REMOVAL OF SO-CHI IN FLUE-GAS BY POLYACRYLONITRILE BASED ACTIVE-CARBON FIBER (PAN-ACF)

Desulfurization capacities of 17 kinds of active carbon fibers (ACF) made from polyacrylonitrile (PAN), phenol resin, cellulose and pitch were studied by measuring the adsorption of SO2 (1000 ppm) in a model flue gas (O2 5%, H2O 10% and N2) at 100 approximately 180-degrees-C using a flow reactor with a fixed chopped fiber bed. Two kinds of PAN-ACF, FE-300 and FE-200, exhibited the highest activities among ACFs when the periods until the SO2 break-through were compared. FE-300 could adsorb 7 x 10(-3) mol of SO2/g ACF before its break-through which is 20 times those of other ACFs. The influences of adsorption condition (such as concentrations of components in the flue gas, W/F and adsorption temperature) on the capacity and desorption profiles of adsorbed SO2 suggest that SO2 is adsorbed as sulfuric acid after the oxidation on ACF and that the adsorption capacity of ACF determines its capacity through the rapid adsorption of SO2 into the pores on the fibrous surface where SO2 is early oxidized into H2SO4. Surface functional groups of ACF as well as its pore size distribution may define its adsorption capacity in the presence of H2O.