Hydro-liquefaction of woody biomass in sub- and super-critical ethanol with iron-based catalysts

Hydro-liquefaction of a woody biomass (Jack pine powder) in sub-/super-critical solution of ethanol without and with iron-based catalysts (5 wt% FeS or FeSO4) was investigated with a stainless steel micro-reactor (10 mL) at temperatures of 473–623 K and an initial pressure of hydrogen varying from 2.0 to 10.0 MPa. Without catalyst, the oil yields were in the range of 17% and 44%, depending on temperature, reaction time and initial pressure of hydrogen. With catalysts, the Oil yields significantly increased while the yields of solid residue and gases and water decreased. A high oil yield of 63% was obtained with FeSO4 at 623 K and 5 MPa of H2 for 40 min. The elemental analyses and GC/MS measurements for the Oils revealed that the liquid products have much higher heating values than the crude wood sample and phenolic compounds were dominant in the Oils, irrespective of whether or what catalyst was used.