Kinetic investigation on partially oxidized Huadian oil shale by thermogravimetric analysis

The kinetic parameters of Huadian oil shale and its solid residues after preheating treatment at different temperatures were evaluated by thermogravimetric (TG) analysis. As per distinct properties of oil shale, TG curves were divided into five separate stages during pyrolysis. The kinetic parameters were calculated based on TG results related to three stages ranging from 250 to 550 °C, using the Arrhenius theory and Coats-Redfern and Flynn-Wall-Ozawa methods. The results showed that the burning of oil shale and its solid residues was a complicated multi-step kinetic process. The activation energies of residues were reduced after preheating treatment below 300 °C. Moreover, the activation energies calculated from the Coats- Redfern method increased with increasing heating rate.