Leave the algae alone

While the first generation of biofuels is wreaking havoc on the environment and the food markets, the second generation is set to make things even worse.

Since it has become clear that ethanol and biodiesel made from food crops are doing more harm than good, the hope for finding a substitute for oil has shifted to algae and cellulose. If we can believe the advocates of this ‘second generation’ of biofuels, these combustibles will deliver way more energy than it takes to make them, without threatening the world’s food and water supplies. Upon taking a closer look, however, this is very hard to believe. They might even cause bigger problems than biofuels made from food crops. Maybe this time around we could sort this out before the damage gets done?

--------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------------------------

The biofuel disaster

Just two years ago, ethanol and biodiesel were heralded by almost everybody as a green substitute for oil. Today, almost everybody realizes that it is a foolish idea. Several studies have confirmed by now that it takes as much or even more energy to produce biofuels than they can deliver themselves. That’s because the crops have to be planted, fertilized, harvested, transported, and converted into fuel, all processes that require fossil energy. If one also takes into account the land that is cleared to plant the energy crops, biofuels have become an extra source of greenhouse gases, while they were meant to lower them. Biofuels also helped to fuel a rise in food prices by competing for agricultural land. And very recently it also became clear that their production poisons water bodies. In spite of this horrible record, both the European Union and the United States keep encouraging ethanol and biodiesel, mainly with the excuse that there is a 'second generation' of green fuels on the way, particularly cellulosic ethanol and algal fuel, which have no harmful effects. Sadly, this promises to be another dangerous illusion.

The cellulosic ethanol disaster

It is too early to say whether or not cellulosic ethanol can ever be produced with a net energy gain as a result – at the moment, it is impossible. We can only hope that scientists will never succeed, because what we do know for sure is that cellulosic ethanol will be an even larger threat to the world’s food supply than the first generation of biofuels.

Cellulosic ethanol is not made from the edible parts of crops, but from their stalks, roots and leaves. It can also be made of non-edible plants, like switchgrass. Therefore, at first sight, it seems unlikely that turning cellulose into fuel could present a danger for agriculture. However, there is one, literally invisible problem: the soil.

In nature, the concept of waste does not exist. The so-called “waste” that we plan to transform into fuel, is an essential element to keep the soil productive. Leaves, twigs and stalks are decomposed by underground organisms, which turn it into humus that can feed a next generation of plants.

If you take away this material, the soil will become less and less fertile until all you are left with is a desert. Of course, this process can be offset by adding more and more artificial fertilizers. But, here's the rub: fertilizers are made from fossil fuels. Almost 30 percent of energy use in agriculture is attributed to fertilizer production (both their production process and their content). This means that the more energy we produce from cellulose, the more energy we will need to keep the soil fertile. In short: this makes no sense.

The first generation of biofuels might endanger the world’s food supply, but that process is reversible. We can decide at any moment to change our minds and use the corn to make food instead of fuel. A similar deployment of cellulosic fuels would destroy our agricultural soils, without any chance to repair them afterwards. We will have mined the soil – a process that is irreversible, because when the soil becomes too exhausted, even fertilizers are of no help. Cellulosic ethanol is a dangerous illusion. And if you don’t believe me, ask any soil scientist.

Nevertheless, as was announced earlier this week, the first cellulosic ethanol plant is scheduled to start working in 2009 (even despite the fact that scientists agree that a net energy gain is not yet possible).

The algae fuel disaster

Also earlier this week, the first algal fuel production facility went online and that generated lots of excitement. If we can believe the hype, it will not take long before we drive our cars and fly our planes on fuel made by algae. The figures sound impressive. Algae are expected to be able to produce 10,000 gallons of fuel per acre per year (some say 20,000 gallons), compared to 700 gallons for palm oil and less than 100 gallons for corn and soy. Algae could also be used as a jet fuel and as a source to make plastics and detergents. Moreover, all this can be done with nothing more than sunlight and CO2 – and without the need for any potable water. If algal fuel plants are placed next to fossil fuel plants, as some companies are planning to do, the algae could even capture the CO2 from the emissions of the coal or gas plant. As one ecogeek summarized; “Welcome to the future, where single-celled plants eat our pollution and power our cars.”

--------------------------------------------------------------------------------------------------------

"There are very detailed figures on the amount of energy that will come out of the process, yet it is very hard to find any information on the energy and resources needed to make this energy output possible"

--------------------------------------------------------------------------------------------------------

This sounds too good to be true. If you take a closer look at the claims of these companies, essential information seems to be missing. They present very detailed figures on the amount of energy that will come out of the process, yet it is very hard if not impossible to find any information on the energy and resources needed to make this energy output possible. If algae don't produce more energy than it takes to produce them, driving cars on algal fuel does not make much sense. And if they also use resources that are needed by agriculture, the game might not be worth the candle. These are important questions, as we have learned from the ethanol and biodiesel fiasco, yet nobody seems to wait for the answers. Some twenty companies are planning commercial facilities to make algal fuel, often backed up by petroleum businesses and government subsidies (see here and here for an overview).

Water in the desert

Algae have higher photosynthetic efficiencies than most plants, and they grow much faster. Up to 50 percent of their body weight is oil, compared to about 20 percent for oil-palm trees. They don’t need fertile ground, so that they can be grown on soil that is not suitable for agriculture. All this sounds very good, but algae also need a few things, most notably: a lot of sunshine and massive amounts of water. To grow algae, you also need phosphorus (besides other minerals), an element that is very much needed by agriculture. (Update june 2008: Scientists warn of lack of vital phosphorus as biofuels raise demand.)

Design of a desert algae production facility : where does the water come from?

Most algae are grown in brackish or salt water. That sounds as if water is no issue, since our planet has not a shortage of salt water. However, just like solar energy plants, algae plants are best located in very sunny regions, like deserts. But, in deserts, and in very sunny places in general, there is not much water to find. That’s not a problem for solar plants, because they don’t need it. But, how are you going to get seawater to your desert algae plant? Check the websites of all these companies: not a word about it.

There are not that many possibilities. You can transport seawater to the desert, but that's going to cost you an awful lot of energy, probably more than what can be produced by the algae. You can also take freshwater from more nearby regions or underground aquifers and turn it into artificial seawater. But, you promised that algal fuel would not compete with food production. A third option is to put your algae plant next to the sea.

--------------------------------------------------------------------------------------------------------

"Algae need a lot of sunshine and huge amounts of water - how do you get seawater to the desert?"

--------------------------------------------------------------------------------------------------------

Now, there are places which are both close to the sea and have lots of sun. But chances are slim that they are as cheap and abandoned like deserts are. Most likely, they are already filled up with tourists and hotels, to name one possibility. So you might be forced to look for a less sunny place close to the sea – which inevitably means that your energy efficiency is going down. Which again raises the question:  will the algae deliver more fuel than is needed to make them?

How much water does algae production need? This information is nowhere to find. “A lot” would be a good bet for an answer, since it’s not enough to fill up the ponds or tanks just once. The water has to be supplemented regularly. Being able to produce 10,000 gallons of fuel per acre per year might sound impressive, but what really counts is how many gallons of fuel you can produce with a certain amount of water.

Contamination

The water issue is not the only “detail” that threatens the energy efficiency of algal fuel. Compared to other plants, the photosynthetic efficiency of algae is high – almost 3 times that of sugar cane for instance. Compared to solar energy, however, the energy efficiency of algae is very low – around 1 percent, while solar panels have an efficiency of at least 10 percent, and solar thermal gets 20 percent and more. So why would we choose algae over solar energy? One reason might be that it takes quite some energy to produce solar panels, while algae can be grown in an open shallow pond with nothing else but sunshine and CO2, which the organisms take from the atmosphere. You will still need energy to turn the algae into a liquid fuel, but other than that no energy input is needed.

However, these low-tech methods (comparable to growing corn, soy or palm trees to make ethanol or biodiesel) are being left behind for more efficient ones, using closed glass or polycarbonate bioreactors and an array of high-tech equipment to keep the algae in optimal conditions. Even though some companies still prefer open ponds (like the PetroSun plant that started production last week), this method has serious drawbacks. The main problem is contamination by other kinds of algae and organisms, which can replace the energy producing algae in no time. Ponds also need a lot of space, because sunlight only penetrates the upper layers of a water body. It's the surface of the pond that counts, not the depth.

The laws of physics

Transparent aquariums (called closed bio-reactors) solve all the problems of open ponds. These bioreactors can be placed inclined or suspended from the roof of a greenhouse so that they can catch more sun on a given surface. And since they are closed, no other organisms can enter. However, this method introduces a host of other issues. Bioreactors have a higher efficiency, but they also use considerably more energy.

First of all, you have to build an array of structures: the glass or polycarbonate containers themselves, the metal frames, the greenhouses. The production of all this equipment might consume less energy (and money) per square meter than the production of solar panels, but you need much more of it because algae are less efficient than solar plants. Moreover, in closed bioreactors, CO2 has to be added artificially. This is done by bubbling air through the water by means of gas pumps, a process that needs energy. Furthermore, the containers have to be emptied and cleaned regularly, they have to be sterilized, the water has to be kept at a certain temperature, and minerals have to be added continuously (because also here, just as with cellulosic ethanol, "waste" materials are being removed). All these processes demand extra energy.

Are algal fuel producers taking these factors into account when they claim efficiencies that are 100 times higher than the ones from biodiesel and ethanol? Only they know. It could be that these businesses are greatly overestimating their energy gains in order to attract capital. One of the few critics of algal fuel, Krassen Dimitrov, calculated that the figures of GreenFuel Technologies are defying the laws of physics. The company says that he is wrong, but his calculations surely look more convincing than the virtually non-existant information on their website.

Feeding algae from smokestacks

Several companies plan to hook up their production facilities to a fossil fuel energy plant, in order to capture the CO2 and nitrogen emissions and "feed" them to the algae. This method is hailed as a way of reducing greenhouse gases emitted by coal and gas plants, which is a ridiculous claim. It's very curious that this capturing technology is criticized when used in the context of "clean" coal, but applauded when it is used to make algal fuel. In both cases, capturing CO2 from smokestacks raises the energy use of the power plant by at least 20 percent.

--------------------------------------------------------------------------------------------------------

"It's curious that capturing CO2 from power plants is criticized when used in the context of 'clean' coal, but applauded when it is used to make algal fuel"

--------------------------------------------------------------------------------------------------------

That not only makes the technology very expensive, it also means that more coal or gas has to be mined, transported and burned. Algal fuel can even be considered a worse idea than "clean" coal. In the "clean" coal strategy, at least the CO2 is captured with the intention to store it underground. In the case of algae, the CO2 is captured only with the intention to release in the air some time later, by a car engine. Last but not least, capturing CO2 from power plants ties algal fuel production to fossil fuels. If we switch to solar energy, where will the algal fuel producers get their CO2 from?

Outsourcing energy use

Again, are algae producers considering the extra use of energy that arises by the capture of the CO2 when they claim that algae can deliver 100 times more energy than first generation biofuels?

This seems very doubtful. All these claims have one thing in common: they focus only on a small part of the total energy conversion chain.

A very good example is the story of Solazyme, a company that cultivates (genetically modified) algae in non-transparent steel containers, similar to those of breweries. In this case the algae do not get their energy from the sun, but from sugar that is fed to them. This method, says the company, makes them produce 1,000 times more oil than they do in sunlight, because sugar is a much more concentrated form of energy than sunlight.

But, where does the sugar come from? The researchers simply leave that part of the process out of their calculation, and nobody seems to care. Growing sugar cane of course requires significant amounts of energy, land and water. In fact, by turning off photosynthesis, the researchers eliminate the only advantage of algae compared to other plants: their higher energetic efficiency. The photosynthetic efficiency of sugar cane is not even half that of algae, which means that if the whole energy chain would be considered, this process can only be worse than that of algae produced in transparent bioreactors.

Stop this madness

While the first generation of biofuels is wreaking havoc on the environment and the food markets, the second generation is getting ready to make things only worse. Behind the scenes, scientists are already working on the third generation, whatever that may be. In five or ten years time, when it becomes clear that algal fuel is devouring our water and energy resources and cellulosic ethanol is mining our agricultural soils, we will be promised that the third generation will again solve all the problems of the previous generation.

--------------------------------------------------------------------------------------------------------

"Producing fuels out of food crops could be a useful and sustainable solution if our energy consumption would not be so ridiculously high"

--------------------------------------------------------------------------------------------------------

It might be a better solution to bury the whole idea of biofuels right here and now and focus on the real problems. The trouble with biofuels is not the technology, but our unrealistic expectations. Producing fuels out of food crops could be a useful and sustainable solution if our energy consumption would not be so ridiculously high. All our habits, machines and toys are built upon an extremely concentrated form of energy, fossil oil, and trying to replace that fuel with a much less concentrated form is simply impossible. In 2003, Jeffrey Dukes calculated that 90 tons of prehistoric plants and algae were needed to build up one gallon of gasoline. We burn this amount of organic material to drive 25 miles to pick up some groceries.

In one year, the world burns up 400 years of prehistoric plant and algae material. How can we ever expect to fulfill even a small part of our fuel needs by counting on present plant and algae material? The problem we have to fix is our energy consumption. Biofuels, from whatever generation, only distract us from what really should be done.

© Kris De Decker (edited by Vincent Grosjean)

Main page / Site map / Search / Comments (18) / Subscribe to feed or email
 
--------------------------------------------------------------------------------------------------------

Related articles :

Bring back the horses

Why bottled water is good for the environment

Is ecotech the new asbestos?

Nuclear reactors, but no fuel 

Carbon sequestration : bury the idea, not the CO2

The ugly side of solar panels

Urban windmills harm the environment

Life without airplanes

Why the electric car has no (wireless) future

Main page / Site map / Search / Subscribe to feed or email
-------------------------------------------------------------------------------------------------------- 

Comments

[Kris De Decker]

(18)

Ah, yes. Just like floating cities and floating energy islands, right? You solve the water issue, that's true. But the cost of your algae farm will skyrocket. And so does the energy penalty of your installation. Because you need not only build the factory itself, but also a platform to keep it afloat - a platform that can survive a severe storm, and a factory that can withstand the corrosive marine environment. Technically this must be possible, but: good luck with the business plan.

[Michael]

(17)

Floating Algae farms.

[Kris De Decker]

(16)

Pell, more specific information on the old techniques you are talking about is welcome, I am all ears.

Concerning your first point: I am afraid it is not that easy. You say the residue is fertilizer, but this remains to be seen:

http://www.sciencedaily.com/releases/2008/07/080712143153.htm

Scientists are investigating the possibility of using the by-product as fertilizer, but there are difficulties.

[pell]

(15)

OK, I take any plant/algae and ferment or process it to remove either ethanol or hydrocarbons. The residue is fertilizer. The manure remains. Why have you assumed it will not return to the soil?

There are many farming techniques with reduced fossil fuel impact and that our fore-fathers used with great success. We can and will relearn them. As well, run the tractor on bio-fuel and you have further leveraged your crop.

Already in Africa old techniques are being relearned and water conserved. Many of these marginal crops use land and species not fit for food production but which provide a cash crop for otherwise impoverished peoples.

While the present 'green hype' is full of as much manure as the products of which we are speaking, the doomspeak won't help either.

All these fuels are just a chemical storage of energy. The key is to get it from the sun to the fuel with a minimum of collateral damage.

[Kris De Decker]

(14)

That's true. My point is not that it is impossible to make algal fuel because the necessary land does nowhere exist. But finding the right place for your algal fuel factory is an issue, something which is completely left out of the promo-talks.

Australia is a good example. Of course, you would be again dependent on imported fuel, be it from another country (I agree that Australia is not comparable to Iraq, but it's yet another advantage of biofuels that disappears).

Also, I hope not that every undeveloped piece of land near the sea will become a biofuel plant. If we want to run not only cars but also planes on algal fuel, we are going to need quite some facilities.

[dan]

(13)

Just because the US might not have an abundance of sunny, coastal areas without development doesn't mean the rest of the world doesn't. What about the possibility of algae farms in Australia, Peru, Chile, Baja California?

[Kris De Decker]

(12)

God bless America

[Uncle B]

(11)

No one single magic wand solution is going to cover all the energy problems faced by todays world. All of the solutions, combined with any newer 21st century breakthroughs are candidates. Any combination of them along with the inevitable lifestyle changes that are occurring as we speak will accommodate the conditions in the world. It is a rare and welcome opportunity for capitalist/entrepreneurs when life-forces cause shifts and openings are created in the market place for new and better products and systems. Thank God for anxious predatory rabidly hungry capitalists and greedy investors. Because of them, we will get the best of the best and suffer the transitions occurring in the world less than the people in other countries.

[Kris De Decker]

(10)

Is that all you can come up with after one week of ruminating? If my claims are broken, prove it. We are waiting.

[Engineer-Poet]

(9)

Then your blog software is as broken as your claims.

[Kris De Decker]

(8)

I am not censoring anything, my blog software just doesn't give me the possibility to make the changes you dictate me.

I don't understand why you can't publish your reaction as it is. As you can see in other comments, posting links is not a problem.

[Engineer-Poet]

(7)

Great. You're even censoring the escaped less-than character.

I've got a long response all written and saved. I'm not going to go and re-write it to be clear with all the crippling exclusions of blockquotes, links and everything else. I've already done my bit, and I'll be damned if I'll kowtow to a petty dictator who hypocritically demands facts and figures while providing none of his own. You aren't worth the effort.

[Kris De Decker]

(6)

Come on man, if you really have something to say, just using *words* will do it

[Engineer-Poet]

(5)

I'll respond to you when you fix your infernal software so it stops censoring essential HTML tags such as:
blockquote>
ol>
li>

I refuse to try to work around such crippling restrictions on clear and precise expression.

[Kris De Decker]

(4)

Thanks for your reaction. But, in spite of it being very lengthy, you don't write a word about the essence of my argumentation: water consumption.

You write several paragraphs claiming that I am wrong on phosphorus, while that is just a detail (and if you don't agree on that, I think it's more useful to react on the page that I am linking to as a source)

Confucius obviously did not experience the ethanol and biodiesel flop, as well as many other ecological disasters caused by man "doing it".

I prefer a quote from Michael Zimmerman: "Too many of us blithely assume that we need not deal with the base causes of our environmental problems becaue soon-to-be-discovered technological solutions will make those problems obsolete." (Science, nonscience and nonsense, 1995)

[Engineer-Poet]

(3)

For an article based on the assertion that the advocates of algal fuels haven't shown their work, the author shows remarkably little work.

The criticisms of the hardware-heavy schemes are apposite; several concepts have failed to make the jump to pilot-scale for exactly the reasons given. But isn't this just the "sorting out" which the author implies isn't being done? Confucius say, man who say something is impossible should stand out of way of man doing it.

It's true that solar energy is highly diffuse, and a worthwhile collector must either be very efficient or very cheap. It's also true that the productivity of single-celled algae is ten or more times that of the average annual crop plant, and perhaps a hundred times as much as the typical tree. Many of these archaebacteria are also nitrogen-fixers. The claim about phosphorus implies that it is used up, which is silly. The fuels and chemical feedstocks we might produce would include alcohols, esters and methane; none of these contain phosphorus, or nitrogen either.

Living stuff is composed mostly of proteins, carbohydrates and fats; after separating the fats for diesel fuel and the simple carbs for fermentation, the remaining proteins (plus byproducts of yeast from fermentation) would be perfectly good food for something. The phosphorus and nitrogen waste products from the animals would be ready to feed algae again. Another possibility is to use the algae to concentrate phosphorus from sewage and animal waste and close the loop on agriculture. We need to treat these effluents anyway, and producing fuel as a co-product would make everything easier. Doesn't this fit completely with the philosophy of "no wastes in nature"?

Getting back to taking close, hard looks at things, there are several different analyses required: one for open-pond systems growing wild algae, one for open ponds growing halophytes (a great possibility where there is brackish water or saline runoff which cannot be returned to local waterways), and closed systems using whatever. A simple closed system might have greenhouses made of polyethlyene tubing, held up by air pressure.

Let's take a cursory look at the last one. If such a system produces 10,000 gallons of ethanol per acre per year, that ethanol could be dehydrated to ethylene and polymerized to make enough polyethylene to cover 9 acres with new heavy half-millimeter sheet. If the system produced 10,000 gallons of vegetable oils instead, the possibilities would be greater. Then you've got the byproducts, many of which would probably be edible; if the breakdown came to 75% fats and ethanol (10,000 gal/ac/yr, ~30 metric tons if it was all ethanol) and the remaining 25% (10 tons) was used for fish food at 50% efficiency, that's 5 tons of fish per acre in addition to the fuel. I don't know about you, but 5 tons of fish would supply most of my extended family with their fill.

The future doesn't have to be dark.

Calculations:

10000 gallons = 37854 liters = ~30,000 kg C2H5OH (MW 46)

30,000 kg C2H5OH -> 11,700 kg H2O + 18,300 kg C2H4

.5 mm thick = .5 liter/m^2 = .5 kg/m^2 = 2026 kg/acre

[Kris De Decker]

(2)

Thanks for the tip, Michael. This zinc-idea is new to me, looks interesting, I will surely investigate it.

[Michael]

(1)

Okay,I'm in total shock.My last hope's been dashed!
I thought algae held out the promise of an ecologically sound future.Likewise for cellulosic ethanol.I guess the only hope left is to get really serious about conservation,and the production of hydrogen via solar towers which reduce zinc oxide to the elemental metal.The resulting powdered zinc can then be safely transported,and then converted to hydrogen on site when reacted with water,and the zinc oxide byproduct can be recycled again.See the following website for the details: http://tinyurl.com/5aqe36