Biomass Pretreatment With Acids

In a lignocellulosic-based biorefinery, the stage related to biomass pretreatment is one of the most important and has attracted great attention due to its influence on technical, economic, and environmental aspects. Although a number of different processes involving physical, chemical, physicochemical, and biological methods have been investigated over the years, those employing chemicals, especially acid solutions, are demonstrated to be highly effective in attacking the lignocellulosic structure, offering the highest sugar yields with the lowest costs that are fundamental to attaining economic success. Pretreatment with acids, especially with sulfuric acid, has been one of the most widely used methods for biomass pretreatment. The goal of this chapter is to provide an overview of the technique of biomass pretreatment with acids. A description of the process using dilute and concentrated acid solutions, major effects on biomass structure, advantages and drawbacks, and the most recent advances/future perspectives for the use of this technique on an industrial scale are discussed.