A rigorous model containing conservation equations of momentum, energy, and mass, with their k-epsilon, t((2) over bar)-epsilon(upsilon) and newly developed c((2) over bar)-epsilon(c) closing formulations was proposed for simulating the gas-solid adsorption process. The feature of the proposed model is that the unknown turbulent mass-transfer diffusivity D-t need not be estimated in advance. With this model, the breakthrough, regeneration, and temperature curves, as well as the D-upsilon were simulated for the methylene chloride adsorption and regeneration processes. The simulated results were closely checked by the published data. It was found that the D-t was unevenly distributed in the axial and radial directions, which means that the Schmidt number or Peclet number is varying throughout the adsorption column and cannot be simply represented by a constant or a simple formula. The simulated results on axial and radial concentration distributions along the column at different time are helpful to understand the process dynamics. The proposed model is especially useful for simulating the adsorption process where the turbulent mass-transfer diffusivity is unavailable.