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GreenShift Licenses Bioreactor Technology for CO2 Scrubbing, Biofuel Production

The bioreactor process. Click to enlarge.

GreenShift Corporation, a business development company that is aggressively expanding its portfolio of renewable or sustainable energy companies, has acquired rights to Ohio University’s patented cynaobacteria-based bioreactor process for reducing greenhouse gases emissions from fossil-fueled combustion processes.

In concept, this is very similar to GreenFuel Technologies’ “Emissions-to-Biofuels” reactor; the implementation is, however, quite different.

Using $1 million in U.S. Department of Energy funding, assistance from Keith Cooksey, a microbiologist at Montana State University who had been researching bacteria found in the mineral hot springs of Yellowstone National Park, and a system of parabolic mirrors, fiber optic cables and slabs of acrylic plastic called glow plates developed by scientists at Oak Ridge National Laboratory, Dr. David Bayless at OU designed a bioreactor based on a newly discovered iron-loving cyanobacterium (blue-green algae), tentatively named Chroogloeocystis siderophila, that Cooksey discovered thriving in a hot stream at Yellowstone.

The algae grow in the bioreactor on membranes of woven fibers resembling window screens interspersed between the Oak Ridge glow plates. Capillary action wicks water to the algae, fiber optic cables channel sunlight into the glow plates, and ducts bring in the hot flue gas.

Spreading the cyanobacteria on membranes maximizes surface area for growth, minimizes water and optimizes the use of sunlight.

This enables us to take one square meter of sunlight and spread it out over 10 square meters of growth surface.

—Dr. Bayless

The algae use the available carbon dioxide and water to grow new algae, giving off pure oxygen and water vapor in the process. The organisms also absorb nitrogen oxide and sulfur dioxide, which contribute to acid rain.

A prototype is capable of handling 140 cubic meters of flue gas per minute, an amount equal to the exhaust from 50 cars or a 3 megawatt power plant.

Once the algae grow to maturity, they fall to the bottom of the bioreactor and are harvested for other uses—processing into biodiesel, used as feedstock for gasification, or for other purposes such as fertilizer.

GreenFuel, by contrast, uses an implementation of an air-lift reactor (ALR), which is a type of pneumatic contacting device in which fluid circulation takes place in a defined cyclic pattern through channels built specifically for this purpose.

The process, called photomodulation, rotates the algae in and out of the sunlight, rather than bringing the sunlight to the algae, as in the GreenShift-OU system. The GreenShift-OU system, however, should require less of a structural footprint to acquire the needed sunlight.

The GreenFuel ALR

The GreenFuel bioreactor consists of a riser tube or channel, a gas separator, and a downcomer tube or channel, applied in a triangular configuration. The difference in the apparent fluid densities between the riser and downcomer provides the driving force for liquid circulation.

GreenFuel inaugurated its first beta test at the 20MW MIT Cogeneration Plant, known as MIT Cogen, on 22 July 2004.

Independent testing documented that the beta system delivered 86% NOx reduction under all conditions, along with 50% CO2 reduction on rainy days, and 82% CO2 reduction on sunny days.




Interesting. The question is whether it could be scaled up to say a coal fired plant of several hundred megawatts. If many acres of arrays were needed and pumping used up a lot of the power output this could detract somewhat. Again for coal I'm not sure how this could work in with gasification since the bugs would presumably be cooked by high temperatures.


The flue gas can probably be cooled to accomodate the algae which can obviously withstand fairly high temperatures since they were found in yellowstone hot springs.


I read the "Hide the Pea" article and it makes the case that this process just transfers the release of carbon downstream. Even assuming this can be done on a large scale, one still needs to track what is being done with the created algae. If it's just being used as fuel in another process, then have we really accomplished very much with respect to cutting our CO2 production. On the other hand, why couldn't this secondary process (using the algae for fuel) also be subject to the same process we used to create the algae in the first place.


It does more then transfer carbon release downstream. If it is used for biodiesel in place of regular diesel then it reduces total carbon output. If it is used as energy at all it displaces other fuel sources and if those used carbon then it does reduce total carbon. As fertilizer it also reduces and temporarily sequesters carbon. Many fertilizers are made with lots of energy.


hmm, well no. It doesn't reduce total carbon output, it shifts the output in space and time. The best it can do is shift it to another place, later on. But not usefully far away (like another planet) or usefully later on (like 100 years, the time co2 remains in the air).

And as fertilizer it's an apples and oranges comparison. To get equivalent value you have to apply 200-500 times as much, instead of 200 pounds per acre of urea you need 20 to 50 tons per acre of compost. It's only 1% nitrogen and only 10%-50% of that is plant available in a timely fashion. That doesn't mean that compost/sludge etc. have no value but it does mean that it isn't any where near as useful as often assumed.


Algaes (and plants) basically work by converting sunlight, water and CO2 into biomass.

The point here is that presumably these algae grow much faster when fed with flue gasses since these have much higher concentration of CO2 than the atmosphere. Higher temperature might also help, of course.

So no, the amount of CO2 emitted by the power plant isn't ultimately reduced, but the entire process still results in less CO2 emissions per energy produced (electrical power of the plant is the same, add in the energy from the biodiesel), since you have to take into account the solar energy that the algae "harvested".


That's a questionable assumption since it takes energy to do all the conversions and transportation. It takes more energy as well as harvesting some sunlight. What's the net benefit? I suspect it is small or even negative when a full accounting is done. And still no carbon reduction.


Although it is correct to say that this process doesn't reduce the production of co2, the point is that we need to lock it up in solution rather than release it in the form of a gas. The Earth has lots of carbon- it's just not in the atmospere.


That's a questionable assumption since it takes energy to do all the conversions and transportation.

Why is that a questionable assumption? Yes, I read your comment but do you have any evidence to back it up?

Growing algae in big ponds for biodiesel production seems to be one of the few promising avenues for biofuel production on a massive scale.

If that approach can be made successful, certainly so can this one, which is essentially the same but has the additional benefit of operating in the aforementioned CO2-rich exhaust gas.


No evidence. That's why it is stated as a suspicion of your assumptions, your beliefs. It smells bad. This type of evasion of true costs is common so it would be a useful issue to investigate.


The only way you can tell whether it workd is by doing it, not talk and talk about it or analyze and analyze without going anywhere. It takes energy to convert( not create-you don't create energy) energy. Any form of energy consumes energy at all stages. The question is how much any form consumes. This is what makes different types pranctical or impractical.

If you are talking about adoption of this kind of technology in marginal land where land is cheap and cannot be used for anything else or where solar energy is plenty then it is within grasp. If scients are able to genetically engineer organisms that double productivity then that makes the system more appealing.

Vic Verghese

I think when people speak of reduction of CO2 emissions, they mean reduction when compared to fossil fuels. I guess the logic goes something like this: if you burn fossil fuel, you release an amount of (say x) CO2 into the atmosphere...this x amount was not originally present.

On the other hand, if you grow algae (or use other plant oils) for biodiesel, the algae (or plants) first consume x amount of CO2 during their photosynthesis (hence the atmosphere now has x less of CO2 = -x). Now, when we use the biodiesel prepared from these algae/plants, they again emit x amount of CO2 into the atmosphere, hence -x +x =0. That is, the net emission is zero. However for fossil fuels, the net emission is x.

I hope I'm not stating that is too obvious :-)

Vic, Castor Oil Online

Michael Foster

What are the energy efficiencies? Not much else is relevant as we to the POP [Peak Oil Production] of our bubble.

Very Respectfully,


E Manoharan

Dear Sir,

Looking forward to hear on option of buying the bioreactor from you.

E Manoharan


Talking about "carbon" misses the point entirely. Carbon is not a problem - the problem is carbon dioxide. If a process converts some carbon dioxide gas into some other type of carbon solid, then less carbon dioxide gas gets in to the air. If the carbon solid then gets burned it generates carbon dioxide again. But, if the carbon solid is not burned, there is a net reduction in carbon dioxide emitted into the air.


No offense intended here, all comments come from a place of reason...

I think you are all missing something really important here, and that is the difference between the chemical components of Algae Oil vs. Crude Oil.

Essentially, Algae Oil is 'Clean' vegetable oil (1 carbon bonds with 1 Hydrogen). Crude is dirty, containing lots of 'crap', most of which does not come out during refining, refining simple adds oxidizers to the mix for easier combustion.

As I understand it, burning 'clean' oil reduces carbon output significantly, when compared to burning 'dirty' oil from the ground filled with who knows what...

Also, many here are overlooking the by-products of Bio-Reactor operation, the major by-product is OXYGEN.

What you have here is a choice between growing new clean oil that creates oxygen as a by-product, therefore introducing the 'fix' our atmosphere needs as a part of oil production...

and the choice of burning 'dirty' oil out of the ground, which requires significant resources to locate, extract, refine, process, oxidize, distribute, and regulate. Additionally, there is no 'oxygen release' mechanism in digging oil out of the ground (or off shore), what those processes do is release more carbon.

When you factor in the FACT that crude MUST be located, extracted, refined, processed, oxidized, distributed, and regulated...

Well growing your own 'clean' oil isn't really a choice, is it. It's a must.

Add to this the FACT that Crude is a limited resource here on Earth, and that Algae oil can be grown perpetually as long as our sun is burning...

I can't think of a single thing Crude has over Algae Oil, save existing infrastructure and lobbying funds from wealthy capatilists.

Thanks for thinking over these points.
Sustainable Now! :)

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