Algae Used to Mitigate Carbon Dioxide Emissions

Greenshift Industrial Design Corporation (GIDC) has acquired technology that uses a blue-green algae that grows in the environment of hot flue gases found in smokestack.  The algae uses photosynthesis to combine water and the CO2 in the flue gas to grow additional algae and form oxygen and water vapor.  The organisms also absorb nitrogen oxide and sulfur dioxide, which contribute to acid rain.

GDIC obtained a non-exclusive license from Ohio University for its patented bioreactor technology for reducing greenhouse gas emissions from the smokestacks of fossil fueled power plants and exclusive rights to the technology for the air pollution control of exhaust gas streams from all other sources.

The reactor is composed of parabolic mirrors, fiber optic cables and slabs of acrylic plastic called "glow plates". The algae grow on membranes of woven fibers resembling window screens interspersed between the 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. By growing the algae on the membranes a lot of surface area is created.  Thus only a small amount of water is needed.  When the algae grows to maturity it drops to the bottom of the chamber where it can be harvested for use as fuel, fertilizer or a soil stabilizer.

A prototype of the technology was built that 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. In Bayless's bioreactor, algae grow on 60 by 120-centimeter membranes of woven fibers.

Dr Bayliss, director of Ohio's Ohio Coal Research Center, had conducted earlier research funded through Oak Ridge National Laboratories which indicated that normal algae would not grow at temperatures required to withstand the high temperatures of flue gas and that it could grow in low light conditions.

He realized that for the reactor to work he needed a carbon-hungry photosynthetic organism that could withstand the blistering temperatures of flue gases. Bayliss got assistance from Keith Cooksey, a microbiologist at Montana State University to find algae which could survive in the hot temperatures.  Cooksey had been researching bacteria found in the mineral hot springs of Yellowstone National Park.  He took some of Bayless's screens and placed them in a hot stream just outside of Yellowstone.  Whatever grew on the screen was a likely candidate.  The best candidate was a newly discovered iron-loving cyanobacterium (blue-green algae), which he tentatively named Chroogloeocystis siderophila.

To take advantage of the algae's ability to grow in low light conditions, Bayless turned to the scientists at Oak Ridge National Laboratory. They had developed a system using parabolic mirrors to collect sunlight and channel it along plastic fiber-optic cable. Ordinarily used to provide office or factory lighting, the Oak Ridge system was modified to use "glow plates," slabs of acrylic plastic that emit sunlight directly onto the bioreactor's algae screens. "The bacteria use only about 10 percent of full-strength sunlight," says Oak Ridge's Duncan Earl. "This enables us to take one square meter of sunlight and spread it out over 10 square meters of glow plates."

In some ways the technology resembles that used by GreenFuel, earlier post, that circulates algae through clear triangular plastic tubes to expose it to sunlight. Bayless likes his fiber-optic system better, however, because it has a smaller "footprint," needing only a tenth of the sunlight.  GDIC has a sister company Mean Green Biofuels that is building a biodiesel plant which could possibly use the algae to make biodiesel.

Resources:

Greenshift Acquires Rights to Patented Carbon Dioxide Reduction Technology, Press Release, December 12, 2005
Blue-Green Acres,  Patrick DiJusto, Sceintific American, August 29, 2005
Carbon Monoxide Mitigation through Controlled Photosynthesis, Ohio University,Department of Mechanical Engineering, Final report for period starting 09/01/1999 through 08/31/2000

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Comments

[Ecacofonix]

Thanks for the useful update. Oil from algae certainly appears to be an exciting area for the future...I found some more inputs on biodiesel & oil from algae @ http://www.oilgae.com

Let's hope algae can provide at least a partial solution to our energy needs

Ec