New Delhi: A new process can turn bulk quantities of just about any carbon source into valuable graphene flakes. A banana peel, turned into graphene, could help facilitate a massive reduction of the environmental impact of concrete and other building materials.
“This is a big deal,” says James Tour, chair in chemistry as well as a professor of computer science and of materials science and nanoengineering at Rice University.
“The world throws out 30% to 40% of all food, because it goes bad, and plastic waste is of worldwide concern. We’ve already proven that any solid carbon-based matter, including mixed plastic waste and rubber tires, can be turned into graphene.”
As reported in Nature, flash graphene is made in 10 milliseconds by heating carbon-containing materials to 3,000 Kelvin (about 5,000 degrees Fahrenheit). The source material can be nearly anything with carbon content. Food waste, plastic waste, petroleum coke, coal, wood clippings, and biochar are prime candidates, Tour says. Tour says a concentration of as little as 0.1% of flash graphene in the cement used to bind concrete could lessen its massive environmental impact by a third. Cement production reportedly emits as much as 8% of human-made carbon dioxide every year.
“Methane that waste food would have emitted in landfills. We are converting those carbons into graphene and adding that graphene to concrete, thereby lowering the amount of carbon dioxide generated in concrete manufacture. It’s a win-win environmental scenario using graphene.”
In the past, Tour says, “graphene has been too expensive to use in these applications. The flash process will greatly lessen the price while it helps us better manage waste.” “With our method, that carbon becomes fixed,” he says. “It will not enter the air again.” The flash graphene process can convert that solid carbon into graphene for concrete, asphalt, buildings, cars, clothing, and more, Tour says.
