Final Word on Ethanol's Efficiency as Vehicle Fuel
by John Laumer, Philadelphia on 03. 4.06
A study by the University of California at Berkeley says that use of ethanol as a transportation fuel offers a positive life cycle energy balance, while producing slightly fewer greenhouse gas emissions than petroleum fuel use. Dan Kammen and Alex Farrell of the Energy and Resources Group (ERG) at the UC Berkeley published their research in the journal Science. While earlier studies suggested that the energy to produce ethanol was greater than the actual energy content of ethanol, this overview work argues that those assertions were incorrect. The ERG research report also noted that most ethanol today is produced through corn and, as such, the subsequent greenhouse gas emissions thought to cause global warming are only marginally cut. That will change, however, when such non sugar feedstock sources as switchgrass are put to use on a large scale, supplanting corn.
The UC Berkeley study examined several earlier assumptions and then corrected for errors and outdated information as it relates to how much energy it takes to grow corn and then make ethanol. The study says that ethanol produced from corn creates 10-15 percent fewer greenhouse gas emissions than burning gasoline. Similarly, a study from the International Energy Agency in Paris agrees, saying that while grain-based ethanol requires substantial amounts of fossil fuel inputs, that fuel additive is still responsible for creating 20 percent fewer greenhouse gas emissions than conventional fuels.
The following studies were reviewed by the Energy and Resources Group:Fossil Energy Use in the Manufacture of Corn Ethanol
by Dr. Michael S. Graboski, Colorado School of Mines, Prepared for the National Corn Growers Association (2002).The Energy Balance of Corn Ethanol: An Update
Hosein Shapouri, James A. Duffield, and Michael Wang, U.S. Department of Agriculture, Agricultural Economic Report No. 814 (2002).The 2001 Net Energy Balance of Corn Ethanol
Shapouri, H., Duffield, J., Mcaloon, A.J. Proceedings Of The Conference On Agriculture As A Producer And Consumer Of Energy, Arlington, VA (2004).The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) Model, version 1.6 Michael Wang, Transportation Technology R&D Center, Argonne National Laboratory.
Thermodynamics of the Corn-Ethanol Biofuel Cycle
Patzek, T.W., Critical Reviews in Plant Sciences 23(6), 519-567 (2004).Ethanol as Fuel: Energy, Carbon Dioxide Balances, and Ecological Footprint
Marcelo E. Dias de Oliveira, Burton E. Vaughan, and Edward J. Rykiel, Jr. BioScience, 55(7), 593 (2005).Ethanol Production Using Corn, Switchgrass, and Wood; Biodiesel Production Using Soybean and Sunflower David Pimentel and Tad W. Patzek, Natural Resource Research, 14(1), 65-76 (2005).
Finally a cohesive and circumspect study published in a reputable journal. We think it's time to get over the Ethanol benefits hangover and move on with the serious business of producing small (2 to 4 passenger) hybrid cars that can be fully recharged from exteral power as well as run with a flex-fuel powered ICE engine.
If the US is serious about scientific learning and technological development, lets take it up a notch. Let's offer low interest loans on these for every top eschelon graduate of an accredited engineering or business school, conditional upon them taking a prerequisite group of ecology and environmental managment courses. Lets make it cool to design green. What though do we offer to the farmers?
Thats For the Story!
A good read for people unsure about the use of ethanol as a viable fuel.
I Digg!
Final word is a bit extreme. It's peer review. Point and counter point. Science is a process. It does not make declarations. Yadda, yadda, yadda. I still think it's an open question if it costs more to make it. I don't like additives at all. Burning in general... fire bad! Anyone see "Ethanol may get a pollution pass" on CNN? Ethanol is not so great if you ask me. I like Hybrid, flex fuels but it never really felt right. Things like that CNN article and this study saying it's efficient, honest, always made me question it. I guess any short term solution will not sit well with a lot of people. I really hate clean energy infighting i.e solar is better than wind but I don't consider ethanol clean at all. I would like to see more research into different types of energy. It always seems to be research wind or solar or bio fuel as if those were the only sources of fuel possible. I think the colleges should have a category called x and start to rank those crazy ideas like cold fusion or zero point energy or nano or whatever. I think that would have more impact than ecology courses. I honestly think something along those lines are the future and not wind, solar or bio fuel.
=== author's response follows ===
Headline was meant to be provacative. Unless EtOH swings to cellulosic feedstock fast the process is doomed to threaten food supplies and induce worse soil erosion. One of the oil majors states that EtOH will cap out at 30% of the needed transit fuel volume, which seems about right. Cooincidentally, the number for wind is similar according to the sensible reviews I'vbe read. But thanks for the circumspect comment!
You can also use ethanol as a catylyst in the transesterification process of making ethyl ester biodiesel. It is not as cheap as methanol but produces a fuel with better flow characteristics within a diesel engine.
a) John is this the same ERG Biofuel Analysis Meta-Model as last month? what is new about it now?
b) is that "UW Madison Process" only for other biofuels or does it 2X the efficiency of ethanol too?
and lastly you are totally right john, "Unless EtOH swings to cellulosic feedstock fast the process is doomed to threaten food supplies and induce worse soil erosion" true true...
==== author's response ====
With many years of environmental modeling behind me, I have this to add. Models have several components that determine result value. In no particular order, the major components are: the 'algorithms' (chained mathematical formulae), the input "assumptions" (data loaded into the model's formulae); boundary conditions; sensitivity analyses and adjustments made to handle boundary assumptions from them, calibration determined precision; and validation step determined accuracy. The value is determined by artful use of all these aspects. Indeed modeling is as much art as science. Accomodating the changes in weather due to climate change or yield increases from GM corn would be good examples of how art enters in. And the point of model use is to ensure that analysis is fast circumpect and thoughtful. It is most critical for modeling team leaders to interact with policy makers to explain the limitations and fair inferences of their art. I had hoped that this post would provoke more of that.
John, I don't think we have to worry about running out of sources for it. It's a scam and sooner or later everyone will figure it out. Headline aside, the piece could have been a little more balanced. See A-maize-ing: Bush has fallen for costly ethanol scam, Rocky News.
How about discussing the fact that you need to buy 33% more E85 to go the same distance as gasoline powered car.
Bush is for ethanol the same as most Congressmen. ADM and the other welfare queens all want the subsidies to keep rolling in, business rules the heck with the common people.
==== author's response follows ====
Your basic assertion is correct. EtOH has an intrinsically lower "energy density" than the average gasoline. Hence, the higher the ethanol fraction, the less the distance would be that you'd be able to drive on a single tank full (or else the more accomodation to a larger tank you'd make when designing a flex fuel vehicle!).
Were we to construct a simple pros and cons table for EtOH-rich gasoline, your point would be in the cons list, near the top. Also pretty high up there in cons would be the increased aldehyde formation in photochemical smog (a sensitizer). This is something proponents seldom bring up.
The pros list is significant however. Besides the locally made and indepence factors, I mean. Near the top would be the fact that EtOH is an oxygenate, which results in reduced CO emissions. Another positive is that ethanol being a natural metabolite, biodegradation of spills and leaks would be fairly rapid. Toxicity is well understood by the public, which means that irrational phobias about introducing a "new" fuel are not a problem as they are for such as methanol or hydrogen.
Cellulose material, such as tree cuttings grass clipping which now go to landfills and thus a costly nuisance and a negative money stream would become a national asset. Based on my understanding of the material flow the biomass beomes dust instead of bulk in a landfill. Is this not something devoutly to be wished and therefor and elegant result.
Firstly, I have to wonder what "XYZ Green" is thinking when he suggests that the efficiency of ethanol is still "an open question". I have been concerned about this issue for quite some time and I have found only one major study (actually two by the same guy) that disputes whether there is a positive ratio. And that study has been refuted over and over by credible, independent scientists. (By "independent" I actually mean that the study was not industry funded.)
Secondly, and much more important, is the question of the direction we should to going, in terms of renewable, alternative energy sources. I don't believe there is a scientist out there that doesn't believe that our only long term option is Hydrogen. For the life of me, I can't understand why "Hydrogen" isn't the very first word out of our mouths at the beginning of any discussion or debate about renewable fuel. It is absolutely the only long term solution! It's inexhaustible, clean as a whistle and no more expensive nor dangerous than gasoline. I don't understand why we are not already in a Hydrogen economy, right now. What is the hold up? For all practical purposes 100% of the science is already there, and has been for quite some time. The only thing in the way is politics! That is to say, big business/industry lobbying, all of their money and good old fashioned human greed! Don't think, for a second, that Big business/industry dosen't know we will eventually have to go with Hydrogen. They just think it is more financially favorable, for them, to first deplete fossil fuels, because of the costs related to retooling and creating distribution infrastructure. Just look at how they fight the ethanol industry, which, of course, is, itself, driven by big, and small, farming interests. We need a huge and sustained human cry to overturn all of that. There is no doubt we can do it, and we have to do it if we really want to save this planet and the human race, for the long haul.
Garyc16537
Has anyone considered an electrricity driven energy system .The electricity needed to produce Hydrogen fuel by electrolysis could be produced by renewable energy sources like windmills ,solar , geothermal ,tides ,etc .
Also Compressed air is another energy source , the Air Car is an interesting alternative . This would require huge amounts of electricity to run air compressors .The waste heat form the compressors can be used as home and office heating sources much of the year . Again use electricity from renewable sources .
This country needs to build thousands of Windmills instead of Ethanol plants