Lignocellulosic Biomass

Lignocellulose (LC) stands as Earth’s most abundant biomass and can be derived from various living organisms, with its primary source being the plant cell wall. Cellulose, hemicelluloses, and lignin are the main building blocks of LC, with the minor components represented by proteins, pectin, extractives, and inorganic compounds (ash). These components vary according to the type of biomass, planting conditions, harvesting, storage, and even the extraction process used. In addition, the high complexity of interactions between the various constituents of LC forms a recalcitrant ultrastructure that hinders the hydrolysis of the cellulose and hemicelluloses, thus reducing their conversion into several sustainable chemical platforms. In faced with this challenge and with the objective of establishing LC as a competitive substrate against fossil-derived products, the selection of an efficient pretreatment technique becomes indispensable. This choice necessitates a comprehensive understanding of the chemical composition and structural characteristics of the plant cell wall within the targeted biomass. Depending on their sources, LC can be classified as follows: agricultural waste, energy crop residues, herbaceous perennial grasses, forest biomass and wastes, and also industrial and municipal wastes. In this context, the present chapter delves into the characteristics of the plant cell wall ultrastructure and its implications in LC conversion processes. It also provides an overview of the main constituent concentration, classifications, and production data related to different LC sources. Furthermore, it explores various possibilities for valuing of the LC primary components to obtain value-added products.