Porous Texture Characterization of Coals and Chars

Abstract
The chemical and physical characteristics of six Spanish coals and their corresponding chars were studied. Apparent surface area, density and porosity data were determined. The apparent surface areas obtained by CO2 adsorption at 298 K and 273 K are much higher than those obtained by N2 adsorption at 77 K. This indicates that a fraction of the micropropores of the samples is not accessible to the N2 molecules. The apparent surface area and porosity of the coal samples were studied as a function of the coal rank. The changes in the porous texture of the coal samples when they are thermally converted to chars were analysed.