Guest Post on Cellulosic Ethanol

The following is a guest post by Don Augenstein and John Benemann. They have many years of expertise in biomass conversion. This essay is in response to Vinod Khosla’s recent posting on ethanol. In my opinion, it is an excellent essay. First is the introduction by Don Augenstein.


This post presents a perspective on ethanol from lignocellulose by my friend and co-worker, John Benemann. We have worked on, and been immersed in, biofuels and analyses of fuels from biomass processes for over 3 decades. We are to substantial degrees biotechnologists, as well as chemical engineers and have successful processes going today (methane from wastes. You can google Don Augenstein). We have worked long and hard on biofuels for entities including Exxon (long ago), the Electric Power Research Institute, and others. Our carefully considered view, for which we will be happy to provide abundant evidence is that severe barriers remain to ethanol from lignocellulose. The barriers look as daunting as they did 30 years ago. Ethanol from lignocellulose may indeed come to pass. But the odds against are so dismal that a hydrocarbon fueled 200 mile per gallon passenger automobile would be more likely to be developed.

We have been tied up with project work and were not able to participate in the interesting, and extensive Oil Drum discussion regarding Vinod Khosla’s views on ethanol from lignocellulose. As you can tell from our paper (abstract at the end of the essay) to the solid waste people (which remains rather obscure, to a limited audience), we think that there is desperate need for more airing of the reasons for skepticism and warning the energy community of the obvious barriers. We are astonished and stupefied that the hype has gone as far as it has.

Better late than never. I present John Benemann’s statement below.

Dr. John Benemann on Cellulosic Ethanol

I read the presentation of Vinod Khosla and most of the responses. I have some experience in this field, about 30 years of being in the ring of biofuels technology development, with first-row seats, so to speak, on the fights I was not in myself.

Re. lignocellulosic ethanol, I am, bluntly, a skeptic. See our abstract, copied below. This is R&D, not something ready for commercial ventures, at least not in any time, or with any risk ratio, a typical venture capitalist would accept. Perhaps Vinod Khosla is not a typical VC, though I have no basis for assuming that.

Much more important, this technology is not ready for policy decisions. It compares with, for one example only, the near-late-lamented Hydrogen Program of the Bush-Cheney Administration. Coming from the same source, talk about curing our addiction to Middle East oil by substituting for it an addiction to Middle America ethanol, has just as much credibility. I note that all long-term R&D (is there any other?) for hydrogen is being terminated next month by the Dept. of Energy.

Of course, the issue is not whether Vinod Khosla is making a wise investment, one that will make him even richer and his investors too, or the opposite is true, or even what the Bush-Cheney administration dictates that our reality will be. The issue is, does the technology work now, can it be made to work in short order, or can we predict when and if it will work with any assurance?

One thing I notice from this entire discussion is an absence of any arguments based on technology. I am among other things a biotechnologist, and very familiar with the associated chemical engineering issues. I would have expected at least some mention of past and recent experiences, of problems, such as needs for extensive feedstock pretreatment or problems with fermentations, about current R&D focus, at least a few citations to the web. Nothing. Neither from Vinod Khosla nor the 360 odd Oil Drum respondents.

The only information presented is that Vinod Khosla has invested in three different technologies. Well, a fair enough investment strategy, but even with a one out of three chance, this is a long shot, even in the long term, by which I mean over 10 plus years, beyond which there are no crystal balls.

I strongly support R&D in this field. Money would be better spent on that than on just one commercial plant. Or even a pilot plant. And, let me hasten to add, that it is perfectly possible to make ethanol from lignocellulosic biomass, it’s just extraordinarily inefficient, with EROEI easily determined to be about 1:5. The Soviets had some wood-to-ethanol plants running during WWII, and kept them going afterwards, with at least one going on until the Soviet Union collapsed. Not a pretty technology, without even looking at the energy balance (cheap coal or then-cheap Soviet natural gas to expensive state subsidized ethanol, an economic model now adopted for corn ethanol in the US.)

And we, in the U.S., even made butanol from seaweed harvested off San Diego during WWI, in a major industrial enterprise that was set up in a few months, a perfect example of necessity as the mother of invention, and showing how fast we can do something when we need to, for our survival. But extrapolating from making explosives for war to transportation fuels for civilians driving SUVs is more than a bit of a reality stretch. I like the analogy of this being the difference between going to the Moon and Mars, another Bush-Cheney vision, I must note. Of course, we still haven’t figured out why to go to the Moon, aside from the feel-good factor.

Bottom line, making ethanol from lignocellulosics is a technical issue, actually many separate technical issues: can we really make 60 or 80 or 100 gallons of ethanol per ton of biomass, can we really ferment pentoses outside the laboratory, will we have a positive energy balance and not run this on fossil fuel as we do corn ethanol? And, coming to the details, can we really use commercial enzymes, or the same fermentation vessels that are used in the corn ethanol business, or do we need to go to very, very expensive contained fermentations. And at the end, do we get a high enough ethanol content in the fermentation beer (above 10%) to have a reasonable distillation cost? And, finally, can we put it all together, starting with the necessary pretreatment of lignocellulose (and what kind at what cost?). Actually, some applications for particular, minor, biomass waste resources, could make ethanol now at food processing plants, breweries and such, but this is not what Bush-Cheney or Gates-Khosla are promoting, to bring up another “venture” investor’s name.

Not that Vinod Khosla lacks information – his semi-public presentations on the topic earlier this year (I saw one of the power point presentations) provide some technology background, which, perhaps not too surprisingly, was almost exactly what was presented just before (or even on) January 31st in the briefing papers for White House, to support the “oil addiction” talk in the State of the Union speech. Another great example of sales of good sounding policy first, supporting facts to be provided later, a well used modus operandi. And now the Bush-Cheney administration has reshaped the federal government funding priorities for biomass R&D, to support their ethanol from lignocellulosics visions.

However, these visions of tens of billions of gallons ethanol per year from biomass must, by all reasonable analysis, be considered a distant possibility not an imminent accomplishment, as is being portrayed. That is the bottom line.

Of course, reasonable researchers will argue about where exactly we are and when and how can we could get there. As one close colleague told me, all the technical problems I talk about (see attached abstract) are actually viewed as “opportunities” by the R&D community. I agree, but there is now the belief that with current high ethanol prices, we have the means to this end at hand. After all, if for the past 25 years we were almost there, according to the National Renewable Energy Laboratory and others working on this. It stands to reason that with ethanol prices two or three times that high we must now be in clover. Right?

Well that is the rub of it. Wrong. We aren’t any more “there” or in clover than before. Yes, we can shave down some of the assumed costs to reach such low, low costs, but the assumptions are still there, only slightly closer to reality. Need I point out that there is only one pilot plant operating, Iogen in Canada, at a quarter of initially announced capacity? That is all we really can, and actually need, say about the commercial status of this technolgoy.

Thus jumping on this bandwagon and joining in the suspension of disbelief, which seems to pervade public discourse, outside some participants of this esteemed Peak Oil blog, is premature.

There is more to this argument, however, than just the issue of whether there is real technology (real could be defined, loosely and very charitably as less than $10/gallon of ethanol, or about a $100/mmBtu liquid fuel). The most important question is: what is a better way to use our billion plus ton per year potential biomass resource (and I stress potential, also not real, maybe one or two hundred million tons are real): conversion to ethanol or use for other purposes? Would it not be better to use surplus and waste wood, crop residues, or energy crops (another whole subject) to heat our homes, using wood pellets or even gasification to make heating oils?

And if we really want ethanol from crops, and I would favor some, 10%, to 20%, of our use if ethanol is economically or energetically feasible, would it not be better to grow high starch crops (requiring lower fertilizer inputs than corn)? Then we can make ethanol the way we know how, while using part of the crop residues for the process heat, rather than coal or natural gas. That should be an improvement what we are doing now, the corn to ethanol fiasco.

Well Vinod Khosla is probably correct, as I read him, that there is nothing that can be done about the world as we find it, and the function and reward of capital is to serve the system as is, not as it should be. And when I ask, do we want to drive our SUVs or freeze in our homes, that is rhetorical, as I do realize that the question is becoming irrelevant, the “we” will include only those who can do both, and they won’t really care, any more than any other ruling class has, about those that can’t heat their houses or drive their cars.

And a final question, should we, including our venture capitalists, foist on to other countries, let me give India as an example I know of personally, our simultaneously myopic energy policy and visionary technology focus? The answers to this and the prior questions are apparent, they hardly need to be answered, but they are not being sufficiently asked.

So I sincerely wish Vinod Khosla all the success in his enterprises. I hope they work for him and his investors, and for all of us. However, I am not enthusiastic about the free enterprise tail enabling — or even able to enable — this preordained policy dog to wag. Bluntly, we should not put our trust and future in ethanol from biomass saving the day. No more than in to that prior canard that H2 would save the day after tomorrow (remember those GM ads so long ago, was it last year, saying that todays’ toddlers would get their H2 cars for high school graduation?). And remember all the venture capital that went into those hydrogen companies? Anyone into financial forensics? But that is not our problem.

OK, as I said, reasonable people can argue the merits of this case, but these merits, particularly the technical nitty gritty, have not been argued to the extent necessary in this forum, neither by Vinod Khosla nor the many who responded to this blog. I hope to add to knowledge, in a minor way, by pointing this out, and some of the technical issues, and suggesting that ethanol from lignocellulosics is not something we should count on, any more than most of the other 1970s ideas and technologies being re-floated (biodiesel from algae being a personal favorite of mine).

Yes, biofuels are and will be very important, we are already doing some things, and need to do much more. Much work is required, in many areas, from anaerobic digestion to crop production, and including R&D on lignocellulosics to ethanol. Maybe we will get the proverbial breakthroughs. But multiple barriers must be overcome, and betting the farm on just this one ticket, on only ethanol from switchgrass and such, is foolish in the extreme. And that is, what I am afraid, the Bush-Cheneys are now attempting and the Gates-Khoslas accomplishing. This single rathole could easily consume most biofuels funding and, most likely, nothing real will be accomplished.

Another victory for the fossil-nuclear energy companies?

John R. Benemann, Ph.D.
Institute for Environmental Management, Inc.
3434 Tice Creek Dr. No.1
Walnut Creek, CA 94595
(925) 939 5864


Abstract of Cellulosic Ethanol Paper

The following abstract is to be presented August 29th at the Conference on Biofuels and Bioenergy: Challenges and Opportunities, Univ. British Columbia, Vancouver, Canada (see


John R. Benemann1*,Don C. Augenstein1, Don J. Wilhelm2 and Dale R. Simbeck2
1Institute for Environmental Management, Inc. 4277 Pomona Ave., Palo Alto, CA 94306 *Presenter and contact,
2SFA Pacific, Inc, 444 Castro St., Suite 720, Mountain View, CA 94041

Proposed lignocellulosic-to-ethanol processes envision a pre-treatment step, to liberate cellulose and hemicelluloses from lignin, followed by a hydrolysis step, to convert the carbohydrates to simpler sugars, and then a yeast or bacterial fermentation step, to yield ethanol, followed by ethanol recovery (distillation, drying). Some steps might be combined, such as in acid hydrolysis (combining pre-treatment and saccharification) or in a simultaneous saccharification-fermentation process. After five decades of intensive R&D, currently only a single pilot plant (Iogen Corp. in Canada) is operating, reportedly producing about one million liters of ethanol per year, though well below its planned capacity.

An independent analysis identified many problems with the currently proposed processes, including the relatively high costs of biomass delivered to commercial-scale plants (which would need to be 200 million liters per year output, or greater, for economics of scale), the problems with pretreatment, the low rates and yields of sugars from enzymatic cellulose hydrolysis, the resulting low sugar and ethanol concentrations, and the overall high energy consumption of the overall process. In addition to not tolerating high ethanol concentrations, genetically engineered organisms developed for combined hexose-pentose fermentations are subject to contamination, which will require prohibitively expensive containment systems.

Even ignoring, as most studies do, such major problems, and using available corn stover and enzymatic hydrolysis, the currently favored biomass resource and process, our techno-economic analysis estimated a cost of ethanol twice as high as that of ethanol from corn. Forest residues and wastes, biomass crops, and municipal wastes are even less promising. The conclusions of this assessment are that none of the existing processes are ready for commercial applications in any foreseeable time frame and that continuing fundamental and applied R&D is required. Some opportunities may exist for near-term applications of cellulose conversion technologies to some specific, modest-scale, agricultural wastes.

15 thoughts on “Guest Post on Cellulosic Ethanol”

  1. They got that same criticism when this was posted to The Oil Drum. I think the essay was written for a mostly non-technical audience, mainly to convey that there are still significant hurdles to wide-scale implementation of cellulosic ethanol. Based on their abstract, I think it is clear that they delve into specific technical issues.

  2. If cellulosic ethanol was so unfeasible, how come I count almost 10 companies (private and public) with announced projects to launch cellulosic ethanol demonstration or commercial plants?

    I also find it difficult to see that Exxon really tried to launch biofuels. Having worked for them as a chemcial engineer, and knowing their record on alternatives, this seems extremely unlikely.

    And as for the froth I see on this blog and other blogs about wind, I work for the provincial utility in Ontario (OPG) and I can say that even in a place as left-leaning as Ontario (with its plan to close down all ‘coal-fired’ generation by 2009, a date which keeps getting pushed back) wind is something of an inside joke. Across North America, Wind will always be more of a PR boost than a feasible energy solution. So stop dreaming of Europe with its heavy tax/subsidy energ policy and wake up to the reality of North America.

  3. If cellulosic ethanol was so unfeasible, how come I count almost 10 companies (private and public) with announced projects to launch cellulosic ethanol demonstration or commercial plants?

    There is a big difference between technical feasibility, and practical/economic feasibility. It is technically feasible for me to turn trees into crude oil. I could even build a plant that would achieve this goal. It would not, however, be economically feasible. It is technical feasible to turn biomass into ethanol, but again, there are hurdles that must be overcome before economic feasibility is a reality. Just because people have announced, or are building plants does not mean long-term feasibility has been achieved. Most will be operating with the assumption that they will crack the technical challenges. Just look at Iogen. They have been doing cellulosic ethanol for a long time now. If they really had a clear-cut economic process, they would be building ethanol plants just as fast as they could.

    I am a bigger fan of direct solar energy than I am of wind power. There are particular areas in which wind power makes good sense. I have been to Denmark several times, and they have been very successful with their wind program there. But we really need better storage technologies before we can count on wind to make a big contribution. One of these technologies that is already further along than cellulosic ethanol is Compressed Air Energy Storage, which I wrote about previously.

  4. I am well aware of the difference between technical and economic feasibility (I have a degree in economics as well). However, do you really think all these companies would be pumping precious capital into projects they believed would end up being economically unfeasible? Businesses make decisions based on demand expectations and profit margins not technical feasibility… and so clearly they must have strong reason to believe that cellulosic will be successful if they are willing to bet their livelihoods on it.

    As for Iogen, it is not true that they’ve been spending the last while doing cellulosic ethanol. When the oil price collapsed in the 80s, they switched to enzyme research and production and stayed there for a good while (based on conversations I’ve had with employees). Other companies, such as SunOpta near Toronto, were in food engineering long before cellulosic became feasible. So its a mistaken notion that companies have been researching this for ages and are just now trying to capitalize.

    The real reason you see cellulosic favourable nowadays is because of the environmental and political movement creating demand for development of this technology, as well as reductions in enzyme costs over the last 10 years. Protein and DNA research has progressed exponentially over the last 20 years, leading to hugely cheaper enzymes for the bottleneck ‘enzymatic hydrolysis’ step of cellulosic ethanol production.

    Are there hurdles remaining? Of course. But using the failure of hydrogen as a basis for skepticism of this new technology is a huge mistake. We’ll never get anywhere if people keep comparing every new technology with hydrogen. If you are so scared of the ‘cost of failure’, surely you should be more concerned about the limits of battery technology for your beloved plug-in car, since that has been around for much longer than cellulosic and significant technical breakthroughs are necessary to make them cheaper (not to mention safer, given the recent laptop battery recall).

    Meanwhile I do think a blog such as yours, Mr Rapier, serves a very useful purpose in criticizing the hype that surrounds this and other energy solutions…even if I believe some of the points brought up are incorrect. Mass media simply cannot be trusted to know enough to do the same. So thank you for your service!

  5. Don’t get me wrong here. I am supportive of cellulosic ethanol. My concern is that the proponents are just a bit too quick to dismiss the hurdles. I think plants are being planned and built because they think the hurdles will be cleared.

    So its a mistaken notion that companies have been researching this for ages and are just now trying to capitalize.

    Research in this area has certainly been going on for 3 decades. I was working on this over 10 years ago, and it wasn’t new at that time.

    My purpose here is not to say it won’t work, but to inject a bit of caution into some of the very optimistic projections I have seen.

  6. Yeah you’re right. Upon further research, I see that R&D efforts have been around for quite a while in this field. BTW Mr Rapier, what do you think of Butanol?

  7. How much is Bill Gates expected to make off of this? He’s rich enough that I’m kind of shocked he would hop on another con job. He’s supposed to be a genius, so how likely is it he’s being duped?

    How hard is he pushing this technology?

    Khosla seems like a liar/con-man. But Gates’ has been doing a lot of charity lately and I was under the assumption he shed his killer business ethics.

  8. I note that all long-term R&D (is there any other?) for hydrogen is being terminated next month by the Dept. of Energy.

    Your buddy needs to qualify this. What exactly is he talking about?
    Publication Date:14-Aug-2006
    “WASHINGTON, DC — The U.S. Department of Energy (DOE) today announced that it intends to fund approximately $1.4 million (subject to negotiation) for two projects to partner with industry to study the economic feasibility of producing hydrogen at existing commercial nuclear power plants…..

  9. Funding For Cellulosic –

    There is a lot of demand for these plants now and we have clients looking for projects. See what we at TRU Group Inc have done in this field.

    Investor Due Diligence
    Novel Gasifier Design
    TRU assesses the technology and techno-economics of a new design for a biomass gasifier. The market potential for the design was assessed as well as competitive technologies. TRU advised our client on the viability of the business and the risks associated with the proposed investment.


    Strategy, Planning and Financing Li-ion batteries Li-polymer carbon anode
    Lithium-ion Battery • New Li-fiber Battery Launch Li-ion battery
    TRU prepared strategies and business plan for a company developing lithium-ion batteries made with a new Li-fiber [carbon-carbon] anode. The new carbon-carbon fiber technology is significantly superior to existing Li-ion and Li-polymer batteries especially for higher energy applications. Seeking $15 million.Ç For more on this Lithium battery opportunity please click here


    Product Substitution & Demand Estimation
    Renewable Energy for Remote Locations & Communities
    TRU conducted an in depth assessment of energy use in remote villages/ camps and other non-grid-connected location. Estimated energy consumption by end use and type. Reviewed technology for displacement by renewable energy such as small-scale hydropower, photovoltaic & thermal solar, wind & tidal power, geothermal, peat and conservation.


    Technology Forecasting & Econometric Modeling

    Green versus Conventional Energy

    TRU evaluated the integrity and usefulness of comprehensive MITRE technology foresight model. The model is multivariate containing technology, manufacturing, and use factors for both conventional and renewable energy. Other econometric models used in analyzing aspects of renewable energy production and use were compared.


    New Product Launch in the United States
    Retrofit Insulation Product

    TRU conducted a market study in a United States regional market to assess the acceptability of a new insulation product to be sold to contractors and homeowners. Surveyed contractors and retailers. Made solid conclusions and provided client with product launch strategy.


    Market and Competition Analysis
    Thermal Solar Panel Market
    TRU undertook an in-depth assessment of thermal solar energy including compiling a comprehensive inventory of installations. Examined the techno-economics of thermal solar for various applications, including commercial buildings, homes, process water heating, and pools. Prepared historical segmented data on usage and forecast of demand.


    NRC R&D Plan for Energy Building Research
    Energy Conservation in Buildings

    TRU worked with the National Research Council to develop research and development priorities for energy conservation in buildings. TRU advised and facilitated a Task Force to examine technological issues that affected energy use in buildings and ways in which R&D could address those issues. Set objectives and scoped out the R&D plan.


    Data Gathering and Survey
    Energy Use in School Buildings
    TRU surveyed the use of various forms of conventional energy in school buildings as part of a program for finding an approach to energy savings. This was a first phase data gathering census of educational institutions in specified regions to be used by the government to institute energy saving measures in buildings that they own.


    Survey of Potential
    Manufacturing Sector Energy Conservation
    TRU undertook a surveys of manufacturing companies to obtain data on their use and attitude towards energy conservation. This was for a major electric utility that was interested in encouraging energy conservation and looking for ways to manage peak power loads on their network.


    Marketing Study for Start-up Company
    Passive Solar Windows
    TRU assisted a start-up company to establish information on markets for their passive solar window designs. Regional market size was calculated, customers identified and product designs assessed. TRU client was advised on methods it should use to penetrate the American market.


    Consumption, Application and Industry Assessments
    Insulation Products & Industry Competition

    TRU conducted an in depth survey of insulation markets and competition with the objective of measuring the impact of the Government’s “Home Insulation Program”. Effectiveness of insulation products were evaluated. TRU Interviewed contractors and insulation manufacturers, and used concurrent homeowner surveys to assess market demand.

    TRU Group Inc – Activating Your StrategicMindset

  10. The manufacture of any fuel that uses more energy to make than you get out of it is foolish and wasteful. That is how the petroleum industry sustains itself: The excess energy is sold at a profit and that profit goes to find and process more oil.

    The Petroleum Industry! They’re Big Oil! They tell LIES! They make big profits and then they try to kill people with Carbon Dioxide!

    Al Gore and Greenpeace types are running the economy into the ground and common sense into the river. It’s the Soviet Union all over again. The right ideology will make anything possible – including violating the second law of thermodynamics.

    Alternative fuels make some sense in some regional markets. We’re not only hemorraging balance of trade with petroleum – now we’re doing it with Brazilian Ethanol! Is anybody home?

    Will cellulose ethanol ever pay more energy than you put in? Nope – not enough to make it pay, anyway.

    I’m still trying to figure out what the Petroleum Inustry will do with all their wealth when they kill everybody in forty years. I guess they will go find other planets and do this same evil scheme

  11. The post mentioned an World War I effort of the United States to turn seaweed into Butanol.

    From what I have heard Butanol is a better fuel than Ethanol, as it can be used by the same infrastructure and engines that currently burn pure gasoline.

    Is it economically feasible to produce butanol? I don’t know, but it would seem possible to bio-engineer new seaweeds/kelps etc to grow in myriad conditions. They would be grown from sewage water.

    A combination of plants can be engineered to grown in vast expanses of equatorial and tropical waters. A type of “floating reef or suspended reef” could be made to grow 20 to 60 feet below the surface of the deep ocean. Perhaps a lattice formed along floating lines of plastic stapled to the ocean floor. The Rain forests grow in very poor soil: what they have is plenty of sunlight, water, and a surface. Equatorial to tropical oceans have plenty of water and sunlight. What they lack is a base or reasonably tight lattice from which highly productive food chains to form.

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