Characterization of carbon cryogel microspheres as adsorbents for VOC.

Adsorption characteristics of carbon cryogel microspheres (CC microspheres) with controlled porous structure composed of mesopores (2 nm<d(p)<50 nm; d(p) is pore diameter) and micropores (d(p)<2 nm) were studied to examine their suitability as adsorbents for a volatile organic compound (VOC). The amount of toluene, as a model VOC, adsorbed on the CC microspheres could be changed by varying either the size of the mesopores or the volume of the micropores. The peak temperature of the temperature-programmed desorption profiles of toluene from the CC microspheres was higher than that from granular activated carbon (GAC) with numerous micropores, indicating that toluene is adsorbed more strongly on CC microspheres than on GAC. To permit the practical use of CC microspheres, the adsorption characteristic of moisture on CC microspheres and GAC were evaluated. The effect of adsorption of moisture on the gas permeation property of an adsorption module prepared from the CC microspheres was also examined.