Chapter 2 - Fast pyrolysis of biomass and hydrodeoxygenation of bio-oil for the sustainable production of hydrocarbon biofuels

Abstract

This chapter discusses the critical aspects of the biomass fast pyrolysis processes and catalytic hydrodeoxygenation of the produced bio-oil. The yield of bio-oil obtained from the fast pyrolysis process can be up to 70–75wt%. However, the high oxygen content (about 35–50wt%) restricts the application of bio-oil as a fuel. Of the many technologies available, catalytic hydrodeoxygenation is a feasible technology to upgrade the pyrolytic oil. The deoxygenation of the oil occurs in the presence of hydrogen and catalyst. The oxygen in the compound reacts with the hydrogen and rejected as water and carbon dioxide to form a more stable hydrocarbon biofuel. Many catalytic systems, such as metal oxides, sulfides, bifunctional catalysts, etc., have been discussed briefly in this chapter. The use of the dual-stage reactor or two-stage hydrotreatment process not only enhances the bio-oil yield and quality but also reduces the catalyst deactivation issue effectively. The perspectives of fast pyrolysis and catalytic hydrodeoxygenation are briefly discussed in the chapter.