Kinetic studies on the pyrolysis and combustion of bio-oil

Thermogravimetric analysis of the bio-oil produced from wood powder by self-heating biomass fast pyrolysis facility was carried out in O(2) and N(2) atmosphere under different heating rates (5 degrees C/min-20 degrees C/min) to a maximum temperature of 1000 degrees C. The results indicate that bio-oil pyrolysis occurs in two steps. The first concerns the evaporation of low-boiling point compounds (formaldehyde, acetone, methanol, ethanol and so on) and the reactions among different compounds and then followed by the cracking of heavy fractions. Bio-oil combustion occurs in three steps. The first two are similar with the process of bio-oil pyrolysis, and then the char formed during the previous process of evaporating and cracking combusts rapidly. Both the DTG and DSC curves show a peak value corresponding to the combustion of the solid residue. On the basis of TG data, the kinetic fittings of each reaction period during pyrolysis and combustion were carried out.