Modeling of heat transfer in carbon material during carbonization

The effective thermal conductivities of porous coke - pitch mixtures were measured during cooling and heating processes. The thermal conductivity of the solid phase(λ_s) is estimated using a heat transfer model for a porous body. In the estimation, porosity was given based on experiments and thermal conductivity of gas phase is estimated using a pyrolysis model. The results demonstrated that λ_s is independent of temperature when no change in true density occurs, and that λ_s increases with increasing true density. λ_s is correlated with hydrogen content. The derived equation is used to predict the effective thermal conductivities of the mixtures and packed coals during carbonization. Pyrolysis models, heat transfer models and models describing macroscopic physical changes are constructed. The models agree with the experiments. This fact shows the applicability of the developed equation to coal.