Pilot Tests on the Catalytic Filtration of Dioxins

Abstract

Tests were conducted to study the removal efficiencies (REs) of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) from flue gas during a test program involving a pilot-scale catalytic filter (CF) module and a full-scale municipal solid waste incinerator (MSWI). The REs attained with the CF on a side stream and a conventional activated carbon (AC) injection and baghouse filtration system in the full-scale MSWI are evaluated via simultaneous sampling and analysis of both gas- and particle-phase PCDD/Fs. Flue gas without AC is supplied to the pilot-scale CF module for evaluating its RE capabilities. The REs achieved with the CF at 180 °C are 96.80 and 99.50%, respectively, for the gas phase and the particulate contained. The gas-phase PCDD/F RE rises significantly at 200 and 220 °C. The air/cloth (A/C) ratio defined as is the gas flow rate (m(3)/min) divided by the filtration area (m(2)) also affects the PCDD/F RE, especially in the gas phase. At 180 °C, a RE of gas-phase PCDD/Fs of 95.94% is attained with the CF at 0.8 m/min, yet it decreases at higher A/C ratios (1 and 1.2 m/min). A significantly lower toxic equivalency (TEQ) concentration (0.71 ng I-TEQ/g) was measured in the filter dust of the CF module compared to that collected by the AC adsorption system (4.18 ng I-TEQ/g), apparently because of the destruction of gas-phase PCDD/Fs by the catalyst.

Emission of unintentionally produced persistent organic pollutants (UPOPs) from municipal waste incinerators in China

“…However, one must notice the higher UPOPs concentration in fly ash of MWI D. The results reveal the drawback of AC adsorption: the mass transfer of UPOPs from gas phase into fly ash via AC adsorption is merely an expedient, but not sustainable solution. As an alternative, catalytic destruction can cause degradation of UPOPs into CO 2 , H 2 O and HCl in the form of catalytic bed (Chang et al, 2007;Hagenmaier et al, 1991;Yang et al, 2012) or filter (Hung et al, 2014;Weber et al, 2001b), would be promising approach to reduce the total amount of UPOPs emission.…”

Formation Pathways of Mono- to Octa-Chlorinated Dibenzo-p-dioxins and Dibenzofurans in Main Organochemical Industries

“…2,11,15 A recent study in Korea showed that Mo-to Tr-CDFs accounted for more than 95% of the total PCDF concentrations in serum samples collected from municipal solid waste incinerator operators and nearby residents. The results emphasized the possible significant impact that less chlorinated PCDD/Fs may have on humans and the environment, which have been almost ignored.…”

14th congress of combustion by-products and their health effects—origin, fate, and health effects of combustion-related air pollutants in the coming era of bio-based energy sources

“…The concentrations of pollutants measured in the fly ash collected in the pilot-scale catalytic filter module were significantly lower than those from conventional flue gas cleaning systems in Taiwan. However, significant formation of PAHs was still observed within the catalytic filtration system and further studies are needed to elucidate this phenomenon (Hung et al 2014, Hung et al 2011). …”