Most advanced biofuel production technologies today are focused towards converting lignocellulosic biomass into transportation fuels. Lignocellulosic biomass refers to plant biomass that is composed of cellulose and hemicellulose, which are natural polymers of carbohydrates and lignin. Cellulose and hemicellulose are tightly bound to the lignin by hydrogen and covalent bonds. Lignocellulose comes in many different types such as wood residues (e. g. sawmill residues), crop residues from agriculture (e. g. corn stover and cereal straws), industrial residues from agro-food processing operations (e. g. wheat bran and sugar beet pulp) and dedicated energy crops (primarily rapidly growing energy grasses such as Miscanthus and switchgrass, and wood species).

21.3.1 Biochemical routes — sugar platform

In order to distinguish biofuels derived from lignocellulose from those derived from existing agricultural commodities (see Section 21.2.1), often the term ‘cellulosic’ is added to the biofuel. This term indicates that these biofuels are based on converting the main carbohydrate fractions, cellulose and hemicellulose, of lignocellulosic biomass into fuels.