New Ethanol Study

A new report by UC Berkley analyzes six studies of the energy efficiency of ethanol, adjusted all of the studies to consistent system boundaries for comparison and based on the current state of ethanol production recalculated the values for corn ethanol and used a "realistic scenario" conditions to calculate the energy to produce cellulosic ethanol from switchgrass. The study found that the net energy ratio (energy out/energy in) is 1.2 for ethanol produced from corn and 8.3 for cellulosic ethanol produced from switchgrass. The net energy value (energy out-energy in) was calculated to be 4.5 MJ/liter for corn ethanol and 22.8 MJ/liter for cellulosic ethanol.  In terms of environmental impact corn ethanol decreases greenhouse gases only 14% when compared to gasoline, while cellulosic ethanol has a much greater reduction of 88% . They also pointed out, as have others, that it takes less energy to produce ethanol than it does to produce gasoline.

The abstract from the report also states some of their other important findings.

To study the potential effects of increased biofuel use, we evaluated six representative analysis of fuel ethanol.  Studies that reported negative net energy incorrectly ignored coproducts and use 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 the large-scale use of ethanol for fuel will almost certainly require cellulosic technology.

The reports that they found erroneous were one by Patzek and and one by Pimental and Patzek.

First of all I hope this report, by an independent organization, will once and for all put to rest the controversy as to whether the net energy value is positive or negative. My support of ethanol for fuel is reinforced by this report.  I see some disruptive times in switching from corn ethanol to cellulosic ethanol which is required to both conserve energy and to produce enough ethanol without compromising our food supplies.  It is also true that it is more efficient to burn the feedstock in a CHP (combined heat and power) generator and use the electricity to power EV's and plug-ins.  This possibly presents another difficult transition in that, at the present time and for the next 15-25 years, our vehicle fleet will be primarily dependent on liquid fuels and we will need all the ethanol we can produce in order to help keep the price of fuels under control.  Our ethanol production capacity is rapidly ramping up to help meet this need and possibly could supply 20% of our liquid fuels by 2020.  By that time gasoline will no doubt cost over $5.00 per gallon compared to less that $3.00 (more likely $2.25) per gallon for ethanol (in 2005 dollars).  Cellulosic Ethanol as being developed by Colusa, Iogen, and Xethanol, or alternately the BRI process should be in commercial use by 2010. Whether to use biomass to make vehicle fuel or for CHP fuel will be the question after 2020-25.  There is also the possibility that by this time the gasification/Fischer-Tropsh processes (BTL) such as the Shell/Choren process will be used to produce both electricity and fuel.  At this time it is not clear to me how this will shake out and I will return to the subject later in the year.  I am sure the Engineer Poet will have a comment at this time.

The paper which was published in Science and the spreadsheet model used to develop the data as well as links to the six studies that were compared are found here: ERG Biofuel Analysis Meta-Model

Green Car Congress and After Gutenberg have also had posts on this report, with emphasis on other aspects of the report which you may want to visit.

Recent Berkley Study: Corn Ethanol is Better Than Gasoline, But Not by A Lot, Green Car Congress, Jan. 26, 2006
UC Berkley Study Boosts Cellulosic Ethanol, After Gutenberg, Jan. 26. 2006

More blogs about biofuels, ethanol, alternative energy, renewable, renewable energy, energy

Comments

[C. Scott Miller]

This study corroborates the findings of a study made last year (BEFORE PIMENTAL's release of his erroneous study) by Michael Wang of the Center for Transportation Research of the University of Chicago/Argonne National Laboratory (work sponsored by the U.S. Department of Energy). http://www.anl.gov/Media_Center/News/2005/NCGA_Ethanol_Meeting_050823.ppt.

Corn and sugar fermentation have been invaluable at helping build our current infrastructure for ethanol (2% of our national liquid fuel consumption is better than 0%). It has also spurred marketing of flex-fuel vehicles and established the 800 stations that offer E85.

But we can do much better with conversion technology (CTs) and regional solutions based on regional feedstock assets. Fossil fuels can also be used in the CTs for the creation of celluosic ethanol. Blending of CT feedstock can produce optimized output results for each region and may develop interesting electricity co-generation solutions.

I would like to see co-siting of CTs with the 85+ existing sugar refineries. That will allow a smooth transition for farmers who would then be able to convert ag waste, switch to other crops, and help profit even with foul harvests.

[Thomas]

Biofuel seems increasingly prosperous. In a recent comment by a professor of The Royal Veterinary and Agricultural University, Denmark, he states that just 16% of Danish farmland could supply ethanol to replace our entire consumption of gasoline! This prognosis included improvements already in the pipeline for the enzymes that break down the cellulosis.

About biofuel in CHP. We have quite a lot of that in Denmark, but I'm personally growing increasingly sceptical. Burning straw is not only technically difficult, because of e.g. hydrocloric acid, but a lot minerals are removed from the soil, only to end up as harmful deposits in the boiler. All these minerals need to be replaced in the soil, usually by fertilizer.

What I like so much about making ethanol is the fact that only the hydro-carbon (which came from sunlight, water and CO2 captured from the atmosphere) is removed. There will be an end by-product that contains all the minerals that the plant had originally taken from the soil. These minerals can probably be re-applied to the soil, thus greatly reducing the need for energy-intensive fertilizer.

This process is much more like the process in a cow's stomach and, as we know, cow manure is excellent fertilizer.

Actually there are other processes to seperate manure into water, hydro-carbon and minerals (left over fertilizer). This left over fertilizer is actually more efficiently absorbed by plants than artificial fertilizer. But that's a whole other discussion.

-Thomas

[Halvo]

I hope that in the push to ramp up biofuel production, we don't forget about the sytems supporting the feedstock. Thomas' point is critical. What water and soil problems will we see if California goes full steam ahead on corn based ethanol. Are there not major water and soil conservation issues there already?

[Jim from The Energy Blog]

C. Scott Miller - The Wang study you referred to was one of the six reports that were analyzed. I did not list the studies because I only wanted to make my main point. Other blogs have listed all six studies.

[G Eddy]

What is switchgrass? How many acres of farmland would be required to produce a barrel of oil equivalent from switchgrass? From corn? From sugar cane?

This begs the question of what will we eat if we use a significant fraction of farm land for fuel production?

[Jim from The Energy Blog]

Halvo - The problems you pointed out are true for corn ethanol, but not as severe for cellusosic ethanol made from swithgrass or Miscanthus grass. They will grow on marginal land and control errosion, require little or no fertilizer and are drought resistant.

[Jim from The Energy Blog]

G. Eddy - Switchgrass is a perennual grass that grows very tall, lives for 10 years or more, thus not requiring the energy input from planting every year. It does not require any cultivation, no fertilizers, is drought resistant and controls errosion. Very similar to Miscanthus grass referred to in the above comment. (see my new post, Switchgrass for more information) I don't remember the yield per acre for corn ethanol, but it is much less than for the grasses. Cellulosic ethanol can also be made from forestry waste. A ORNL study, made last year, concluded that we could obtain 30% of our liquid fuels from biomass without compromising out food production.

[SwitchgrassLover]

Great work here. There is much more potential than the nay-sayers think. When you consider all of the unused land available(some of which our farmers are collecting revenue not to farm!) we could put a serious dent in traditional oil requirements.

[eric blair]

What water and soil problems will we see

If there is no provision for returning the 'waste' organic material back to the land, the eventual effect will be a stripping of the micro elements and the destruction of the soil food web via the starvation of many of the symboitic fauna the flora needs to grow and prosper.

Switch grass is a perannual grass that grows very tall, lives for 10 years or more, thus not requiring the energy input from planting every year. It does not require any cultivation, no fertilizers, is drought resistant and controls errosion.

Please double check the 'no fertilizer' claim. Most of the data I've seen says 'light' nitrogen, and I've not seen any data showing what happens with you harvest the grass without returning ash or the dead grass back to the land. (Eric- You are right, I really should have said "little or no fertilizer." My post on switchgrass goes into a little detail on this. - Jim)

Otherwise - spot on.

corn ethanol,

The corn idea exists to provide a 'demand floor' for corn.

Great work here. There is much more potential than the nay-sayers think.

But unless 'the plan' puts back the organic material left over from obtaining 'liquid energy', what WILL happen is, over time, the land will eventually unable to support plant life.

To get the 'waste' back to the land, the closer the process of biobits to fuel is to the growers of the biobits, the more likely it is the 'waste' will return to the soil.

'the ideal plan' would put the energy extraction process right on the biobits growers property. Then the bio-bit farmer can sell off excess capacity and would be responsible for 'closing the waste loop'.

So unless you are pushing the return of 'organic waste' material to the land switchgrasslover,

[eric blair]

Oh, I almost forgot. People are treating the production of Ethanol like it is either a 'corn' or 'switchgrass' solution.

Personally, I'm growing sugar beets for making sugar-squeezings. The chipped beet? Fodder for the various critters and goes right back on the land as compost.

And this solution is 'only one farm'-style solution.

[SwitchgrassLover]

Despite my adoration for switchgrass, I completely agree Eric that a variety of feedstocks should be employed in our efforts to reinvigorate the small farming communities and reduce our dependance on imported energy. Diversity is strength.

[halvo]

Jim- At first glance, switchgrass seems to make a lot more sense to me than corn. My worries about corn based ethanol production in California stem from the only pure play on ethanol out there. Cascade Investments LLC (Bill Gates) recently agreed to an $84 mil investment in this ethanol pure play and their future product line "emphasizes clean-burning corn-based ethanol". The first plant is probably coming on line in the 4th quarter of this year and I believe they have 8 corn based ethanol plants in mind for California. I doubt they will be trying to import corn from out of state, so my concern is based on the assumed increase in irrigation and fertilization that will be required to meet the demand for California corn. There is definitely room for greater efficiency in California irrigation systems, but will efficiency improvements be enough to cope with increased consumption? Also, ADM is currently the largest producer of ethanol in the states. As far as I am aware, ADM is not all that into perrenials, so there could be some serious challenges in producing the most sensible ethanol product in the US.

[Robert]

Something like half the capital investment in a bioethanol plant is in the purification equipment, which doesn't really care how you made the ethanol. (A few adjustments might need to be made for various impurity purges; nothing major.)

So a plant built to make ethanol by one fermentation process, could conceivably be rebuilt to use a different fermentation process, (or either fermentation process), as a viable alternative to building completely new plants.

[brother_bones]

I'm still not seeing the issues of land use addressed. I don't see ethanol ever supplanting gasoline. At best it will be a suppliment.

[Jim from The Energy Blog]

Brother Bones - Land use is not a problem yet, but certainly could become one if corn remains the primary feedstock for ethanol plants. The solution is being addressed by developing a process for cellulosic ethanol which can use any plant material as feedstock. This will help in two ways 1)feedstock grown on marginal lands can be used and 2) the entire plant, rather than just the seed corn can be used, thus increasing the amount of ethanol that can be produced from a given amount of land. R&D is well underway to do this and DOE, as president Bush has popularized by his recent statements about switchgrass, is going to fund several pilot/prototype plants in the next couple of years. Studies have been done that indicate that using cellulosic ethanol up to 30% of our fuel can be produced from biomass. One study indicates that this plus conservation, through adoption of hybrid and all electric vehicles and increased mileage standards, could eliminate the need to import petroleum oil to produce liquid fuels by 2050. It could be a rough transition in the next ten years as we struggle to develop and implement cellulosic technology. In the meantime prices for both corn and oil could increase dramatically as shortages of both develop.

[brother_bones]

Land use isn't an issue now because production is not on a nationwide level. What about the Jeffrey Dukes report (http://globalecology.stanford.edu/DGE/Dukes/Dukes_ClimChange1.pdf) that shows every year we burn 400 years worth of plant material in fossil fuels? How can we possibly match that consumption from any other source? Or any other combination of sources?

30% fuel from biomass, hybrid and electric vehicles, conservation; this is all very Jimmy Carter of you, but I'm not seeing the upside to going this route rather than investing in some other technology. Do these studies take into account rising energy needs or do they look at our needs today as a static number? Do they take into account the developing worlds new found industrialism that will require finite resources that are currently being sold to us?

At least you're more realistic about this technology and the maximum amount of petroleum it can replace. I've seen others talk as if ethanol was some wonder product that can end the worlds energy ills. I just don't see why we should waste time on a product that must be coupled with several other technologies over the next 45 years when we could be putting our resources into something better.

[Lou Ann Hammond]

I just found this site and was reading the info above. I've written an article about cellulose ethanol that you might find of interest.

Iogen; cellulose ethanol
http://www.carlist.com/autonews/2006/autonews_254.html

[sandra]

I just found this site and think that this is very interesting information

[W. Koch]

The food value in the production goal of 8 billion gallons of ethanol per year would feed 220 million people for one whole year on a 2000 colorie per day diet. With literally 1000's starving to death in Africa, we are using FOOD FOR FUEL FOR OUR FORDS.
Oh well, let them eat cake---

[B. Kutzera]

No comment on ethanol made from sugar cane? I've heard it is much more efficient than corn or switchgrass. We should deregulate the sugar industry in this country and import all the cane or ethanol from Brazil that we can take before setting up this huge corn based system.

[Slim]

This is just such exciting stuff. Great blog.

[Gavin Guy]

Royal Chevrolet Cadillac in Lynchburg, Virginia has flex-fuel vehicles in stock now. If you and me want to save money, then we needed to produce and buy theses type of cars!!!

[Jenna Soule]

I am a senior at Rush-Henrietta High School and my chemistry class has been very involved in the study of ethanol and what it may do for us in the future. My aunt lives in Pittsford and has been offered an oppertunity to partisapate in a ethanol plant production. She owns about 5 acres of land that is used for the production of corn. She wasn't too sure that it was a good idea untill I talked to her about this and how it may change the way we live in America in about 20 years. She thought it was great and then decided to get into the project. I would like to learn more about these things and what else is going on with ethanol. If anyone would be interested, please send me more information to my e-mail address and keep me posted. Grlsinger1988@yahoo.com Thank you!!!

[Kristine]

I personally think that anything is better than gasoline. Whether its ethanol or switchgrass whichever gets the United States independent from other countries. Could this be why we are fighting in Iraq... I think so! We need to find a better way that will be cheaper and easier to get and make.

[Kristine]

I personally think that anything is better than gasoline. Whether its ethanol or switchgrass whichever gets the United States independent from other countries. Could this be why we are fighting in Iraq... I think so! We need to find a better way that will be cheaper and easier to get and make.