Bio-Oil from Hydro-Liquefaction of Bagasse in Supercritical Ethanol

The liquefaction of sugar cane bagasse in supercritical ethanol, with or without various proportions of water as a proton donor, was conducted in a batch reactor to evaluate the optimal conditions for bio-oil production. The following variables were studied: temperature, initial H 2 pressure, and catalyst type (FeS, Fe 2 S 3 /AC, and FeSO 4 ). For noncatalytic liquefaction using ∼100% (v/v) ethanol, a high oil yield of 59.6% (daf) and biomass conversion of 89.8% were obtained at 330 °C under initial H 2 pressure of 4.93 MPa. For catalytic liquefaction in the presence of FeSO 4 under the same conditions, the oil yield increased to 73.8% (daf) and the biomass conversion reached 99.9%. The bio-oil obtained had a 1.81-fold higher heating value (26.8 MJ/kg) than the original starting sugar cane bagasse (14.8 MJ/kg). From gas chromatography/mass spectrometry (GC/MS) analysis, the dominant components of the liquefaction oil were found to be phenolic compounds, aldehydes, and esters, such as phenol, phenol derivatives, and furan derivatives.