Bio-oil Deoxygenation by Catalytic Pyrolysis: New Catalysts for the Conversion of Biomass into Densified and Deoxygenated Bio-oil

This work proposes an innovative catalytic pyrolysis process that converts bio-refinery residues, such as spent grains, into intermediate bio-oil with improved properties compared to traditional bio-oils, which allows the use of existing crude-oil refinery settings for bio-oil upgrading into fuels. The integration of bio-oil into a crude-oil refinery would decrease the economic disadvantage of biomass compared to fossil fuels. The catalytic pyrolysis was able to produce bio-oil with a lower O and N content and high levels of aliphatics and H by using activated serpentine and olivine at 430460?degrees C. The activated materials seem to be beneficial to the bio-oil energy content by increasing it from less than 20 MJ?kg-1 in the original biomass to 26 MJ?kg-1. Approximately 7074?% of the starting energy remains in the bio-oil using activated olivine (ACOL) and activated serpentine (ACSE) at 430?degrees C, whereas only 52?% is retained using alumina (ALU) at the same temperature. There was a strong reduction of the O content in the bio-oils, and the deoxygenation power decreased in the following order: ACOL>ACSE>ALU. In particular, ACOL at 430-460?degrees C was able to reduce the O content of the bio-oil by 40?%. The oxygenated bio-oil macromolecules interact in the catalysts active sites with the naturally present metallic species and undergo decarboxylation with the formation of C5C6 O-depleted species.