Özet:

Kinetic modeling of thermochemical conversion methods such as pyrolysis is one of the most challenging issues for bio-refineries. It is known that cellulose together with hemicellulose and lignin mainly affect the characteristics of biomass pyrolysis. However, there is still limited knowledge about the thermal behaviors of biopolymers that go into complex multi-phase pyrolysis reactions in the literature. Therefore, cellulose pyrolysis kinetics and thermodynamics were investigated in this study. Kinetic parameters of the pyrolysis process were calculated by a combined method of master-plots and Friedman method. Active pyrolysis of cellulose is found to occur between 263 and 455 °C. Applied Friedman method was perfectly fitted with the experimental data and activation energy of the thermochemical conversion process was found between 150.8 and 190.2 kJ/mol while the mean activation energy was calculated as 164.3 kJ/mol. The comparison of kinetic models used of solid-state thermal decomposition processes indicated that the cellulose pyrolysis mechanism is a diffusion-controlled (D3) degradation process at lower conversions (0<α<0.5) and the process can be explained by reaction-based mechanisms at higher conversion degrees.

Anahtar Kelimeler: