Tuesday, July 22, 2008

Scientists found a workable way of reducing CO2 levels

Physorg.com reports - Scientists say they have found a workable way of reducing CO2 levels in the atmosphere by adding lime to seawater. And they think it has the potential to dramatically reverse CO2 accumulation in the atmosphere, reports Cath O'Driscoll in SCI's Chemistry & Industry magazine published today.

Adding lime to seawater increases alkalinity, boosting seawater's ability to absorb CO2 from air and reducing the tendency to release it back again.

The important point is that when you put lime into seawater it absorbs almost twice as much carbon dioxide as is produced by the breaking down of the limestone in the first place.

The Cquestrate project has a web page; here's how they describe the idea; and here's a chance of getting involved. I think this is HUGE!

They also have this awesome slideshow presentation, which goes into the gory but interesting details of all the chemical reactions.

Here is their idea of how they would do it (subject to economic feasibility):
  • The Nullarbor Plain is the world's largest single piece of limestone and occupies an areas of about 200,000 km2
  • With an average thickness of 50m, there is 10,000 km3 of limestone
  • To sequester 1 billion tonnes of carbon (GtC) would require the excavation of 1.5 km3 of limestone
  • Between 1750 and 2004 humankind has emitted 305 GtC. Current emission rates are about 7 GtC per year
  • Thus employing this process on 500 km3 of limestone (about 5% of the limestone in the Nullarbor Plain) would return carbon dioxide levels to pre-industrial levels.

I hope all of this comes true. I think, economic viability of converting CaCO3 into CaO will be the biggest hurdle.

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2 Comments:

Anonymous Anonymous said...

What will happen to the vast ocean life with change in ph. I am sure there are people with better sense.
http://www.decisioncare.org

8:03 AM  
Anonymous Anonymous said...

Removal of limestone will have some unforeseen consequences on land. The amount of damage done to carry out the operation itself is an unknown. The effect on marine ecosystems with consequences for land mammals, another unknown. All we get is a drop in CO2 levels, hopefully oxygen stays at current levels.

5:49 PM  

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