Adsorption and steam regeneration of n-hexane, MEK, and toluene on activated carbon fiber

The adsorption and steam regeneration of n-hexane, MEK, and toluene on an a ctivated carbon fiber (ACF) were conducted for single, binary, and ternary systems and were compared with those on a granular activated carbon (GAC). An ACF bed showed not only larger adsorption capacity but also faster steam regeneration than the GAC bed. Also, the tailing effect of desorption on a GAC loaded with polar MEK was significant compared with the result on an A CF. Especially, after several adsorption-desorption cycles, there was a sig nificant drop in the adsorption capacity of the GAC within 20% whereas the adsorption capacity of the ACF dropped within 5%. Because adsorption affini ty on the ACF became stronger for toluene, MEK, and n-hexane in sequence, r oll-up phenomena appeared for binary and ternary systems. Because the roll- up phenomenon was affected by the molar ratio (MR), the magnitude of roll-u p increased with a decrease of MR. Therefore, the adsorption step in a TSA process could be determined largely by the behavior of a weak adsorbate in the adsorption bed, whereas a strong adsorbate could play a key role in the steam regeneration step. However, under a high MR, both the high concentra tion component and strongest adsorbed component played an important role in steam regeneration.