BACKGROUND: A researcher at Ohio University’s Ohio Coal Research Center has developed a bioreactor that cleans up carbon dioxide emissions from fossil fuel exhaust with the help of heat-loving algae and hybrid solar lighting. David Bayless believes that the easiest way to eliminate CO2 from coal-burning power plants is to use the natural process of photosynthesis.
HOW IT WORKS: Bayless designed a box packed with blue-green algae spread onto vertical screens. The algae use the CO2 and water from the power plant to grow new algae, giving off oxygen and water vapor in the process. The organisms also absorb components of acid rain, such as nitrogen oxide and sulfur oxide. Building a workable prototype had its share of challenges. For instance, there was a problem of limited space – it just wasn’t possible to cover an area of around 100,000 acres with algae. So Bayless instead placed screens of woven fiber with algae vertically. Since algae need sunlight to thrive he brought in hybrid solar lights that collect sunlight with curved mirrors and then channel it through the reactor via optical fibers. And instead of trying to genetically modify any kind of algae, he found a species that naturally thrives in the hot springs of Yellowstone National Park, and does equally well in the exhaust of a power plant. A remaining challenge is how to dispose of the large quantities of algae produced by the bioreactor; one option is to collect it and use it as a biologically derived fuel.
ALL ABOUT ALGAE: Algae are relatively simple organisms that capture light energy through photosynthesis and use it to convert inorganic substances into organic matter. Photosynthesis is the process of producing sugar from sunlight, carbon dioxide and water, with oxygen as a waste product. Nearly all life depends on this complex biochemical process, which occurs most famously in plants, but also in phytoplankton, algae, and some bacteria, among other organisms. They are usually found in damp places or bodies of water. They vary from single-celled forms to complex forms made of many cells, such as giant kelps, which can grow as much as 65 meters in length. It is estimated that algae produce between 73% to 87% of the net global production of oxygen.
FACTOID: In 1796, Jean Senebier, a Swiss pastor and botanist, demonstrated that green plants consume dioxide and release oxygen under the influence of light.
The American Geophysical Union, American Society for Microbiology and the Optical Society of America contributed to the information contained in the TV portion of this report.