An Algae Bioreactor from Recycled Water Bottles

Step 7 Growth and Harvesting

After several days of sunlight and CO2 exposure, the algae are much denser. A French press is then used to extract the algae from the solution. The biomass of the dried algae can then be used as a fuel. As a by-product of this process, a large amount of atmospheric CO2 is sequestered.

By: Michael Fischer, Stanford University, mfischer @t stanford.edu

Comments

[dawgz031]

wow...this is a really nice step to reduce global warming when connected to the co2 scrubber....
the co2 scrubber gets the co2 in the air...then it is feed to the algae......and more  i saw some article about specific algae that can be cultured so it can be used as a fuel or something when it is processed...

but there are still questions about the process on how to transform algae to a fuel.....and how to extract co2 of caustic soda....

can some on please help me???
is there some one who know more about caustic soda and algae???

[Pe-ads]

Isn't the algae a good enough scrubber? :D

Plants are carbon-neutral, as all the CO2 that gets released when you burn it, gets absorbed when a new plant grows.

[tomas.savage]

fossil fuels are technically carbon-neutral as well. they were once plants that took CO2 from the atmosphere.

'carbon neutrality' doesn't apply to specific fuels, it applies to a process of removing the same amount of carbon from the atmosphere as you put in; for whatever good or damage that will do.

[gaiatechnician]

Perhaps it should read "biosphere neutral"? Adding fossil carbon to the biosphere changes the composition of the biosphere.
Thats the big problem.

[tomas.savage]

that would be a more accurate term since the biosphere remains equipoise.

as for that being the big problem, it's just the popular opinion at this time. popular opinions aren't always right.

CO2 is the primary plant fertilizer. i wouldn't be keen on removing too much of it. i would rather be worried about increasing the O2 supply as that is becoming dangerously low.

[squenchmeister]

By primary, do you mean limiting plant fertilizer? If so this is not true. Phosphorus and Nitrogen are limiting, and much less abundant. It is these nutrients that dictate plant growth, and of course carbon consumption. It should not matter how much carbon you pump at a photosynthetic organism. It will not take up any more than is dictated by these two nutrients. This is why forests would not be adequate carbon sinks.

I can see this becoming a problem as well. I would imagine that if done at an industrial level, companies only trying to make a buck will pump more and more fertilizers into their algae farms. These are the same chemicals that cause algae growths in streams and lakes when they run off from farms, lawns, etc.. Eutrophication is an environmental catastrophe which is destroying aquatic life and resources. The dead zone off the coast of New Orleans is a result of this process and others.

Judging on the fuel industry's track record, I am positive that it will end badly. It is a shame too. This seems like a great biofuel.

[nsupple]

The motivation for a company not too pump too many fertilizers into there algal solution would simply be the cost f fertilizers, that would be one of an algae farms biggest costs, and with money on the table you can bet the company will use just the right amount...Just a thought, perhaps one of these such farms could sit on the Mississippi river and simply feed their algae on the water in it, we all know theres plenty of fertilizers within

[squenchmeister]

You would think this is a major motivation, but industry, agriculture, and lawn care enthusiasts f**k this up all the time. This is why the Mississippi river is so rich in fertilizers. Every time anyone in the Midwest over fertilizes it ends up in the Gulf of Mexico. This is on top of all the other inefficiently used pollutants found in run off, and all the failing sewage treatment plants.

Lets not forget, it would be energy companies (BP, Exxon, Shell, etc.) doing the energy production. They seem to find a ways to screw up every last detail, and then fight tooth and nail to deny responsibility. Did it make sense for BP to construct a crappy well that failed, killed 10 people, lost millions of gallons of valuable crude oil, and lost them over 20 billion dollars? ...Somehow yes.

On the positive side, I think it would be a great Idea to use algae in this way. What about using algae farms as pretreatment for sewage? I wonder what other pollutants could be processed by algae into less harmful chemicals.

[nsupple]

You have good point there, i have often thought, if only we could someone convince farmers that it would be cheaper to use less..... On the waste treatment idea, I don't think algae works very well with waste treatment, the newest system for that (atleast where i live, near the mississippi) seems to be simply open air tanks for a period to kill of bacteria then draining across a large field that treats the water over a period until it washes in wetlands....Usually bacteria are better suited for such waste treatment

[squenchmeister]

http://www.oldcastleprecastonsite.com/algae_wheel_MAIN.html

Check out this site. The only problem with this is the algae use the CO2 produced by the bacteria, not by the later burning of the algae as fuel. Similar symbiotic relationships are found in eutrophication. Do the algae farms discussed in this instructable account for this? We are dealing with a more controlled environment, but how easily could the bacteria that eat dead algae contaminate the operation? If they did they would be the primary contributors of CO2 to the algae, and possibly decrease biomass yields. This might defeat the purpose.

[nsupple]

Interesting thought, In the case of this instructional obviously no bacteria is present, though also in reality the farmand process depicted in this instructable is only useful as a concept, since, in all likely hood the process above requires more energy than it produces....But back to the bacteria i really don't know, that would certainly be something to consider

[gaiatechnician]

Different types of plants take up CO2 at different rates. So this "fertilizer" gives some plants a big advantage over their neighbours. Result, extinction of the neighbour! It is also well known that if you boost fertilizer to a plant, you have to boost water supply too in drought areas.
Thank you, you have highlighted another of the destructive effects that we have as we boost the CO2 levels in the atmosphere and in the sea and fresh water bodies.

[hargee]

The increase of CO2 in the atmosphere decreases the number of stoma on the plant, thus decreasing the amount of water used by the plant. More CO2 equals happy planet. There was a time where the percentage of CO2 in the atmosphere was much higher than present day - that was the time of 3 foot dragonflies and ferns that dwarfed trees of today.

[tomas.savage]

yes. the percentage of oxygen was much higher as well.

there is a downward oxygen trend and if it goes below 15%, we could have a mass extinction event.

http://www.pnas.org/content/vol96/issue20/images/medium/pq1991262002.gif

[tomas.savage]

you haven't made much of a case. expanding on this logic; reducing CO2 would then give advantage to the plants that absorb CO2 more slowly thus driving the plants that absorb it faster to extinction.

fortunately, it doesn't work that way. there are many other environmental factors that determine the success or failure of a particular species. you even mentioned one of those factors... availability of water!

[campbellu2002]

And here is your transformation :D http://www.instructables.com/id/Convert-your-Honda-Accord-to-run-on-trash/

[Arano]

Na2CO3 + water +heat transforms to NaOH+co2 one of the easiest ways to transform your algae into somehting useful would be heating it up which would transform the algae into coal and burnable gases

[rbarba]

Here is a solution:
Dry up the algae then use biomass to make some pellets and finally use algae-pellets into a simple gasifier.
See for example this 'open-fire' gasifier: Luciastove at www.worldstove.com

It is possible to put aside most of the woodgas produced while the stove is burning only 5% of it.
Luciastove byproduct is biochar that is very good to enrich the soil.

http://www.youtube.com/watch?v=QsH_Gh-n2Mg

http://www.youtube.com/watch?v=Iy4XXD2N_nY

[yellowcatt]

As I see it there are three ways of using the algae for fuel:
1. Dry it and burn it.

2. Extract oil and burn that, you would still have biomass that could be either burnt or used as fertiliser. I suspect that to get a viable yield of oil will require particular varieties of algae and possibly careful balancing of the nutrients. To use the oil as a fuel it would need processing from a triglyceride to a methyl ester.
Craig Venter of Synthetic Genomics is working on bioengineered algae for this:
http://www.guardian.co.uk/environment/2009/jul/14/green-algae-exxon-mobil

3. Use the algal biomass in an anaerobic digester to produce methane, you would still have biomass left which could be used as fertiliser or dried and burnt as fuel.

All are possible but economic and technological factors will decide which are most viable, the algae oil has the most potential but also requires the most development to become viable.

[photis22]

this is a good design, being that it recycles the bottles, but a little impractical, the ones I make at home use 2.5 inch clear pvc tubing to grow the algae in, and a small fluorescent tube light inside which is protected by a water-proof cover, this provides maximum lighting, this design also includes a single powerful air-pump which provides high air pressure to feed multiple tubes, i run it on CO2 released from my hot water heater, but eventually you need to stress in to create maximum oil content, you also need to think about the species you should use, botryococcus braunii tends to have up to 50% oil content if treated properly, but only 2% of that oil, or oil in almost any algae can be used for biodiesel, another algae you might use is chlorrela which is a green algae know to have heavy nutrient levels, which can be made into fertilizer or health drinks , both spiceis can be purchased at utex.edu, the UT campus website, where one of the largest algae depositories in the world is located

[michaelkaer]

I live in Canada; would UTEX be able to ship it here?

[Nyxius]

Awsome tip! Thanks!

[nickk]

Hello Is algae oil suitable to be used as cooking oil ? does it have any strange taste or odor ? what color is the oil ?

[Nyxius]

algae is suitable for cooking. however, it does have a peculiar taste of it's own (like olive oil).  one important note is that if you plan on using your algae for this, you might want to consider using filtered humic acid from a compost pile instead of fertilizer. most fertilizers are not meant to be ingested and can make you very ill.

[___]

you wouldnt want to eat this because of the fertiliser that help the algae grow

[nickk]

i asked to see if the idea of producing commercial cooking oil out of farmed algae is possible.

[Mach5]

Yes algae oil can be used for cooking. I have no clue as to flavor but I have seen a video of a man eating a brownie made with it and another of researchers drinking it straight.

[remeika]

Can algae be grown in slowly moving water? If so, perhaps algae could be pumped from bottle to bottle and then through a central collection device that would skim off some algae, add fertilizer, and then pump a algae inoculation and new fertilizer back into the system... I realize that I need to stop hypothesizing about a new feature on this site and just build it!

[ampeyro]

i've been working on a idea like this, with polycarbonate (like the used in vindows), but i chosed the wrong algae

[Emilie06]

hey , do you know wich algae is the right algae for this progect?

[ampeyro]

i tried with haematococcus, the problem was that it turned into a brown and red paste, the other candidates are some chlorocoous, and maybe any kund of blue algae(i abandoned the project because the summer ended, and in the next year will continue it, i didn't find my notebook abut it , so the names could not be exact)(sorry for the ortography, i'm not native english)

[Nyxius]

this is a great tip, thanks. I've actually had a very sim idea to remeika's.  What if U used a chain bubbler like in the vid, but connected the bottles and then used the slow water flow. something convection powered? that way highest growth rate would be furthest from the harvesting source & would maximize absorption.

[auroraoutdoorlighting]

Yes, it can be grown in slowly moving water. In fact, watch this video:
http://www.valcent.net/s/Ecotech.asp?ReportID=182039

I think this guy is on to something big. Have you built anything similar? Would love to see it.

[p07gbar]

That is brilliant.

[amateur6]

I love it! But... "The biomass of the dried algae can then be used as a fuel." Isn't that a little "Step 2 -- then a miracle occurs"-ish? I guess I was hoping for a little more, teased by the word "bioreactor". After all, if we simply burn the dried algae (just as an example), all the CO2 sequestering we've done is for naught. Thanks though!

[Mother Natures Son]

Actually, burning it would probably release less CO2 than just letting it decay--I'm not certain, mind, but it seems like some carbon would remain sequestered in the ashes. Yes? No?

[OruKun]

Can i put the bio mass into my care in substitute for diesel? IF not what is the purpose or possibility for using this fuel source if uts in such smalll quantities?

[OruKun]

Sorry car, can it be used to fuel my car....

[Baiji]

Unless an organic medium is not burned completely, what you have left after a complete burn is all the inorganic material. The organic stuff burns away.

[red-king]

you are correct.... ashes are mostly carbon i believe...