A little more on algae
Posted by Heading Out on August 17, 2006 - 2:33pm
Topic: Alternative energy
Tags: algae, biodiesel [list all tags]
With a postulated 2+ barrels/acre/day of product (if I do the arithmetic right) even if the acres are "special" makes it sound as though it might be a somewhat intriguing approach.
UPDATE: Well I guess I hadn't better laugh about this, but what the broadcast was about related to the benefits of growing the algae in the unused sections of old mines, and in cross-cuts, where the climate can be easily controlled, and the infrastructure (walls, roof etc) are already in place. It resolves some of the issues that were a problem in New Mexico, and allows the use of the third dimension (height) in the creation of the reactors - hence the high level of productivity, and it does not conflict with land-use requirements, etc etc. Ah, well!
What the heck is this "grin" shit? Aren't you guys supposed to be posing as serious analysts? Is this an IRC channel?
And you wonder why people don't take you seriously.
The tone of my post was way out of line. Sorry.
It's just that you used the same expression twice in an earlier article and I lost it for a second.
http://www.theoildrum.com/story/2006/8/16/13213/1413#more
It certainly is a very relaxed style. But if there is no intent to reach a wide main stream audience, not a problem.
For the record, I'm not to be taken seriously. (As if there was any danger of that).
http://en.wikipedia.org/wiki/A%C3%A9rotrain
I thought it was great. Much more economical. Not sure why the aerotrain was abandoned for the maglev. I guess politicians like to fund pie-in-the-sky technologies instead of something simple.
It may be the 2 barrels/acre/day of production statement?
You know in order to not be considered an IRC channel, comments and critics need to be well stated also. We need to be more fact based in our statements. If you go to the cellulosic ethanol thread, you will see lots of questions and idea exchanged on the possibility of biodiesel from algae.
As for taking us seriously, It will be harder for me to take you seriously if you cannot articulate something more accuratly. Credibility is obtained trough good communication and comprehension. For having good communication, real physical presence is needed. Nevertheless, the kind of interaction in a blog allow for a certain amount of good communication, albeit less optimal, more efficient for reaching a large number of people. For attaining that kind of credibility, please write clearer messages and use better language.
I like the idea but after seeing little movement from the proponents at UNH I want to see more in the way of data, working examples, all the little caveats which factor into all real systems, etc.
Nonsense, no matter how cheap you can make the manufacturing oil from alge process it will never be as cheap as just finding in in the ground and pulling it out.
"supposed to be posing"
supposed to be posing
And you mean exactly what with such a statement?
supposed
accepted as true but doubtful: accepted, at least by some, as correct, real, or having a quality, but on slender or uncertain evidence
posing
2 : to affect an attitude or character usually to deceive or impress
Are you doubting the acting ability of Heading Out to be a serious analyst?
What was your point?
I think we both nailed him shut. If it would have been in gheto street talk, it wouldnt have been better.
I didnt read or notice other useful comment from him, but I may have just missed them, who knows?
I fiew out to NREL last week and dug up many of the reports from the cancelled Aquatic Species program. Once I get thought the hundreds of pages, I'll post an update.
RealAudio stream or Podcast
- Harvesting is much more difficult and energy intensive than most people realize. I have had to deal with this issue in regards to wastewater pond effluent.
- Random natural algae tend to start taking over from artificially seeded algae fairly rapidly unless the pond is covered, and covering ponds is a fortune.
- Ponds often have to be lined to meet groundwater regulatory requirements, which adds quite a bit to costs.
However, I concede that with a great deal of research, algae ponds may eventually have a role in biofuels in select locations.My only familiarity with the concept of fuel from algae is what I have read on the internet so far. However, I do have quite a bit of background in wastewater treatment and sludge processing. The three big problems with algae that you mention are exactly the same problems I think will be encountered.
I think it should be plainly evident that it's one thing to grow high-yield special-strain algae in a totally enclosed sterile lab reactor, but something else again to try it in a large open pond, which will eventually acquire its own ecology, an ecology that may not be favorable to the type of algae you want growing.
And covering even a small pond with a transparent roof is exceedingly expensive.
Still, I'd like to see more results by researchers in this field.
Another consideration is the harvesting of the algae. Even though an algae-choked pond may look quite dense, I very much doubt if the algae concentration, in terms of percent solids dry weight, is much more than one percent. It is not easy to maintain sufficient dissolved oxygen by natural means if the algae concentration gets too high. Mechanical aeration can boost this, but that of course consumes energy.
So, I would image that the harvesting operation must include some sort of liquid/solid separating step(s) - possibly chemical flocculation and settling and/or belt filtration. Even with a good dewatering step, the best you are probably going to achieve is to get the solid concentration up to maybe 40%. If that is good enough for the oil extraction step, fine; but if it has to be drier then that, then we are talking about energy-intensive heat drying.
Does anybody here know exactly what operation is used to extract the oily material from the harvested algae? Is it just physical pressing, or does the algae have to be cooked in some fashion? Any chemical reagents used?
Then there is the question: what to do with the organic residue that remains after the oil extaction step?
I would think that if you ran the straight algae-containing water through a high-shear mixer or ultrasonic device, you are are liable to emuslify the oily fraction. If so, then you are not going to remove it with a gravity plate separator unless you first put it through demulsification step, most likely involving some form of chemical treatment.
Furthermore, high-shear mixing is very energy intensive, due to the fact that the required mixing energy very rapidly increases with mixer volume. So, if you have a large flow rate going through the mixing step, it could get expensive real fast.
I haven't read anywhere about what is the prefered method of extracting the oily material from the algae.
Also, I found this neat retrospective on DOE's algal-biodiesel research. Two interesting points made - first, start with native species of algae that colonize your pond, and experiment with nutrient deprivation and/or breeding/genetic engineering on them to increase oil production, rather than try to adapt your lab culture to the outdoors. Second, some of the research was on green algae. This includes the kinds of algae that form colonies - the clumps you find in stagnant ponds. If you can use a species that forms macro-sized clumps, harvesting would be vastly simpler & less energy intensive than sewage-sludge separation, where you're dealing with a sludge of micro-sized groups of cells. As far as I can see, you could simply filter it out, drain it, and press the oil out.
I know algae produce oxygen (at least during photosynthesis), but what about the respiration period during hours of darkness? I'm not saying you would or should use mechanical aeration, but if the algae concentration gets too high, I suspect there might be mass transfer problems that might require some physical mixing. Not sure - just speculating.
Well, that's good.
Do you know what is the proposed method in some of these schemes for extracting the oily material from the algae?
Shelef, G. (1984b) "Marine microalgae separation and harvesting." Proceedings of the April
1984 Principal Investigators' Meeting, Aquatic Species Program, Solar Energy Research
Institute, Golden, Colorado, SERI/CP-231-2341, pp. 206-224.
Shelef, G.A.; Sukenik, A.; Green, M. (1984a) "Microalgae harvesting and processing: A
literature review." Report to the Solar Energy Research Institute, Golden, Colorado, SERI/STR-
231-2396.
Shelef, G.; Sukenik, A.; Sandbank, E. (1985) "Separation and harvesting of microalgae from
saline media." Proceedings of the March 1985 Principal Investigators' Meeting, Aquatic Species
Program, Solar Energy Research Institute, Golden, Colorado, SERI/CP-231-2700, pp. 244-270.
Benemann, J.R.; Goebel, R.P.; Weissman, J.C.; Augenstein, D.C. (1982a) "Microalgae as a
source of liquid fuels." Proceedings of the June 1982 SERI Biomass Program Principal
Investigators' Review Meeting, Aquatic Species Program Reports, Solar Energy Research
Institute, Golden, Colorado, SERI/CP-231-1808, pp. 1-16.
Benemann, J.R.; Goebel, R.P.; Weissman, J.C.; Augenstein, D.C. (1983) "Production of liquid
fuels and chemicals by microalgae." Proceedings of the March 1983 Principal Investigators
Meeting, Aquatic Species Program, Solar Energy Research Institute, Golden, Colorado,
SERI/CP-231-1946, pp. 19-32.
Weissman, J.C. (1984) "Cultivation of microalgae for liquid fuels." Proceedings of the April
1984 Principal Investigators' Meeting, Aquatic Species Program, Solar Energy Research
Institute, Golden, Colorado, SERI/CP-231-2341, pp.132-149.
Weissman, J.C.; Goebel, R.P. (1985) "Design, fabrication, and operation of innovative
microalgae culture experiments using open ponds." Final Report, Subcontract XK-3-03135, Solar
Energy Research Institute, Golden, Colorado.
Weissman, J.C.; Goebel, R.P. (1985) "Production of liquid fuels and chemicals by microalgae."
Proceedings of the March 1985 Principal Investigators' Meeting, Aquatic Species Program,
Solar Energy Research Institute, Golden Colorado, SERI/CP-231-2700, pp.141-161.
Weissman, J.C.; Goebel, R.P. (1987) "Design and analysis of pond systems for the purpose of
producing fuels." Report to the Solar Energy Research Institute, Golden, Colorado
SERI/STR-231-2840.
Weissman, J.C.; Goebel, R.P. (1987) "Factors affecting the photosynthetic yield of microalgae."
FY 1986 Aquatic Species Program Annual Report, Solar Energy Research Institute, Golden,
Colorado, SERI/SP-231-3071, pp. 139-168.
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open ponds and tubular reactors." Bioeng. Biotech. 31:336-344.
Thanks for the references.
I will try to check some of these out the next time I'm at the local university library.
You obviously have quite a bit of familiarity with the subject. Have you ever did any work in this area?
We are in a race against the peak oil clock and we need to focus our research dollars where they are most needed.
Being more informed on this is the first step that I will have to go trough.
Is the UNH group doing a good job? Is it also a good place to start reading?
You seem to have read a lot, can you tell what are the main issue?
Thanks a lot for the info!
I think it's a great place to start reading. I spoke with Michael Briggs there about a year ago, and he gave me some useful information. I am not sure exactly what they are doing, though, at this point. It would be nice to know if they are testing various strains of algae and turning it into diesel, but that isn't apparent from the material I have read on their site.
I suggest you read some papers on the subject. You are just adding confusion to the discussion with incorrect statement.
Can you point me to any such papers that discuss the actual method(s) used for extracting the oily material from the algae?
I think you might be picturing algae physically similar to seaweed. It's not. It is typically a dispersed growth of very small clumps of oganisms that don't even settle very well, much less be amenable to skimming.
It appears to me that there are some serious (but not necessarily insurmountable) material handling considerations that need to be sorted out before algae can go full scale commercial.
Algae encompasses quite a bit of different taxonomical areas - including 'seaweed.' It's not even confined to one kingdom - simple marine plants and some protists qualify for the title.
Obviously that wouldn't work in a bioreactor. Still, it's basically just a filtration problem: run the water through a screen, and scrape the screen periodically. That's not rocket science. What am I missing here?
A) floating sun-loving microalgae in the absence of predators will tend to form a film on the top 10cm of the pond
B) the top of that layer tends to be dead from overexposure to the sun
Skimmers should be viable. So should filters:
http://www.spirulinasource.com/microjourdan.html
I also believe it is the only possible alternative for petroleum for liquid fuels. (Of course, that doesn't mean we should stop all conservation, etc)It would be tough to calculate a EROEI without having a known system, but I'd bet it would be pleanty high if the right system were employed.
An unused piece of land [bigger than] the size of New Jersey is avaiable in the USA. It also has lots of sunshine and access to lots of needed saltwater. It's called the Sonoran desert in Arizona etc, with 120000 mostly empty square miles.
If we can solve a couple of engineering problems it would probably get us over the hump. Keeping the desired strain of algae growing doesn't require covered ponds, just an artificial river with a beginning and an end. Spike it with known good algae at the beginning, and harvest gobs at the end, recycling the water. Even the stuff left after the oil is removed could be fermented into Butanol. I think the secret will be to have a series of tanks full of different microorganisms each taking the previous stuff and attacking the previous organisms, then fermenting the result. Tada... out comes biodiesel and butanol and fertilizer.
By the way, does anybody know if biodiesel can be catalytically cracked into something like gasoline?
It can, but it would be far better if we took measures to increase penetration of diesel vehicles in this country. You will take a substantial energy penalty by cracking to gasoline.
These tenacious little beasts serve as the lingua-franca for transportation in the African bush, the Australian outback, they work as troop carriers for terrorists in the mountains of Afghanistan, they do the work of larger counterparts in most of Eastern Europe and they are celebrated as the four wheel drive of choice in South America.
One would think that duty as grocery getter in American suburbia would be a foregone conclusion and a comparitively cushy job for the little monsters.
Curiously they are wholly absent from the American vehicle formulary.
So is any American equivalent and also any small and efficient diesel option in compact American sedans.
I find it hard to believe that the American vehicle buying public cannot be marketed in a manner which would help them identify the attractiveness of a small and efficient diesel option on a wide variety of vehicles