Chapter 20 - Valorization of lignocellulosic-based wastes

Abstract

The production of energy and chemicals from renewable biomass provides an ideal alternative to petroleum-based refinery reducing the dependence on fossil-fuel resources and contributing to the decarbonization and sustainable growth of the society. Lignocellulosic-based wastes have been recognized as the most important renewable source, not competing with food crops. In this sense, the valorization of lignocellulosic-based wastes for the production of value-added compounds contributes for achieving a circular economy, which aims to develop new income streams by the creation of novel sectors, adding value to products and promoting jobs. Lignocellulosic biomass is mainly composed by nonstructural components (such as extractives, ash, protein, and other minor components) and structural components (cellulose, hemicellulose, and lignin). The selective fractionation of lignocellulosic-based wastes allows the use of separate fractions for a suitable and specific application. This approach is known as lignocellulosic biorefinery. This chapter will approach the main commercial products obtained from lignocellulosic components and the biomass sources for the extraction of these fractions. Moreover, the most important applications of these biomass-derived products will be addressed, as well as some more recent techniques of processing for the extraction of extractives, cellulose, hemicellulose, and lignin.