Keith has built a tower, 4 feet wide and 20 feet tall, with a fan at the bottom that sucks air in. Keith expects the air coming out at the top to have approximately 50% less carbon dioxide than the air coming in.
The tower features in an episode of Discovery Channel’s new “Project Earth” series on TV. The series has the largest budget of any in Discovery Channel’s history, and it may eventually attract a global viewership of more than 100 million.
The episode on Keith’s research has already aired in the U.S. - if you're missed it, you can watch it on Discovery Channel’s website, at: http://dsc.discovery.com/tv/project-earth/project-earth.html - click on “Episodes.”
If the program hasn't aired in your country, you may not get access to the online episode, but you can read more at: http://dsc.discovery.com/tv/project-earth/lab-books/fixing-carbon/guide1.html - also click on the links under "MORE CARBON".
The picture below describes the Big Picture of recycling, in which I envisage aviation to fund CO2 air capture. When talking about recycling, most people think about recycling of industrial products only. They may also see composting of organic waste as a (second) way of recycling. Instead of composting, I actually envisage organic waste to be burned by means of pyrolysis, in order to produce agrichar and hydrogen. I also envisage a third way of recycling that includes removing CO2 from the air. This CO2 could also be used for the production of agrichar and for commercial purposes such as to enrich greenhouses and for the production of building material, carbon fiber, etc. Furthermore, this CO2 could be used as fuel for aviation.
To tackle emissions by aviation, we can switch to airplanes and helicopters that are powered by batteries and hydrogen, or switch to fuels other than fossil fuel. Growth of algae could be assisted by such captured CO2, which could also be turned directly into fuel.
By financially supporting air capture of CO2 and the use of such CO2 to produce fuel, aviation could close the circle of this third way of recycling. This could make aviation environmentally sustainable. Since government is such a large user of aviation (both the military and civil parts of government), it makes sense for the government to start funding such air capture as soon as possible. An international agreement, to be reached in Copenhagen in 2009, could further arrange for the proceeds of environmental fees on commercial flights to fund such air capture and its use for fuel.
Further links:
http://dsc.discovery.com/tv/project-earth/explores/carbon.html - Discovery Channel
http://www.ucalgary.ca/news/september2008/keith-carboncapture - David Keith
http://www.ucalgary.ca/~keith/AirCapture.html - David Keith
http://www.ucalgary.ca/~keith/Misc/AC%20talk%20MIT%20Sept%202008.pdf - M.I.T.
views.blogspot.com - by Sam Carana
The post below is added for archival purposes. It was originally posted by Sam Carana at knol in 2009, which has meanwhile been discontinued by Google. The post received 4513 views at knol.
Funding of Carbon Air Capture
HOW CAN CO2 CAPTURE FROM AMBIENT AIR BEST BE FUNDED?
FEES ON JET FUEL CAN HELP FUND THE DEVELOPMENT OF CARBON CAPTURE FROM AMBIENT AIR.
Why target jet fuel? In most other industries, there are ready alternatives to the use of fossil fuel. Electricity can be produced by wind turbines or by solar or geothermal facilities with little or no emissions of greenhouse gases. In the case of aviation, though, the best we can aim for, in the near future at least, is biofuel or synthetic fuel, produced from CO2 captured from ambient air. As discussed below, development of these two forms of renewable energy can go hand in hand.
Additionally, the aviation industry can offset emissions, e.g. by funding air capture of carbon dioxide. The carbon dioxide thus captured could be partly used to produce fuel, which could in turn be used by the aviation industry, as pictured on the top right image. The carbon dioxide could also be used to assist growth of biofuel, e.g. in greenhouses and in algae bags, as described below.
The NASA article conservatively mentions that some types of algae can produce over 2,000 gallons of oil per acre per year. In fact, most of the oil we are now getting out of the ground comes from algae that lived millions of years ago. Algae still are the best source of oil we know.
In the NASA proposal, there's no need for land, water, fertilizers and other nutrients. As the NASA article describes, the bags are made of inexpensive plastic. The infrastructure to pump sewage to the sea is already in place. Economically, the proposal looks sound, even before taking into account environmental benefits.
Jonathan Trent, lead research scientist on the Spaceship Earth project at NASA Ames Research Center, Moffett Field, California, envisages large plastic bags floating on the ocean. The bags are filled with sewage on which the algae feed. The transparent bags collect sunlight that is used by the algae to produce oxygen by means of photosynthesis. The ocean water helps maintain the temperature inside the bags at acceptable levels, while the ocean's waves also keep the system mixed and active.
The bags will be made of “forward-osmosis membranes”, i.e. semi-permeable membranes that allow fresh water to flow out into the ocean, while preventing salt from entering and diluting the fresh water inside the bag. Making the water run one way will retain the algae and nutrients inside the bags. Through osmosis, the bags will also absorb carbon dioxide from the air, while releasing oxygen. NASA is testing these membranes for recycling dirty water on future long-duration space missions.
As the sewage is processed, the algae grow rich, fatty cells that are loaded with oil. The oil can be harvested and used, e.g., to power airplanes.
Jul 19, 2010
There are several efforts under development to produce a carbon-neutral fuel. Two of them were recently described in article in New Scientist, entitled: Green machine: Cars could run on sunlight and CO2.
http://www.newscientist.com/article/dn18993-green-machine-cars-could-run-on-sunlight-and-co2.html
See also Sandia
https://share.sandia.gov/news/resources/releases/2007/sunshine.html
Whereas many may think that this is a good way to power cars, I agree with you that it makes more sense to have electric cars. However, aviation is a bit more difficult to clean up, that's why aviation in particular can benefit from such technology, and that would justify that aviation made financial contributions to fund such developments.
As air capture technology matures with financial assistance funded by fees on aviation, it will be in a better position to develop into a more general technology used to reduce CO2 in the atmosphere to more acceptable levels.
http://www.newscientist.com/article/dn19308-the-next-best-thing-to-oil.html
http://www.sciencemag.org/content/330/6012/1797
Milking algae
Instead of harvesting algae for processing into biofuel, there is prospect for "milking" the algae, i.e. extracting oil from the algae without killing them.
This method is followed by Joule Unlimited.
http://www.theglobeandmail.com/news/opinions/opinion/a-brave-new-world-of-fossil-fuels-on-demand/article1871149/
And also by Algenol, Synthetic Genomics (Craig Venter’s venture) and BioCee
http://theenergycollective.com/tyhamilton/50300/joule-cool-not-alone-quest-sunlight-fuel-game-changer
Jul 5, 2011
British company set to make renewable jetfuel
British company Air Fuel Synthesis plans to capture carbon dioxide from the air, and mix it with hydrogen extracted from water through electrolysis, in order to make liquid hydrocarbon fuels for transport, including for aviation.
http://www.airfuelsynthesis.com/technology.html
http://www.airfuelsynthesis.com/technology/technical-review.html
http://www.airfuelsynthesis.com/faqs.html