EFFECTS OF RELATIVE HUMIDITY ON THE ADSORPTION CHARACTERISTICS FOR METHYL-ETHYL-KETONE VAPOR ON THE ACTIVATED CARBON

摘要

In this research, the effects of relative humidity (RH) in waste gas for the adsorption characteristics of methyl-ethyl-ketone (MEK) vapor on the activated carbon are investigated. The adsorption characteristics, such as adsorption capacity, isotherm curve, adsorption rate, and breakthrough curve, for methyl-ethyl-ketone vapor on activated carbon at various relative humidity values are determined. From the experimental results of this research, the relative humidity and the concentration of MEK vapor both are inter-linking to affect the adsorption characteristics of MEK vapor on the activated carbon. The adsorption capacity of water vapor on the activated carbon will increase very quickly, when the RH in inflow gas is greater than 70-80%. The effects of RH for MEK adsorption on activated carbon are very slightly when the RH in inflow gas is lower than 60% and the inflow concentration of MEK vapor is 200 ppm. But, when the concentration of MEK vapor increases from 200 ppm to 4500 ppm, the effects of RH for MEK adsorption on activated carbon are gradually significant. Especially, the MEK adsorption capacity decreases to 56-77% as the RH in adsorption process increases to 90%. The adsorption rate constants, k_v, of Wheeler equation for MEK vapor on activated carbon at the various RH% are fitted. The fitting results are shown that the average k_v values at the various RH%, 0%, 30%, 60%, and 90%, are 4802, 4828, 3829, and 3108, respectively. In this study, the best fitting correlation between k_v and RH is obtained by the following equation: k_v = -0.21 (RH)~2 - 1.6 (RH) + 5802, R~2 = 0.96