Dechlorination/hydrogenation and destruction reactions of PCDDs in OCDD-added fly ash heated under vacuum

Misaka, Youhei; Abe, Tsuyoshi; Takeuchi, Keigo; Ohba, Kazuo; Sawabe, Kyoichi; Shobatake, Kosuke

doi:10.1016/j.chemosphere.2006.01.079

Cited by 11 publications

(7 citation statements)

References 27 publications

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“…Several methods for dioxin detoxification of incineration fly ash have been proposed both in solid phase [26][27][28][29][30][31][32][33] and in liquid fly ash extracts [34][35][36][37]. Among them, liquid phase catalytic hydrodechlorination (LP-HDC) over Pd supported catalyst is a promising technique for fly ash dioxin degradation since high conversions are obtained after short reaction times under moderate reaction conditions [34][35][36][37].…”

Section: Introductionmentioning

confidence: 99%

Characterization of fly ash from a hazardous waste incinerator in Medellin, Colombia

Cobo

Gálvez

Conesa

et al. 2009

Journal of Hazardous Materials

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Section: Introductionmentioning

confidence: 99%

Characterization of fly ash from a hazardous waste incinerator in Medellin, Colombia

Cobo

Gálvez

Conesa

et al. 2009

Journal of Hazardous Materials

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“…A further increase in the oxygen content to 21% in Experiment B-2 decreased the concentration of PCDD/Fs to 103 ± 27 pg g −1 (2.4 ± 0.4 pg I-TEQ g −1 ). Similarly, the study by Misaka et al 22 indicated that increasing oxygen content promotes the thermal degradation of PCDD/Fs, while Shibata et al 23 indicated that the formation of PCDD/Fs via the de novo synthesis weakens under an oxygen content higher than 10%.…”

Section: Resultsmentioning

confidence: 93%

Thermal reaction characteristics of dioxins on cement kiln dust

et al. 2018

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Cement kiln dust is commonly recycled back into the production process. This results in elevated concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the flue gases of cement plants. The present study investigated the effects the reaction temperature, oxygen content, and origin of kiln dust had on the thermal reaction characteristics of PCDD/Fs. The concentration of 2,3,7,8-PCDD/Fs that were desorbed from the kiln dust decreased as the reaction temperature was increased and the higher temperature facilitated the degradation of PCDD/Fs. However, the oxygen content, which ranged from 6-21%, had only a minor impact on the thermal reaction characteristics of PCDD/Fs. Finally, the thermal reaction characteristics of PCDD/Fs were largely affected by the origin of the kiln dust; 1.2 pg I-TEQ g À1 was desorbed from kiln dust originating from a cement plant that co-processed refusederived fuel (RDF) and 47.5 pg I-TEQ g À1 was desorbed from kiln dust originating from a cement plant that co-processed hazardous waste. The study also found that PCDD/F formation pathways were dependent on the origin of the kiln dust; precursor synthesis dominated PCDD/F formation on the kiln dust collected from a cement plant that co-processed RDF, while de novo synthesis dominated the formation of PCDD/Fs on the remaining samples of kiln dust.

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“…The dust was mostly fine fly ash particles, which would have been carried by the flowing nitrogen. Misaka et al (2006a) measured destruction of PCDDs in OCDD-added fly ash (to give an OCDD content of 5500 ng g −1 ) was heated under vacuum. They found that the TEQ decreased by more than 99% when the fly ash was heated to 377 °C for 4 h, but the total amount of desorbed PCDDs and dibenzo-p-dioxin present in flue gas relative to that of added OCDD was about 17%.…”

Section: Desorption and Regeneration Behaviour Of Pcdd/fsmentioning

confidence: 99%

A full-scale study on thermal degradation of polychlorinated dibenzo-p-dioxins and dibenzofurans in municipal solid waste incinerator fly ash and its secondary air pollution control in China

Gao

Yan

et al. 2016

Waste Manag Res

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Degradation of polychlorinated dibenzo- p-dioxins and dibenzofurans in municipal solid waste incinerator fly ash is beneficial to its risk control. Fly ash was treated in a full-scale thermal degradation system (capacity 1 t d) to remove polychlorinated dibenzo- p-dioxins and dibenzofurans. Apart from the confirmation of the polychlorinated dibenzo- p-dioxin and dibenzofuran decomposition efficiency, we focused on two major issues that are the major obstacles for commercialising this decomposition technology in China, desorption and regeneration of dioxins and control of secondary air pollution. The toxic equivalent quantity values of polychlorinated dibenzo- p-dioxins and dibenzofurans decreased to <6 ng kg and the detoxification rate was ⩾97% after treatment for 1 h at 400 °C under oxygen-deficient conditions. About 8.49% of the polychlorinated dibenzo- p-dioxins and dibenzofurans in toxic equivalent quantity (TEQ) of the original fly ash were desorbed or regenerated. The extreme high polychlorinated dibenzo- p-dioxin and dibenzofuran levels and dibenzo- p-dioxin and dibenzofuran congener profiles in the dust of the flue gas showed that desorption was the main reason, rather than de novo synthesis of polychlorinated dibenzo- p-dioxins and dibenzofurans in the exhaust pipe. Degradation furnace flue gas was introduced to the municipal solid waste incinerator economiser, and then co-processed in the air pollution control system. The degradation furnace released relatively large amounts of cadmium, lead and polychlorinated dibenzo- p-dioxins and dibenzofurans compared with the municipal solid waste incinerator, but the amounts emitted to the atmosphere did not exceed the Chinese national emission limits. Thermal degradation can therefore be used as a polychlorinated dibenzo- p-dioxin and dibenzofuran abatement method for municipal solid waste incinerator source in China.

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Dechlorination/hydrogenation and destruction reactions of PCDDs in OCDD-added fly ash heated under vacuum

Cited by 11 publications

References 27 publications

Characterization of fly ash from a hazardous waste incinerator in Medellin, Colombia

Characterization of fly ash from a hazardous waste incinerator in Medellin, Colombia

Thermal reaction characteristics of dioxins on cement kiln dust

A full-scale study on thermal degradation of polychlorinated dibenzo-p-dioxins and dibenzofurans in municipal solid waste incinerator fly ash and its secondary air pollution control in China

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