Three-dimensional numerical simulations of the combustion process in a heat-recovery coke oven were carried out using the eddy dissipate concept combustion model, which give an in-depth understanding of behaviors in the heat-recovery coke oven and provide useful information for optimizing operations and design. Four different coal devolatilization models, including a single-step model, a two competing reaction rate model, and distributed activation energy models (k = constant, and k = ae(bE)), were employed to assess the volatile matter evolution rate and temperature distribution in the oven. In comparison to the experimental data, the distributed activation energy model (k = ae(bE)) gives a more satisfied prediction and was further extended to study the distributions of volatile species and pressure in the oven. All of the simulation results have been proven to be converged, grid-independent, and reliable.