Removing CO2 From the Air Efficiently

Canadian scientists have created a device that efficiently removes CO2 from the atmosphere. "The proposed air capture system differs from existing carbon capture and storage technology ... while CCS involves installing equipment at, say, a coal-fired power plant to capture CO2 produced during the coal-burning process, ... air capture machines will be able to literally remove the CO2 present in ambient air everywhere. [The team used] ... a custom-built tower to capture CO2 directly from the air while requiring less than 100 kilowatt-hours of electricity per tonne of carbon dioxide."

Comments

Reference point to CO2 emissions

[Hays]

Assuming that 1 tonne = 1000kg, this machine requires approximately 1 kilowatt hour of electricity to remove 10kg of Carbon Dioxide from the atmosphere. How efficient is this?

From http://www.glumac.com/section.asp?catid=140&subid=152&pageid=564

"For home energy use, carbon dioxide emissions vary widely from state-to-state and from day-to-day. The national average is about 1.3 pounds of carbon dioxide for every kilowatt-hour of electricity used in your home."

Not bad. If it really works, you can redirect 10 to 15% of your electricity to achieve Carbon neutrality.

Re:it this

[compro01]

Only a lot more efficient. An average tree will use roughly 22kg of CO2 per year. These things are estimated to remove 20 tonnes per year per square metre, so it's in excess of 1000 times more effective. Even after you factor in the CO2 produced to provide the power needed for these things, you're still likely coming out way ahead.

Re:Natural device?

[citizen_senior]

Just wonder how much do we have to wait for a fart capture device (cow farts are actually a major source of trouble)

This has already been done in Holland - no waiting required, therefor - a university study group has work in progress on the subject of cow farts. There are groups of cows standing around with cylinders strapped to their backs in order to (forgive the word) fuel this study. Saw it on /.

Re:Storage Issue

[logicnazi]

Hmm, but while you are at it you will hugely acidify the ocean. The chemicals that react with the CO2 only enter the ocean so fast.

The deep ocean trenches may be deep enough to simply liquefy the CO2 so it simply pools on the bottom. This may be more promising. Still not as good as geological storage, however.

Cow Farts... wrong end!

[Enter the Shoggoth]

Actually, it's a common misconception that "cow emissions" are from cow's farting, it's actually the way a ruminant will burp during the processing of a cud that produces large volumes of methane (which is of course more troubling than CO2 emissions)

They won't be making a pile of cash out of trees.

Can't resist:

1) Identify a possible source of trouble 2) Invent a fix, no matter how convoluted it is 3) Patent it and market it 4) Profit

Just wonder how much do we have to wait for a fart capture device (cow farts are actually a major source of trouble)

Re:Natural device?

[Markspark]

The scrubber uses Sodiumhydroxide and Calciumhydroxide that are circulated and regenerated in the process. The power demand comes from separating the CO2 from the CaCO3 back into Ca(OH)2.
But you are correct in the fact that this would require maintenance, since there's no such thing as maintenance free pumps.
However i still feel if this could be a good solution, if it's cost and energy efficient, and being financed by carbon-taxing, and last but not least, F/OSH (free/opensource hardware).

Better article available

[IcyHando'Death]

More details from http://www.cbc.ca/technology/story/2008/09/30/carbon.html

The tower acts as a scrubber, with sodium hydroxide, also known as caustic soda, reacting with air blown into its base. A metal honeycomb system inside the tower slows down the flow of caustic soda, allowing it to efficiently scrub CO2.

While Keith said the technology isn't new -- it's been used since the 1950s in industrial processes that call for carbon dioxide-free air -- he believes his team has surmounted one of the two biggest obstacles to CO2 capture.

For the system to be effective, it must remove more carbon dioxide from the air than it emits as a byproduct of the energy used to run the scrubber. This summer's experiment showed that can be done, said Keith.

He estimates that if the electricity used to run the ambient air scrubber were to come from a coal-fired power plant -- a heavy emitter of CO2 -- he could capture 10 times more CO2 than the coal plant emitted.

Re:Natural device?

[psychosol]

Its True! Trees do remove CO2 from the air! The problem starts, and this is where there is much misunderstanding, with what happens to the carbon in the long term. A tree will absorb a large amount of CO2 during its lifetime, but when after its lifetime, that carbon is released again as the tree decays, or is burned as fuel, etc. The point of CCS is to place the captured carbon in a state that it can be stored for the long term (1000's of years). The problem isn't so much that we are performing processes that release CO2 into the atmosphere, but that the CO2 we are releasing is "new", as in it used to be sequestered underground in a stable form, and now it is being added to our atmosphere. That is why bio-diesel, even if it wasn't less harmful than oil-based diesel, is still an advantage because the CO2 it releases was taken from our atmosphere to begin with, making it close to carbon-neutral. The point is to stop ADDING CO2 to our atmosphere, and start removing and storing it for the long term.