Rice University Turns Trash Into Graphene

Scientists at Rice University have unveiled a new process that can turn bulk quantities of just about any carbon source into valuable graphene flakes. The team says that the process is quick and cheap and is known as "flash graphene." The technique can convert a ton of coal, waste food, or plastic into graphene for a fraction of the cost of other bulk graphene production methods.

Researchers on the project note that the development is a "big deal" as huge amounts of food get thrown out because it goes bad, and plastic waste is a global concern. The technique they have developed can convert solid-carbon-based matter and mixed plastic waste, including rubber tires, into graphene.

Flash graphene is made in 10 milliseconds by heating carbon-containing materials to 3,000 Kelvin. The source can be anything with carbon content, including waste food, plastic waste, petroleum coke, coal, wood clippings, and biochar. Graphene is very costly today, with the price at $67,000 to $200,000 per ton. Being able to turn waste material into the expensive substance is a big deal.

Potential applications for this type of graphene include mixing it into cement used to bind concrete in concentrations as small as 0.1% could reduce the environmental impact of concrete by a third. The team says that cement production emits as much as 8% of the human-made carbon dioxide every year.

Using graphene in concrete could make it cheaper to manufacture and transport. The process would trap greenhouse gases like carbon dioxide and methane that waste food would have emitted in landfills. The new process produces significantly more graphene than other processes available, including chemical vapor deposition on a metal foil. The other techniques require more effort and produce less graphene.