Indian researchers say that the food industry generates a lot of waste products, but one of these, eggshells, could help combat climate change.
Basab Chaudhuri of the University of Calcutta and colleagues have shown that the membrane that lines an eggshell can absorb almost seven times its own weight of the greenhouse gas carbon dioxide from the atmosphere.
AdvertisementThe carbon dioxide thus trapped could be stored in this form until energy-effective methods of using the gas could be found that would not compound the environmental problems associated with carbon emissions.
The research team explains that eggshell comprises three layers, a cuticle on the outer surface, a spongy calcium-containing middle layer and inner layer.
The second and third layers are composed of protein fibers bonded to calcium carbonate. The membrane is just below the shell and is about 100 micrometers thick.
Separating the membrane from the cuticle is currently not an efficient process.
The team demonstrated that a weak acid could be used to separate the membrane from the shell for use as a carbon dioxide adsorbant.
The researchers point out that a mechanical separation method would be needed to make the process viable on an industrial scale.
However, Chaudhuri also muses that we could all help reduce CO2 levels by exposing our egg membranes to the air after eating our eggs.
The study has been published in the International Journal of Global Warming this month.