Review of Catalytic Conditioning of Biomass-Derived Syngas

Thermochemical conversion of biomass to create fuels and chemical products may be achieved through the gasification route via syngas. The resulting biomass-derived raw syngas contains the building blocks of carbon monoxide and hydrogen as well as undesired impurities, such as tars, hydrocarbons, hydrogen sulfide, ammonia, hydrogen chloride, and other trace contaminants. These impurities require removal, usually through catalytic conditioning, to produce a quality syngas for end-use synthesis of liquid fuels, such as mixed alcohols and Fischer-Tropsch liquids. In the past decade, significant research attention has been focused on these catalytic processes. This contribution builds on previous reviews and focuses on capturing the work on catalytic conditioning of biomass-derived syngas that have been performed since the Dayton review in 2002, with an emphasis on tar destruction and steam reforming catalysts. This review organizes and discusses the investigations of catalytic conditioning of biomass-derived syngas with various catalyst formulations and also discusses the roles of catalyst additives. Key technical challenges and research areas for the advancement of liquid fuel synthesis via thermochemical conversion of biomass are also discussed.