Supercritical solvent composition influence on bio-oil model compound deoxygenation

Hydrofining of oxygen-containing compounds of bio-oil allows efficient use of the final product as a liquid fuel from biomass. Deoxygenation is considered to be one of the most perspective ways to modernize bio-oil. Generally, deoxygenation is carried out under fairly strict conditions in the presence of hydrogen in a medium of high-boiling hydrocarbons. This paper describes a new approach to deoxygenation of model compounds of bio-oil using supercritical liquids as a solvent and hydrogen donor. The possibility of using a complex solvent consisting of non-polar n-hexane with a low critical point (Tc = 234.5 °C, Pc = 3.02 MPa) and propanol-2 used as a hydrogen donor is evaluated. Experiments have shown that in the presence of 20 vol.% propanol-2 in n-hexane a maximum (99%) conversion of model bio-oil compounds with the formation of phenols with a yield of up to 95% is observed.