%0 Journal Article
%T Catalytic Upgrading of Bio-Oil by Reacting with Olefins and Alcohols over Solid Acids: Reaction Paths via Model Compound Studies
%A Zhijun Zhang
%A Charles U. Pittman
%A Shujuan Sui
%A Jianping Sun
%A Qingwen Wang
%J Energies
%D 2013
%I MDPI AG
%R 10.3390/en6031568
%X Catalytic refining of bio-oil by reacting with olefin/alcohol over solid acids can convert bio-oil to oxygen-containing fuels. Reactivities of groups of compounds typically present in bio-oil with 1-octene (or 1-butanol) were studied at 120 ˇăC/3 h over Dowex50WX2, Amberlyst15, Amberlyst36, silica sulfuric acid (SSA) and Cs 2.5H 0.5PW 12O 40 supported on K10 clay (Cs 2.5/K10, 30 wt. %). These compounds include phenol, water, acetic acid, acetaldehyde, hydroxyacetone, d-glucose and 2-hydroxymethylfuran. Mechanisms for the overall conversions were proposed. Other olefins (1,7-octadiene, cyclohexene, and 2,4,4-trimethylpentene) and alcohols ( iso-butanol) with different activities were also investigated. All the olefins and alcohols used were effective but produced varying product selectivities. A complex model bio-oil, synthesized by mixing all the above-stated model compounds, was refined under similar conditions to test the catalystˇŻs activity. SSA shows the highest hydrothermal stability. Cs 2.5/K10 lost most of its activity. A global reaction pathway is outlined. Simultaneous and competing esterification, etherfication, acetal formation, hydration, isomerization and other equilibria were involved. Synergistic interactions among reactants and products were determined. Acid-catalyzed olefin hydration removed water and drove the esterification and acetal formation equilibria toward ester and acetal products.
%K bio-oil upgrading
%K model compound reactions
%K solid acid
%K reaction pathways
%K olefins
%K alcohols
%U http://www.mdpi.com/1996-1073/6/3/1568