Lignocellulose, the major component of biomass, makes up about half of the matter produced
by photosynthesis. It consists of three types of polymers cellulose, hemicellulose, and lignin
that are strongly intermeshed and chemically bonded by non-covalent forces and by covalent cross-linkages. Lignocelluloses in nature derive from wood, grass, agricultural residues, forestry wastes and municipal solid wastes.

The major component of lignocellulose materials is cellulose, along with lignin and hemicellulose. Cellulose and hemicellulose are macromolecules from different sugars; whereas lignin is an aromatic polymer synthesized from phenylpropanoid precursors. The composition and percentages of these polymers vary from one plant species to another.

Moreover, the composition within a single plant varies with age, stage of growth, and other conditions. Long cells enveloped by a characteristic cellular wall form wood. This wall is a complex structure that acts at the same time as plant skin and backbone.