 24 million gallons of ethanol we will need 24,000,000/2.5 = 9,600,000 bushels of corn." Wrong. The most recent data on productivity of ethanol plants shows throughput of 2.8 gallons per bushel. So the calculation should have been: 24,000,000/2.8 = 8,571,000 bushels
not 9,600,000 bushels.

You state: "At 115 bushels/ acre we require 9,600,000/115 = 11,700,000 gallon of fossil fuel."

WRONG. the current yield (for the last 4 years) has been above 149 bushels per acre(check with USDA site) YOur error is 23%.

the CORRECT calculation is: 8,571,000/149 = 57,526 acres NOT 83,500 acres you calculated (an error of 45%).

You use 140 gallons of fossil fuel per acre to raise corn. taking data from Shappouri (USDA) the actual number is 64 gallons of fossil fuel per acre - YOUR ERROR on this input is 119%. You more than DOUBLED the required fuel per acre!

The correct calculation of gallons of fossil fuel needed to produce 24 million gallons of ethanol is: 64 * 57,526 = 3,681,687 gallons (NOT 11,700,000). YOur error is 216%, high!

Then you calculate 7 million gallons of fossil fuel saved based on 33,000 BTUs /gal "for distillation". But there is more to the process than distillation. LEts use Shappouri's numbers for fossil fuel usage in the production process - they cme to 49,721 BTUs per gal (check Farrel and Kammen's worksheet, online).

The correct calculation of fossil fuel saved is then: 49721*24,000,000/119,000 BTUs per gal(per Farrell and Kammen) 10,087,754. NOT 7,000,000 gallons of fossil fuel saved tha tyou calculated.

so far you're not doing too well!

NOw we come to coproduct credit, something you left out. You cannot ignore coproduct credits. Some portion of the energy consumed is shared by both the ethanol product and the DDGS produced by this process. Corn is the raw material for both of these products. Both products must recieve allocations of energy consumed in the process.

Now there are about 4 different ways of valuing the imputed energy (to produce) value assigned to the coproducts. You can use Weight (or mass), market value, energy content and energy consumed in individual processes (a systems simulation approach). I don't know which method E3 Biofuels (the company who owns the plant discussed in the article) is using but a likely choice would be the Market Value of the coproducts - just for it's simplicity. Incidentally, valuing the production energy for coproducts using the Mass basis or Energy Content basis yields a much higher coproduct credit (which would reduce the energy allocated to ethanol product even MORE).

using a Market Value basis of valuing the coproduct credit (which a businessman would be likely to use) gives a figure of 3,598,337 (4.97 MJ/L*3.785 L/gal divide by 119,000 BTUs/gal (Farrell & Kammen) and multiplying by 24,000,000).

So the energy consumed to produce the corn was: 3,681,687
The coproduct credit comes to:                   :       3,598,337
Th e difference is to:                   :       :                 83,350


10,087,754 (gal fossil fuel saved) divided by 83,350 = 121. This means a 1:121 ratio, or considerably above the 1:47 quoted in the article. But keep in mind we are using production cost figures from a study of most of the ethanol industry and applying it to one particular company. Obviously, this is a very approximate method.

But it shows that the 1:47 figure quoted in the article is possible. You cannot ignore the coproduct credits. When you include allocation of consumed energy consumed in the production process to all the products of that process you get an accurate idea of the return on energy consumed for each product produced.

This is why using renewable fuels to replace the fossil fuels is so powerful. It magnifies the return on fossil fuel invested in the end product. In the future Biodiedeal will be used more on farms and this will start reducing fossil fuel use on the farm too. Then you will see the anergy return ratio (on fossil fuel consumed)really climb!

At any rate the statements maade by the representativ eof E3 biofuels are credible.. the post I am reaasponding to is replete with errors and of course leaving out the coproduct credit ( a gambit of the discredited Pimentel and Paatzek) invalidates the whole calculation anyway.

[GliderGuider]

42. That really got under your skin, didn't it?

The original article article lied by omission. The fact that growing the corn to make the ethanol was ignored, while the headline implied that you could get 47 BTUs of ethanol for every BTU of fossil fuel, makes it a piece of propaganda, and that got my dander up.

I really don't care whether it takes 9.6 million or 8.5 million bushels of corn to make the ethanol. Either figure makes ethanol production from corn a criminal enterprise IMO.

[JohnWxy]

43. what's important here is NOT the bushels of corn but the replacement of fossil fuel by a renewable

fuel (cattle poop) which drops the fossil fuel input down so low that:

"... the energy consumed to produce the corn was: 3,681,687
The coproduct credit comes to: : 3,598,337
The difference is applied to ethanol: : : 83,350


10,087,754 (gal fossil fuel saved) divided by 83,350 = 121. This gives a 1:121 ratio, or considerably above the 1:47 quoted in the article. But keep in mind we are using production cost figures from a study of most of the ethanol industry and applying it to one particular company. Obviously, this is a very approximate method."

My post showed that the article was certainly credible while your calculations piled error upon error and then ignored the coproduct credit (or i prefer coproduct energy allocation) - which is dishonest and a fraudulent methodology. But what should we expect of someone whose hero is the ignominious Pimentel (a retired entomologist, who now goes around calling himself an agricultural ecologist. - a title without tutelage?).


REgarding dishonesty let me take this opportunity to quote Farrell & Kammen speaking about the work of Pimentel and Patzek (Ethanol Can Contribute to Energy and Environmental Goals, Science, Jan 2006):

-------------------------------------------------------------------------------------------------------

"Two of the studies stand out from the others
because they report negative net energy values
and imply relatively high GHG emissions and
petroleum inputs (11, 12). The close evaluation
required to replicate the net energy results showed
that these two studies also stand apart from the
others by incorrectly assuming that ethanol
coproducts (materials inevitably generated when
ethanol is made, such as dried distiller grains with
solubles, corn gluten feed, and corn oil) should
not be credited with any of the input energy and
by including some input data that are old and
unrepresentative of current processes, or so
poorly documented that their quality cannot be
evaluated.

Notes:
11. T. Patzek, Crit. Rev. Plant Sci. 23, 519 (2004).
12. D. Pimentel, T. Patzek, Nat. Resour. Res. 14, 65 (2005).
---------------------------------------------------------------------------------------------------------
{in other words, Pimentel & Patzek's stuff is -- BULL-FUCKING-SHIT}(since you seem to be having a hard time getting the point I put it in terms I thought you would better understand. - My apologies to other readers.)


You cannot ignore coproduct credits. To doso is to ignore reality. Doing that can lead to other aberrant behavior such as .. searching Area 51 looking for little green men in speedos.(remember, I warned you about that before). And membership in the Bullshit Luck Club with Pim & Pat.

[GliderGuider]

44. So what?

Everybody knows you can replace methane from a well with methane from digested poop. That's not news. What you use it for, whether it's home heating or boiling mash, is immaterial. Linking the standard technology of biomethane digesters to ethanol production was part of the propaganda.

It doesn't matter what the numbers are, the production of fuel ethanol from food sources is a crime against humanity.

[JohnWxy]

47. Yeah a 1 : 121 ratio of fossil fuel used to ethanol produced is a real bore. LOL. Immoral? check

the link: http://icasualties.org/oif/default.aspx

U.S. Deaths Confirmed By The DoD: 3161
Reported U.S. Deaths Pending DoD Confirmation: 9
Total: 3170

[amandabeech]

46. The article is B.S. and of course they know it.

Just a couple of thoughts on your calculations from someone who's seen a lot of debate on this topic.

Corn yields per acre in the U.S. cornbelt are generally much higher than 115/acre. Top spots in Iowa or Minnesota might get over 200 in a good year. For the corn belt, you'd use something more like 150.

The cattle will eat as part of their diet the distillers' grains left over when the water and ethanol are removed. Putting the cattle close to the distillery cuts down on transportation or drying energy costs which are not insubstantial.

That's a lot of cattle slurry to move. Not all the slurry will end up as fertilizer because its heavy and expensive to transport and not all farmers have the equipment or desire to fool around with slurry as fertilizer. As the price of nat gas goes up, more will be interested, but the slurry doesn't have an extremely high nitrogen count. It's good for phosphorus and potassium, though. Nonetheless, you probably won't see many farmers use it on soybeans 'cause beans make their own nitrogen.

The big and often forgotten kicker with ethanol is that it cannot be transported through a petroleum pipeline. Ethanol is a solvent that picks up all the goo in the pipeline, or so I'm told. It must be shipped to the distribution point for the gasoline and mixed in there. That means that you're carting Iowa ethanol to California by truck or rail, there being no barge route west from Iowa. That's a lot of diesel even if you go rail. But is there enough rail to transport 5%, say, of the nation's liquid fuel supply? I doubt it. You surely can't take it east because there's little rail space for much of anything but coal trains.

At least with NNadir's nuclear-backed electric transport, finding a truck or a train for the fuel supply isn't a major problem. With ethanol, it's huge.

[Kolesar]

16. Biogas was detailed in a recent issue of Home Power Magazine

Large polymer bags laid in a trench with a gas collection port. Page 92 http://www.homepower.com/files/ALLEETOC/Issue116.pdf?search=biogas