Researchers have come up with an efficient method to convert carbon dioxide and inedible plant material, such as grasses and agricultural waste, into plastics. The carbon dioxide required for the process could be obtained from power plant or factory emissions. This could represent a low-carbon alternative to the petroleum-derived PET plastics commonly used to make bottles.
Stanford University chemistry professor Matthew Kanan and his colleagues reported the new method in the journal Nature.
The material that they have made, called polyethylene furandicarboxylate (PEF), is not new. Others have made it before, but the production methods have been expensive and not sustainable.
That’s because PEF is made from two components: ethylene glycol and a chemical called furandicarboxylic acid (FDCA). Scientists previously used fructose from corn syrup to make the FDCA. But that requires a lot of land, energy, fertilizer, and water, not to mention the competition with food production. “It would be much better to make FDCA from inedible biomass, like grasses or waste material left over after harvest,” Kanan said in a press release.
This is precisely what he and his colleagues have done. They have found a way to make FDCA from furfural, a well-known compound made from agricultural waste, and carbonate. To produce FDCA, the researchers simply heat up carbonate, carbon dioxide, and a chemical called furoic acid that is made from furfural. All the materials are abundant and cheap, which means there should be a simple, low-cost way to manufacture FDCA—and with it the low-carbon plastic PEF.
“We believe that our chemistry can unlock the promise of PEF that has yet to be realized,” Kanan said. “This is just the first step. We need to do a lot of work to see if it’s viable at scale and to quantify the carbon footprint.”
The team is now trying to apply the method to making renewable fuels and other compounds from hydrogen and carbon dioxide.