The influence of increased excess air on the formation of PCDD/PCDF in a municipal waste incineration plant

Nottrodt, A; Duwel, U; Ballschmiter, Karlheinz

doi:10.1016/0045-6535(90)90351-s

Cited by 9 publications

(5 citation statements)

References 4 publications

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“…To decrease the PCDD/ Fs emission effectively, it is necessary to investigate the effects of the furnace temperature on their formation during waste incineration. However, the furnace temperature is determined by operating conditions such as the amount of air and waste supplied, making it difficult to examine those effects in detail in actual waste incineration facilities (10). Additionally, in many cases, flue gas temperature at the outlet of the combustion furnace is controlled as the combustion temperature in the actual facilities and the temperature of each part in the furnace, such as primary and secondary combustion zones, are not examined separately.…”

Section: Introductionmentioning

confidence: 99%

Effects of Combustion Temperature on PCDD/Fs Formation in Laboratory-Scale Fluidized-Bed Incineration

Hatanaka

Imagawa

Kitajima

et al. 2001

Environ. Sci. Technol.

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Combustion experiments in a laboratory-scale fluidized-bed reactor were performed to elucidate the effects of combustion temperature on PCDD/Fs formation during incineration of model wastes with poly(vinyl chloride) or sodium chloride as a chlorine source and copper chloride as a catalyst. Each temperature of primary and secondary combustion zones in the reactor was set independently to 700, 800, and 900 degrees C using external electric heaters. The PCDD/Fs concentration is reduced as the temperature of the secondary combustion zone increases. It is effective to keep the temperature of the secondary combustion zone high enough to reduce their release during the waste incineration. On the other hand, as the temperature of the primary combustion zone rises, the PCDD/Fs concentration also increases. Lower temperature of the primary combustion zone results in less PCDD/Fs concentration in these experimental conditions. This result is probably related to the devolatilization rate of the solid waste in the primary combustion zone. The temperature decrease slows the devolatilization rate and promotes mixing of oxygen and volatile matters from the solid waste. This contributes to completing combustion reactions, resulting in reducing the PCDD/Fs concentration.

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Section: Introductionmentioning

confidence: 99%

Effects of Combustion Temperature on PCDD/Fs Formation in Laboratory-Scale Fluidized-Bed Incineration

Hatanaka

Imagawa

Kitajima

et al. 2001

Environ. Sci. Technol.

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“…A correlation between formation of polyaromatic hydrocarbons (PAHs) and low CE has been reported (4); however, the conditions that favor the formation of PAH have been found to suppress the formation of CDD/Fs as well (4,5). Low levels of CO and/or high oxygen level in the combustion gas are not a guarantee for low OMP emissions or vice versa (4,(6)(7)(8)(9)(10)(11). The level of CO in the combustion gas is not the only parameter of importance for the CDD/F emission.…”

Section: Introductionmentioning

confidence: 99%

Influence of Variation in Combustion Conditions on the Primary Formation of Chlorinated Organic Micropollutants during Municipal Solid Waste Combustion

Wikström

Tysklind

Marklund

1999

Environ. Sci. Technol.

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The aim of this study was to investigate the influence of variation in combustion conditions on the primary formation of organic micropollutants (OMPs). The flue gas samples were taken at a relatively high flue gas temperature (650 °C), to enable mechanistic studies on the high temperature formation (primary formation). Eleven experiments were performed in a laboratory scale fluidized bed reactor fed with an artificial municipal solid waste (MSW). The samples were analyzed for mono- to octachlorinated dibenzo-p-dioxins and dibenzofurans (CDDs/Fs), tri- to decachlorinated biphenyls (CBs), di- to hexachlorinated benzenes (CBzs), and di- to pentachlorinated phenols (CPhs). In addition to chlorinated OMPs, nonchlorinated dibenzo-p-dioxin (DD), dibenzofuran (DF), and biphenyl (BP) were analyzed. The experiments show that variations in the CE influence the degree of chlorination of the organic micropollutants. A correlation between low CE and formation of non- and low-chlorinated OMPs was seen and a distinct relationship of higher chlorinated homologues and efficient combustion condition. Thus, the DiCDFs and DiCBzs are formed during low combustion efficiency (CE), while the PeCDF and PeCBzs formation take place at higher CE. The distribution between primary and secondary air is important for the formation of higher CDD/Fs and CBzs. The primary formation of CDDs and CDFs is through different mechanisms. The CDDs are mainly formed by condensation of CPhs, while the CDFs are formed through a non- or a low-chlorinated precursor followed by further chlorination reactions.

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“…Correlations between PCDD/Fs and flue gas chemical parameters such as fluoridric acid, chloridric acid, water, carbon monoxide, oxygen, nitrogen oxides, and polycyclic aromatic hydrocarbons in a large volume of MSWI emissions in Flanders, Belgium, have been evaluated without any significant result. 1 Combined effects of oxygen, carbon monoxide, and temperature in PCDD/F formation were shown by Nottrodt et al, 3 while the influence of oxygen-nitrogen atmosphere has been found by Pekarek et al 13 Effects of combustion temperature on PCDD/F formation in laboratory-scale incineration have been found by Hatanaka et al, 14 while Weber et al 8 found that less PCDD/F is formed on fly ash with high pH in fluidized bed incinerators. Other authors evaluated the influence of a large number of chemical, physical, and operating parameters on PCDD/F emission levels from different kinds of MSWIs.…”

Section: Principal Pcdd/f Formation Mechanism In Mswismentioning

confidence: 97%

“…Literature data concerning the contents of PCDD/Fs in fly ash collected in the flue gas lines of MSWIs are scarce. Nottrodt et al 3 tested samples of boiler ash and ESP dust under different operating conditions. This paper describes the results obtained on PCDD/F contents in fly ash collected at two MSWIs.…”

Section: Introductionmentioning

confidence: 99%

Generation of PCDD/F in Fly Ash from Municipal Solid Waste Incinerators

Littarru

Vargiu

2003

Journal of the Air & Waste Management Association

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Fly ash from municipal solid waste incinerators (MSWIs) has been characterized in terms of polychlorinated dibenzyl-p-dioxin and polychlorinated dibenzofuran (PCDD/F) content. Increasing values of PCDD/Fs have been found to correlate with decreasing temperatures of sampling points in flue gas treatment lines of the plants, confirming other researchers' findings about temperature as the major controlling parameter for the PCDD/F formation. Measured PCDD/F ratios show that de novo synthesis is the dominant formation mechanism. The increasing trends of particulate-bound PCDD/Fs can be explained not only through the dominant de novo synthesis process but also considering the adsorption of gaseous PCDD/Fs on fly ash deposits, even outside the typical de novo synthesis temperature ranges. The effective role of a postcombustor unit, imposed by Italian law to destroy PCDD/ Fs, also needs to be carefully reconsidered.

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The influence of increased excess air on the formation of PCDD/PCDF in a municipal waste incineration plant

Cited by 9 publications

References 4 publications

Effects of Combustion Temperature on PCDD/Fs Formation in Laboratory-Scale Fluidized-Bed Incineration

Effects of Combustion Temperature on PCDD/Fs Formation in Laboratory-Scale Fluidized-Bed Incineration

Influence of Variation in Combustion Conditions on the Primary Formation of Chlorinated Organic Micropollutants during Municipal Solid Waste Combustion

Generation of PCDD/F in Fly Ash from Municipal Solid Waste Incinerators

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