Recent Advances in Upgrading of Bio-oils from Pyrolysis of Biomass

Crude bio-oils from biomass pyrolysis contain a wide variety of oxygenated compounds such as acids, phenols, aldehydes, etc., and they can only be used as transportation fuel after upgrading. Most researchers focus on deoxidation of crude bio-oils to reduce the content of oxygen. We proposed another approach as to convert chemically unstable and corrosive oxygenated components into stable and flammable oxygenated compounds. The experiments showed that the amount of acids, phenols, aldehydes, etc., decreased dramatically, while esters, alcohols, and ketones increased greatly. The recent progress in upgrading of bio-oils in authors' group is reviewed.