Algae: The scum solution

June 27, 2011 5:23 PM

When you imagine the crops that will provide biofuels, what is the first image that enters your mind? A field of corn or sugar cane? Maybe you should be picturing pond scum instead.

Algae, the organisms that cover ponds with a green film and turn tides red, are a promising source of biofuels. Researchers estimate that algae could yield 61,000 litres per hectare, compared with 200 litres to 450 litres from crops such as soya and canola. And, as the price of petroleum soars, that sort of yield is drawing interest from government and industry alike. Last year, the US Department of Energy gave US$44 million to create a research consortium to advance the technology for turning algae into fuel.

posted by Blasdelb (30 comments total)

A sea of green
posted by Blazecock Pileon at 5:32 PM on June 27, 2011

"An implicit and almost universal assumption of discussions published in professional and semipopular scientific journals is that the problem under discussion has a technical solution. A technical solution may be defined as one that requires a change only in the techniques of the natural sciences, demanding little or nothing in the way of change in human values or ideas of morality."

- Garreth Hardin, 'The Tragedy Of The Commons', 1968.
posted by mhoye at 5:32 PM on June 27, 2011 [7 favorites]

When I think pond scum, I imagine standing on a wooden footbridge in the middle of swampland. I think of that muddy swamp smell. I do not think of pristine, coiling aquamarine trenches. I'm sure they're pretty nasty up close, but that's the magic of the wide shot.
posted by Uppity Pigeon #2 at 5:37 PM on June 27, 2011 [1 favorite]

When I think of pond scum, I think of the Grimsby pubs I used to endure in my youth.
posted by Decani at 5:44 PM on June 27, 2011

I've been reading about this area of study for probably six or seven years. It shows a lot of potential and I hope it matures enough to be useful.

Interestingly, I just finished watching a show on the potential of using termites to produce hydrogen. It seems that termites don't eat wood, but actually use a host of bacteria in their guts to break down cellulose into sugars they can use. Hydrogen is the byproduct - a single termite can produce 2 liters of hydrogen from one sheet of paper. Just think, if we could devise a simple way to make fuel from cellulose our energy shortage issues would essentially disappear.

Thinking outside of the box. Looking for solutions in nature. Pretty cool.
posted by Benny Andajetz at 5:46 PM on June 27, 2011 [2 favorites]

mhoye: "An implicit and almost universal assumption of discussions published in professional and semipopular scientific journals is that the problem under discussion has a technical solution. "

Yeeeeeeup. You're damned right I'm hoping there's a technical solution. Because if we're hoping for a solution based on changing people's values... well let's just say I've grown accustomed to the luxuries of modern life, such as: reliable power, sanitation, transportation, and you know food.
posted by danny the boy at 5:48 PM on June 27, 2011 [3 favorites]

Science sailed beyond the sun until it found the sea of green?

Groovy.
posted by cmyk at 5:50 PM on June 27, 2011 [1 favorite]

For years I've been hoping that genetically modified algae (or something similar) would provide the (maybe even clean-burning) liquid fuel of the future.
This kind of science is so very new in the grand scheme of things, I think it's reasonable to hope. Feed a silkworm some leaves, and you get silk. Feed a cow some grass, and you get milk. We're only just starting to catch up with nature. As yet there's no reason to think we couldn't feed algae some sunlight and get reasonably eco-friendly fuel.
posted by uosuaq at 5:51 PM on June 27, 2011 [1 favorite]

This makes way more sense, as far as algae use goes, than that part of Battlestar Galactica where they find an algae planet and then somehow magically turn that algae into, like, noodles and cereal and shit.
posted by NoraReed at 5:55 PM on June 27, 2011 [1 favorite]

So let's see here. 61,000 liters per hectare is equal to 6,521 gallons per acre (according to Google conversion).

There are 42 gallons in a barrel of oil, so that works out to 155.27 barrels of oil per acre. The world consumes 31.5 billion barrels of oil per year, so in order to match that we'll need to farm a little over 207 million acres of pond scum.

For reference, the state of Texas is 172 million acres.
posted by fremen at 6:21 PM on June 27, 2011 [1 favorite]

I would happily donate Texas to this effort...that gets us well over halfway there!
Besides, I think this kind of thing can get *much* more efficient over time. But in the meantime...yeah...Texas.
posted by uosuaq at 6:29 PM on June 27, 2011 [3 favorites]

"I would happily donate Texas to this effort...that gets us well over halfway there!
Besides, I think this kind of thing can get *much* more efficient over time. But in the meantime...yeah...Texas."

Texas doesn't have much water, which is if anything a more limiting reactant than sunlight

Detailed in TFA
posted by Blasdelb at 6:32 PM on June 27, 2011

Fair point, Blasdelb, but not really where I was going with my comment. Granted, it wasn't a very civil comment.
posted by uosuaq at 6:36 PM on June 27, 2011

Algae is cool and fascinating and worthy of study.

But as an innovative solution to the oil shortage, it's limitations are obvious. The water required to produce the algae to sustain the level of fuel we need (to live in the house that jack built) is a real concern. I'm not willing to sacrifice any of our rapidly dwindling fresh healthy water supply, necessary for our very survival, just so we can all keep on trucking.
posted by misha at 6:58 PM on June 27, 2011 [1 favorite]

I have been following this industry for a while, but even the cellulostic ethanol producers are struggling. Federal mandates and subsidies don't seem able to move these technologies to commercial scale. The yeilds of algae per acre are theoretical and have not been proven in real conditions.

Most of the early stage companies have realized that fuels are too difficult to make money off of at this point and instead are going after more premium markets like cosmetics and chemical supply.
posted by humanfont at 7:37 PM on June 27, 2011 [1 favorite]

Algae is indeed cool especially given that there is a decent arsenal of tools to genetically modify them to make stuff we want. This is going to be a much bigger player, in the long run, than photovoltaics (unless you can figure out how to prevent people from stealing banks of Stirling engines for the metal/parts).

The problem is the water. Algae can be engineered/selected to tolerate brackish water, sure, or otherwise "bad" water (say, grey or even black water) and probably even to decrease water evaporation. But what about mosquitos? I guess a workaround could be to alter the water (pH, maybe) to discourage mosquito larva and engineer/select the algae to tolerate those conditions.

I'ld love to see a system for urban deployment that mixed algae and shrimp/prawns a la Gibson's Count Zero. I've seen nano systems involving 3x 55 gallon barrels with rice and tilapia/freshwater shrimp (and algae).
posted by porpoise at 7:45 PM on June 27, 2011

Algae have been found to promise everyting. From curing cancer, feeding the hungry, now fueling cars. Yet, nothing has ever worked out.

If I think biofuel then I thin cellulose and 2nd generation biofuels but not algae.

Yet, CO2 absorption by fertilizing oceans with iron seems to be an interesting take - at least if you believe in CO2 induces climate change.
posted by yoyo_nyc at 7:59 PM on June 27, 2011

*snorts*

As if those subsidized ethanol companies have any reason to stop supporting corn.

Nice idea, you read it here, and it will disappear like many other pie in the sky ideas.
posted by BlueHorse at 8:06 PM on June 27, 2011

Luckily we don't have to rely on "the promise" of pie-in-the-sky tech based on shaky numbers (ala Wall Street, ala "fusion!!") for real solutions in a timeframe that will let many, but far from all, of us enjoy "the luxuries of modern life" we've "grown accustomed to".

Those luxuries were bought at a cost of squandering millions of years of accumulation in a century at a disastrous cost to the environment. If we're going to try to duplicate that level of squandering in a couple of decades, we'll need to pull many, many rabbits out of many, many hats. Especially considering that we need to bicker at least that long to accomplish much, much smaller feats (70 years for the St. Lawrence Seaway, for example).

I would not bet on that happening. Therefore we'll need to entertain the strong possibility that what we want and what we need are two different things - unless we're prepared to sit back and watch billions die for our "luxuries" we've "grown accustomed to".
posted by Twang at 10:16 PM on June 27, 2011 [2 favorites]

"But what about mosquitos?"

Agitate the water - wave machines, aeration, etc. Mosquito larvae won't tolerate that, and it'd benefit the algae (agitated water = increased surface area = increased oxygen interchange).

And an area 1½ x Texas to supply the world's current oil needs? Sounds quite low to me, though I haven't checked the numbers. If it works out, it'd be a bargain - that's only 0.6% of the world's land surface area (excluding Antarctica). By comparison, arable land is about 30%, snow/ice-covered & deserts make up about 20% each, and reasonably flat land without topsoil is about 10%.
posted by Pinback at 10:56 PM on June 27, 2011

For comparison, today's high-end solar cells are more efficient than photosynthesis's theoretical max. Liquid fuel is kind of nice, assuming you don't want to lift a finger on infrastructure (other than flooding Texas with algae). But I think it's reasonable to assume a fair amount of oil usage can be converted to electricity with relatively little pain. The idea that we would just map existing fossil fuel use to algae, 1 for 1, is weird.
posted by ryanrs at 12:32 AM on June 28, 2011

Wishing and hoping, but we might want to have a bit of a contingency on the off chance the algae system doesn't work out. Or is that the fusion reactor program?
Perhaps a contingency that works would be good too.
posted by bystander at 1:48 AM on June 28, 2011

Huh. I just noticed the related post list below:
Liquid Hydrocarbons on Demand? January 19, 2011
Fly the biofuel skies… January 9, 2009
Biocrude April 18, 2008
Note to self: Invest in Algae November 29, 2006

Shouldn't these guys be pumping oil by now?
posted by bystander at 1:49 AM on June 28, 2011

Wishing and hoping, but we might want to have a bit of a contingency on the off chance the algae system doesn't work out.

Jellyfish!

Last year, some Swedish researchers extracted green fluorescent protein from jellyfish, added it to electrodes they'd embedded in silicon dioxide (the GFP actually forms protein strands between the electrodes to make a circuit), then zapped the whole setup with ultraviolet light to create an electrical charge. So now they have a bio-powered fuel cell.

It only takes a drop of GFP to power the cell and it's cheaper and more reliable than solar cells ("Gratzel cells" need titanium dioxide to mimic photosynthesis for solar power and that's expensive).

The problem is, we're talking about nano levels of electrical current, so we'd need a lot of jellyfish. But, as it happens, there's actually an overpopulation of jellyfish in the world's oceans, and getting rid of some jellyfish could help restore the natural balance. So using this power source is very green, too.
posted by misha at 2:38 AM on June 28, 2011

So let's see here. 61,000 liters per hectare is equal to 6,521 gallons per acre (according to Google conversion).

There are 42 gallons in a barrel of oil, so that works out to 155.27 barrels of oil per acre. The world consumes 31.5 billion barrels of oil per year, so in order to match that we'll need to farm a little over 207 million acres of pond scum.

For reference, the state of Texas is 172 million acres.

Purely out of numerical pedantry, your figures aren't equivalent: you quote world oil consumption as volume per time unit, then provide a volume (and associated acreage) of pond scum without taking into account its rate of production. Having briefly had to look after someone's garden pond, it seems that in order for it not to get choked up with yuck, you need to scoop the green slime out every week or so in the warm season (and how cold does it really get in Texas?*). This suggests to me that your figures should actually require 207 million / 52 acres per year, i.e. about 4 million acres, an area which is totally capable of being fitted into Texas without any unnecessary disruption to urban areas.

*Apparently there is a certain amount of winter at times. Pond scum is likely to be unhappy with this, with associated reductions in production capacity. This is totally Someone Else's Problem. As is the above-mentioned issue of Texas not having all that much water.
posted by Lebannen at 3:26 AM on June 28, 2011 [1 favorite]

Some algae skepticism. The 61,000 figure is not very reliable, an extrapolation from laboratory conditions that no one has produced anything near like in the field.

Overall, there's a push me-pull you aspect to algae production which the article mentions but rather glosses over, and I don't think it's going to be so easy to solve. Fast-growing strains means thicker scum which lowers the production level for a large proportion of the acreage. The conditions which spur lipid production inhibit growth. Growing algae in open ponds is expensive (well north of $50 a barrel, as Rapier points out); the cost of growing it in photobioreactors is ten times that.

it seems that in order for it not to get choked up with yuck, you need to scoop the green slime out every week or so in the warm season (and how cold does it really get in Texas?*).

I believe the 61,000 is per year. According to John Brennerman, a researcher who's spent his career studying algae and whose paper is linked in the Rapier article, you have to harvest the stuff every other day as it is. He also says that current production methods for algae ---- how much oil you'd get if you took some of the best lab strains of oil-producing algae and managed to grow them using the best commercial production methods available --- is about 14,000 liters per hectacre per year, or 1,500 gallons per acre per year, which doesn't cover costs. He think you might get it up to 5,000 gallons, eventually (48,000 litres per acre per year), but "many productivity claims and projections currently being made exceed this level and are clearly unobtainable; some even violate theoretical limits."
posted by Diablevert at 4:40 AM on June 28, 2011 [1 favorite]

Purely out of numerical pedantry, your figures aren't equivalent: you quote world oil consumption as volume per time unit, then provide a volume (and associated acreage) of pond scum without taking into account its rate of production.

Lebannen, I made the assumption that the 61,000 liters per hectare was per year. The rest of my numbers follow from that assumption.
posted by fremen at 5:45 AM on June 28, 2011

Because if we're hoping for a solution based on changing people's values... well let's just say I've grown accustomed to the luxuries of modern life, such as: reliable power, sanitation, transportation, and you know food.

You and everyone else (including me), and even more on the way from the third world.

Yeah we can either try to wish away / legislate against human nature (in vain) or work as hard as we can on the chance that technology will save us / delay the inevitable.
posted by ZenMasterThis at 6:11 AM on June 28, 2011

Yeah we can either try to wish away / legislate against human nature (in vain) or work as hard as we can on the chance that technology will save us / delay the inevitable.

Isn't there also the possibility that we could exercise our free will and choose a simpler, less resource-intensive way of life? That we could decide that it's important to take care of the environment that enables our existence and act on that belief? That we could stop looking for something to save us from ourselves, stop despoiling our planet, and start working together to create/live a tolerable or even enjoyable existence that won't kill our host?

I really like technology and all, I've been a big proponent and recipient of its benefits in many ways throughout my life, and I work in IT, but frankly, the hope that technology is going to save our society from the mess we've created with technology is far more idealistic than the idea that we, as people, can change the way we live.
posted by nTeleKy at 9:07 AM on June 28, 2011 [2 favorites]

Isn't there also the possibility that we could exercise our free will and choose a simpler, less resource-intensive way of life? That we could decide that it's important to take care of the environment that enables our existence and act on that belief? That we could stop looking for something to save us from ourselves, stop despoiling our planet, and start working together to create/live a tolerable or even enjoyable existence that won't kill our host?

Based on my observations of human nature: No.
posted by ZenMasterThis at 12:24 PM on June 28, 2011