This week, researchers at George Washington University (GWU) unveiled a new method to convert carbon dioxide into nanoscale carbon fibers that may serve as valuable future building materials (think: aircrafts, fitness equipment and sports cars), as well as another potential weapon against climate change.
The new technology captures airborne carbon dioxide and employs an electrochemical process to convert it to carbon nanofibers and oxygen. The method is more efficient and potentially significantly cheaper than existing methods, according to Stuart Licht, a professor of chemistry at GWU.
“We’re very excited about this because carbon nanofibers are a very valued product,” Licht said in a recent interview. “So we think there’s going to be an impetus for bringing down carbon dioxide levels in the air.”
If the process is powered by renewable energy, the result will be a net removal of atmospheric carbon dioxide. It’s also a “means of storing and sequestering carbon dioxide in a useful manner, a stable manner and in a compact manner,” Licht said.
In a recent demonstration, Licht’s research group used a unique concentrated solar power system using infrared sunlight and visible light to generate the large amount of heat needed to run the desired reaction.
The researchers demonstrated the ability to make a variety of different nanofiber shapes and also showed they could make very uniform fibers. Licht says the mechanisms underlying the formation of the fibers still need to be better understood, but he’s confident the group can keep developing greater control over the nature of the fibers it makes.
Licht is optimistic about the technology’s emissions-cutting potential. He calculates that given an area less than 10 percent of the size of the Sahara Desert, the method could remove enough carbon dioxide to make global atmospheric levels return to preindustrial levels within 10 years, even if we continue emitting the greenhouse gas at a high rate during that period.
He also says his approach is different from traditional carbon-capture and sequestration processes. Sequestration involves the binding of carbon dioxide with various other substances so it can be stored under the earth, or extracted and concentrated. In Licht’s process, carbon dioxide is transformed into something new.
The success of this approach hinges on its scalability; its contribution to climate change mitigation would require a huge increase in demand for carbon nanofibers. Licht believes this is possible: the material’s strength and lightweight properties will spur greater use as its cost comes down.
Imagine that carbon fiber composites eventually replace steel, aluminum and even concrete as a building material, Licht says. “At that point, there could be sufficient use of this that it’s actually acting as a significant repository of carbon.”
Some in the scientific community are skeptical, however.
“I am extremely skeptical of these claims,” Ken Caldeira of the Carnegie Institution for Science told New Scientist. Caldeira doubts that Licht’s solar-to-chemical conversion technology is anywhere near economically viable. “I would be highly surprised if these people have cracked this nut.”