Which renewable fuel is made by fermenting cellulose-rich plant material into alcohol?

Cellulosic ethanol is a renewable fuel made by breaking down cellulose-rich plant material and fermenting the resulting sugars into alcohol.

Unlike conventional corn or sugarcane ethanol, cellulosic ethanol can use agricultural residues, grasses, wood waste and other non-food plant matter. Cellulose is locked inside a tough structure with hemicellulose and lignin, so pretreatment and specialized enzymes are needed before fermentation.

The process can expand the range of biomass used for liquid fuel and reduce direct competition with food crops. However, separating plant fibres economically has historically been difficult, limiting large-scale commercial production.

Cellulosic ethanol is still ethanol, but its feedstock and processing distinguish it from starch-based grain ethanol.