Soft drink waste could tackle global warming

The by-products of some soft drinks remove carbon dioxide from gas streams and could therefore help reduce global warming, according to new research.

Published in Microporous and Mesoporous Materials, researchers from Cornell College and Oak Ridge National Laboratory in Tennessee show how a simple procedure can convert waste soft drinks to porous carbon, which is capable of absorbing carbon dioxide. As well as addressing global warming, this will also help limit the high volume of waste caused by expired soft drinks and the production process.

“In this research, we are looking at turning one waste material into something of value,” said Craig Teague, Professor of Chemistry at Cornell College. “We looked at waste soft drinks — asking could we possibly find a way to make that waste useful by doing a simple process in the lab and taking the carbon out? That carbon, by the way we synthesised it, has tiny pores, which are able to capture carbon dioxide.”

The researchers reduced Coca-Cola, Push Orange, Diet Mountain Dew and Diet Pepsi to carbon powder using a simple, hydrothermal synthesis process. The remaining carbon powder has micropores or tiny spaces that capture the carbon dioxide.

Push Orange and Mountain Dew, which both contain citric acid, produced the best results, Teague said.

“We did find that the soda powders were able to take up more gas than almost any material they had ever measured [in the research group’s lab],” said co-author Caitlin Stieber. “One of the measurements examined how much carbon dioxide would bind to the material, and with the instrument we used, the powder was the second-highest measurement they had ever recorded. That was a big deal because it was so easy to make.”

Although this method of carbon dioxide separation is not ready for industrial use, Teague suggested the research brings chemists closer to finding a cost-efficient waste product.

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