Removal of PCDD/F from Incinerator Flue Gases by Entrained-Phase Adsorption

Abstract

The emission abatement of polychlorinated dioxins and furans (PCDD/F) issued from municipal solid waste incineration is growing in importance because of more stringent emission standards and general concern about their toxic characteristics. These substances cannot be separated by conventional gas cleanup processes but are successfully removed through adsorption onto carbonaceous materials. The simplest technique is the entrained-phase injection of pulverized adsorbents in the flue gas, followed by fabric filter separation. The various related techniques are briefly reviewed here. Operating conditions and results obtained from Flemish MSWIs are given. The results illustrate the excellent overall removal efficiency. Furans are adsorbed to a slightly higher extent than dioxins.PCDD/F removal by carbonaceous adsorbents is thereafter modeled from first principles for the contribution of both entrained-phase ( 1 ) and cake filtration ( 2 ) to the overall efficiency ( T ). Application of the model equations and comparison of measured and predicted overall efficiencies for the Flemish municipal solid waste incinerators (MSWIs) demonstrate that the approach is meaningful and that the dominant parameters are the operating temperature, the dosage and activity of adsorbent, and the fraction of adsorbent in the filter cake. The model equations enable the MSWI operators to predict the adsorption efficiencies for any combination of operating parameters and to assess the sensitivity of the process to varying operating conditions.

Catalytic combustion of volatile organic compounds

“…Reactions (1) and (2), and (4) and (5) are clearly not independent. The overall equilibrium is hence determined by reactions (2) and (4).…”

“…At present, the principal technology is adsorption on activated carbon [2], which however transfers the environmental burden from the gas to a solid phase, to be disposed off. Direct combustion has been the conventional incineration treatment for (C)VOCs, but temperatures exceeding 800-1200 • C are required to achieve complete destruction.…”

Evaluation of gas-particle partition of dioxins in flue gas I: Evaluation of gasification behavior of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in fly ash by thermal treatment

“…doi:10.1016/j.jhazmat.2007. 10.016 residues in flue gas are almost entirely eliminated by entrainedphase (e.g., active carbon powder or lignite coke powder) adsorption and filtration with a fabric filter (bag filter) [10][11][12]. Installation of the above-mentioned PCDD/F abatement techniques has dramatically decreased PCDD/F emissions from municipal waste incinerators.…”

Evaluation of gas-particle partition of dioxins in flue gas II: Estimation of gas-particle partition of dioxins in dust-rich flue gas by parallel sampling with different conditions

“…Some researchers estimated the gas-particle partition of PCDD/Fs on the basis of their partition in each collection device, and varying results are reported [1,[8][9][10][11][12][13]. Variations seem to be attributed to the obvious difference in temperature between flue gas and collection devices.…”