Kinetic analysis: Simultaneous modelling of pyrolysis and combustion processes of dichrostachys cinerea

The pyrolysis and combustion of Dichrostachys cinerea were studied by dynamic thermogravimetry and derivate thermogravimetry (TG-DTG) at heating rates of 5, 20 and 40 °C min−1 at atmospheric pressure. For the simulation of pyrolysis processes a kinetic model including three independent parallel reactions was used, corresponding to the decomposition of the hemicelluloses, cellulose and lignin. For the combustion process, a fourth step is added for the oxidation at high temperatures of the pyrolytic residue. The was experimental thermogravimetric data of pyrolysis and combustion processes were simultaneously fitted to determine a single set of kinetic parameters able to describe both processes at the different heating rates. The model proposed achieves a good correlation between the experimental and calculated curves, with an error of less than 5% for the three heating rates. The experimental results and kinetic parameters may provide useful data for the design of a thermo decomposition processing system using D. cinerea as feedstock.

► Was achieved the simultaneous modelling of the pyrolysis and combustion process. ► Was determined a single set kinetic parameters with the introducing the influence of oxygen. ► The model predicts with a deviation of less than five percent the decomposition curves.