SO2 adsorption capacity of K2CO3-impregnated activated carbon as a function of K2CO3 content loaded by soaking and incipient wetness

The SO2 adsorption capacity of K2CO3-impregnated activated carbons, prepared by soaking carbon in large volumes of K2CO3 in solution of various concentrations, varies linearly with respect to the loading of K2CO3 on the carbon up to about 12% K2CO3 by weight. Above 12%, the capacity for SO2 levels out and then decreases. This suggests that at high loadings the K2CO3 either aggregates and/or blocks pores of the activated carbon. In contrast, the adsorption capacity of carbons prepared by repeatedly (maximum of three times total) loading K2CO3 via incipient wetness is much larger than that of the soaked samples, up to 70% more, when the loading of K2CO3 is greater than 12%. Static and dynamic adsorption, DSC, SEM, EDX and incipient wetness studies of the samples show that the impregnant aggregates but does not block carbon pores.