The concentration of atmospheric carbon dioxide is at its highest levels in hundreds of thousands of years and as matters get worse, it’s more crucial than ever to find a way to reverse it. A study released earlier this month presents a novel idea with what to do with the gas humanity can’t seem to stop making: Turn it into something useful. Specifically, high-quality carbon nanotubes.
The main cause of global warming, carbon dioxide is a heat-trapping gas that is released through using fossil fuels and processes like deforestation. While some carbon dioxide is natural and healthy, people are generating far more carbon dioxide than the Earth’s natural levels. And too much of it would likely have catastrophic results.
Beyond simply producing less carbon dioxide, ideas on what to do with carbon dioxide include storage and repurposing it. That second one has always been something of a longshot, to the extent that there’s an XPrize dedicated to trying to find uses for the substance.
Scientists at Vanderbilt University in Tennessee, alongside private sector scientists there, have developed a non-traditional way to construct small-diameter carbon nanotubes, called CNTs, while actively using carbon dioxide. Their results have been published in Applied Materials and Interfaces.
The process relies on a type of molten salt known as lithium carbonate, or Li2CO3. More commonly used for health purposes, lithium carbonate is often used in tandem with treatment of mental health disorders. But here, the scientists melt it by heating it up to 723°C. This process creates dilithium oxide (Li2O) and releases both oxygen and carbon into the air.
Scientists are able to capture this liberated carbon and place it on an iron catalyst. When that connection occurs, it creates carbon nanotubes. The Li2O reacts with carbon dioxide already in the air and becomes lithium once again.
CNTs have a wide variety of uses. They are 100 times stronger than steel but with only one-sixth the weight, as well as remarkable thermal conductivity, and small amounts are used in thigns like high-end baseball bats and golf clubs.
There’s still work to be done on the process. The iron catalyst isn’t that stable and depending on how long it’s in use is creating irregularly size CNTs. But, the scientists argue, figuring out how to stabilize the iron could be worth the effort. Once the electricity is figured out, the entire endeavor would only cost half of what CNTs go for on the market.
The other method of dealing with carbon, capturing it, is already being implemented across the globe. But the more uses scientists can find for carbon, the better chances are for humanity.
Source: Ars Technica
Previously Published By: Popular Mechanics USA