Boffins patent process to generate hydrogen from discarded eggshells

Ohio State University researchers have patented a process that uses discarded chicken eggshells to soak up carbon dioxide from a reaction that also produces hydrogen fuel.

Washington, Sept 27 : Ohio State University researchers have patented a process that uses discarded chicken eggshells to soak up carbon dioxide from a reaction that also produces hydrogen fuel.

The process also uniquely peels the collagen-containing membrane from the inside of the shells, so that the collagen can be used commercially.

The team of doctoral student Mahesh Iyer and Prof. of chemical and biomolecular engineering, LS Fan, hit upon the idea when they were trying to improve a method of hydrogen production called the water-gas-shift reaction.

With this method, fossil fuels such as coal are gasified to produce carbon monoxide gas, which then combines with water to produce carbon dioxide and hydrogen. Eggshell plays a critical role in this reaction.

"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 Prof. Fan.

That gave the team the idea to use eggshells, which mostly consist of calcium carbonate.

Calcium carbonate is one of nature's most absorbent materials and is a common ingredient in calcium supplements and antacids.

With heat processing, calcium carbonate becomes calcium oxide, which then absorbs any acidic gas, such as carbon dioxide.

In the laboratory, Prof. Fan and his colleagues demonstrated that ground-up eggshells could be used in the water-gas-shift reaction.

Prof. Fan said calcium carbonate captures 78 percent of carbon dioxide by weight, which essentially means that given equal amounts of carbon dioxide and eggshell, the eggshell would absorb 78 percent of the carbon dioxide.

This would make it the most effective carbon dioxide absorber ever tested, he said.

Prof. Fan is currently working with a major egg company to produce large quantities of the eggshell granules for testing. The university plans to license the technology for further development.

ANI