Introduction to the Lignin Subject

Lignin, a macromolecule obtained from lignocellulosic biomass, is a residue or coproduct from industrial sectors as cellulose pulp and paper and second-generation ethanol. It is classified as sulfur containing lignin and sulfur-free lignin, that depends on the extraction process. In this chapter aspects related to an overview of the lignin production, its global availability, market, and products and applications are treated in order to introduce the relevance of lignin as an industrial renewable macromolecule with several usages.