Lignocellulose refers to plant dry matter (
biomass), so called lignocellulosic biomass. It is the most abundantly available raw material on the
Earth for the production of
bio-fuels, mainly
bio-ethanol. It is composed of carbohydrate polymers (
cellulose,
hemicellulose), and an aromatic polymer (
lignin). These carbohydrate polymers contain different sugar monomers (six and five carbon sugars) and they are tightly bound to lignin. Lignocellulosic biomass can be broadly classified into virgin biomass, waste biomass and energy crops. Virgin biomass includes all naturally occurring terrestrial plants such as trees, bushes and grass. Waste biomass is produced as a low value byproduct of various industrial sectors such as
agricultural (
corn stover, sugarcane
bagasse, straw etc.),
forestry (
saw mill and
paper mill discards). Energy crops are crops with high yield of lignocellulosic biomass produced to serve as a raw material for production of second generation
biofuel examples include switch grass (
Panicum virgatum) and
Elephant grass.