Minimum feeding rate of activated carbon to control dioxin emissions from a large-scale municipal solid waste incinerator.

To obtain a minimum feeding rate (F(min)) of activated carbon (AC), a series of measurements on dioxin emission concentration were carried out in a large-scale municipal solid waste incinerator. It was found that dioxin removal efficiency (eta) increased with an increase in AC feeding concentration. This had an almost linear function to F/Q when F/Q was less than 65 g/Nm(3), where F was the AC feeding rate (mg/min), and Q was the volumetric flow rate of flue gas (Nm(3)/min). However, it did not seem to be affected by F/Q, when F/Q was larger than 150 mg/Nm(3). On the basis of the experimental data obtained in this study, the removal efficiency of dioxins by the application of AC could be correlated as eta (%)=100/[1.0+(40.2/(F/Q)(3))]. It is valid in appropriate conditions (F/Q=10-300 mg/Nm(3)) suggested by the study with a statistical error of +/-18%. The correlation would be applied to estimate the dioxin removal efficiency (eta) using the F/Q value. For engineering applications, the (F/Q)(min) could be solved using a graphic illustration method, by which the minimum feeding rate (F) was obtained if the flue gas volumetric flow rate (Q) was known.