Adsorption of ethanol onto parent and surface treated activated carbon powders

摘要

In this paper, adsorption isotherms and kinetics of ethanol onto highly porous activated carbon powders have been investigated. Adsorbents used in the present study are (ⅰ) parent Maxsorb Ⅲ, (ⅱ) KOH-H_2 treated Maxsorb III, and (ⅲ) H_2 treated Maxsorb Ⅲ. Adsorption isotherms and kinetics of the assorted pairs have been measured using magnetic suspension adsorption measurement unit (MSB-VG-S2). Experiments have been conducted across assorted adsorption temperatures that are useful for the operation of adsorption chillers. The Dubinin-Astakhov equation is used to fit adsorption isotherms of parent Maxsorb Ⅲ/ethanol and KOH-H_2 treated Maxsorb Ⅲ pairs whilst the Dubinin-Radushkevich isotherm model is found to be more suitable for fitting of adsorption uptake of H_2-treated Maxsorb Ⅲ/ethanol pair. Adsorption kinetics of assorted pairs are presented by the Fickian diffusion model. Experimental results show that, among the assorted pairs, H_2 treated Maxsorb Ⅲ/ethanol pair possesses the highest adsorption equilibrium uptake. However, the diffusion time constant of KOH-H_2 treated Maxsorb Ⅲ is found to be higher than that of other two studied pairs.