High-efficiency SO2 removal on Fe-impregnated activated carbon fiber-oxidized using low-concentration oxygen gas

Carbon-based adsorbents exhibit strong adsorption capabilities for low-concentration SO₂, and thus exhibit high-efficiency removal performance of SO₂ from exhaust gas. This study aims to further improve the SO₂ adsorption capacity of pitch-based activated carbon fiber (ACF) through controlled oxidation. Pristine ACF (PACF) and Fe-impregnated ACF (FeACF) were oxidized using low-concentration oxygen gas (2 % O₂ in N₂). The results showed that the oxidation of ACFs using low concentration O₂ increased the contents of oxygen-containing surface functional groups, and the oxidation of ACFs followed by heat treatment increased the specific surface area and widened the pore size. The adsorption capacity of PACF was 150.8 mL/g-ACF. Oxidization of FeACF at 450 °C for 1 hour and heat treatment at 1100 °C increased the SO₂ removal capacity, reaching 491.0 mL/g-ACF.