14 DAY TRIAL // Garbage could be the solution for the future's fuel crisis. A team at Ohio State University has tried to figure out how to transform discarded chicken eggshells into an alternative energy source. The new technique employs eggshells to absorb carbon dioxide while delivering hydrogen fuel and could also lead to a new method of using the collagen from the egg's shell in a comercial way.
The research team got the idea while attempting to improve a hydrogen production technique named the water-gas-shift reaction, in which fossil fuels like coal are gasified to obtain carbon monoxide gas, which further reacts with water and thus resulting carbon dioxide and hydrogen.
"The key to making pure hydrogen is separating out the carbon dioxide. In order to do it very economically, we needed a new way of thinking, a new process scheme." said lead researcher L.S. Fan, Professor of chemical and biomolecular engineering. Eggshells are made mostly of calcium carbonate, one of the most absorbent natural materials. When heated, calcium carbonate turns into calcium oxide that absorbs any acidic gas, including carbon dioxide and ground-up eggshells, a method called water-gas-shift reaction.
"Calcium carbonate -- a key ingredient in the eggshells -- captures 78 % of carbon dioxide by weight," said Fan. This value makes it the beat carbon dioxide absorber ever tested.
Hydrogen fuel cells will turn into an important power source in the future, but this requires the discovery of affordable methods of producing big amounts of hydrogen, but also how to get rid of the byproducts resulted from producing the gas. Annually, in US about 91 billion eggs are produced, translated into 455,000 tons of shell that could be employed in hydrogen production.
"Still, even if all that shell were utilized, it would only provide a portion of what the United States would need to seriously pursue a hydrogen economy. Eggshell alone may not be adequate to produce hydrogen for the whole country, but at least we can use eggshell in a better way compared to dumping it as organic waste in landfills, where companies have to pay up to $40 dollars per ton disposal cost," said Fan.
Before grinding up the egg shell, the inner membrane must be removed; the team developed an organic acid for that. The membrane is made up of about 10 % collagen, which values for about $ 1000/gram and has various uses from food to pharmaceuticals, and medical ones (it helps burned victims regrow skin and it is also employed in cosmetic surgery).
"We like that our technology can help the egg industry to dispose of its waste, and at the same time convert the waste to a useful product. And in the long term, we're demonstrating that carbon-based fuel sources, like coal or biomass, can be efficiently converted to hydrogen and liquid fuel. The goal is an energy conversion system that uses a dependable fossil energy source, but at the same time has very little environmental impact," said Fan.