for the micropore dausivity, the Di values given in Table 2 correspond to ro = 10 microns. Such dgusivities are of the order of 1 x lo-" m2/s and are somewhat lower for the more strongly adsorbed SO? and H2S than for COP. Values of the same magnitude were reported by Chihara et al. (1978)for rare-gas adsorbates in molecular-sieving carbon and by Walker et al. (1966) for micropore transport of COP in coal particles. The activation energies obtained from an Arrhenius plot of the DJr:, values increase from 1.4 for CO, to 1.8 for H2S and to 5.0 kcalimol for SOz. The lower micropore digusivities for H2S and SO, are expected in view of the stronger attraction between wall atoms and absorbate molecule for t h e sulfur-containing gases.Further, such results would not be expected if the micropore transport occurred by a pore-volume rather than a surface transport process.