The Digester

UNSW turns peanut shells into high-quality graphene

Feb 26th 2026

A UNSW team has developed a two-step, chemical-free heating technique that turns peanut-shell waste into single-layer graphene in minutes, potentially cutting costs and using other plant waste as feedstock.

  • UNSW engineers led by Professor Guan Yeoh published a chemical-free method in Chemical Engineering Journal Advances that converts peanut-shell waste into graphene.
  • The process uses the shells' lignin content, first heating them to about 500°C for five minutes to produce a carbon-rich char.
  • The char is then subjected to flash joule heating that raises temperature to around 3000°C for milliseconds to form single-layer graphene.
  • The whole method takes roughly 10 minutes, uses no added chemicals, and UNSW estimates energy costs at about US$1.30 per kilogram of graphene.
  • Researchers have produced only small quantities so far but say commercial-scale development could be possible within three to four years.
  • The team says the technique could be applied to other lignin-rich biomass such as coffee grounds or banana peels for sustainable graphene production.

Sources

unsw.edu.au