Adsorption of SO2 and chlorobenzene on activated carbon

Abstract

Activated carbon is very effective for simultaneous removal of multiple pollutants. The adsorption of SO2 and chlorobenzene modeling of VOCs on activated carbon was investigated in a fixed-bed reactor by four kinds of activated carbon. The results show that the SO2 adsorption is affected by the BET surface and basic functional groups as C=O and π–π* groups of the carbon, while the chlorobenzene adsorption is strongly affected by the carbon pore structure, with the micropore volume deciding the adsorption amount and larger pores increasing the adsorption rate. The chlorobenzene adsorption is little affected by the chemical properties of activated carbon as the O/C ratio detected by XPS. The effect of SO2 on the chlorobenzene adsorption was investigated, with the results showing the SO2 seriously restricts the individual chlorobenzene adsorption and this effect becomes smaller in the presence of O2. The adsorption products were analyzed by TPD-MS and the initial decomposition temperatures are 380 K for chlorobenzene and 500 K for SO2, showing that SO2 is much more stable adsorbed than chlorobenzene. The changes of the carbon functional groups that the CO2 desorption peak emerges at 700 K and decreases at 1000 K with the chlorobenzene adsorption, were observed by TPD-MS, indicating that the lactone and quinone groups on the carbon are likely to combine with the chlorobenzene and form weakly chemisorbed chlorobenzene.