How Waste From Soft Drink Production Could Be Used to Tackle Global Warming

Carbon capture—or the removal of CO2 from the atmosphere—has been proposed as a potential avenue for mitigating greenhouse gas emissions and limiting global warming to the internationally agreed threshold of 2 C above pre-industrial temperatures.

To date, scientists have put forward several different methods to do this. A team from Cornell College, the Oak Ridge National Laboratory and the University of Tennessee has now identified another potential mechanism to achieve this by using waste products from the production of soft drinks.

In a study published in the journal Microporous and Mesoporous Materials, the team demonstrated how some by-products of soft drinks can be converted, using a simple procedure, into a porous material that is capable of absorbing carbon dioxide—the most abundant greenhouse gas.

Not only could this help to tackle global warming, but it would also provide a use for some of the vast amounts of waste generated by the soft drink industry. Much of this waste stems from drinks that have expired, or the production process itself.

"In this research, we are looking at turning one waste material into something of value," Craig Teague, lead author of the study from Cornell, said in a statement. "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 synthesized it, has tiny pores, which are able to capture carbon dioxide."

In the study, the researchers focused on four soft drinks (Coca-Cola, Push Orange, Diet Mountain Dew and Diet Pepsi) and used a simple procedure to reduce the beverages into a carbon powder. This substance contains tiny holes—known as micropores—that proved to be particularly adept at trapping carbon dioxide.

"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]," Caitlin Stieber, another author of the study from Cornell, said in the statement. "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."

Usually, to create microporous materials of this kind, harsh chemicals need to be used, but the new process does not require these, the researchers say. Nevertheless, this technique is far from ready to be used in real life situations, much like many other methods being developed by scientists to remove carbon from waste streams.

"At this point, researchers around the world are pursuing several different experimental approaches because we don't know which one will ultimately pan out to be best or which one might be best for certain applications," Teague said.