Researchers at the South Dakota State University agricultural and biosystems engineering department used a pyrolysis process to turn various materials (corn stover, dried grains and grasses) into graphene. The pyrolysis process turns the plant materials into bio-oil and biochar, and further processing turns it into biofuel.
Turning biochar into graphene can have many uses, like replacing activated carbon coatings of electrodes used in supercapacitors. Graphene has a much higher monetary value than the plant products in this process, so it can be highly worhtwhile to turn these agricultural residues into graphene.
Once the plant substance is transformed to biochar, it is mixed with a chemical that functions as a catalyst with the biochar and heats the mixture to 1,292 degrees Fahrenheit for one hour to make porous graphene. The scientists also hope to adapt a new plasma processing technique developed at SDSU that reduces the processing time to five minutes and the temperature to 302 degrees Fahrenheit to convert biochar to graphene.