Study on the Optimized Design of DeSO_x Filter Operating at Low Temperature in Diesel Exhaust

Abstract

The removal of sulfur dioxide (SO₂) contained in the combustion exhaust gas from medium-scale facilities is necessary because of its role as an air pollutant. In this study, we focus on dry DeSO_x filters that use simple desulfurization materials to capture SO₂; in particular, we used manganese dioxide (MnO₂) that takes part in the sulfation (MnO₂+SO₂→MnSO₄). We determined the reactivity of high-surface-area MnO₂ (HSSA MnO₂) with SO₂ using thermogravimetry. We obtained the desulfurization rate for a sample of MnO₂ that was wash-coated on a monolith. The MnO₂ sample, having a specific surface area of 250 m²/g, absorbed 0.43–0.45 g_SO2/g_MnO2. Under this experimental condition, the conversion of the sulfation was dependent on the amount of the supported MnO₂. The absorption efficiency of these samples was more than 90.0%. Based on our results, we estimated that 20 m³ of absorbent was required to capture the exhaust gas of an ocean ship with a crossing time of 20 d, operating at 8,500 kW power at 450°C.