This paper presents the numerical analysis of spherical carbon adsorbents produced by the single-step steam pyrolysis of a polystyrene-divinylbenzene resin. The porous structure of the materials produced this way was easily controlled by varying such factors as the carbonization temperature, atmosphere or the heating rate, allowing carbonaceous materials to have a controlled microporous structure. Due to their unique properties, the obtained adsorbents can be considered applicable in various processes in technology and environmental protection. The fast multivariant fitting procedure with the new adsorption numerical models of the LBET class was used for the analysis of the microporous structure. The computer calculations using the LBET class models with the fast multivariant identification procedure were carried out with the application of the nitrogen (77.15 K) adsorption isotherms. (C) 2012 Elsevier B. V. All rights reserved.