Palygorskite as an excellent adsorbent material shows a predominant performance on the adsorption of small gaseous polar molecules

which can be remarkably improved by suitable thermal treatment. In this study

the SO2 removal from the flue gas is investigated with the palygorskite treated at different temperatures. The structural transformation of palygorskite desulfurizer during the heat treatment process was characterized by XRD，BET and TPD. A correlation between structural characteristics and desulfurization performance of palygorskite adsorbent was discussed. Results indicate that

as the heat treatment temperature increases

the micro-crystal structure of palygorskite displays significant step changes

which is suggested to be closely related to the removal of water in different forms from palygorskite surface. The adsorption capacity of SO2 on palygorskite first increases and then decreases as the heat treatment temperature increases. Based on these results

it can be deduced that the water adsorbed on the surface and that in the pores of palygorskite inhibit the adsorption of SO2

but the crystalline water is favorable for SO2 adsorption.