Eggshells: Another Interesting Way to Fight Global Warming

October 27th, 2010 by Tina Casey

Carbon sequestration technology is still in its infancy so it stands to reason that researchers are pursuing any number of odd and unusual avenues, and among these the eggshell thing has to be among the oddest. Researchers at the University of Calcutta have found that eggshell membranes can absorb almost seven times their weight in carbon dioxide, making them an ideal sponge to soak up excess quantities of this greenhouse gas.

Eggshells and Membranes

Anyone who has ever cracked an egg can discern the thin membrane that clings to the inside of an eggshell. To make any kind of dent in global carbon dioxide emissions, there would have to be a highly efficient method of separating the membrane from the shell. The Calcutta team found that a weak acid can do the trick, but that would be impracticable on a commercial scale. A mechanical method would be preferable. It’s possible that the egg farmer of the future will be able to market egg membranes as a value-added byproduct, much as biogas technology has provided the livestock industry with a means of producing marketable fertilizer.

Expose Your Eggshells

Lead researcher Basab Chaudhuri suggests that until eggshell membrane salvage is commercially viable, it might help if we all just let our eggshells air out a bit after emptying their contents. That’s not as far-fetched as it may seem. There’s a lot of eggs cycling through the world these days. India consumes about 1.6 million tonnes (that’s a metric ton, or 2,305 pounds) of eggs annually all by itself, and some nations are encouraging a sharp increase in egg consumption, South Africa being one example. The U.S. is no slouch either – for example about half a billion eggs were recalled in a salmonella outbreak last summer, barely causing a ripple in the market. Global egg consumption is expected to reach about 1,154 billion eggs by 2015.

Image: Eggshells by dfinnecy on flickr.com.

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Tags: carbon dioxide, carbon sequestration, eggs, eggshells, University of Calcutta

About the Author

Tina Casey Tina Casey specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. Views expressed are her own. Follow her on Twitter @TinaMCasey and Google+.

Alex J

If successfully developed, this could help a little bit, but the weight of an eggshell membrane is a tiny percentage of the total egg weight. Globally, humans already emit almost 30 gigatons of CO2 annually (~8 Gt carbon equivalent). So you can imagine how much membrane would need to be carbon-infused AND permanently sequestered to make much difference.
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Why not eggshell memberence can comercialy used in potary industry for carban sequence purposes and as a raw metterial of bio-gas production industry in small sacle

Piume Bentarage
wizbot

Would all the co2 not go right back into the air when the membranes decomposed?

If not, please provide some figures. How much carbon would be absorbed if x% of eggs were exposed to the atmopshere?
- Tina Casey
  
  Wizbot: The concept for a commercial-scale operation would be to extract the carbon dioxide and use it in such a way that carbon emissions are greatly reduced or eliminated. For individuals who air out their eggshells and then discard them, the variable woud be thel disposal method.
  - http://twitter.com/GCBrodie Brodie Stephens
    
    If the eggshell membrane, and the eggshell itself, were composted after the eggshell and membrane were exposed to the air – would the creation of soil through composting capture the carbon in the soil? How long does the eggshell have to be exposed?