Adsorption and thermal regeneration of methylene chloride vapor on an activated carbon bed

An experimental and theoretical study was made of the adsorption and regeneration of methylene chloride vapor in a fixed bed of activated carbon, using nitrogen carrier gas. A nonequilibrium, nonadiabatic mathematical model was developed to calculate concentration and temperature curves for both adsorption and regeneration runs. A linear driving force mass transfer model was found to be an acceptable fit to the experimental data. Experimental and modeling results were used to study the effects of operation variables, such as purge temperature, initial bed temperature, and feed concentration of adsorption step. Also, regeneration efficiency was discussed on the basis of specific energy requirement and purge gas consumption. The optimum purge gas temperature increased as the desorption process progresses and the regeneration time was not affected by changes in feed concentration during the adsorption step. The cooling step followed by hot purge regeneration step in the TSA cycle might be omitted for the methylene chloride vapor and activated carbon system. (C) 1997 Elsevier Science Ltd.