The effect of reaction temperature on catalytic upgrading of bio-oil in ethanol

Experiments on catalytic upgrading of bio-oil were demonstrated in ethanol using 5wt%Pt/SO₄²-/ZrO₂/SBA-15 catalyst under 0.5MPa initial hydrogen pressure. The effect of reaction temperature (220°C, 240°C and 260 °C) on bio-oil upgrading performance was investigated. The results showed that the physical properties and organic composition of the upgraded bio-oil were all improved in contrast to crude bio-oil. With the temperature increasing from 220°C to 260°C, the proportion of desired products (esters, alcohols, ketones and ethers) increased and the pH values, heating values deducting the content of ethanol and water were elevated remarkably. The coke selectivity at the reaction temperature of 260°C was reduced evidently and presented a minimum compared with that at 220 °C and 240 °C. The results of analysis proved that the supercritical ethanol at 260 °C facilitated the catalytic upgrading process better than subcritical and near-critical ethanol.