SO2 adsorptive properties of activated carbons prepared from polyacrylonitrile and its blends with coal-tar pitch

Activated carbons prepared by steam activation of chars produced by pyrolysis of polyacrylonitrile (PAN) and its blends with coal-tar pitch (CTP) were used as the adsorbents of sulphur dioxide. The pore structure was examined by adsorption of nitrogen, benzene and carbon dioxide. Surface chemistry was monitored by XPS and pHPZC measurements. SO2 adsorption capacity at initial stage of the adsorption is directly proportional to the atomic percentage of both forms of basic nitrogen and not correlated with pore volume. At higher concentration the amount of adsorbed SO2 increases with the micropore volume calculated from benzene isotherms. Studied materials display superior SO2 adsorptive properties at concentrations close to those occurring in coal-fire utilities.