Adsorption of volatile organic compounds on three activated carbon samples: effect of pore structure

LI Li-qing(李立清) ¹, SONG Jian-fei(宋剑飞) ^1,2, YAO Xiao-long(姚小龙) ¹, HUANG Gui-jie(黄贵杰) ¹, LIU Zheng(刘峥) ¹, Tang Ling(唐琳)

(1. School of Energy Science and Engineering, Central South University, Changsha 410083, China;
2. School of Chemical and Biological Engineering, Changsha University of Science and Technology,
Changsha 410083, China)

Abstract:To investigate the influence of the activated carbon pore structure on the adsorption of volatile organic compounds (VOCs), three commercial activated carbon samples were chosen. The fixed-bed thermostatic adsorption experiments were conducted under certain conditions, where toluene, acetone, and 1, 2-dichloroethane acted as adsorbents. Then, the incidence relation between the experimental results and the activated carbon pore structure was analyzed. After that, the results of the correlation analysis were verified in accordance with fractal theory and adsorption characteristic curve analysis. The results show that the pore diameter gradient is helpful for strengthening the internal diffusion. under the same condition, the adsorption of organic gases tends to be selective, and the positions of toluene, acetone and 1, 2-dichloroethane adsorbed on the activated carbon are mainly in the ranges of 1.27-1.49 nm, 0.67-0.84 nm and 1.39-1.75 nm, respectively. The relationship between adsorption capacity and activated carbon pore volume can accurately explain the spreading process of the adsorbents in the activated carbon.

Key words:activated carbon; volatile organic compounds; adsorption; pore structure; selectivity