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GliderGuider Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 01:36 PM
Original message
A very critical analysis of biofuels
Edited on Thu Feb-08-07 01:38 PM by GliderGuider
Here's a little hand grenade to toss into the discussions on ethanol and biodiesel:

The Dirty Truth about Biofuels by Dale Allen Pfeiffer.

He relies heavily on Pimentel and Patzek, as well as George Monbiot. Here are some of the conclusions about ethanol:

When you take into account all of the fossil fuel inputs, one hectare of corn-for-ethanol generates 7475 kg of CO2, or 2200 kg more CO2 than would be generated by burning an energy equivalent amount of gasoline. In other words ethanol generation produces 42% more atmospheric CO2 than gasoline.

Let me restate this for emphasis. The main reason why we are currently subsidizing ethanol production is the mistaken belief that ethanol contributes less CO2 than gasoline. There is also talk about ethanol being a renewable fuel source. However, in reality, ethanol produces 42% more atmospheric CO2 than an equivalent amount of gasoline, and it requires 10% more energy to produce than it provides. What is more, to remediate all the pollution of corn-ethanol production would require a minimum of 7 times the maximum amount of work that ethanol can produce in a car engine.

Industrial corn-ethanol production is not renewable and it is far from sustainable. Furthermore, analysis shows that there are no process changes that can make the system viable. We would be better off to abandon corn ethanol production right now.

Snip

Not only does ethanol not reduce the emission of greenhouse gases, ethanol burning contributes notable amounts of atmospheric nitrogen oxides, which then combine with volatile organic compounds (VOCs) to produce ozone. Studies show conclusively that ethanol leads to an increased ozone problem. Within half a year of switching entirely to ethanol additives, California ozone levels rose 22%, and exceedences of the 8 hour standard rose to a maximum concentration of 40%.

I'm sure there are holes to be poked in some of the arguments, but this is one of the most exhaustive and devastating popular articles I've read about the scam of green fuels.
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Ezlivin Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 01:42 PM
Response to Original message
1. Careful with that axe, Eugene
You'll be called names for questioning the efficacy of biofuels to allow us to continue our consumptive lifestyle.

It seems that many biofuel proponents see it as a direct substitute for gasoline, thus enabling us to continue to build suburbs and commute. Many of them seem unwilling to call for a change in the American lifestyle (something akin to Cheney's remark that the "American lifestyle is not negotiable").

We can add CO2 to EROEI for reasons against widespread use of ethanol. Not to mention the requisite subsidies.

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tnlurker Donating Member (698 posts) Send PM | Profile | Ignore Thu Feb-08-07 01:52 PM
Response to Original message
2. Bio fuels only make since when
You use the waste products from agriculture or food production to make it.

For example if you can make ethanol form the corn stalks after you have harvested to corn for food production then bio fuel would make a good use of the waste.

Using left over vegetable oil from food production to make bio diesel also makes good use of a waste product.

Growing corn just to make ethanol is saving any energy.
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GliderGuider Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 02:04 PM
Response to Reply #2
3. Perhaps not even then.
Remember that any "waste" that is removed from the growing site to produce fuel carries with it carbon and nitrogen as well as other nutrients that are not returned to the earth. They must be replaced, either with some other organic material or synthetic fertilizer, or the soil fertility is depleted. If this depletion is permitted, the whole process is no longer sustainable. If the nutrients are replaced with other organic matter, that material had to be produced somewhere else thus merely shifting the site of the depletion. If you use synthetic fertilizers to restore fertility, you are in effect using fossil fuels (natural gas).

It's starting to look more and more as though the entire notion of "sustainable renewable biofuels" is a chimera, especially when a whole-system life cycle analysis is used.
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amandabeech Donating Member (1000+ posts) Send PM | Profile | Ignore Sat Feb-10-07 07:06 PM
Response to Reply #3
36. One of those other nutrients is phosphorus.
The U.S. has a 60-70 year supply.

Other major phosphorus-supplying nations are Morocco, several in the Middle East and China.

Those folks are clearly our friends, and we surely will have all the biodiesel that we need to ship and process the phosphorus 70 years from now.

If we got back to recycling animal wastes, we could stretch out supply of such vital nutrients, as well as nitrogen.

CAFO operations seem to make the recycling more difficult, as do (dare I say) environmental regulations, at least according to many farmers.
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Rabbit of Caerbannog Donating Member (742 posts) Send PM | Profile | Ignore Thu Feb-08-07 02:21 PM
Response to Original message
4. True if you only consider kernel corn, however
cellulosic ethanol can be made from any plant-based matter - including wood waste, stover, bagasse (squeezed sugar cane) etc. Once the bugs are worked out, it will be a net energy gain. As for the carbon issue - any fuel (sans fossil fuel input for production) is carbon neutral
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GliderGuider Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 02:26 PM
Response to Reply #4
6. My comments above about soil depletion apply here too.
When considered from a whole-system perspective including the soil and water remediation requirements, I don't think a plant-based biofuel process as a whole can be considered a winner. In addition, given that the excess energy you are trying to harvest is solar which is captured at very low efficiency by plants, you need to be very parsimonious with your energy inputs to avoid going negative.
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Rabbit of Caerbannog Donating Member (742 posts) Send PM | Profile | Ignore Thu Feb-08-07 02:57 PM
Response to Reply #6
13. True - but consider
the vast amounts of cellulosic material currently going to waste, i.e. burned (here in VA developers clearcut land for developements and bulldoze up hugh piles and burn it), landfilled, not to mention all the animal waste (manure etc). Not a panacea - but part of a brader solution - as is biodiesel, wind, low-hear hydro, CONSERVATION. And don't get me going on solar - solar rocks! Efficiencies are going up, prices are going down, and manufacturers are finally wizing up and making products that go beyond traditional 2" x 4" panels bolted to rooftops (solar shingles, metal roofing, skylights, facade glazing, etc...). I've devoted my entire career in this area and finally feel I'll be vindicated before I'm dead :P
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gravity Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 03:17 PM
Response to Reply #13
16. Its probably just as good to throw them out
Using waste as fuel creates co2 too, which completely offsets any of the benefits.

The problem is not about the source of energy, but the actual energy itself. If we could have used biofuels for all our energy needs, we wouldn't need them to begin with, since the crops could still be used to take the co2 out of the air produced. The problem is that the amount of energy our society uses far exceeds the amount photosynthesis produces.

Other renewable sources can't be used enough to replace fossil fuels. They only make up about 2% of the worlds need for energy so far, and the numbers aren't going to improve too drastically either.

What we really need to focus is on using less energy, but thats not as politically appealing as biofuels, since it requires real sacrifice, not just wishful thinking.
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Moby Grape Donating Member (105 posts) Send PM | Profile | Ignore Thu Feb-08-07 02:24 PM
Response to Original message
5. why would anybody produce a useful product?
that creates jobs, and conserves foreign exchange.

when the alternative is to do nothing,
thus avoiding the whatever-they-are pitfalls
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GliderGuider Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 02:29 PM
Response to Reply #5
8. When producing that "useful product" damages the biosphere there may be good reason for caution.
Edited on Thu Feb-08-07 02:29 PM by GliderGuider
This world is all we have left of the Garden of Eden. I'd rather we didn't get ejected from this one too.
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amandabeech Donating Member (1000+ posts) Send PM | Profile | Ignore Sat Feb-10-07 07:12 PM
Response to Reply #5
37. It takes lots of diesel for field work and transporting both inputs and
the corn to ethanol plant. We import 2/3 of our oil, and that includes both finished diesel and the crude oil used to make it.

Nitrogen fertilizer is made from natural gas. Natural gas is not widely found in North America and much more of it is used to generate electricity and now to make something useful out of the tar sands.

Importing liquefied natural gas in special ships is quite expensive. The usual suspects plus Russia are the big producers.

Instead of import NG, we import the fertilizer and have closed down most of the U.S. fertilizer plants. We get much fertilizer from Trinidad and Tobago, but also from Russia and Middle East oil and gas producers.

Since the energy gain on corn ethanol is non-existent or perhaps up to .67 per gallon, if everything goes right and the byproducts (mostly cattle feed) can be used cheaply, you're not going to cut the trade deficit using ethanol.
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jobycom Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 02:28 PM
Response to Original message
7. I haven't read through the whole article, so I shouldn't comment yet
But does this study take into account the energy used to produce and transport gasoline and other petro-fuels, especially overseas? The comparison above seems only to be comparing the production cost of a certain amount of ethanol to the cost and output of the same energy equivalent in gasoline. Maybe I misread it, but that summary seems to be comparing the entire ethanol process to the finished gallon of gasoline.

Also, as we've seen, there is a cost to acquiring fuel from overseas that isn't directly measurable in the production of the fuel. Human lives, bombs, equipment, massive amounts of fuel used to fuel our military, etc.

The article may discuss this, I haven't read it yet.

Also, there's the issue that the study is looking at technology as it exists today. The corn growing industry is geared towards a certain volume requirement for food purposes. Gearing the industry towards fuel might result in new growing technologies and ag techniques. Increased hydroponics, for instance (since taste and nutritional content wouldn't be important).

Just thoughts. Not complete ones, just impressions as I read the summary above.
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jpak Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 02:30 PM
Response to Original message
9. The Dirty Truth about Bullshit - from the Proceedings of the National Academy of Sciences
Edited on Thu Feb-08-07 02:33 PM by jpak
http://www.pnas.org/cgi/content/abstract/0604600103v1

Environmental, economic, and energetic costs and benefits of biodiesel and ethanol biofuels

Departments of *Ecology, Evolution, and Behavior and Applied Economics, University of Minnesota, St. Paul, MN 55108; and Department of Biology, St. Olaf College, Northfield, MN 55057

Contributed by David Tilman, June 2, 2006

Negative environmental consequences of fossil fuels and concerns about petroleum supplies have spurred the search for renewable transportation biofuels. To be a viable alternative, a biofuel should provide a net energy gain, have environmental benefits, be economically competitive, and be producible in large quantities without reducing food supplies. We use these criteria to evaluate, through life-cycle accounting, ethanol from corn grain and biodiesel from soybeans. Ethanol yields 25% more energy than the energy invested in its production, whereas biodiesel yields 93% more. Compared with ethanol, biodiesel releases just 1.0%, 8.3%, and 13% of the agricultural nitrogen, phosphorus, and pesticide pollutants, respectively, per net energy gain. Relative to the fossil fuels they displace, greenhouse gas emissions are reduced 12% by the production and combustion of ethanol and 41% by biodiesel. Biodiesel also releases less air pollutants per net energy gain than ethanol. These advantages of biodiesel over ethanol come from lower agricultural inputs and more efficient conversion of feedstocks to fuel. Neither biofuel can replace much petroleum without impacting food supplies. Even dedicating all U.S. corn and soybean production to biofuels would meet only 12% of gasoline demand and 6% of diesel demand. Until recent increases in petroleum prices, high production costs made biofuels unprofitable without subsidies. Biodiesel provides sufficient environmental advantages to merit subsidy. Transportation biofuels such as synfuel hydrocarbons or cellulosic ethanol, if produced from low-input biomass grown on agriculturally marginal land or from waste biomass, could provide much greater supplies and environmental benefits than food-based biofuels.

<end PNAS abstract>

and furthermore...from the journal Science

Carbon-Negative Biofuels from Low-Input High-Diversity Grassland Biomass

David Tilman,1* Jason Hill,1,2 Clarence Lehman1

Biofuels derived from low-input high-diversity (LIHD) mixtures of native grassland perennials can provide more usable energy, greater greenhouse gas reductions, and less agrichemical pollution per hectare than can corn grain ethanol or soybean biodiesel. High-diversity grasslands had increasingly higher bioenergy yields that were 238% greater than monoculture yields after a decade. LIHD biofuels are carbon negative because net ecosystem carbon dioxide sequestration (4.4 megagram hectare1 year1 of carbon dioxide in soil and roots) exceeds fossil carbon dioxide release during biofuel production (0.32 megagram hectare1 year1). Moreover, LIHD biofuels can be produced on agriculturally degraded lands and thus need to neither displace food production nor cause loss of biodiversity via habitat destruction.

<end Science abstract>

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GliderGuider Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 02:50 PM
Response to Reply #9
12. I've got no problem with the argument that non-food-based biofuels are better
They would certainly be better than their food-derived equivalents. That is pretty much all these extracts are arguing.

The net energy return of 25% for ethanol cited in the PNAS abstract is being strongly disputed, and the extract from Science makes no reference to the production technology used to arrive at their figures. The only way one can remain optimistic about biofuels is if one adopts a very narrow view of what is counted as part of the process. Expanding that view to include all process energy as well as water and soil remediation (which is essential if the process is to be considered sustainable) significantly reduces the attractiveness of the idea.

Current plant-based biofuel proposals, including all those based on cellulosic waste and low-input biomass are not sustainable by definition. Plant growth requires concentrations of nutrients in the soil. Producing and burning fuel diffuses those elements throughout the biosphere, in an entropic process analogous to thermodynamic heat death. The re-concentration of those elements to provide for further growth requires energy that must be factored into the equation. Plant-based biofuels simply won't work over the long haul.
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jpak Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 03:05 PM
Response to Reply #12
14. The Science paper IS discussed in the OP (which is not a peer reviewed study)
Edited on Thu Feb-08-07 03:11 PM by jpak
And I take issue with the statement that it takes 4 kg of wood fuel to produce 1 kg of wood pellets.

According to folks that actually operate wood pellet mills, only ~15% of the feedstock is used to provide process heat...

http://www.pelletheat.com/pellets/process_12.php#photo

The dude has it bassackwards...
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GliderGuider Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 03:15 PM
Response to Reply #14
15. Can you point me to the reference?
I see no discussion of a paper by Tilman in the article I linked.

And of course it's not a peer-reviewed study, it's a synthesis article for the popular press. It even has an obvious bias. But it does draw out some most uncomfortable conclusions based on the peer-reviewed studies it uses as its foundation.
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jpak Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 03:28 PM
Response to Reply #15
17. Reference 3 is the Farrell et al. Science paper - not the Tilman Science paper - my bad
But the conclusions are the same as the Tilman et al. PNAS paper...

http://rael.berkeley.edu/EBAMM /

Ethanol Can Contribute to Energy and Environmental Goals

Alexander E. Farrell,1* Richard J. Plevin,1 Brian T. Turner,1,2 Andrew D. Jones,1 Michael O'Hare,2 Daniel M. Kammen1,2,3

To study the potential effects of increased biofuel use, we evaluated six representative analyses of fuel ethanol. Studies that reported negative net energy incorrectly ignored coproducts and used some obsolete data. All studies indicated that current corn ethanol technologies are much less petroleum-intensive than gasoline but have greenhouse gas emissions similar to those of gasoline. However, many important environmental effects of biofuel production are poorly understood. New metrics that measure specific resource inputs are developed, but further research into environmental metrics is needed. Nonetheless, it is already clear that large-scale use of ethanol for fuel will almost certainly require cellulosic technology.

<end abstract>

Also, David Tilman's given name was Titman - he had it changed for obvious reasons...

:evilgrin:
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TexasProgresive Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 02:35 PM
Response to Original message
10. I was told yesterday that Cargil?? is offering $5.00 a bushel for
corn with a 3 year contract to supply ethanol plant in Illinois. The guy who told me has a father and brother farming in Illinois. He said that farmers are plowing up their winter wheat to ready that acreage for corn. His father and brother have sold all their cattle so that the pasturage can go to corn and that they have no plans to plant soy beans or other crops that they normally plant.

The upshot of this is that the cost of feed is rising fast, even feeds that don't have much corn because of the growing shortage of other grains. Meat, milk, bread, eggs and oatmeal will go up in price. This is not the way to do it.
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greenman3610 Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 02:38 PM
Response to Original message
11. it's like trying to think of the internet built around the TRS-80
that would be ridiculous.
But only because the Trash-80 was a 1.0
version of the computer revolution.

Current corn to ethanol schemes are only the
slim leading edge of a technology that will eventually
be converting algae, garbage and sewage to biofuels,
with efficiencies hundreds or thousands of time what
we see now.

Also, important to remember, efficiency of end use
is not standing still.
We will be going from
SUVs to Hybrids to carbon composite
lightweight plug in Hybrids - eventually
increasing gas mileage by many factors, if
not eliminating the need for liquid transportation
fuel.

The lesson is, you can create a disaster scenario
with any trend that you extend out infinitely.
That is not how the world works, however.
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Ready4Change Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 06:28 PM
Response to Original message
18. I read the article. I've two questions/comments.
1. Unfortunately the article doesn't address biodiesel produced from algae, which appears to be the most promising source.

2. It criticizes green fuels for CO2 production, without addressing the fact that the crops from which green fuels are derived absorb CO2 in the growth process. The end result is neither a gain nor loss of atmospheric CO2.

However, I agree with it's critical assessment of ethanol, particularly when produced from Corn. It aggravates me to no end that Corn/Ethanol gets the most attention when it is pretty widely acknowledged as the LEAST suitable source of green fuels.

Ah well.
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GliderGuider Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 07:08 PM
Response to Reply #18
19. Here are my thoughts
Edited on Thu Feb-08-07 07:09 PM by GliderGuider
There is no algal biodiesel yet, at least not in the stable commercial quantities that would make a valid analysis possible.

A biofuel itself is of course CO2 neutral, in that all its carbon came from the air originally. The analysis in this article addresses the other sources of CO2 in the planting, growth, harvesting, production and distribution processes. Those emissions are much more significant on a per-barrel basis than they are for petroleum - enough greater, in fact, to cancel out the carbon neutrality advantage of the fuel itself.

Here's the problem with the externalities of plant biofuels as I see it. You need energy to run the process: for disking and plowing the land, fertilizing, planting, irrigating, harvesting, transportation, preparation, fermentation and distillation (or pressing and trans-esterifying the oil in the case of biodiesel), then cleaning up and disposing of the wastes. If you get that energy from within the process (e.g. by burning plant waste) you are depleting the soil and reducing the sustainability of the process as well as increasing the energy required for soil remediation. You are essentially reducing the net energy of the process. On the other hand, if you get that energy from an exogenous source (like oil...) you are releasing stored CO2 that negates the desired emission neutrality of the fuel. By doing that you are perhaps even making the overall process a worse CO2 offender than just burning the equivalent fossil fuels.

I do not believe there is any way out of this box using plant biofuels, at least over the long term. You can legitimately argue that the fuel has a short-term value that offsets these costs, but I don't think you can argue that it's sustainable - which should be one of our goals. Humanity has already made one ghastly mistake in not considering the sustainability and externalities of one energy source. We have the knowledge now to avoid making a similar one. Let's try to do better this time.

Just Say No to coal and plant-based fuels.
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madokie Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 07:13 PM
Response to Original message
20. New approach for biomass gasification to hydrogen, sorry its pdf
http://ec.europa.eu/research/energy/pdf/efchp_hydrogen1...

This to me is the direction we should explore
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GliderGuider Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 07:22 PM
Response to Reply #20
21. Take a look at this company
Eprida - they have a biomass gasification process that returns charcoal as its "waste" product. The charcoal is then plowed back into the earth to act as a simultaneous growth enhancer and carbon sequestration mechanism. Soil remediation, fuel and carbon storage all from one process. That one I might be able to get behind.

Terra Preta rocks!
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madokie Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 07:31 PM
Response to Reply #21
22. My brother has a sawmill business and there is a lot of waste so I done a little research into
a gasifier and in that I learned that the gas produced is high in hydrogen, around 20%. Which is a gas suitable for fuel cells
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NNadir Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 08:01 PM
Response to Reply #20
24. The gasification of any carbon source is well understood and is superior
Edited on Thu Feb-08-07 08:12 PM by NNadir
to all of the elaborate biofuels day dreams involving ethanol.

It is the subject of a considerable amount of research around the world, and has been evaluated for many forms of biomass, from walnut shells to crushed olives, to used paper.

From direct crops, biodiesel is a much better game than ethanol, but it's potential is also limited.

If one insisted on having ethanol - probably a poor choice of a fuel because of its affinity for water - one could easily make it from ethylene derived from biomass or just about <em>any</em> other carbon source.

No one here, I predict, will ever see the cellulosic ethanol craze play out in a meaningful way. Ethanol will probably produce a single exajoule of energy in this country in a year. If it were to do so, the external cost in environmental damage would probably make it wholly unsustainable.

Here are some links to some discussions of biomass gasification that I have discussed here in previous times:

http://www.democraticunderground.com/discuss/duboard.ph...

http://www.democraticunderground.com/discuss/duboard.ph...

http://www.democraticunderground.com/discuss/duboard.ph...

These are only a few of the many similar approaches being studied. The few posts I have made on this subject is hardly even close to being comprehensive.

A commercial gasification project from biological waste products, the internal organs of dimembered turkeys, operates in Missouri. I don't think it makes much money but it works.
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JohnWxy Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 07:55 PM
Response to Original message
23. Your thinking is definitely lighter than air. Did you read the Farrell an Kammen study and examine
the excel spreadsheet at http://rael.berkeley.edu/EBAMM / ?

Coal and gas inputs to ethanol process came from Wang's study. de Olievera didn't give any allocations of energy to coproducts (as Pimentel and Patzek) invalidating his results.

this article you pasted here is nonsense.

Farrel and Kammen stated "the Ethanol Today Scenario need not be (and we thnik is not likely to be) representative of future ethanolproduction"

Farrel and Kammen's calculations of GHG emissions of ethanol production were based on the "Ethanol Today" scenario.

All the scientific evidence shows ethanol produces more energy than it take to make it. REpeating the laughable mythology of Patzek and Pimentel doesn't change that fact.






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GliderGuider Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Feb-08-07 09:46 PM
Response to Reply #23
25. Hmmm. A metastudy that modifies the assumptions of the research it analyzes...
Their main objection to Pimentel and Patzek is that they discount the value of DDG. So they have an input to their methodology that allows them to replace P&P's assumptions with their own. And it's even worse than that: "We used EBAMM to (i) add coproduct credit where needed, (ii) apply a consistent system boundary by adding missing parameters (e.g., effluent processing energy) and dropping extraneous ones (e.g., laborer food energy), (iii) account for different energy types, and (iv) calculate policy-relevant metrics (19)"

Hmmm. It kind of sounds like they modified a lot of parameters to suit their own judgment. As they note, the results are very sensitive to considerations of system boundaries. By altering them they have significantly reduced the value of their own result. They also give the game away when they say in the longer paper, "A more appropriate set of metrics would a) be closely correlated with key policy outcomes, ..."

The study also says, "The impact of a switch from gasoline to ethanol has an ambiguous effect on GHG emissions, with the reported values ranging from a 20% increase to a decrease of 32% ... However, current data suggest that only cellulosic ethanol offers large reductions in GHG emissions." Not terribly hopeful, is it? Especially since there is no commercial cellulosic ethanol process available for systems analysis.

Then we get to Fig. 1(A). What's this? The graph would look significantly different if hey had used absolute instead of relative MJ on the X axis. This is a standard statistical trick to sway the innumerate. Given that ethanol has an energy content of about 20 MJ/litre, the range shown (excluding that speculative outlier for cellulosic) is from about 16 to 25 MJ. Not that much of a range, especially given those system boundary issues and the fact that bogus technologies like tar sands synthetic crude would show about three times that. Their placement for cellulosic ethanol is, as far as I can tell, nothing but a a SWAG. They seem to imply that cellulosic ethanol will require virtually no external energy inputs, which doesn't pass my sniff test.

This "science" shows distressing signs of having been worked backwards from a predetermined, desired outcome. I have absolutely no confidence, based on this paper, that the studies they like (aka not Pimentel) correctly set the system boundaries. I also have no confidence in their treatment of the original studies' metrics. However, given the essentially insignificant disagreement (at least in functional real-world terms) between P&P and the others, it's not worth arguing over. In this study the GHG advantage of ethanol is insignificant to negative, the net energy return is likewise insignificant, and the sustainability of the process isn't even discussed.

Plant based ethanol is great for drinking, but the last place we should be trying to put it is in the fuel tanks of vehicles.

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bananas Donating Member (1000+ posts) Send PM | Profile | Ignore Fri Feb-09-07 04:43 AM
Response to Original message
26. Pimentel has been thoroughly debunked
Here's a recent article from "Chemical & Engineering News" titled, "Ethanol - Is it worth it?"
http://www.democraticunderground.com/discuss/duboard.ph...

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GliderGuider Donating Member (1000+ posts) Send PM | Profile | Ignore Fri Feb-09-07 05:18 AM
Response to Reply #26
27. That article doesn't read like a "thorough debunking" to me
Edited on Fri Feb-09-07 05:18 AM by GliderGuider
It sounds like a reasonable dispute over a process that's not well understood yet. The fact that ADM, Monsanto and a bunch of economists think ethanol is a great idea does set off my warning bells, though. I wonder what they'd all think if the subsidies were removed?
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bananas Donating Member (1000+ posts) Send PM | Profile | Ignore Fri Feb-09-07 06:07 AM
Response to Reply #27
28. "a bunch of economists think ethanol is a great idea does set off my warning bells"
You doomers, your warning bells would be set off by anything.
Well, almost anything, at least you're not claiming Anna Nicole Smith's death is a sign of impending doom.
:hi:

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JohnWxy Donating Member (1000+ posts) Send PM | Profile | Ignore Fri Feb-09-07 01:36 PM
Response to Reply #27
29. the 51 cent excise tax credit per gallon of ethanol blended goes to the Oil refinery doing the
Edited on Fri Feb-09-07 02:13 PM by JohnWxy
blending. None of it goes to the ethanol producer.


Farrell and Kammen study stated that two s

"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).

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

Any paper that includes data inputs that are not documented is not a legitimate paper - especially since Pimentel and Patzek have been doing this sort of thing for years.


a few Ethanol studies showing a net energy gain for producing ethanol:

Kammen and Farrell


U.S. Dept. of Agriculture

MIchigan State UNiversity

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GliderGuider Donating Member (1000+ posts) Send PM | Profile | Ignore Fri Feb-09-07 01:57 PM
Response to Reply #29
30. That's not a "debunking"
Edited on Fri Feb-09-07 02:03 PM by GliderGuider
That's a disagreement over assumptions, that happens all the time in science. They assert that P&P's decision to discount DDG was incorrect, but don't present any supporting argument - in this paper it's simply their assertion. I happen to agree with Pimentel that DDG should not be counted, but hey, that's just my opinion.

Whether or not the exclusion of DDG is correct is not the core issue, though. The fact that determining whether the net energy of the process is negative or positive hinges on this one factor means that the net energy is borderline to begin with. We should not be considering borderline energy processes - certainly not for large scale applications like transportation fuel. This isn't AA batteries we're talking about here.

And the subsidy is certainly an issue for the farmers, even if they don't benefit directly. The subsidy creates a guaranteed demand and provides a price support for their corn, resulting in a preference to take other crops out of production in favour of corn - as has already been observed and reported by another poster.
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JohnWxy Donating Member (1000+ posts) Send PM | Profile | Ignore Fri Feb-09-07 02:28 PM
Response to Reply #30
32. It helps if you read. Sound it out:

"and
by including some input data that are old and
unrepresentative of current processes, or so
poorly documented that their quality cannot be
evaluated
."


This is quote from the Farrell and Kammen study. It is speaking about the Pimentel and Patzek studies. Any 'study' which includes data or assumptions not documented unequivocally is not to be trusted. Pimentel and Patzek are not considered legitimate researchers by those in this field. Their stuff does not withstand critical scrutiny.

NOt providing allocations of energy to coproducts which in the physical reality of the process do absorb heat is not a debatable point to a scientist or any rational person. It's a matter of fact not philosophy.

Your desire to redifine reality (is this the latest tactic of the conservative fossil fuelophiles? - just deny reality, deny , deny deny. Hoping you will convince somebody that your mania is has some legitimacy.) to fit your needs is not a scientific, rational approach. It's called megalomania.

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GliderGuider Donating Member (1000+ posts) Send PM | Profile | Ignore Fri Feb-09-07 02:44 PM
Response to Reply #32
34. Hey, ease up on the ad hominems there.
We have a philosophical and scientific disagreement here. No need to get personal.

The point you reference above is yet another of their assertions. They provide no information about what the "old, unrepresentative or poorly documented" input data is. I guess we're just supposed to accept their word for it? That's simply not good enough for real science.

I say that it doesn't matter whether you include or exclude the DDG - the net energy is too close for comfort either way.

And if you're going to label me you'd best take a look at my web site first. I'm anything but a "fossil fuelophile". If anything, I'm an overshoot Malthusian, who believes we got into our current predicament by not understanding the implications of unsustainable energy use and failing to grok the significance of exponential functions. Fossil fuel is killing our species and possibly the planet. I just don't see plant-based ethanol (with or without added DDG) as a solution to the problem.
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hunter Donating Member (1000+ posts) Send PM | Profile | Ignore Fri Feb-09-07 02:26 PM
Response to Original message
31. Starvation is one of the most heinous tools of oppression.
Any more I think that's what this promotion of ethanol is all about. Upper and middle class U.S. citizens don't pay much attention to the price of food -- food costs are not a huge fraction of their income. But if you are poor it is another story.

I think the Machiavellian cretins who run this nation believe destabilization of central and south American nations, especially those that lean left, is a good thing, and that restricting the overall supply of inexpensive food in the Western Hemisphere is one means of accomplishing that.

Ethanol as a a transportation fuel is stupid on the face of it -- the technology for making much better fuels than ethanol from agricultural products is solid. That's why I think something else is going on here.

Or maybe it's simply old-fashioned dumb-ass U.S. corruption and hookers at the Watergate Hotel.

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JohnWxy Donating Member (1000+ posts) Send PM | Profile | Ignore Fri Feb-09-07 02:34 PM
Response to Original message
33. ONe of the characteristics of disinformation is to redefine an issue to better make your point.
Edited on Fri Feb-09-07 02:36 PM by JohnWxy
There are TWO reasons for developing alternative fuels to gasoline.

one is to reduce our dependence on imported oil.

the other is to reduce Greenhouse gas emissions from gasoline.

Even if ethanol did not reduce GHG emeission any more than gasoline the first reason would still be a compelling one for developing ethanol and other biofuels.

the fact that ethanol is renewable is also a powerful reason for developoing it as we are eventually going to run out of fossil fuels. As the plants grow that we make ethanol from (either starch based or cellulosic based) they pull carbon out of the atmosphere and leave some of it in the soil. This does not happen with fossil fuels.


The Farrel and kammen study did not take into account any future developments in the ethanol technology which will reduce GHG emission by improving efficiency and by eliminating the use of fossil fuels in the production of ethanol. The Farrell and Kammen study only provided a snapshot of the ethanol industry as it existed in the 2000-2002 time frame. To assume the the ethanol technology will remain static is not realistic. Improvements will come in farming techniques and in process technologies.







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GliderGuider Donating Member (1000+ posts) Send PM | Profile | Ignore Fri Feb-09-07 03:00 PM
Response to Reply #33
35. There's another way to reduce the danger of your dependence on imported oil
That would be to establish better relations with the exporters. But it's probably too late for that - you're even starting to alienate Canada.

And I would claim that it's impossible to reduce your dependence on oil imports by moving to biofuels, at least to the low-grade energy of plant biofuels.

I would further claim that the "dependence on imported oil" is not the real danger. It's merely a political construct intended to promote xenophobia and consolidate the control of your domestic power brokers. The real danger is that all the oil, domestic and imported, is about to start going away. As that happens, importing nations are going to be disproportionately impacted. Net exports will decline faster than overall production as nations retain what oil they produce to preferentially satisfy domestic needs over exports. That puts the USA in a very vulnerable position. The reason I don't think ethanol is going to help is due to the time scale. I strongly suspect you will see American oil imports begin to fall by 4%-6% per annum starting within two years (as Cantarell crashes). If you try to plug that gap with plant biofuels you will severely damage the ecosphere, and I don't think you'll succeed anyway.

You'd be much better off, frankly, championing efficiency and conservation. They will be essential to meet the challenge, much more so IMO than having a bit more ethanol available for the easy motoring set.
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NNadir Donating Member (1000+ posts) Send PM | Profile | Ignore Sat Feb-10-07 07:30 PM
Response to Reply #33
38. Ethanol is not renewable if it depends on oil.
Where are the closed systems operating? When did Iowa ban oil imports? Nebraska? Illinois? Kansas?

Nowhere in fact has ethanol displaced oil or even come remotely close.

Studies are not industrial plants, despite silly attempts to represent them as such. Every thinking person on the planet - and note the operative word is "thinking" knows that George W. Bush's "cellulosic ethanol" SOTU speech was wishful thinking. There have been studies of ethanol for many decades now, subsidies for ethanol, Presidential candidates burning alms at the temples of ethanol and still people have to debate Pimentel. I would submit that if ethanol were so great, nobody would be debating a word of Pimentel says. They would simply be remarking on how ethanol displaced oil. But no one is so remarking. The real problem is that a domestic ethanol industry exists and it is completely and ludicriously unable to stem the tide of oil and now ethanol imports.

I would argue that in the only country that has come even close to displacing oil with ethanol. That is Brazil, Brazil being the country from which, GEORGE W. BUSH AND DICK CHENEY, ETHANOL SUPPORTERS, :bounce: :rofl: want to import ethanol. Brazil is a terrible climate change disaster. This is because they had to ravage rain forests to make sugar cane plantations. The fact is that ethanol is a scheme by agricultural interests to rototill every spare bit of land on earth.

Of course, George W. Bush, ETHANOL SUPPORTER, has experience with ethanol dependence and imported ethanol, no doubt as well.

Ethanol, foreign or domestic, will never displace oil, no matter how much crap its ill informed and misleading advocates wish to whine and cry about the subject.
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