CHARACTERIZATION OF MODIFIED ACTIVATED CARBONS - EQUILIBRIA AND DYNAMICS STUDIES

The effect of pore structure on the adsorption equilibria and dynamics of a commercial activated carbon has been investigated. Pore structure was varied by carefully activating the virgin carbon in CO2 atmosphere at 800 degrees C. We have found that surface area and micropore volumes generally increase with the degree of burn-off. Adsorption capacities of two sorbates, propane and benzene, are found to increase in the range of 0-10% burn-off, and decrease in the range 10-19%, beyond which they increase again. Within the range of burn-off studied in this investigation, this increase in the adsorption capacity was 22% for propane and 27% for benzene. These activated carbons of various degrees of burn-off are also evaluated in terms of their rate of adsorption of 10% propane at 30 degrees C. It was found that the rate of adsorption increases montonically with the degree of burn-off.