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US DOE Releases Roadmap for Cellulosic Ethanol

The research agenda focuses on three main areas: better feedstocks, better processes for breaking down cellulosic materials, and optimizing fermentation. Click to enlarge.

The US Department of Energy (DOE) has released a detailed research agenda for the development of cellulosic ethanol as an alternative to gasoline. The 200-page research roadmap—Breaking the Biological Barriers to Cellulosic Ethanol: A Joint Research Agenda—resulted from the Biomass to Biofuels Workshop held in December 2005.

The roadmap identifies the research required for overcoming challenges to the large-scale production of cellulosic ethanol, including maximizing biomass feedstock productivity, developing better processes by which to break down cellulosic materials into sugars, and optimizing the fermentation process to convert sugars to ethanol. Cellulosic ethanol is derived from the fibrous, woody and generally inedible portions of plant matter (biomass).

The roadmap responds directly to the goal recently announced by Secretary of Energy Samuel Bodman of displacing 30% of 2004 transportation fuel consumption with biofuels by 2030. This goal was set in response to the President’s Advanced Energy Initiative.

The focus of the research plan is to use advances in biotechnology developed in the Human Genome Project and continued in the Genomics: GTL program in the Department’s Office of Science to jump-start a new fuel industry the products of which can be transported, stored and distributed with only modest modifications to the existing infrastructure and can fuel many of today’s vehicles.

The December 2005 workshop was hosted jointly by the Office of Biological and Environmental Research in the Office of Science and the Office of the Biomass Program in the Office of Energy Efficiency and Renewable Energy. The success of the plan relies heavily on the continuation of the partnership between the two offices established at that workshop, according to the DOE.

The fundamental barrier to the widespread and cost-effective production of ethanol from cellulosic biomass is the inherent recalcitrance of the biomass to such processing.

Biomass is composed of nature’s most ready energy source, sugars, but they are locked in a complex polymer composite exquisitely created to resist biological and chemical degradation.

Key to energizing a new biofuel industry based on conversion of cellulose (and hemicelluloses) to ethanol is to understand plant cell-wall chemical and physical structures—how they are synthesized and can be deconstructed. With this knowledge, innovative energy crops—plants specifically designed for industrial processing to biofuel—can be developed concurrently with new biology-based treatment and conversion methods.

Recent advances in science and technological capabilities, especially those from the nascent discipline of systems biology, promise to accelerate and enhance this development. Resulting technologies will create a fundamentally new process and biorefinery paradigm that will enable an efficient and economic industry for converting plant biomass to liquid fuels. These key barriers and suggested research strategies to address them are described in this report.

The roadmap lays out a three-stage technical strategy:

    The three-stage strategy. Click to enlarge.
  • Phase 1: Research. This phase, to last no more than five years, is focused on gaining an understanding of existing feedstocks. research will center on the enzymatic breakdown of cellulosic biomass to pentose and hexose sugars (5- and 6-carbon) and lignin using a combination of thermochemical and biological processes. Cofermentation of the sugars will follow.

  • Phase 2: Deployment. This phase, within 10 years, includes the creation of a new generation of energy crops optimized for sustainability, yield and composition, coupled with processes for the simulataneous breakdown of biomass to sugars and cofermentation of sugars via new biological systems.

  • Phase 3: Systems Integration. Within 15 years, this phase is to incorporate concurrently engineered energy crops and biorefineries tailored for specific agroecosystems.




Why not Pentanol? (BP is working on it)


Jeebus. This is beginning to sound like hydrogen. And here I thought that CE was just around the corner. Not in my life time, I guess. And here's an interesting tidbit.

"Biomass is composed of nature’s most ready energy source, sugars, but they are locked in a complex polymer composite exquisitely created to resist biological and chemical degradation."

Perhaps there is a very good reason for this from an evolutionary standpoint.

Furthermore, given the apparent fact that part of their plan is to develop a bioengineered solution to this problem, they should address the possible impact on natural systems if these enzymes get out of control.

Ala James Kunstler, perhaps we should be making other arrangements in the mean time. By the time we start rapidly sliding down the other side of peak oil, these magic bullets will still be just over the next horizon.


I'll agree with Neil and then one up him:

Why no Butenol?

Also the key element to this entire subject was missing. What funding will all of this research recieve? It's absolutely imperative to come up with short, medium and long term plans for development of biofuels, no doubt about that. From this short synopsis, it seem very resonable and mildly agressive in scope and schedule; but if DOE only allocates $10 million to the program, how much of this will actually take place? Probably not much. Proper funding is critical to the sucess of this venture (well, any venture really ;p)

It's time for our government and the people of this country to get serious about changing the paradigm of how we use energy, not only in the transportation sector, but across all sectors. It's in our own best interests to do so.


allen Z

How good is this companiny's process? They claim to be able to turn celluose/paper into sugar for ethanol fermentation.


Perhaps the aim here is to simply add some basic research to help improve processes that are already in the works (Iogen, BP) etc..

Rafael Seidl

Don't forget that the Bush administration is beholden to the US oil & gas industry. Politics therefore requires the DOE to look as if it was doing something without actually accomplishing much of anything - at least not anytime soon. Hence, no mention of any real funding and a focus of five years of further research before any infrastructure gets built.

The US ethanol lobby is not pushing butanol, which would be preferable in terms of fuel properties, because the protectionist tariff of $0.54 per gallon applies only to ethanol.

BP and DuPont have indeed embarked on a project to produce biobutanol, initially using sugar crops in the UK. That country used butanol in Spitfires during WW2 and does not maintain a protectionist tariff on ethanol. A process for turning cellulose into simple sugars (hexose and pentose) is in the works. Once you have sugars, you can produce any alcohol you like with the appropriate (genetically engineered) bacteria. Ethanol fermentation is simply better-understood than most because we've been doing it for millenia. Unlike butanol, pentanol's octane numbers are too low for use without an octane improver.

Shell, VW and Iogen are investigating the feasibility of producing cellulose ethanol from straw in Germany. It looks likely that the US will not be the first country to produce industrial quantities of alcohol fuel(s) (additives) from (hemi-)cellulose.

Joe Rocker

How about ethanol from coal??? If you use bacteria to make fuel from coal, it won't have the nasty side effects of the conventional coal to liquids process, such as huge amounts of C02.


It is also possible to bioengineer an environmental limitation on an organism such that it will only survive in specific lab conditions. This would control the possibility of "escape into the wilds".

Rafael Seidl

Joe -

ethanol from coal is technically feasible. Reportedly, ADM is actually doing that right now, in addition to producing ethanol from corn kernels. Part of the reason for not producing regular alkanes (higher energy density, suitable for transport in pipelines) via Fischer-Tropsch is that ethanol enjoys a protectionist tariff of $0.54 per gallon in the US. Three guess who had a hand in securing that.

The downside of ethanol from coal is that net CO2 emissions are higher than those of gasoline from crude oil. Therefore, you trade off dependency on foreign (read OPEC) oil against global warming.

If you ran the scrubbed and cooled flue gases from coal power stations through an array of nearby ponds for growing selected algae species, you would not have to make the trade-off. Given enough nutrients and heating during the night, the algae will yield 30x the biomass of conventional crops per acre, much of it as either starches or lipids. The former are easily converted into fuel alcohols (butanol would be closest to gasoline), the latter to biodiesel.

tom deplume

Considering there are at least 3 thermal BTL processes I wonder about these token research projects. F-T and TDP are both more energy efficient than fermentation and distillsation. Ethanol is not a benefit to farmers as much as it is a pay back for campaign contributions from ADM and Cargill.


A press releace by GSPI refers to a joint venture with 2 other companys to produce both Bio-Diesel and CE at combined plants both in USA and elsewhere


Commuter vehicles that run on Alternative Fuel such as Natural Gas, Ethanol and others should be offered incentives or rebates from the government to purchase or drive them. And the more people you commute with would increase incentives. Public transportation is fine but people feel inconvienced by them as they do not want to walk that extra block but myabe need to.


Ok, I erred in one respect with my prior comment. My initial reading of this news was incorrect. I thought the report was saying we would replace 30% of our fossil fuel use within 15 years (based on the technology timeline). Ok, that's agressive but probably doable. Actually, they are saying we would replace 30% of our fossil fuel use in 25 YEARS!

Talking about aiming low. Hell, isn't hydrogen supposed to be THE fuel by then? What the heck is GM doing showing a hydrogen car (by the way, I must admit, it is pretty darned cool) if we are only barey starting to reduce fossil fuels with biofuels in 25 years?

Conceptually, this program is a good idea, but obviously if the program is only pushing a 1% market penetration per year, it's not significant. That could very well happen based on market forces alone. How the heck can Brazil be enery independent TODAY and the USA is aiming for 30% biofuel use in 25 years? It really disgusts me. We really need an administration (Repugnican or Donkeycrat, I don't care) that is willing to WORK THE PROBLEM by allocationg the billions of dollars and resources necessary to protect our interests, both politically and environmentally. Once again, it's for our own damned good.


Roger Pham

Thanks, Rafael, for eloquently voicing my suspicion regarding the DOE's motive in the CE agenda.

It seems to me that there is already a much simpler and more efficient way to exploit energy from cellulosic biomass, and that is the high-temp pyrolysis or gasification of dry biomass. This is a very simple process of using high heat up to 800 degrees C in the absence of O2 to heat up the biomass until thermal breakdown of complex organic molecules into simple hydrocarbon molecules such as methane, ethane, and CO and some hydrogen occur, depending on the temperatures and other conditions. The methane and H2 can be use directly in ICE or home heating, or be used to synthesize liquid hydrocarbon fuel via the FT process. Unlike the ethanol making process using low temp heat that cannot be recuperated for electricity production, the high-temp gasification process uses high temp heat that can be recycled to run steam turbine for electrical generation at very high efficiency at above 40% thermal efficiency, thus the EROIE is much better for the gasification process. No enzymes used, and no genetically-engineered organism used, either, so no fear of unknown environmental consequences should these "mutants" escape! Imagine a super bacteria used to digest cellulose now got into the gut of termites or other bugs (ants) and they are invading your wooden house!!
Thus, gasification of cellulosic of biomass can be used to provide biomethane and hydrogen to start the transition into the future, when low-cost hydrogen and methane can be produced inorganically en masse from concentrated solar energy via the solid-oxide high-temp electrolysis of H2O and CO2. If xTL fuel is desired, the methane and hydrogen feedstock is already available in large quantity for FT synthesis, and it's only up to the end user and local air-quality regulatory body to decide whether very clean gaseous fuel to be used locally, or synthetic liquid fuel to be used instead, where air pollution is not a major issue.

An Engineer

How about ethanol from coal???
I nominate this for dumb idea of the year! Get all the environmental disadvantages of coal, coupled with all the practical disadvantages (corrosion, transportation, etc.) of ethanol!

Got my vote.

An Engineer

This report exposes many of the practical difficulties of ethanol: getting the biomass into a form that can be fermented, the high energy requirements to distill the resulting beer and then, of course, the properties of the resulting ethanol itself.

Tom D is right, BTL is the way to go.


I am more into making biomass into syngas, methane, methanol and if you have to, hydrogen... then store the CO2.


I am thinking after reading Rafaels postings I must be needing to distill cellulosic ethanol for drinking or any ethanol! This conspiring politics hatings mixing with energy theries is looking backward to me. Please be sticking to energies to help find solutions more soon. Ethanol is being a good drink and longer carbon chain better fuel.


IMAO, BTL is the wrong feedstock for the wrong system.  The losses in conversion to liquids, plus the losses in the legacy systems which require liquids, add up to unsustainability at our current standard of living.  We need something like 5x the efficiency of BTL + combustion engines; fortunately, charcoal + direct carbon fuel cells can actually deliver it.

But good luck getting serious support for that.

allen Z

I think the emphasis on ethanol instead of butanol may be of three reasons.
1) The farmers grow crops that can be easily turned into fuel via yeast. Farm lobby may have a hand at this. There is electroal politics, and the kabuki dance in Iowa every four years for the presidential caucuses/elections. It is established, and anyone who does not toe the line may be seen/percieved to be hostile to the american farmer. No one with preidential ambitions will commit political suicide on this issue.
2a) If ethanol costs per gallon the same as gasoline, but not per BTU/mile, then there may be a profit to be made. Lets say (for argument's sake) that the gallon of gasoline goes back down to $2.50 a gallon. The real cost of a gallon of ethanol/E-85 per mile may be 50%/40% higher; it may be even more. Thus the real cost would be in the $3.70 range. ChChinn! Do I hear the cash register?
2b) The increased real cost may push the consumer to drive less/more efficiently. Thus consumption may go down. The thought of going 20 mpg on Ethanol and burning 6 gallons instead of the old 30 mpg/4 gallons a day for commuting may make people think. It is regulations/policies by market mechanisms and would fit in with the Bush White House.
3) With ther real cost by driving with ethanol higher, it may make the consumer go back to gasoline, or onto diesel. Big Oil may be letting ethanol blossom for this reason. It makes an alternative available, while stunting/drawing off $$$&brains for more R&D into better fuels/fuel production. Meanwhile, they slowly develop/ obtain replacements for Fossil energy to dominate the direct/indirect solar energy processes of the future. Thus ensure their future survival/success, hence their influence on the economy and politics, and thereby..... ...power.

allen Z

...butanol or any other biofuel may be of three reasons...

Harvey D.

Eng.-Poet. Certain information sources claim that Large Direct Carbon Fuel Cells have twice the efficiency of basic Coal fired power generating plants, (70% to 80% vs 35% to 40%) and produce 50% less CO2.

Would this be CO2 by ton of coal (or other feed stocks) used or by Kwh of electricity produced? Assuming that it is by Kwh produced, even a 50% CO2 reduction would represent an unsustainable level, when used on a massive scale.

Are there any of those Large Direct Carbon Fuel Cells in operation? If so, what are the proven economic and environmental impacts or advantages/disadvantages over other power generating facilities?

Roger Pham

Thanks, Allen,
for elaborating on Rafael's initial comment on the true motive of the US government & DOE. The Bush Adm is beholden to the oil& gas industry. So this convoluted cellulosic scheme can be summed-up as "Much Ado about Nothing."

Harvey & Eng-Poet,
Don't believe what you've read about "direct carbon fuel cell." having 70-80% efficiency, as the number is too farfetched. Actually, Coal can be exploited much more efficiently than currently using it to heat up steam for steam turbine. Steam turbine is limited to a max temp. of 600-800 degrees C, hence efficiency no more than ~40% range. However, coal gasification in the present of H2O but no O2 will produce syngas. This syngas will be used to power a gas turbine with ~40% efficiency, then the 600-degree C heat from this gas turbine will be used to power a steam bottoming cycle turbine to gain another 20% efficiency, and you'll get 60% efficiency out of Coal. This is what's known as Clean Coal technology. So far not widely adopted due to high capital expense. What's required is more gov. commitment toward GHG reduction to legislate requirement for Clean Coal Technology to bring about large-scale adoption of this technology.
This Clean Coal technology can also be used to produce methane, H2 and CTL products for transportation use as well. Uh Oh! Now you can really see why the Bush Adm has not done anything to promote this can compete with Big Oil...Oh La La!


Roger Pham:  The IGCC plants lose a substantial amount of energy in the gasification process (plus back-work to run the air separation unit); the efficiencies I've seen are around 40% from Wabash River.  That's good, but nowhere near as good as DCFC.  John Cooper claims to have routinely measured 80% efficiency, and that's based on the HHV, not LHV.

Harvey:  I don't know if any large DCFC's are in operation.  If I were running the energy department, getting a test plant up and running would be one of my top priorities.  The total efficiency of DCFC's is high enough that we could run the whole country on biomass-produced charcoal (zero net carbon), and the CO2 could either be sequestered or fed into the same sorts of processes proposed for growing fuel algae from fossil-plant exhaust.  That gives you a power system which could be strongly carbon-negative.  IMO, we need that yesterday.


Amount of required oxygenate blending is calculated according to oxygen content. Ethanol contains 35% of oxygen by mass, while for butanol it is only 22%.

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