Carbon Gasification Promoted with Coexisting Components of NO and H₂O for Oxidative Sorption Process of SO₂ over Porous Carbon

Abstract

Gas mixtures simulated a stational exhaust, composed of SO₂(1000ppm), 0₂(5%), H₂O (8%), NO(1000ppm) and N₂ as balance gas, were applied for the desulfurization carbon sorbents with or without Fe₂O₃ prepared from impregnation of saw dust powder into water or a ferrous sulfate solution followed by drying and carbonization in a N₂ stream at 850°C. Thermogravimetric analyses were carried out on the weight increase by oxidative sorption of SO₂ and the weight decrease by carbon gasification in the various gas mixtures at a constant temperature over 150°C to 350°C.
Coexistence of H₂O or NO-H₂O into the SO₂-O₂-N₂ mixture enhanced both oxidation potential of SO2 and gasification potential of carbon component of the sorbent: the sorption of SO₃/H₂SO₄ predominated to increase sample weight at lower temperature 150°C, but carbon gasification predominated at above 250°C, where no gasification occurred with the SO₂-O₂-N₂ mixture below 250°C.