Thermal decomposition kinetic of hybrid poplar sawdust as biomass to biofuel

•The kinetic analysis of hybrid poplar sawdust was investigated.•The existence of a complex multi-step reaction that occurs during thermal decomposition.•The calorific value of the biomass was 19539 kJ/kg.

In order to reveal the kinetic mechanism of thermal decomposition of hybrid poplar sawdust as biomass to produce biofuel, the thermogravimetric experiments were carried out at four different heating rates, 5, 10, 15 and 20 °C min−1 using a thermogravimetric analyzer under air atmosphere. The kinetic analysis was performed according to the Ozawa-Flynn-Wall method. The results showed that the activation energy altered from 38.08 kJ/mol to 141.47 kJ/mol. The pre-exponential factor values showed empirical first order reaction. The Gibbs free energy values changed from 102.76 kJ/mol to 184.82 kJ/mol, and the entropy changes were negative, showing that the disorder degree of products obtained by degradation was lower than that of initial compounds. The calorific value of the biomass was 19539 kJ/kg.