Estimation of Dioxins Removal Efficiency by Activated Carbon

Abstract

The effect of valid particle diameter of activated carbon on dioxins removal efficiency was explicated using a fixed bed column and 1, 2, 3, 4-tetrachlorinated dibenzo-p-dioxin (T₄CDD). In the adsorption process of T₄CDD on to activated carbon, the mass transfer rate of T₄CDD in a boundary film on activated carbon could be evaluated by the valid diameter calculated from the pressure drop through the packed bed. The mass transfer rate of T₄CDD in the pores of activated carbon increased with increasing roughness of the surface of activated carbon particles.
The dioxins removal efficiencies of a bag filter with activated carbon injected into the inlet flue gas and an adsorption tower filled with activated carbon were estimated quantitatively, using the mass transfer model and the linear-isotherm system (Henry’s law). The adsorption coefficient of activated carbon with a surface area of 181 m²/g for pores of 2-50 nm in diameter was estimated to be 6.1×10⁵ m³/kg at 170°C.