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 activated 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 ACF. Especially, after several adsorption-desorption cycles, there was a significant drop in the adsorption capacity of the GAC within 20% whereas the adsorption capacity of the ACF dropped within 5%. Because adsorption affinity on the ACF became stronger for toluene, MEK, and n-hexane in sequence, roll-up phenomena appeared for binary and ternary systems. Because the roll-up phenomenon was affected by the molar ratio (MR), the magnitude of roll-up 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 concentration component and strongest adsorbed component played an important role in steam regeneration.