Biomass Conversion in Supercritical Water

This chapter describes the possibility of chemical recovery from biomass by using supercritical water as the reaction solvent. First, we demonstrate that cellulose can be dissolved by treating it with high-temperature water that can enhance bioreactions such as hydrolysis and fermentation. By controlling the reactions, supercritical water can serve as an acid or a base catalyst for converting cellulose or lignin. In this chapter, reaction mechanisms in supercritical water and solvent effects are explained. Then, we show that the hydrolysis of cellulose is possible without a catalyst. A hydrolysis product, glucose, can be converted, with high selectivity, into valuable chemicals such as aldehydes. Furthermore, lignin can be selectively converted into chemicals by tuning the reaction atmosphere.