Combustion characteristics and kinetic analysis of bio-oil from fast pyrolysis of biomass

The combustion characteristic of bio-oil from fast pyrolysis of pine wood sawdust in oxygen atmosphere at various heating rates was investigated by thermogravimetric analysis. It is found that there are three stages for combustion process of bio-oil:vaporization of water and devolatilization process of volatilizable components, pyrolysis process of non-volatilizable oligomers and lignin pyrolysis products, rapid combustion process of secondary coke formed by the previous two stages. According to TG data, the most probable mechanism functions selected from 22 kinetic functions in the temperature range of 400-430°C were determined and the kinetic parameters were calculated by Popescu method. It can be concluded that the combustion process in the above temperature range is a chemical reaction control process. Kinetic equations are da/dt=Ae^-E/RT(1-α)² (400-406°C), da/dt =0.5Ae^-E/RT(1-α)³ (406-416°C) and da/dt=2Ae^-E/RT(1-α)^3/2 (416-430°C) respectively.