Wood waste to reduce cost of carbon fibre

Carbon fibre is becoming increasingly important in the automotive sector because of its high strength and low weight. However, its price confines its use to premium vehicles. Researchers from Washington State University now claim to have found a way to reduce its cost while also making use of a material that is currently discarded as waste.

Lignin is the natural polymer that helps give wood its strength. A complex, fibrous structure of phenolic groups, it occurs in the cell walls of woody plants, making them rigid, But many industrial process that use wood or other tough plants as a raw material — notably papermaking and ethanol production in biorefineries — use only the cellulose content of the material, leaving lignin behind as a waste.

Currently, much of the waste lignin is burned to produce steam for biorefineries, or is simply sent to landfills. But researching ways to make better use of this waste stream, Birgitte Ahring and colleagues decided to look at using lignin a raw material for carbon fibre.