Whither Cellulosic Ethanol?

[editor's note, by Prof. Goose] This is a guest post from TLS's friend Don Augenstein (Pomona96 on TOD)

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.

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

Subj: Vinod Khosla FROM Jbenemann

TO THE OIL DRUM - drumbeat

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 Benemann

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 www.task39.org).

ETHANOL FROM LIGNOCELLULOSIC BIOMASS - A TECHNO-ECONOMIC ASSESSMENT

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, jbenemann@aol.com
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.


This is probably more a question for RR, but, how much harder is it to get useful amounts of butanol from a fermentation process? Given that the above problems are all solved?

Are there a lot of fermentation bugs that make butanol?

Butanol from microorganisms is a fairly new process. I made trace amounts in grad school from rumen and termite microorganisms, but nothing in commerical quantities. When I worked for Hoechst Celanese, I worked on butanol processes for many years, but we made it the traditional way from petrochemicals.

If the claims that are made at www.butanol.com are valid, then we should be shifting to butanol production as quickly as we can. The claim is that the per gallon yields from corn are almost the same for butanol as for ethanol, yet butanol has an energy density similar to gasoline, and the distillation process is much less energy intensive.

What about butanol synthesis from ethanol feedstock. If there is a good catalyst for it I'd think it would not add to the overall cost. The wike says it can be made from ethanol via electrolysis http://en.wikipedia.org/wiki/Butanol#Production But I suspect there is a catalytic route. I found one here http://www.sangi-co.com/e/index.html Butanol Synthesis from Ethanol Using a Hydroxyapatite Catalyst Everything I've read points to butanol being almost the perfect fuel as far as pollution and energy density goes.
I don't think you would want to synthesize it from ethanol. I think you would be deeply in the hole on the energy balance. Given that ethanol is already marginal, you are going to end up with a butanol product that definitely required more energy input than the final product contains. Far better to synthesize it directly.

Well I think you just answered the question about using ethanol for anything but high value needs. If its too expensive to use as a chemical feedstock then its proabably not worthwhile to burn it for general transportation.

If people don't feel its valuable as a feedstock then why the hell use it for transportation ?

Oil/Natural gass feedstocks don't suffer these problems. GTL for example is viable even CTL's.  

I think we do need to find a renewable reduced carbon source for future transportation needs mainly the airline industry and critical off grid transportation and for chemical feedstocks.

Ethanol does not solve this problem.

Would butanol need to be moved via truck, similar to ethanol, or could it be piped?
According to RR's post it might be able to be piped. It does not dissolve in water as readily as ethanol, in fact it separates spontaneously at concentrations above 7 %. Whether or not it can be piped depends on other factors, however. Does it absorb moisture from the atmosphere if exposed to it? Or could it be contaminated with water in other ways? If so, how much water does it eventually contain? How harmful would that water ratio be to a piping-based infrastructure? I've no idea if anyone knows the answer to those questions.
The claim is that it can be piped. It is not very hygroscopic. It will absorb some water, but is not completely soluble in water like ethanol, and therefore should be less corrosive. Even better options would be C5 or higher alcohols, because they are completely insoluble in water.

Interesting you mention that I was wondering why they don't do fermentation targeting a alcohol that's insoluble in water then the fermentation product separates and you don't poison your culture and you don't need distillation. Even with butanol if the fermentation culture can survive at its soluble concentration you would just have to decant the excess alcohol.

This seems the way to go to me since it solves lots of problems.

There is some discussion here.

http://www.greencarcongress.com/2006/08/dupont_bp_and_b.html

Butanol solubility is about 9ml/100ml or 9%v/v so if a culture can withstand that your looking at a residual of 9% of the production remaining in the culture which is not bad.

Butanol can be produced by fermentation of biomass. The process uses the bacterium Clostridium acetobutylicum, also known as the Weizmann organism. It was Chaim Weizmann who first used this bacteria for the production of acetone from starch (with the main use of acetone being the making of Cordite) in 1916. The butanol was a by-product of this fermentation (twice as much butanol was produced). The process also creates a recoverable amount of H2 and a number of other by-products: acetic, lactic and propionic acids, acetone, isopropanol and ethanol.
(So it is "new" like most of the chemical industry)
http://en.wikipedia.org/wiki/Butanol_fuel

The manipulation of the pH levels to shift the ABE reactions to buytol alcohol is what is new.  (Acetone, Butanol,Ethanol)

The manipulation of the pH levels to shift the ABE reactions to buytol alcohol is what is new.

Yes, I should have been more clear in my wording. Many chemicals have been made from biological processes long before they were made from purely chemical processes, but the claimed ability to make it in commercial quantities from biomass is new.

It was made commercially that way before the use of oil-derived hydrocarbons.

The new patent is based on keeping the biological portion in the butynol side of the reaction.

(I looked up their patent in the past....I don't want to spend the time looking it up again, so perhaps someone here will)

No need to look up the patent. They summarize the history of butanol, with links to additional information (and to the patent) at http://www.butanol.com/.
Regarding Re. lignocellulosic ethanol, I am, bluntly, a skeptic

And

Much more important, this technology is not ready for policy decisions

I have a simple question. Why are we talking about it then?

Who killed the electric car?

That's what this biofuels "debate" is all about. The fantasy, the dream, that people will continue their happy motoring based on liquids from biomass converted to liquids. Forget it. Kunstler's right. We are still trying to invest in a lifestyle that has no future. That's why the subject is so popular.

Let's move on, OK?

The thing is, Dave, that we are in a war of ideas. If the other side wins this war, then we may stray far down a path, and waste a lot of time, before realizing that the "solution" is unworkable. If this fantasy is demolished at an early stage, then maybe more people will get serious about taking action to prevent the worst case scenarios envisioned by hardcore doomers.

That's why these biofuels threads are so popular, IMO.

Good point.

However, there are lots of other paths we are straying down. CO2 injection for recovery of stranded oil for one. Offshore drilling of America's continental shelves for another. Coal for everything -- power generation, conversion to liquids, you name it. If you believed all the propaganda, the US has more recoverable liquid reserves than Saudi Arabia. I'm not kidding. Biofuels is small potatoes compared to what I just brought up.

Small Potatoes

So, here we are talking about corn, switchgrass, God Knows What to make stuff to put in your car. Give me a break!

It is imperative that the lumpen populace maintain their belief that life will continue as it is forever.  We all know that is the rationale for all this stuff.
EXACTLY, I keep trying to bust some such propaganda but my attempts are not well received by the naïve and simple minded.

I just had an argument with Nick (after some with odograph and eric blair), but to the idiots crowd it is ME who is the "stalker".

If bio ethanol (be it from any source) is not efficient and will not be able to sustain the current demand,why do we keep talking about it?

I think the car way of living is a dead end.  Light rail and better urban policies (implemented by legislators or by pure necessity) is more of an answer.

However, I think we need a liquid fuel substitute for some applications.  

Can anyone tell me how good biodiesel from algae could be as a product (efficiency wise and EROEI wise)?  I know that in april or may a company in New Zealand did bring a technology to use waste water to produce algae in a closed system.  Do anyone think it's a viable technology?

Do I need to go trough the literature to know the complete picture or is this techology just not ready at all?

The University of New Hampshire seems to be a good start to read on this.  Is it a good place to start?

I ask all those question because biodiesel from algae is part of my simple solution system to peak oil.  I'm currently talking with many city officials and planers in my home town and in nearby town.  I dont want to promote a solution that is doomed at the start.

Also I'm preparing for a regional conference for september 23. I will do a speach on the problem and lead a workshop on solutions that can be implemented.

The local high school is also welcoming the idea of giving small conferences in diferent classes.  I plan to go talk in geophysics class, geopolitic class, biology and environmnent class and in the brand new nature and environment program. The later is a special program, much like a sport-study or music-study program.  

All the work I do here lean on being very credible and well informed.  I dont want to mislead people in first place.

Advices on this are welcome!

Algae has huge potential.  It also has a long way to go.

FWIW, current-technology batteries are more than sufficient to provide lots of personal mobility indefinitely.  New cells on the market like the A123Systems' cells used by DeWalt can make an electric which eats Corvettes for breakfast and gets an effective 135 MPG.  Don't count the car out.

Hi,

Has you certainly know, a battery is only a energy storage device albeit this one looks good.

How do you think you can power US normal current demand AND new incomming demand from car recharging using the same old electric generation technology?

You do know that unlike in Quebec most other places use coal, nat gas and oil to make electric power.

Also time and ressources are needed to produce and sell enough "any kind" of car replacement and Hirsh think that we dont have that time.  If you own an electric car and is not useful to you because the paradigm has shifted, do you think it will make you look powerful or ridiculous?

Here is the technology I think will be more useful :

  • light rail for people and goods (medium and long distance)
  • Buses and trucking (short to medium distances)
  • Walking, cycling and skiing (short distances)

That's why urban design will have to be rethinked.  That will happen no matter what the PTB will do.
Hi,

in order to give you a rough idea of what is feasible in a big city with a very good public transport system:

Breakdown of personal trips in Berlin, Germany (1998)

Walking: 25%
Cycling: 10%
Public Transport: 27%
Cars, motor-bikes: 38%

Newer figures are not yet available.

How do you think you can power US normal current demand AND new incomming demand from car recharging using the same old electric generation technology?
I think it can be done because I ran the numbers two years ago.

Besides, the problem isn't technology (though new technology improves things radically), the problem in the short term is fuel supply.  Given that we can cut fuel demand by a factor of 3 or better by burning oil in IGCC turbines and charging batteries compared to gasoline, the backup fuel supply might as well be oil.

Also time and ressources are needed to produce and sell enough "any kind" of car replacement and Hirsh think that we dont have that time.
He may be right, but parking the guzzling SUV's and driving our old beater econoboxes will buy us a fair amount of time right there.
If you own an electric car and is not useful to you because the paradigm has shifted, do you think it will make you look powerful or ridiculous?
How is an electric car not going to be useful to me?  If we wind up without electricity, everybody is screwed.  Besides, I can buy PV panels and make my own electricity.
That's why urban design will have to be rethinked.
Vehicles are replaced much faster than housing.  Urban design may change, but it's always going to trail things with shorter life cycles.
A few points:  

None of the technology that you deem to be useful can be pursued on an individual basis.  That's great if light rail is going to help with transportation in the future, but I can't go out in front of my house and start laying down track.  

Walking, cycling and skiing...maybe those will be useful in the future, but in current society they face serious limitations.  I could bike down to the trolley stop, but that doesn't matter because it doesn't go where I need it to.  I could bike to the store, but frankly I'd be afraid of doing so, because the streets are not designed for bikes, and drivers are very inconsiderate of bikes and view them as an annoyance.  Regardless, walking and cycling cannot work for me, nor for many others in current society.  At the current time they are impractical.  

Now, meanwhile, converting a car to EV is something you can both do yourself, and which will allow you to function practically in today's society.  Why the animosity toward EVs?  You think someone is going to look ridiculous for owning an EV?  No more ridiculous than everyone who owns cars and who can't afford to fill them up.  And what are we talking about, 20 years down the line when everything has changed?  I doubt anyone driving an EV today, or who is thinking about converting to an EV today and does not have one yet, is concerned about what comes to pass in 10 or 20 years.  When things are changed maybe the EV won't be needed.  I don't see how that makes you look ridiculous?  

I really have a hard time seeing how someone who converts to an EV can look ridiculous except if their motivation is purely economic, and then gas prices drop to $0.99 a gallon.  I'm sure quite a few are willing to take the risk of that in stride.  

Obviously there are major process problems with algae, but it appears that the underlying energy physics---yield of fuel---is sufficiently high by enough of an order of magnitude to pursue it.

That may not be the case with ethanol etc: even if we solve all the nasty fermentation problems, what is the end yield?  Not very good.

And two titanic advantages for algae:

  •  Uses seawater, not fresh water
  •  Uses deserts, not fertile cropland

Re algae farms:

It seems that you have to keep them closed, so that they are not invaded by organisms which outcompete the fuel algae but do not produce useful endproducts, and reasonably warm.

And of course cheap.

What about arrays of water+algae filled waterbeds, clear on top (UV resistant of course), black on the bottom, made of cheap plastic, and "swimmming pool tech" connections and pumps to the oil separators?

Put them in the Sonoran desert or South Texas or South Australia or South Arabia (!), fill with seawater.

It seems that you have to keep them closed, so that they are not invaded by organisms which outcompete the fuel algae but do not produce useful endproducts, and reasonably warm.

And the cost of enclosing and maintaining  to obtain the oil-based watts VS making, placing and maintining PV cells is?

If it's as about as much as the cost of a greenhouse, it's still a lot cheaper than PV.
If it's as about as much as the cost of a greenhouse, it's still a lot cheaper than PV.

Ever looked into the regulations about greenhouses?

These days, you can't use glass... it has to re-enforced saftey glass.  And that increases the price.

So don't be too sure about the 'alot cheaper'.  Unless you don't use glass and use polycarbonite plastic.

Most of the greenhouses I see are made from plastic film.  Further, you could float this on top of an algae pond (like a bubble-wrap pool cover).  You'd still have to find some way to get CO2 to it, but the thing itself would be pretty cheap.
The National Renewable Energy Lab spent 30 years looking at algae oil production and closed its program in 1998 believing that the process was not going to work. The microorganisms are just not designed to produce lipids in a useful quantitiy and any talk of bioengineering and breakthroughs is just dreaming.

The research found that individual cell lipid production was not compatable with cellular reproduction and overall colony growth. Furthermore, microalgae are difficult to cultivate axenically. They are very vulnerable to bacterial contamination, pH fluxuation, and critical Co2 levels.

I presume that's why researcher talk about closed system production for algae.

In 1998 the price of oil was only 20$.  I know that the biology has almost nothing to do with that, as I asked I'm more interested in the effectiveness of the solution.

Huge potential = R&D = huge risk = why wasn't done before?

Feasible = investment = jobs = just allocation ressources and effort.

Why in Wikipedia do they talk about the huge differences in yield?  From Wikipedia :

From 1978 to 1996, the U.S. National Renewable Energy Laboratory experimented with using algae as a biodiesel source in the "Aquatic Species Program". A recent paper from Michael Briggs at the UNH Biodiesel Group, offers estimates for the realistic replacement of all vehicular fuel with biodiesel by utilizing algae that has a greater than 50 % natural oil content, which he suggests can be grown on algae ponds at wastewater treatment plants. [citation needed] On 2006-5-11. Aquaflow Bionomic Corporation from Marlborough, New Zealand announced it had produced its first sample of bio-diesel fuel made from algae found in sewage ponds.[4] Unlike previous attempts, the algae was naturally grown in pond discharge from the Marlborough District Council's sewage treatment works.

The production of algae to harvest oil for biodiesel has not been undertaken on a commercial scale, but working feasibility studies have been conducted to arrive at the above yield estimate. In addition to a high yield, this solution does not compete with agriculture for food, requiring neither farmland nor fresh water.

Independent results have shown that Green Fuel Technologies[7], a Cambridge, MA company founded by Isaac Berzin, has been successful in producing biodiesel growing algae on flue gas emissions from power plant smokestacks. Using a patented algae bioreactor, GreenFuel utilizes microalgae and a process of photomodulation to reduce emissions: 40% less carbon dioxide and 86% less nitrous oxide. This oil-rich algae can then be extracted from the system and processed into biodiesel, and the dried remainder further reprocessed to create ethanol. The company is testing their method at the MIT cogeneration facility and at an undisclosed 1000-megawatt power facility in the southwestern U.S. [citation needed]

Is it a good path to look into or does it smell stinky?

Is it a good path to look into or does it smell stinky?

The base unit of energy is the photon.   almost every algae scheme you have hardware being built to hold the algae, expose the algae to excessive CO2 and photons to obtain algae fat with fat.

You have capitol costs in running the reactor in addition to making the reactor.

VS

Taking PV cells and converting photons to hi-grade electricity.

All the algae schemes are therefore tied to large producers of CO2.  Somehow these CO2 producers will have to have enough photon gathering space to support the algae-photon gathering method.  Then they will have to have the space to process the fat algae.

How many CO2 producers have that kind of space?

In the province where I live, we have 98% of electricity generation done using large scale and very large scale hydraulic dam.  We are pioneer in those technology for many aspect of it and the high-voltage electric conductor has been invented in Quebec.  Unlike most of desert and prairie land of many places, we have many many rivers and lake.  I woke up every morning beside a lake that contains 31 billion barrel of water.  I even use it has a figure for the world oil consumption.  We dont have a water shortage around here.

We DONT need electric power generation, especialy using PV cell.  Look at the study done by Ted Trainer for bemol regarding PV cell feasability.

What we need is LIQUID fuel, thus the question about the efficiency of biodiesel from algae.

We DONT need electric power generation,

Really?   On what basis are you making that assumption?   Based on the way we now live life?

especialy using PV cell.  Look at the study done by Ted Trainer for bemol regarding PV cell feasability.

Mr. Trainer analysis is flawed.   Horribly flawed.

Basic phyics shows that his analysis is flawed.

The biggest energy input into the biosphere is in the form of photons.  PV, Wind, water. organic liquids fuels from whatever source all owe the state from which we extract energy are because of the photons that hit the earth.

Without the running down of the Sun's fusion reaction, there is no energy or life on this planet.

Looking at his 'analysis' "Again a 15% loss in transmission "  The reality is that PV is used where it is generated 1st, then sent on the grid...if there is any extra power left.  So a 15% "loss" is flaws.

More of his 'analysis':
"The most significant problems for solar electricity supply are set by the need to store energy for supply at night. Storage in the form of hydrogen gas will be assumed here. "

Hydrogen storage?   Picking the storage form with the highest conversion penality.   There are other menthods, once you unlock your mind from the "we must keep things the way they always have been" mindset.   Like supply-based electrical metering.  

Tell ya what.... you want to accept Mr. Trainer's paper as some form of ultimate truth.  Fine.  Lets say that spending the money to create enought PV cells to power the nation is dumb.

Now you make the claimn What we need is LIQUID fuel,

Mr. Trainer says "Therefore the cost of a generating plant 87 million square metres in area would be $130.6 billion."
Iraq war spending to date: Overall, Congress has approved about $192 billion for the Iraq war itself,
http://www.csmonitor.com/2005/0519/p01s03-usmi.html
Is $192 billion a fine way to keep what you demand LIQUID FUEL?

Yea, using the priamary energy source of photons in the most direct way is just SO costly.