Catalytic routes for upgrading pyrolysis oil derived from biomass

Abstract

The modern energy industry faces the challenge of reducing its carbon footprint, mainly due to fossil fuel use, while satisfying the continuously increasing demand for fuels, electricity, and chemicals. Biomass is one of the six ways to produce renewable energy. It can provide all energy types and become our primary source of chemicals and materials. While energy can also be derived from the other five renewable sources (hydro, solar, wind, ocean, and geothermal), biomass is the only renewable energy source that is further a renewable carbon source. It can potentially complement the production of all C-based raw materials, which are the building blocks of our chemical and biochemical industry. Among the various biomass-conversion technology platforms, ‘pyrolysis’ is one of the most promising to produce bioenergy and biomaterials, particularly bio-oil. The usefulness of bio-oil in transportation is restricted by its high oxygen concentration. This review summarises the recent progress in catalytically upgrading pyrolysis bio-oils to biofuels and chemicals. The first part of this chapter is on the pyrolysis process itself; it focuses on fast pyrolysis and the resulting bio-oil due to the consensus about this technology’s superiority. The second part of this chapter provides an overview of the bio-oil upgrading routes. A comprehensive collection of the results on the type of catalysts used in such processes and their relevant functions are provided. Finally, this chapter closes with a discussion of the challenges and limitations of the bio-oil upgrading processes.