Experimental study on bio-oil upgrading over Pt/SO42-/ZrO2/SBA-15 catalyst in supercritical ethanol

The effects of reaction conditions, including the initial hydrogen pressures (0.5 MPa, 2.0 MPa), the mass ratios of ethanol to bio-oil (5: 1, 3: 1, 2: 1, 1: 1) and reaction temperatures (260 degrees C, 280 degrees C, 300 degrees C) on catalytic upgrading of fast pyrolysis bio-oil were investigated in this work. Experiments were carried out in supercritical ethanol with bifunctional 5% Pt/SO42-/ZrO2/SBA-15 catalyst. The physical properties and organic compounds of upgraded bio-oil were compared and the mass and energy balance of certain upgrading processes were studied. The results showed that higher initial hydrogen pressure (2.0 MPa) could inhibit coke formation effectively. Increasing mass ratio of ethanol to bio-oil (5: 1, 3: 1) was helpful for desired products formation and heating value improvement as well as lower coke yield. With the rising temperature, the heating value of upgraded bio-oil increased, but the amount of desired products reduced and the formation of coke became much more serious. (C) 2012 Elsevier Ltd. All rights reserved.