The morphology of the sample was observed by SEM (scanning electron microscopy) and can be seen in Fig. 5. Two images were recorded and shown that an average‘crystal’ size is difficult to specify for the case where micropore controls the diffusion process, so the parameter D /r will be reported. Also the shape is not very well cc defined, reason why we will use the sphere model for micropore diffusion, as a first approximation. In Table 3 we present the physical properties of the adsorbent.