MARKED INCREASE OF SO2 REMOVAL ABILITY OF POLY(ACRYLONITRILE)-BASED ACTIVE-CARBON FIBER BY HEAT-TREATMENT AT ELEVATED-TEMPERATURES

The adsorption capacity of poly(acrylonitrile)-based active carbon fibers (PAN-ACFs) for SO2 removal in flue gas was studied at a temperature range of 298-423 K, using a fixed bed flow reactor. Heat treatment at 1073 K tripled the capacity of ACFs until the breakthrough, the amount of adsorbed SO2 at 373 K being most markedly increased from 1.1 mmol g-1 for as-received ACF-FE-300 to 3.2 mmol g-1 for the heat-treated one. Such a marked increase of adsorption capacity by heat treatment may come from the appropriate numbers of oxygen functionalities on the pore walls of PAN-ACF which are controlled through the evolution of CO and CO2 with the least decrease on the surface area.