12.3.1 General Overview

The production of high added-value chemicals from biomass process streams, as lignin, is crucial in the integrated approach of multiple processes and multiple major products in the concept biorefinery [86]. Consequently, reaction and sepa­ration processes for the production of compounds from biomass, namely ligno — cellulosic, have been continuously the subject of applied research. Due to its structure and somewhat complex chemistry, lignin is one of the most fascinating targets of research in three essential modes [38]: one aiming to breakdown the tridimensional network for conversion to aromatic (or non-aromatic) chemicals (thermochemical processes, Figs. 12.4, 12.5); the other one intending to use the lignin functionalities to integrate it in more complex matrices or construct renewable polymers; and the third one, dealing with lignin as source of power (green fuels and syngas [87] Fig. 12.4).