Ethanol Deception - Is It Really Better Than Gasoline?

[Averagesupernova]

Okay, I wasn't aware of the higher compression ratios possible, but since these cars are not available and the reality is what we actually have, ethanol probably offers no financial advantage.

And for anyone who want to do the calculation, when you see the 400 gallon per acre yields for corn, after the processing requirements, multiply by 0.3 [best case for corn] as the net gain. Others claim that the real multiplier is more like 0.1 or 0.2, and some even argue that the multiplier is 0.0 - that ethanol energy is just hidden petroleum energy and it is only competitive due to subsidies.

I'm not quoting this to argue the numbers. I want to point out that after the alcohol is taken out of corn there is a lot of useful product left. It cannot be dismissed. If we need products from corn to start with, or any other crop for that matter, then what is the problem with getting the alcohol out of it when it will be grown regardless?

 

[Ivan Seeking]

I will be back later today or tonight. I wasn't ready with my links and need time to sort things out. I've been puting together a presentation for something else [related], and much of my information is in my notes at this point.

 

[Ivan Seeking]

If we go to CNN.com we can find the article http://www.cnn.com/2007/AUTOS/05/24/cr_mpg_survey/index.html" placed today on the CNN website.

Okay, that is the story referenced in yesterday's report. Apparently the news anchor had bad info as I think it was he who actually said that according to the CS study, ethanol was comparable to gasoline, when in fact their own report tells a different story, but they didn't show the entire report. It seems that what I saw was a leader story for this report. So it was the fault of CNN and CR got it right.

 

[Ivan Seeking]

Please see: A.E. Farrell et al., "Ethanol Can Contribute to Energy and Envoronmental Goals", Science, Vol. 311, p. 506-508, 27 January 2006 (www.sciencemag.org[/url]).[url]http://rael.berkeley.edu/EBAMM/FarrellEthanolScience012706.pdf[/URL][/QUOTE]

I still need to take some time to review this - till now I have been trying to find a great link that I forgot to log and can't find. But for now, this gives an overview of the debate.

[quote]...The stickiest question about ethanol is this: Does making alcohol from grain or plant waste really create any new energy?

The answer, of course, depends upon whom you ask. The ethanol lobby claims there's a 30 percent net gain in BTUs from ethanol made from corn. Other boosters, including Woolsey, claim there are huge energy gains (as much as 700 percent) to be had by making ethanol from grass.

But the ethanol critics have shown that the industry calculations are bogus. David Pimentel, a professor of ecology at Cornell University who has been studying grain alcohol for 20 years, and Tad Patzek, an engineering professor at the University of California, Berkeley, co-wrote a recent report that estimates that making ethanol from corn requires 29 percent more fossil energy than the ethanol fuel itself actually contains.

The two scientists calculated all the fuel inputs for ethanol production—from the diesel fuel for the tractor planting the corn, to the fertilizer put in the field, to the energy needed at the processing plant—and found that ethanol is a net energy-loser. According to their calculations, ethanol contains about 76,000 BTUs per gallon, but producing that ethanol from corn takes about 98,000 BTUs. For comparison, a gallon of gasoline contains about 116,000 BTUs per gallon. But making that gallon of gas—from drilling the well, to transportation, through refining—requires around 22,000 BTUs.

In addition to their findings on corn, they determined that making ethanol from switch grass requires 50 percent more fossil energy than the ethanol yields, wood biomass 57 percent more, and sunflowers 118 percent more. The best yield comes from soybeans, but they, too, are a net loser, requiring 27 percent more fossil energy than the biodiesel fuel produced. In other words, more ethanol production will increase America's total energy consumption, not decrease it. (Pimentel has not taken money from the oil or refining industries. Patzek runs the UC Oil Consortium, which does research on oil and is funded by oil companies. His ethanol research is not funded by the oil or refining industries.)[continued][/quote]
[url]http://alt-e.blogspot.com/2005/07/alternative-fuel-ethanol-fuel.html[/url]

Also, sure, it is possible to divert the energy demand to other sources, but this does not make ethanol truly competitive as an alternative. It becomes more of an energy carrier rather than an energy source. So in this sense ethanol would be more like hydrogen, in which case we might as well just make hydrogen. And we don't need to load-up the grid driving alternative options. This is one point on which even Russ and I agree.

Also, BobG's quote
[quote]How much corn you could get if the entire US were devoted to corn growing is irrelevant. Only 3.6% of US land is devoted to growing corn [/quote]

Combined with an optimistic estimate given earlier
[quote]Right now, about 16 percent of the U.S. corn crop is going into ethanol production, but the fuel makes up less than one percent of U.S. demand for liquid fuels, once you take into account the amount of energy needed to produce the ethanol, Stephanopoulos said. Even if all U.S. corn went into ethanol production, there would only be enough for 4 to 5 percent of U.S. annual liquid fuel consumption...[/quote]

we come up with a demand of ~20 or 25 X 3.6% = 72% to 90% of the land area of the US, so already we are close to my statement of twice the land area without getting specific about where all of the petroleum energy goes, and at what efficiency. But it is true, when I figured this I was not assuming that we in effect cheat by diverting the energy of processing to other sources as this really doesn't solve the basic problem.

Oh yes, apparently that number of 3 parts in 10,000 gain [0.03%] was for cellulosic ethanol from corn, which I know nothing about at this point.

Also, note that the values will vary quite a bit from source to source, including the raw energy densities.

 

[Ivan Seeking]

First, in spite of prior objections, I maintain that energy is a perfectly good way to compare fuels as long as the efficiency is known for each application. After all, in the end, sooner or later, we have to talk about the work done. This is ultimately what we have to compare. And the increased efficiency wrt ethanol in high compression engines does not apply to what we are actually driving, which was my point of reference. The CS/CNN report showed a 27% decrease in mileage in going from gasoline to ethanol, and if we take the ratio of the energy content of each as 125,000 and 76,000 BTUs per gallon respectively (76/125), we might expect about a 39% decrease, which isn't too bad as a ball park estimate given no other specifics. And of course we find significant differences in the raw energy estimates as well as differences in the fuel quality at the pump that could account for this, in addition to any efficiency variances between fuels. Not to mention that the test may have had a large margin of error.

Here are some more good links including:

Ethanol fuel from corn faulted as 'unsustainable subsidized food burning' in analysis by Cornell scientist

http://www.news.cornell.edu/releases/Aug01/corn-basedethanol.hrs.html

http://journeytoforever.org/ethanol_energy.html

Overall, we use about 100 quads [quadrillion BTUs] of energy each year from all sources, and in 1998 [easiest reference], 38.8% of this energy came from petroleum.

We can consider the typical efficiencies of diesel to include most petroleum energy [when taken with the estimates earlier for the ethanol needed for gasoline], and then consider how much ethanol we need to replace this. In fact we might just be generous and assume that ethanol would be as efficient as diesel as a starting point.

The total demand for refined products is listed here
http://tonto.eia.doe.gov/dnav/pet/pet_cons_psup_dc_nus_mbbl_a.htm

For 2005, I count about 3 thousand million barrels of fuel oil at 42 gallons per barrel, and assuming 139,000 BTUs per gallon, we get a total of 1.75E16 BTUs. Now, if we assume the same efficiencies for ethanol at [76,000 BTUs per gallon] as we get from the fuel oil, we get 2.3E11 gallons of ethanol, and at 30% yields we need 7.8E11 gallons, or about 1.7E9 acres of corn to replace diesel fuel and oil used for heat. This would be in addition to the ethanol needed for gasoline, so as you can see, we can easily get to absurdly large numbers and about twice the land area of the US at 2.2E9 acres. But again, this assumes that we don't steal energy from other sources to make the ethanol. And of course the potential error is fairly large, but we are working in units of nuclear bombs anyway, and we can get close enough for perspective. Also, we assumed the ethanol would be as efficient as diesel, and today it's not, so we might add as much as another 30% to our 1.7 billion acres. And lastly, I don't know of any large trucks that run on ethanol.

Now should we consider aviation?

When I used the word deception, I didn't mean to imply that there is a conspiracy. No doubt most scientists and enthusiasts are sincere in supporting their position in this issue, whatever that may be, but the idea that ethanol is a real option is clearly a fallacy at this time. And we need to think about the options that exist today.

Ethanol from corn may be an alternative fuel, but it is not an alternative.

 

[Aether]

Also, sure, it is possible to divert the energy demand to other sources, but this does not make ethanol truly competitive as an alternative. It becomes more of an energy carrier rather than an energy source. So in this sense ethanol would be more like hydrogen, in which case we might as well just make hydrogen. And we don't need to load-up the grid driving alternative options. This is one point on which even Russ and I agree.

Ethanol today could be considered largely an energy carrier rather than an energy source, but:

Our best point estimate for average performance today is that corn ethanol reduces petroleum use by about 95% on an energetic basis and reduces GHG emissions only moderately, by about 13%.

Ethanol today is effective at reducing U.S. dependence on foreign oil today. Ethanol may also have a future as a primary energy source.

...the idea that ethanol is a real option is clearly a fallacy at this time. And we need to think about the options that exist today.

If you have an alternative in mind (biodiesel?) then please compare it to ethanol directly.

Although biofuels offer a diverse range of promising alternatives, ethanol constitutes 99% of all biofuels in the United States.

 

[Averagesupernova]

Ivan you haven't commented on my first post. My point is that you cannot count all of the fuel it takes to raise a crop since that crop is used for other things even after the alcohol is taken out. If you intend to calculate the amount of fuel it takes to get a unit of ethanol in the manner that they are in your post #39 then you have to assume that no crop was raised prior to ethanol production which is completely false and that no other products come from the crop once the ethanol is taken out which is also completely false. I do not wish to argue for or against ethanol from crops I just want to point out that the methods arrived at figuring gains/or losses are bogus.

 

[Ivan Seeking]

Ethanol today could be considered largely an energy carrier rather than an energy source, but: Ethanol today is effective at reducing U.S. dependence on foreign oil today. Ethanol may also have a future as a primary energy source.

If you have an alternative in mind (biodiesel?) then please compare it to ethanol directly.

Estimates and three decades of testing indicates that by using algae, we can produce as much as a net 10,000 gallons of biodiesel per acre-year - say 7000 if we stay conservative and allow for a 30% processing demand. See the aquatic species program [in addition to plenty of more recent links found with a simple search] which predicted that algae could be competitive when diesel was at about $2 a gallon, or twice 1996 levels. [see part ii, page 4]
http://www1.eere.energy.gov/biomass/pdfs/biodiesel_from_algae.pdf

Not that we would want to, but a simple estimate suggests that we could replace all sources of energy - petro, coal, NG, hydro, nuclear, wind, solar - with about 400 X 400 miles of land and or water. In the process, algae can be grown while cleaning up CO2 or other industrial, agricultural, or municipal emissions or waste.

From everything that I have seen on the web and in my own testing, it was just a matter of time and price. It appears that algae became competitive [hit the break even point] about mid 2004 at ~40 a barrel for crude. It should be a viable option at today's prices.

Also, keep in mind that much of the literature focuses on making algae competitive at much lower prices, which it isn't, but today this is likely not an issue.

 

[Ivan Seeking]

Ivan you haven't commented on my first post. My point is that you cannot count all of the fuel it takes to raise a crop since that crop is used for other things even after the alcohol is taken out. If you intend to calculate the amount of fuel it takes to get a unit of ethanol in the manner that they are in your post #39 then you have to assume that no crop was raised prior to ethanol production which is completely false and that no other products come from the crop once the ethanol is taken out which is also completely false. I do not wish to argue for or against ethanol from crops I just want to point out that the methods arrived at figuring gains/or losses are bogus.

We can't play shell games: We have to look at the real costs to produce what we need. We have to assume that we create new farmland to produce the fuel since we clearly don't have enough now [unless we plan to stop producing food]. And byproducts are great, but when we start talking about twice the land area of the US, they don't count for much. It is clearly not a viable option in the big picture. But as I stated earlier, it might be used to ease the crunch as it is today.

I also suggest that even if we could grow enough corn, due to the amount needed, most byproducts would not be valuable due to supply and demand. This has already happened in the biodiesel market. One byproduct is pure glycerin, which now has relatively little value due to the amount of biodiesel produced.

However, as a best case perhaps, a byproduct of algae is... algae. After getting the biodiesel, in principle it can be used to produce ethanol, and then hydrogen, but I don't know if this has ever been done in a practical way. Also, people are working with algae for hydrogen and ethanol production alone, so the picture is bigger than just biodiesel, but down the road - another "future" option. Still, one important concept wrt algae is the carbon all goes somewhere - either as sugars for ethanol, or hydrocarbons [fatty acids] for biodiesel. As it turns out, the most efficient path today is for hydrocarbon production.

The residual mash can be used as a high quality feed for cattle, or as fertilizer for other food or algae crops.

 

[Ivan Seeking]

Oh yes, 400 X 400 miles X 640 acres/ sq. mile X 10,000 gallons/acre X 118300 BTUs per gallon = 120 quads.

So maybe 80 quads in practice. Again, we use about 100 quads from all souces, and when you sort it out a bit, the efficiencies don't change the picture greatly. And to replace just petroleum, but all petroleum, which unlike ethanol, biodiesel could since it could be used in the trucking and other industries [and is currently being tested for aviation], we would only need about 39% of this, or about 250 X 250 miles of land or water [good farmland not needed]

But the point of this thread was to show that based on the technology that we have today, ethanol, and esp ethanol from corn, is not a long term solution to the energy problem. Some even argue that it is part of the problem [a net loser].

Late edits: Going to back a point made earlier, we can also reduce this requirement [land needed for algae] as we do use energy to transport crude from other counties, and then to refine it here. I think the avg chain efficiency for petro fuels is a little under 80%, so we can legitimately derate the requirements accordingly. I need to check on the exact number though; that is about what I think it was...

 

[Averagesupernova]

We can't play shell games: We have to look at the real costs to produce what we need. We have to assume that we create new farmland to produce the fuel since we clearly don't have enough now [unless we plan to stop producing food]. And byproducts are great, but when we start talking about twice the land area of the US, they don't count for much. It is clearly not a viable option in the big picture. But as I stated earlier, it might be used to ease the crunch as it is today.

I also suggest that even if we could grow enough corn, due to the amount needed, most byproducts would not be valuable due to supply and demand. This has already happened in the biodiesel market. One byproduct is pure glycerin, which now has relatively little value due to the amount of biodiesel produced.

However, as a best case perhaps, a byproduct of algae is... algae. After getting the biodiesel, in principle it can be used to produce ethanol, and then hydrogen, but I don't know if this has ever been done in a practical way. Also, people are working with algae for hydrogen and ethanol production alone, so the picture is bigger than just biodiesel, but down the road - another "future" option. Still, one important concept wrt algae is the carbon all goes somewhere - either as sugars for ethanol, or hydrocarbons [fatty acids] for biodiesel. As it turns out, the most efficient path today is for hydrocarbon production.

The residual mash can be used as a high quality feed for cattle, or as fertilizer for other food or algae crops.

I'm not sure what you mean by 'play shell games'. The simple fact is that X acres of crop will be raised regardless of whether we take ethanol out or not. So until ethanol usage shorts some other product that requires the carbohydrate, NOT taking alcohol out is the most inefficient way to go. Residual mash left from ethanol from corn is also a high quality source of feed for cattle. It's a good protien source commonly known as distillers grain. I'm betting that there is a lot more residual left from corn after distillation than alcohol. We all need to remember that we need to eat too which has always been and hopefully always will be the main role of agriculture.
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I'm certainly not saying that ethanol from corn is a cure all. Obviously it's not. My point is that the method arrived at determining the net gain/loss is bogus and you can't/won't see it.

 

[Ivan Seeking]

The fact is, already the use of ethanol has doubled the corn prices - food and energy are in competition, and we see the result. And we have barely scratched the surface.

Where is that benefit again? Earlier I posted a Reuters quote showing that chichen prices have started to rise [up 6 cents a pound for wholesale at that time], and there is upward pressure on beef prices, all because of ethanol. There are already a million [figuratively speaking] uses for corn and corn products, and anything using these products will be affected.

And it is not true that demand for ethanol will have no impact on how much corn we grow - supply and demand says otherwise.

 

[Averagesupernova]

I would bet a years pay that corn prices will not stay at current levels for any length of time. And I'm not talking about a 5 to 10 year trend. If they do, everything else will inflate along with. In 1996 corn spiked well over $5.00 per bushel. It happens every so often. You are talking very short term. Take a look at corn prices over the last 30 years and you'll see what I mean. Food is already in competition with energy. It takes energy to get food and until everyone moves back to small farms and things go back to manual labor it will remain so.
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Anyways, that is not my argument, so please don't even bother. My point is (which you've ignored) the method used to determine the net gain/loss of energy in ethanol production. Crops will continue to be grown as they always have so the same amount of fuel will be expended to do so with or without taking the ethanol out. It makes me wonder what else is overlooked in all of the other energy source schemes being dreamed up.

 

[Ivan Seeking]

You seem to forget that we need the corn grown today. This is not a surplus grown for no reason.

The increased cost of corn is attributed directly to ethanol, but the other market forces still apply, so we would expect to see tremendously high spikes in the future if ethanol production increases significantly. When we apply the law of supply and demand, and we create a huge new demand, the prices will certainly rise accordingly. This is basic economics.

 

[Ivan Seeking]

Another advantage that biodiesel has today [without even growing algae yet] is that the feedstock base is highly diversified - we can and do use many different kinds of plants as a source- so the impact can be spread out over many different products. For example, in some areas the source is canola, others cotton seed, and in many areas we make it from soybeans. Rapeseed is another strong source of feedstock today.

I think the majority of biodiesel in the US is coming from soybeans right now, but this is driven by demand. As the demand increases, more crops will come online with greater capacity. In principle it could help ALL farmers, and not just corn farmers.

I know that Willie Nelson [BioWillie] drives a Mercedes that runs on cotton seed biodiesel.

He has a sticker on the front window: No War Required.

 

[Ivan Seeking]

First, in spite of prior objections, I maintain that energy is a perfectly good way to compare fuels as long as the efficiency is known for each application. After all, in the end, sooner or later, we have to talk about the work done. This is ultimately what we have to compare. And the increased efficiency wrt ethanol in high compression engines does not apply to what we are actually driving, which was my point of reference. The CS/CNN report showed a 27% decrease in mileage in going from gasoline to ethanol, and if we take the ratio of the energy content of each as 125,000 and 76,000 BTUs per gallon respectively (76/125), we might expect about a 39% decrease, which isn't too bad as a ball park estimate given no other specifics. And of course we find significant differences in the raw energy estimates as well as differences in the fuel quality at the pump that could account for this, in addition to any efficiency variances between fuels. Not to mention that the test may have had a large margin of error.

A small correction: Since they were using E85 and not pure ethanol, considering just the reduced energy density we would expect to see about a 33% decrease in the mileage, which is getting very close to the 27% measured.

 

[Averagesupernova]

Ivan I'm NOT the one forgetting that we need the corn grown today, that's my whole point. It WILL BE GROWN REGARDLESS OF WHETHER WE TAKE ALCOHOL OUT. You seem to skip over the fact that the only thing taking the alcohol out does is remove the sugars from the corn. It is still quite useful after. I am not favoring ethanol over biodiesel at all. You speak of basic economics. Well here's some food for thought: Right now a corn/soybean crop rotation is fairly common. As there is more demand for corn more of these acres are switched over from soybeans to corn. We now raise corn on the same ground year after year on more acres than previously. This naturally affects the market price of soybeans and some other crops as there are less grown. The same thing will happen if the demand for ethanol goes down and the demand for biodiesel goes up. It will be more profitable to raise soybeans and other biodiesel crops so there will be less corn grown and this shortage will raise the price of corn. Take a look at the market price for both corn and soybeans over the last few years and you will find that they track each other.
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If you don't want fuel to directly compete with food then keep energy production out of agriculture and find some other source for it.

 

[Ivan Seeking]

Ivan I'm NOT the one forgetting that we need the corn grown today, that's my whole point. It WILL BE GROWN REGARDLESS OF WHETHER WE TAKE ALCOHOL OUT. You seem to skip over the fact that the only thing taking the alcohol out does is remove the sugars from the corn. It is still quite useful after.

Sure, it can be used for some applications, but what about those that need the corn intact? The fact is that we can't process all of the corn for ethanol which is already needed for other uses, but perhaps some could be.

I am not favoring ethanol over biodiesel at all.

I also want to be clear that I am not against ethanol because of biodiesel, rather, I became a biodiesel fan on its own merits, and have been very disappointed to learn about the reality of ethanol which I once saw as a promising option to petro.

You speak of basic economics. Well here's some food for thought: Right now a corn/soybean crop rotation is fairly common. As there is more demand for corn more of these acres are switched over from soybeans to corn. We now raise corn on the same ground year after year on more acres than previously. This naturally affects the market price of soybeans and some other crops as there are less grown. The same thing will happen if the demand for ethanol goes down and the demand for biodiesel goes up. It will be more profitable to raise soybeans and other biodiesel crops so there will be less corn grown and this shortage will raise the price of corn. Take a look at the market price for both corn and soybeans over the last few years and you will find that they track each other.

Absolutely a valid point. Parts of the solution are the other crops like cotton, canola etc which helps to spread out the pain, but...
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If you don't want fuel to directly compete with food then keep energy production out of agriculture and find some other source for it.

I see it like this: Biodiesel is superior to ethanol in many ways, not the least of which are: The diversified base of feedstock; 1.5 times the energy density; a more efficient [as a percent of yield] processing chain. Now, if we didn't have algae as a real option today, biodiesel would have the same problem as ethanol in that we couldn't possibly grow enough. But we do have the algae option, and macro plants are available today to help with the short term demand for biodiesel. In turn, biodiesel is the carrot to go diesel. So we go diesel, then biodiesel from all crops, then we begin to supplement the macro crops with algae until eventually it could supply the majority of the feedstock [of course, in reality these are concurrent events]. And most important of all, unlike ANY other option that I have ever seen, bio from algae offers a permanent solution - and one that need not compete with food.

If it wasn't for algae, there would be NO good options ready today that could actually solve the problem. [less nuclear, which I don't see as a practical reality in an age of terrorism even if we could build the plants fast enough, which we can't.]

Also, just to avoid any confusion, algae has been a practical option for some time, but it has not been competitive due to price...until now.

 

[Averagesupernova]

Ivan where do you get the 1.5 times energy density of biodiesel compared to ethanol? How is that figured?

 

[Ivan Seeking]

Biodiesel has 118330 BTUs per gallon. Ethanol has 76000 BTUs per gallon. This taken with the efficiency of the engine used for each fuel is a direct measure of the work that can be done with each gallon of that fuel. [118/76 ~= 1.5.]. Of course that 1.5 times ignores the greater efficiency of diesel over combustion engines, which makes the comparion even more drastic, as is seen below.

While we are still using regular diesel - as we convert to bio - we get 139,000 BTUs per gallon in engines that are more efficient than gasoline or ethanol powered engines. It begins to help even before we convert to bio. And the diesel cars are here or coming.

Diesel engines are already high compression engines, so the comparison is valid even if we consider engines not yet available for ethanol.

The higher energy density of bio, the greater efficiency of diesel engines, and the more efficient processing for bio suggests that Bio has about a 400% energy advantage over ethanol - every four gallons of ethanol produced can move a car down the road as far as every gallon of bio produced.

 

[Averagesupernova]

Ok. That is pretty much what I expected, but not everything I want to know. How many gallons per bushel of each? And how many bushels per acre of each?

 

[Ivan Seeking]

Note that I have a bunch of late edits in the last post [struggling for clarity]

Most common stats cited for gross yields:
Corn yields 400 gallons of ethanol per acre-year.
Algae yeilds about 10,000 gallons of biodiesel per acre-year.

Net yields [after we pay the energy price to grow and process the fuel]:
Corn = 120 gallons per acre-year
Algae = 7000 gallons per acre-year

I just saw that BBC World News is running a story that asks the question: Should we grow food to feed the world's starving, or grow crops for fuel?

 

[Aether]

Most common stats cited for gross yields:
Corn yields 400 gallons of ethanol per acre-year...

Net yields [after we pay the energy price to grow and process the fuel]:
Corn = 120 gallons per acre-year...

As I quoted earlier, according to A.E. Farrell: "Our best point estimate for average performance today is that corn ethanol reduces petroleum use by about 95% on an energetic basis...". Therefore, in order to compute "net yields" you need to be using 0.95 instead of 0.3; and then your number above for net yields would be "...Corn = 380 gallons per acre-year".

 

[Averagesupernova]

What about soybeans and other biodiesel crops? Also, what is figured in for inputs to the crop? On a corn/soybean rotation it is common to not use fertilizer at all for the soybeans. Plant food is derived from the residue of the previous years crop as well as some of the fertilizer applied for the corn crop. I guarantee you that soybeans on the same ground year after year will require some kind of fertilizer. I know next to nothing about algae but I have a very hard time believing that all it requires is air and sunlight. There must be other input to net the amount of biodiesel we are talking about.

 

[Aether]

What about soybeans and other biodiesel crops? Also, what is figured in for inputs to the crop?

The EBAMM model (ERG Biofuel Analysis Meta-Model) provides a thorough analysis of all inputs, including the agricultural phase, of ethanol production. I don't know if they provide similar information on biodiesel.

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

 

[Ivan Seeking]

As I quoted earlier, according to A.E. Farrell: "Our best point estimate for average performance today is that corn ethanol reduces petroleum use by about 95% on an energetic basis...". Therefore, in order to compute "net yields" you need to be using 0.95 instead of 0.3; and then your number above for net yields would be "...Corn = 380 gallons per acre-year".

This has nothing to do with it. We measure the yield and look at how much energy it took to produce that yield. The multiplier is ~0.3 for net yield...and based on the technology in use, that is a best case.

 

[Aether]

This has nothing to do with it. We measure the yield and look at how much energy it took to produce that yield. The multiplier is ~0.3 for net yield...and based on the technology in use, that is a best case.

The multiplier is ~0.3 for net energy, but it is 0.95 for farm land. Ethanol plants use coal and natural gas as energy inputs which accounts for the difference. If these plants had to use all ethanol or petroleum as their only energy inputs then the number for farm land would be ~0.3; but they do not have to do that, nor do they choose to do that in practice.

 

[Ivan Seeking]

What about soybeans and other biodiesel crops? Also, what is figured in for inputs to the crop? On a corn/soybean rotation it is common to not use fertilizer at all for the soybeans. Plant food is derived from the residue of the previous years crop as well as some of the fertilizer applied for the corn crop. I guarantee you that soybeans on the same ground year after year will require some kind of fertilizer. I know next to nothing about algae but I have a very hard time believing that all it requires is air and sunlight. There must be other input to net the amount of biodiesel we are talking about.

Some crops are much better than others, and the amount of fertilizer needed is a critical part of the energy calculation no matter what crop we use. I don't know the specifics of soybeans but it is one of the best options after algae. I'm sure that plenty of information is found with a search as soybean is a major crop used today for biodiesel.

Nitrogen and other nutrients are needed for the algae. This was all considered in the aquatic species program and later research.

One nice thing about algae is that given the proper selection of algae strains, it can survive and even thrive in highly contaminated water. This is why it can be used to clean-up industrial, ag, and municipal waste. What is considered pollution can grow algae at tremendously high rates.

Another part of what makes algae so competitive is the percent yield as a function of oil by weight. There is one strain that has been measured as having as much as 86% oil by weight. Typical yields range between 30 and 50% oil by weight [oil weight compared to weight of dry algae before processing]. And it isn't that hard to understand when you think about it. Algae is a very simply organism that only does a few things. It is also very small - often in the range of about 5 to 10 microns in size - so it is very efficient in that it occupies 100% of the light incident area, and almost all of this is going towards fuel production rather than growing stalks, leaves, etc.

 

[Ivan Seeking]

The multiplier is ~0.3 for net energy, but it is 0.95 for farm land. Ethanol plants use coal and natural gas as energy inputs which accounts for the difference. If these plants had to use all ethanol or petroleum as their only energy inputs then the number for farm land would be ~0.3; but they do not have to do that, nor do they choose to do that in practice.

This is not what the multiplier means. It is a measure of total efficiency. What you are talking about is using other energy to make ethanol, and this is not a viable option as we don't have the power needed to make it. In effect, what you are saying is that we should convert to coal power. And either way, we still couldn't possibly grow enough corn.

In the case of an energy carrier, hydrogen is more efficient as it returns about 50% of the energy used to make it, not 30%. And we don't need corn, just water. Also, hydrogen can be burned in traditional engines.

 

[Aether]

This is not what the multiplier means. It is a measure of total efficiency.

You are trying to use this multiplier to support your claim that farm land yields only 120 gallons of ethanol per acre-year instead of 380. This is clearly wrong.

What you are talking about is using other energy to make ethanol, and this is not a viable option as we don't have the power needed to make it. In effect, what you are saying is that we should convert to coal power.

No, what I am talking about at the moment is how many acre-years of farm land it takes to make 380 gallons of ethanol.

In the case of an energy carrier, hydrogen is more efficient as it returns about 50% of the energy used to make it, not 30%. And we don't need corn, just water.

Maybe so, but that doesn't have anything to do with how many acre-years of farm land it takes to make 380 gallons of ethanol.

Incidentally, if ethanol has 30% net energy, then that means that it returns 130% of the energy used to make it; not 30%.

 

[Ivan Seeking]

If we use coal power to make ethanol, yes, it would take less land. Of course we still couldn't grow enough corn. You keep ignoring this point.

Where are we going to get the power? We don't have it, so we would have to either build a tremendous number of coal plants to produce ethanol, or use ethanol energy produced on-site to make the fuel. Either way we need to get the energy from somewhere.

When we talk about net energy returns, what we mean is how much of the available energy do we get to use. This is 30%. This is how we measure the net energy gain. You can play games all day, but the energy has to come from somewhere, and ethanol can't provide the energy, so ethanol is not an energy solution, which was the point of this thread.

Oh yes, your point about hydrogen is valid. I was using two different ways to compare. With ethanol we put in 66 BTUs and get 100, so we see a 50% gain in this sense. With hydrogen we put in 66 and get back 33 [or so].

 

[Aether]

If we use coal power to make ethanol, yes, it would take less land.

Well, this is how we make ethanol today; using coal and natural gas.

Of course we still couldn't grow enough corn. You keep ignoring this point.

Maybe so, but this is a different issue. You don't mind if we discuss (and resolve) one issue at a time do you?

Where are we going to get the power? We don't have it, so we would have to either build a tremendous number of coal plants to produce ethanol, or use ethanol energy produced on-site to make the fuel. Either way we need to get the energy from somewhere.

We currently get the energy from domestic coal and natural gas; future plans are to use cellulosic ethanol where the energy comes entirely from lignin which is a part of the plants themselves.

When we talk about net energy returns, what we mean is how much of the available energy do we get to use. This is 30%. This is how we measure the net energy gain.

Wrong. If you look at the EBAMM spreadsheet you will see the detailed data from six separate published studies on the subject of the net energy of ethanol production. Here is a summary; output energy includes "coproduct credits":

Patzek: 27 MJ/L energy input vs. 25 MJ/L energy output = 93% return.
Pimentel: 26 MJ/L energy input vs. 23 MJ/L energy output = 88% return.
Shapouri: 21 MJ/L energy input vs. 29 MJ/L energy output = 138% return.
Graboski: 22 MJ/L energy input vs. 25 MJ/L energy output = 114% return.
de Oliviera: 20 MJ/L energy input vs. 25 MJ/L energy output = 125% return.
Wang: 19 MJ/L energy input vs. 25.2 MJ/L energy output = 133% return.

 

[Ivan Seeking]

Currently we have 600 coal plants producing a total of about 22.9 quads of energy annually. All petroleum used has about 38.8 quads of energy with a chain efficiency of about 80%. So we need about 31 quads of energy to replace petro, or 23 quads to make enough ethanol [with a 50% gain based on input power]. So, in order to produce enough ethanol using coal power, we would need about another 600 additional coal plants.

Late edits: I was assuming that we still need to allow for efficiencies already accounted for.

 

[Ivan Seeking]

Well, this is how we make ethanol today; using coal and natural gas.Maybe so, but this is a different issue. You don't mind if we discuss (and resolve) one issue at a time do you? We currently get the energy from domestic coal and natural gas; future plans are to use cellulosic ethanol where the energy comes entirely from lignin which is a part of the plants themselves.

Future options don't count. When they are viable, then they become part of the discussion.

Wrong. If you look at the EBAMM spreadsheet you will see the detailed data from six separate published studies on the subject of the net energy of ethanol production. Here is a summary; output energy includes "coproduct credits":

Patzek: 27 MJ/L energy input vs. 25 MJ/L energy output = 93% return.
Pimentel: 26 MJ/L energy input vs. 23 MJ/L energy output = 88% return.
Shapouri: 21 MJ/L energy input vs. 29 MJ/L energy output = 138% return.
Graboski: 22 MJ/L energy input vs. 25 MJ/L energy output = 114% return.
de Oliviera: 20 MJ/L energy input vs. 25 MJ/L energy output = 125% return.
Wang: 19 MJ/L energy input vs. 25.2 MJ/L energy output = 133% return.

I will have to take some time later to look at what you have, but coproducts don't count unless we can show that first, we can use the byproducts, and next, that we would be saving energy already used today. When one considers the amount of production involved, it is extremely unlikely that we could use most of the byproducts [as a signficant percent of the total yield]. The example of glycerin from biodiesel given earlier is a perfect example. Even now, with only a trickle of biodiesel produced as a percent of total demand, the glycerin market is flooded and the price has dropped. When considering byproducts, we have to first consider the demand for that product, and then the energy used to produce that product today, otherwise the projections are meaningless and the coproduct may even end up as a liability - you will be paying to get rid of it as garbage.

The 0.3 multiplier is correct as an honest measure of the gain based on yield. You are talking about using power from other sources that don't exist.

 

[Aether]

Estimates and three decades of testing indicates that by using algae, we can produce as much as a net 10,000 gallons of biodiesel per acre-year - say 7000 if we stay conservative and allow for a 30% processing demand. See the aquatic species program [in addition to plenty of more recent links found with a simple search] which predicted that algae could be competitive when diesel was at about $2 a gallon, or twice 1996 levels. [see part ii, page 4]
http://www1.eere.energy.gov/biomass/pdfs/biodiesel_from_algae.pdf

Not that we would want to, but a simple estimate suggests that we could replace all sources of energy - petro, coal, NG, hydro, nuclear, wind, solar - with about 400 X 400 miles of land and or water. In the process, algae can be grown while cleaning up CO2 or other industrial, agricultural, or municipal emissions or waste.

The report that you cited was generated in 1998 upon the close-out of the Aquatic Species Program, and here is what this agency has to say about biodiesel today:

Note: The Department of Energy's Office of Biomass Program has refocused its research and development portfolio and the technology on this page is no longer a research priority.

http://www1.eere.energy.gov/biomass/renewable_diesel.html

Currently we have 600 coal plants producing a total of about 22.9 quads of energy annually. All petroleum used has about 38.8 quads of energy with a chain efficiency of about 80%. So we need about 31 quads of energy to replace petro, or 23 quads to make enough ethanol [with a 50% gain based on input power]. So, in order to produce enough ethanol using coal power, we would need about another 600 additional coal plants.

Biodiesel production seems to be dependent on CO2 from coal plants, and therefore it may not be practical on the scale that you envision.

The main focus of the program, know as the Aquatic Species Program (or ASP) was the production of biodiesel from high lipid-content algae grown in ponds, utilizing waste CO2 from coal fired power plants...Algal biodiesel could easily supply several “quads” of biodiesel—substantially more than existing oilseed crops could provide. Microalgae systems use far less water than traditional oilseed crops. Land is hardly a limitation. Two hundred thousand hectares (less than 0.1% of climatically suitable land areas in the U.S.) could produce one quad of fuel.

Future options don't count. When they are viable, then they become part of the discussion.

...the technology faces many R&D hurdles before it can be practicable...