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Extracting energy from algae

post #1 of 18
Thread Starter 

In the ocean acidification thread, gncp stated

 

If you grind through all the energy you need to use to produce fuel from ocean biomass, and do it honestly by not neglecting things like the need to rinse all the salt out of the biomass before processing, you will find it is an energy-losing proposition (similar to how producing alcohol from corn uses more energy than it produces).

 

This topic needs more discussion.  At least for freshwater, harvesting algae for fuel seems to be feasible.  The Holtzapple group in Texas has a mixed alcohols process that may also be applicable.  Further 2/3 partners have signed on and commited research grants to start a new research project pertaining to the use of algae to clean waste water.  I am interested in uses for the algae that will be produced.

post #2 of 18

We have a introductory wiki here: Algae Biofuels

 

I'm very, very interested in this as well. Algae biofuels have been a bit of a darling of the cleantech investment world - and it hasn't really sat right with me in thinking you can get more energy out than you put in (particularly in those instances where artificial light is being used to grow the algae.) Some of the business models described in that wiki make a lot of sense to me (taking over environments that are overrun with algae and harvesting it.) But again - sounds incredibly energy intensive.

 

That said, the wiki says "Carbon Negative" not, energy positive, so maybe that's the core of the value proposition? The algae can absorb lots of carbon during development, then not release as much when burned?


Edited by deej - Tue, 06 Jan 2009 17:19:57 GMT
post #3 of 18
Quote:
Originally Posted by Whiteshell001:

I am interested in uses for the algae that will be produced.

 

Back in June 2007, Clayton B. Cornell wrote an article about the use of algae biofuel for aviation.  Here's a bit of the article:

 

The long term is where things get really exciting, and Boeing is extremely optimistic about the potential of algae:


With the potential for algae of providing 10,000 gal/acre/year, some 85 billion gallons of bio-jet could be produced on a landmass equivalent to the size of the US state of Maryland. Moreover, if these bio-jet fuels were fully compatible with legacy aircraft, it would be sufficient to supply the present world’s fleet with 100 percent of their fuel needs (fig. 13) as well into the future.”

Then...one year later, in June 2008, one of the Wired blogs published an article called Boeing Throws Its Weight Behind Algae.  Here's the first paragraph:

 

Boeing has become an algae true believer. The company has joined scientists, academics and industry types in founding the Algal Biomass Organization to "facilitate commercialization and market development of microalgae biomass specifically for biofuels production and greenhouse gas abatement" and put two of its executives on the board.

 

And more recently...I found this article from December 8, 2008 on USA Today:

 

Boeing, airlines and engine makers are testing jet fuel made from algae and a nonfood plant called jatropha.


Continental Airlines says it will test the biofuel on a demonstration flight, with no passengers, Jan. 7 in Houston.

 

So I guess we'll be hearing about the flight tomorrow!

 

And in other news, I just found out that the Algae Biofuels World Summit is taking place in San Francisco in March.

post #4 of 18

ah great. thanks whiteshell i was gutted when he said that. i'll read all that and get back.

post #5 of 18

The core issue I have with all these schemes is that it gives people the hope that someday, somehow, they can all drive their V8 trucks to the store to pick up pre-formed beef patties from cattle raised 2000 miles away, buns made from wheat grown 2000 miles away, frozen french fries from potatoes grown 2000 miles away, and for desert strawberries flown in from New Zealand, go home to a nice comfy air-conditioned house, watch a wide-screen plasma TV until they go to sleep under and electric blanket and do all that in a carbon neutral way.  It simple ain't ever going to happen, and the sooner we all grapple with the fact that our lifestyles are inherently unsustainable, no amount of fiddling with the source of the joules to live those lifestyles will make the least bit of difference (unless you can figure out a way to use solar energy directly, without first converting it into a hydrocarbon using photosynthesis). 

 

The physics professor ignores the energy costs in pumping water around, for instance.  Look up how much power it takes to run the Windscale Gap pumps.  He ignores the fact that production of fertilizer is expensive, and while he might be able to cash in at first on nitrate/phosphate available as excess from traditional agriculture, phosphate in particular is a mined resource, and if we start using it as a primary energy source rather than simply to grow food, it will become scarcer and scarcer until simple economics will drive us back to using fossil fuels.  He ignores the energy used in processing the algae (and in disposing of the tons and tons of algae that isn't extracted as oil), and he ignores the environmental costs that will be incurred if all of a sudden there are hundreds of millions of diesel vehicles on the road (diesels produce a lot of NOx, a primary ingredient in photochemical smog).  Couple the increase in NOx with an increase of volatile organics from the wide-scale cultivation of algae (which all produce some form of volatile organic to regulate their buoyancy) and you have the recipe for some killer continental scale smog episodes.  (I haven't looked closely, but if they are proposing to use algae that produce DMS as a by-product, they are blowing more smoke than a 1989 Dodge Caravan with bad rings.)  He also ignores more mundane issues, yet ones that will likely to turn out to be even more problematical like how do you only grow the algae you want?  If you pump in raw seawater, it will have all sorts of other critters in it.  Sterilizing water takes a lot of energy, what do you do if your huge oil-algae pond suddenly blooms with something else?  Or all of a sudden gets infested with jellyfish?

 

If we all can't face the fact that we need to learn how to live rich, full lives without driving everywhere, eating food from thousands of miles away, and relying on energy for recreation, we as a civilization are doomed.  It really is that simple.  Someone once linked to a George Carlin monologue where he made fun of modern environmentalists for not really being concerned for the environment, but merely wanting a nice safe place to drive their Volvo to in order to sip wine and watch the sunset.  I didn't agree with anything else he said, but algae/biofuels is a perfect example of what Carlin was talking about. 

 

A curmudgeon before my time. 

 

post #6 of 18

Dude, don't be dissing physics professors.

post #7 of 18
Quote:
Originally Posted by dana1981:

Dude, don't be dissing physics professors.

 

Wait until you hear me slag off on environmental scientists.  :-)

 

Ok, here's a joke I made up myself:

 

Q:  You get knocked out and kidnapped.  You wake up strapped in a chair with a man in a black faceless hood pointing a loaded crossbow at your forehead.  He asks you if you would rather spend the next 15 years trapped in a small, windowless room with a physics professor or an environmental science professor.  What is your response?

 

A:  Pull the trigger.

 

post #8 of 18
Quote:
Originally Posted by dana1981:

Dude, don't be dissing physics professors.

 



Edited by gcnp58 - Wed, 07 Jan 2009 07:12:17 GMT
post #9 of 18

Who the heck still uses a crossbow?

post #10 of 18
Quote:
Originally Posted by dana1981:

Who the heck still uses a crossbow?

 

Normally, it's a shotgun.  But this is a green website and I thought I would use renewable technology. 

post #11 of 18
Quote:
Originally Posted by stins:

And more recently...I found this article from December 8, 2008 on USA Today:

 

Boeing, airlines and engine makers are testing jet fuel made from algae and a nonfood plant called jatropha.


Continental Airlines says it will test the biofuel on a demonstration flight, with no passengers, Jan. 7 in Houston.

 

So I guess we'll be hearing about the flight tomorrow!

 

 

Indeed we will.

 

Continental Airlines on Wednesday became the first U.S. commercial carrier to conduct a demonstration flight powered in part by alternative fuels, though large-scale use of such fuel is forecast to be several years away.


The Houston-based company, the nation's fourth-largest airline, made the flight with a Boeing 737-800 that left from Bush Intercontinental Airport, its large hub. The flight took about 1 hour, 45 minutes and had no passengers.


Continental chairman and chief executive Larry Kellner said the goal was to analyze technical aspects of using biofuels, including effects on the plane's mechanical systems. In this case, the alternative fuel was derived from algae and jatropha plants and used in only one of the plane's two engines.


Kellner and others acknowledged it will likely be several years, a decade perhaps, before biofuels make up a significant percentage of the fuel used by Continental and other major carriers. At present, adequate supplies — and the facilities to make them — simply aren't available.


"The challenge will be to produce it in an efficient way in the quantities we need," Kellner said.


...Last week, Air New Zealand tested a passenger jet powered partially with oil from jatropha...


Continental said its flight was the first to use algae as a fuel source, and the first test involving a two-engine aircraft. One engine ran on a mixture of one-half biofuel and one-half traditional jet fuel. The other ran solely on jet fuel.

 

The biofuel exceeded specifications for regular jet fuel, and no modifications to the plane or its engines were needed.

 

...as production ramps up in the next few years, she predicts biofuel could amount to 3 percent to 5 percent of the fuel used by big airlines by 2012. By 2020, the level could grow to as much as 20 percent...

 

Pretty cool stuff.  To echo gcnp's sentiment, we need to decrease our overall air travel, but at least using biofuels will help matters.

post #12 of 18

This was in Earth 2 Tech about the flight:

 

The twin-engine Boeing 737-800 flew out of Houston with one engine operating on a 50-50 blend of biofuels and conventional jet fuel, and the other using all conventional fuel for comparison....After swooping over the Gulf of Mexico toward Louisiana, the Boeing returned to Houston’s international airport at 1:45 p.m. Boeing spokesperson Terrance Scott told us the engine with the biofuels mix ran more efficiently than the control engine: “It blew it out of the water,” he said.

 

And this is from a BBC article:

 

The 90-minute flight by a Continental Boeing 737-800 went better than expected, a spokesperson said.

post #13 of 18

interesting bit here on some plankton that bypass the phosphorous thing altogether, and some cyanobacteria that dont need either P or N. (sargasso sea)

 

post #14 of 18
Thread Starter 

I wonder how much of a penalty the N and P free cyano bacteria pay.  If I wasn't creating a Frankenstein, t would be tempted to put those genes to work in corn to reduce its fertilizer requirement.  There would of course be unintended consequences...

post #15 of 18

it seems to say the are using sulphur instead. i dare say that came in handy during the half dozen ocean anoxia events in the 4 billion odd years they have been around, but presumably isnt so efficient or all green things would use it.

post #16 of 18
Quote:
Originally Posted by gerda:

it seems to say the are using sulphur instead. i dare say that came in handy during the half dozen ocean anoxia events in the 4 billion odd years they have been around, but presumably isnt so efficient or all green things would use it.

 

I am not trying to get people mad, really I'm not, and I'm not a biologist so I might be wrong, but I don't think these cyanobacteria in question are completely free from using phosphate.  They are photosynthetic and live in aerobic conditions, and those cyanobacteria use something called the Calvin cycle, which uses phosphate.  The key to these particular guys is they require a lot less phosphate because they don't make their cell membranes out of phospholipids, instead substituting sulphate-based polymers. There are a lot of analogs of this in surface chemistry, where you can make sulfate- or phosphate-based detergents and surfactants.  I doubt these cyanobacteria living in the photic zone are using anaerobic respiration, since any free H2S present would be quickly oxidized abiotically by reacting with oxygen.

 

So, I think, what is going on is an example of natural selection, where an organism will adapt to local conditions, in this case substituting a sulfate-based membrane instead of a phosphate-based membrane, in order to conserve phosphate it does have for the more important process of photosynthesis.  I suspect if you put these critters back in a high-phosphate environment, gradually they would evolve to make phospholipid membranes like other cyanobacteria (maybe they already have the genes for doing so, requiring only to be exposed to more phosphate for those genes to be "turned on").  You see this a lot with bacteria, the example I know of was when they tried to genetically engineer e. coli to eat things like DNAPLs, PCBs and dioxins.  In the lab, they could get the microbes to eat the pollutants, but once they were exposed to real environmental samples, where there were other things to eat besides dioxins, the e. coli quickly reverted to eating anything besides dioxins, mainly because nearly anything is a better energy source than chlorinated hydrocarbons. 

 


Edited by gcnp58 - Wed, 25 Feb 2009 18:36:54 GMT
post #17 of 18

 awww gcnp, that is my fault. sorry about the biochar thing.

  re available diet, i go along with that - makes perfect sense. i suppose the sulphur thing would be useful in nutrient poor waters, maybe like for power station flue stripping?

post #18 of 18

Here is the link to the paper that discusses this.  It's kind of like I said, the algae use less phosphate, but they are not completely free of needing phosphate. 

 

http://www.nature.com/nature/journal/v458/n7234/full/nature07659.html

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