http://science.reddit.com/info/2lngq/comments

if you are so inclined...our authors thank you for your support.

Robert,

I want to thank you for all the time and effort you have expended in getting to the truth about peak oil and the ethanol hoax in particular. Your fair-minded efforts have made a real difference in the energy policy in the U.S., if nothing else I believe you've slowed down the implementation to where wiser heads will stop the ethanol insanity hopefully before there is so much investment that its unstoppable.

The historic debates on whether and by how much the energy gain of ethanol was positive have been a red herring. Irrespective of that bottom line, the other limiting inputs to corn ethanol make it far inferior to gasoline. Even if cellulosic ethanol lives up to its claims of higher energy return (which I find doubtful because the initial ethanol solution is less concentrated than with starch ethanol) it will still have the scalability problems of other limiting inputs.

But it is natural to want to find a 'replacement' for something, in fact we are conditioned to do so. In the end, changing our way of life and moving away from the internal combustion engine will serve us much better than scaling up land, material, soil and water inputs to create an inferior fuel. But it will take time for this message to sink in, because its a very difficult one (at first) to accept.

I'm mostly concerned about water. David Pimentel told me the Kreider study seriously understates the amount of water needed for corn ethanol, which is presumably a boundary issue which Im trying to suss out.

About 10.2 kg of corn is required to produce 1 gallon of ethanol. The average water requirement per kilogram of biomass is 1,000 liters. In Pimentels latest water paper they report that 650 liters of water are required to produce 1 kg of corn. This means 6630 liters of water for just the corn in 1 gallon of ethanol - or about 1754 gallons of water. And still a little more water is required in the fermentation and processing operation.

Water, like oil, is seemingly cheap, unless one lives in Western US. As nasty as oil and gas production are, they at least limit their environmental impacts to small land areas relative to biofuel production.

Systems analysis at the highest levels of government needs to address the linkages between water and energy. Fully 50% of our nations water use goes to the energy sector already. If we scale non oil and gas energy sources - what will this mean for water? In the end I think most of us would rather drink than drive...

The section on cellulose ethanol is weak. Soy beans are more likely to be made into biodiesel. If (a very big if) cellulose ethanol ever becomes commercially viable, the raw material could be wood residues, garbage or native species with a low impact on soil such as switchgrass.

Burning biofuels impacts the nitrogen cycle. When you take dinitrogen from the atmosphere and convert it to n02 and n03 you are increasing the local concentration of fixed nitrogen in the air and soil. This has all kinds of negative impacts on the environemnt.

Robert:

I am not a big fan of ethanol, but I do believe that there is another ethanol feedstock worthy of further study: sweet sorghum.

As you know, the EROI for ethanol from Brazilian sugar cane is far superior to that of ethanol from US maize (corn). I have seen EROI figures in the range of 3-4, but there has been so little research wrt sweet sorghum that I don't know how firm those figures may be; one would intuitively assume that the EROI falls somewhere between maize and sugar cane. This in turn suggests that the EROI for sweet sorghum would be at least 2-3 times higher than for maize. Given that maize ethanol is barely more than a break-even proposition, this certainly suggests that if we are going to do ethanol at all, sweet sorghum is worth a closer look.

An important reason why I think that sweet sorghum warrants further study is that its culture is very similar to that of maize, but perhaps not so input-intensive. In the Southern Appalachians, where I live, one sometimes sees maize and sweet sorghum growing adjacent to each other; to the uninitiated eyes, the crops look almost identical. The important difference is the absence of vulnerable ears of grain in the sweet sorghum crop. Massive inputs of fertilizer, water, and pesticides are required for maize plants to produce high yields of grain. In contrast, the sweet sorghum plants need only grow the stalk, which is far less vulnerable to pest damage and is less demanding of water and fertilizer. Because the crops are so similar (differing in their culture only at harvest), it would not be too difficult a transition for farmers to switch from growing maize to growing sweet sorghum. Harvesting at large scale would require different equipment; however, the harvesting equipment is inherently less complicated than that required to harvest maize.

One obvious disadvantage of sweet sorghum over maize is that it cannot be stored for a long period of time. The juice must be extracted from the stalks (traditionally done by a simple crank press, which could be scaled up to industrial levels) fairly soon after harvest. To make sorghum syrup, considerable energy is required to boil the juice down. More likely, the juice would not need to be concentrated to that level in order to become a suitable feedstock for a fermentation process. I am not certain how long such juice could be held in storage prior to being fermented, but there must be an optimal level.

Which raises the other obvious disadvantage: existing maize ethanol production facilities would require substantial retrofits to process sweet sorghum. I suspect that at least some of the installed distillation equipment would still work, but there might need to be some reconfiguration. The bigger problem would be the need to process the entire year's crop in a short period of time. Existing processing facilities have been built on the assumption of a year-round supply of maize feedstock. This might be an argument for concentrating the sweet sorghum juice to a higher level for storage, and then diluting it as needed. This in turn would then also require the construction of large storage tanks. All of this weighs against and reduces the EROI, but probably still results in a higher EROI than maize ethanol.

As I said, I'm not a fan of ethanol. But it does appear that political pressures are going to dictate that a substantial quantity of ethanol be produced, and produced from feedstocks grown in Midwestern farm states. Because sweet sorghum could be grown in those same farm states and promises a better EROI than maize ethanol, we ought to at least take a good look at it from a damage control perspective if for no other reason.

Robert unimaginable scale has unimaginable environmental impact. To grow corn for all our gasoline needs would require 978,261 square miles. To replace our all crude petroleum would require 1,200,000 square miles of corn, or 1/3 of the United States of America. Put another way, all our corn converted to ethanol only accounts for 19% of our gasoline.

I am inclined to think that the most insidious environmental harm is the fact that ethanol is believed by the general public to be a "solution" to the oil problem such that nobody will need to make any changes to their lives other than to buy a flex-fuel car.

Clean (very low emissions) thermochemical processes like pyrolysis and gasification can be used for the creation of syngas (CO and H2) that can be combusted in place of natural gas. They don't require any water and to a great extent the feedstock supplies the fuel for continuing the thermal process.

According to the DOE, syngas can also be catalyzed or fermented into ethanol and other higher alcohols. The heat from the reaction can be captured to generate electricity. The yield is projected to be between 70-125 gallons per ton of feedstock based on pilot plant results.

Feedstock can be anything containing C-H-O including: fossil residues like petcoke; automobile waste like autofluff and tires; forestry wastes from the forest products industry; ag wastes like stover; decaying tree residues from wildfires and bug infestations; municipal solid waste; sludge; etc., etc.

This means that clean biofuel production creates a profit stream for solving a multitude of environmental problems and catastrophes.

These are the technologies that I am watching - not corn fermentation. I am not particularly enamored with enzymatic hydrolysis either but I am willing to support the research because the rate of technological development is much faster than ever before thanks to personal computers and communications.

I am inclined not to rule anything out under the circumstances.

I am amazed that the oil industry has not built any refineries in the U.S. for thirty years. Surely there have been some leaps in innovation that could be better deployed in a new facility rather than retrofitted to an old one.

I wrote the article on Peak Soil you refer to above (latest version at http://www.energyskeptic.com/Peak_Soil.htm ), and there are some additional unsustainable, environmentally damaging aspects to growing any kind of plant for biofuels you didn't mention above:

1) Soil Biota

Soil creatures and fungi act as an immune system for plants against diseases, weeds, and insects – when this living community is harmed by agricultural chemicals and fertilizers, even more chemicals are needed in an increasing vicious cycle (Wolfe 2001).

2) Soil compaction

Plants and creatures underground need to drink, eat, and breathe just like we do. An ideal soil is half rock, and a quarter each water and air. When tractors plant and harvest, they crush the life out of the soil, as underground apartments collapse 9/11 style. The tracks left by tractors in the soil are the erosion route for half of the soil that washes or blows away (Wilhelm 2004).

3) Soils store more carbon than the atmosphere and vegetation

Soils contain 3.3 times the amount of carbon found in the atmosphere, and 4.5 times more carbon than is stored in all the Earth’s vegetation (Lal 2004). If we want to reduce global warming, storing carbon in the soil will be essential. But that will be hard to pull off, because Climate change could increase soil loss by 33% to 274%, depending on the region (O'Neal 2005). Intensive agriculture has already removed 20 to 50% of the original soil carbon, and some areas have lost 70%.

3) Continuous corn increases global warming by 71% (Powers 2005)

4) Destruction of CRP land, hardwood forests, wetlands, and range land to grow more biomass (and food) will reduce stored carbon & biodiversity

Farmers want to plant corn on highly-erodible, water protecting, or wildlife sustaining Conservation Reserve Program land. Farmers are paid not to grow crops on this land. But with high corn prices, farmers are now asking the Agricultural Department to release them from these contracts so they can plant corn on these low-producing, environmentally sensitive lands (Tomson 2007).

Population in the United States could reach over one billion people by 2100 (U.S. Census Bureau 2000), so what will happen is that we'll need more crop land and have to cut down bottomland forests and fill in wetlands to grow food, which will reduce stored carbon and biodiversity even further.

Deforestation of temperate hardwood forests, and conversion of range and wetlands to grow energy and food crops increases global warming. An average of 2.6 million acres of crop land were paved over or developed every year between 1982 and 2002 in the USA (NCRS 2004). The only new crop land is forest, range, or wetland.

5) Fertilizers increase global warming, acid rain, and eutrophication, but they provide no ecosystem services like organic matter (a.k.a. "waste" biomass), such as putting carbon back into the soil, increasing soil structure to let air and water to plant roots, preventing erosion, water retention, etc.

6) Rainforest destruction

Rainforest destruction is increasing global warming. Energy farming is playing a huge role in deforestion, reducing biodiversity, water and water quality, and increasing soil erosion. Fires to clear land for palm oil plantations are destroying one of the last great remaining rainforests in Borneo, spewing so much carbon that Indonesia is third behind the United States and China in releasing greenhouse gases. Orangutans, rhinos, tigers and thousands of other species may be driven extinct (Monbiot 2005). Borneo palm oil plantation lands have grown 2,500% since 1984 (Barta 2006). Soybeans cause even more erosion than corn and suffer from all the same sustainability issues. The Amazon is being destroyed by farmers growing soybeans for food (Wallace 2007) and fuel (Olmstead 2006).

7) Surface Albedo.

“How much the sun warms our climate depends on how much sunlight the land reflects (cooling us), versus how much it absorbs (heating us). A plausible 2% increase in the absorbed sunlight on a switch grass plantation could negate the climatic cooling benefit of the ethanol produced on it. We need to figure out now, not later, the full range of climatic consequences of growing cellulose crops” (Harte 2007).

Alice

Another thought comes to mind regarding corn. I have been reading "The Omnivore's Dilemma", which talks about how Big Ag has essentially created these perverse incentives whereby farmers will raise corn as fast as they can, get paid less than it cost them to grow it (and then get a gvmt check to make up the difference). All of the excess corn is then used to fatten cattle and make corn syrup and other nutriceuticals, which consumers then eat in increasing quantities to the detriment of public health.

The corn ethanol thing really just got going again a few years ago. The increased corn prices are hugely popular with farmers who previously were just struggling to get by, and of course it is popular with Big Ag.

environmental benefits of using ethanol as fuel?

Perhaps if it was done right (and assuming cellulosic ethanol works)

the grasses took in more carbon dioxide from the atmosphere than was released from the fuel used to grow and process them. The carbon dioxide removed - around a third of a tonne per hectare per year - was taken up by the roots and so remained in the soil after the harvest. This means that the greenhouse gas savings from wild-grass ethanol could be up to 16 times as great as those from corn (Science, DOI: 10.1126/science.1133306).

Hill's work also suggests that wild grass could be farmed more efficiently in mixed species plots, mimicking the make-up of natural prairie. When his group combined eight species of grass in a single plot, yields were more than 150 per cent higher than from grass monocultures. In 16-species plots, the improvement was 238 per cent.

Such diverse mixes provide better havens for wildlife. In Wisconsin, Sample has studied field-sized plots of mixed grasses of the type that would be suitable for biofuel farming. He found that a typical plot hosted three threatened bird species, while the average for corn was less than one species per plot. Harvesting the grass should not wipe out these gains in biodiversity, because it would have a similar effect to the fires that sweep through natural prairies most years. It all suggests that America's prairies, which now cover just 1 per cent of their original area, could be partially restored by biofuel farming, Hill says.

http://environment.newscientist.com/channel/earth/mg19526173.400-can-bio...
(subscription required)

Article in Science:
Carbon-Negative Biofuels from Low-Input High-Diversity Grassland Biomass

Across their full life cycles, biofuels can be carbon neutral [no net effect on atmospheric CO2 and other greenhouse gases (GHG)], carbon negative (net reduction in GHG), or carbon sources (net increase in GHG), depending on both how much CO2 and other greenhouse gases, expressed as CO2 equivalents, are removed from or released into the atmosphere during crop growth and how much fossil CO2 is released in biofuel production. Both corn ethanol and soybean biodiesel are net carbon sources but do have 12% and 41% lower net GHG emissions, respectively, than combustion of the gasoline and diesel they displace (14). In contrast, LIHD biofuels are carbon negative, leading to net sequestration of atmospheric CO2 across the full life cycle of biofuel production and combustion (table S3). LIHD biomass removed and sequestered more atmospheric CO2 than was released from fossil fuel combustion during agriculture, transportation, and processing (0.32 Mg ha–1 year–1 of CO2), with net life cycle sequestration of 4.1 Mg ha–1 year–1 of CO2 for the first decade and an estimated 2.7 to 3 Mg ha–1 year–1 for subsequent decades. GHG reductions from use of LIHD biofuels in lieu of gasoline and diesel fuel are from 6 to 16 times greater than those from use of corn grain ethanol and soybean biodiesel in lieu of fossil fuels

http://www.sciencemag.org/cgi/content/full/314/5805/1598

OFF TOPIC WARNING...Robert, a request, we need your technical help since your posting with us for a bit..:-)

Canadian Tar Sands, recently much discussion about THAI (Toe to Heel Air Injection) for in situ extraction, by Petrobank, Canadian firm....what can you tell us about prospective validity....we need an unbiased view, and a great petro technician, so can we draft you on this one?
:-)

RC
Remember, we are only one cubic mile from freedom :-)

Not sure if this falls under "Ethanol and the Environment". It's worth pointing out that the energy density of EtOH is only 70% that of gasoline. You can get some of that back by taking advantage of the higher octane, but not all of it. This only adds to EtOH's VOC -> ozone problem. It is an oxygenate and has no sulfur, which helps with PM formation, at least directly (one has to be careful about PM metrics).

The flame temperature of EtOH is a little lower than that for gasoline, which should lead to lower NOx, although with the heavy EGR modern engines use it's not clear that the reduction is significant. In any case, that wouldn't make up for the higher VOC emissions as far as smog is concerned, and in urban areas (which are all VOC limited) would only compound the problem.

It seems that using the term ethanol, rather than specifying corn-based ethanol (when that is the case) is sloppy and leads to inaccuracies.

If you were to replace several of the uses of the term ethanol with "all ethanol", they would clearly be wrong.

Sugar cane-based ethanol does appear to have a far better energy balance than corn-based ethanol. Sugar cane is not typically irrigated, so the water issue doesn't seem to directly apply.

Khon Kaen Sugar is a publicly listed company in Thailand that discloses a lot of data on the costs and process of their refining. This could be useful. Try the annual report and their investor presentations. The presentations used to be easy to find on the site, but just now i didn't see the link. I can send one if you can't find it.

http://www.kslsugar.com/modules/investor/index.php?lang=en

Scalability is obviously an issue. But I think Nate's attack on both scalability and searching for replacements is a bit inconsistent. If you are looking for a replacement, scalability is a huge problem. If you are talking about providing 5% of total liquid fuels over a timeframe of about ten years as a transition to better ways of doing business, scalability is much less crucial.

I once calculated that we could get a few percent of total fuels just by cutting sugar consumption in half.

I don't think ethanol will ever be a major part of the energy picture. Neither do I think it is a permanent solution. It will serve a small and temporary role. I don't think it makes sense to curse a silver BB because it is not a magic wand.

It does seem the objective of the piece you are writing is not to oppose the ridiculous US ethanol policy, but to inform people about the topic. The title of the ethanol FAQ certainly implies that is not a strictly US-centric piece.

So, I would suggest that you either state up front that the piece is about US corn-based ethanol, or make the piece broader than just US corn-based ethanol.

Hi Robert,

Thanks for this tremendous effort, for sticking with it - and for asking for feedback.

1) When you start off talking about “benefits…as well as negative environmental consequences”, as I read this, I’m waiting for the shoe to drop, perhaps in the form of a question like “Do the benefits outweigh the negative consequences?”

Because you seem to contrast the two (benefits and consequences). Perhaps another sentence or two that either states your position – and/or… asks something like “How do we weigh one against the other?” , i.e. lays out your criteria for answering the question. (Just a thought.)

2) re: “Because of ethanol's marginal energy balance, there is a marginal reduction in greenhouse gas emissions per distance driven. Researchers have also found that ethanol produces less carbon monoxide when it is burned in an internal combustion engine.”

Well, in my role as naïve reader (and thanks for your patience)…I’d enjoy just a tad more explanation here.

Q: A “marginal reduction” – when… ethanol is blended with gasoline? When ethanol is used as a replacement (by what percentage?) in gasoline? (Any other qualifiers? ie., “distance driven” – regardless of vehicle type, size, etc.?)

Q: re: “less carbon monoxide” - less than what? (This sentence just seems to lack a reference.) BTW, are you referring to gasoline and diesel and NG when used as ICE FF and contrasting them w. ethanol use? Or…?

3) I like Nate's comment back at http://www.theoildrum.com/node/2874, where he starts esp. the "big picture" idea in his question “What would be the best use for all that natural gas, land and diesel?”

“What NEEDS to be being debated is not the absolute energy yield but its comparison to what its replacing. The net energy of gasoline is in the neighborhood of 8:1, vs ethanol at .2:1 - it is an order of magnitude less - the more we replace of substance A with substance B, the less amount of energy available to do work for society. In effect, the energy balance should be used as a societal energy budgeting tool. What would be the best use for all that natural gas, land, and diesel? Corn is probably near the worst idea.”

And I also like his paragraph in this thread where he says:
“But it is natural to want to find a 'replacement' for something, in fact we are conditioned to do so. In the end, changing our way of life and moving away from the internal combustion engine will serve us much better than scaling up land, material, soil and water inputs to create an inferior fuel. But it will take time for this message to sink in, because its a very difficult one (at first) to accept.”

Perhaps you can take these as a cue, or re-write (taking out the “buts”) – i.e., do you agree w.his assessment that ethanol is “an inferior fuel”?

If so, perhaps this might help in forming a one or two sentence Q or statement along the lines of: “When we look at environmental costs, we need to keep in mind that the decline in availability of oil means we have a limited amount of time to put in place the kinds of infrastructure that can use electricity supplied by renewable energy technologies, such as wind and solar. To lose sight of this time window is to risk spending our endowments of natural gas, water and topsoil on the wrong things.” (Not that I’m saying this well, just to give an example.)

Or, “The ‘big picture’ of environmental costs is the risk of degrading our ecosystem…”

4) When you quote an article at length, it might be nice to sum it up in a sentence or two (of your own words) at the end, so as to add some continuity for the reader.

5) A small stylistic point for readability – perhaps just list out the “positives” and “negatives” and then label each one before you talk about it. eg. “We have X number of benefits the industry itself considers positive, and, on the other hand, we have the ten following negative environmental consequences: A, B, C, D…” (Do the positive outweigh the negatives for large-scale uses?)

6) Jack’s point about specifying the types/sources of ethanol seems important and

7) Alice’s many points seem crucial - and fascinating. Many thanks, Alice. I like the way these are classified as being true for growing any kind of plant for biofuels.

(Robert, does this pose a challenge to evaluating the benefits of your other biofuels project?)

If so, then perhaps it would be a good idea to separate the “environmental impacts” Q into sections, such as “negative impacts from any plant source for biofuels production” and “additional negative impacts specific to corn as a plant source”.

8) Although looking at Alan’s quotes on the non-row crop farming of plants for biofuels…it might be nice to have some direct dialog between these two on this topic. If we could get more into it. http://www.theoildrum.com/node/2934#comment-234658

9) The point about water is so important. Nate’s “rather drink than drive” – exactly. “have to”, in fact. (This might be a good place to talk about the fact that humans need “the environment”.) There’s a lot to be said on this topic, and all of it seems really important.

This would be a lot more work. OTOH, it seems like you’d really have something really useful to many people.

10) Anewland’s point on scalability seems like a very important one in the “big picture” – and its succinct: http://www.theoildrum.com/node/2934#comment-234619, like “Okay, what is our environment? Well, in the US, it’s a land mass of X, …”

11)PS and as an aside, someone brought up in the other comments section, the idea of corn subsidies for ethanol v. oil co subsidies. I just wondered if there was a reasonable way to actually compare them in money terms. Also, this does seem to be another red herring, still, it’s one that is likely to come up again, so wonder if it might be good to address it early on.

I'd like to simply post a link to show Brazil's ethanol miracle has a major downside -

http://www.guardian.co.uk/international/story/0,,2029908,00.html

This energy efficiency (EROI) claim is based on essentially free (read SLAVE) labor - such a surprise that this could happen, with ownership by such paragons as Cargill, ADM, and George Soros and Bill Gates, I know

this article would cause any ethical person to reconsider - even without all the worry that the extended loss of the Amazon Rainforest may soon reach (if it hasn't already)a tipping point where the trees all die and the self-propagating weather of the region ceases - and this likely will in turn disrupt global weather patterns -
Nice little side effect of this "renewable"

Yes, i know sugar doesn't grow well in ex RF - but you have to realize that land expropriated for sugar pushes other uses (like subsistence farming/clearing)outward into the RF

Some of these darned poor just refuse to die quietly!
(PLEASE-this is meant as a brutal but true reflection of what the corporations consider good business -not my opinion)