Mechanism and mathematical model of Huadian oil shale pyrolysis

In this paper, pyrolysis characteristics of oil shale obtained from Huadian, China, are investigated by thermogravimetry method. The effect of operating conditions, such as particle size, heating rate on the pyrolysis process is analyzed, and kinetic parameters of pyrolysis at different heating rates are calculated using a two-stage Arrhenius model that is solved by the Freeman-Carroll method. On the basis of these experimental results and theoretical analysis, a mathematical model, fully suitable for the pyrolysis characteristics of oil shale, is developed: mass loss rate is described by a two-stage intrinsic kinetics equation for reducing the calculation error; pyrolytic heat value of volatile is contained in energy equation, and density equation is considered as well, due to the release of a large amount of volatiles in pyrolysis process. Thermogravimetric experimental data are used to validate the described models.