Development of the Ammonia Injection Technology (AIT) for the Control of PCDD/PCDF and Acid Gases from Municipal Solid Waste Incinerators

Takács, László; McQueen, Ann; Moilanen, George L.

doi:10.1080/1073161x.1993.10467172

Cited by 15 publications

(2 citation statements)

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“…Actually, Iino and Gullett (36) have pointed out that the formation mechanism of PCDFs is completely different from that of PCDDs. Some researchers (34,(37)(38)(39) have also suggested that PCDDs and PCDFs might form in separate regions of an incinerator. While within each dioxin and furan homologue, equilibrium between the isomers seems to be easily established (12,14,35), reactions between PCDDs and PCDFs must be kinetically inhibited.…”

Section: Resultsmentioning

confidence: 99%

Thermodynamic Modeling of PCDD/Fs Formation in Thermal Processes

Tan

Hurtado

Neuschütz

et al. 2001

Environ. Sci. Technol.

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Three thermodynamic databases of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), derived using the Group Additivity approach and two computational molecular modeling methods, Modified Neglect of Diatomic Overlap (MNDO) and Parametrized Model 3 (PM3), respectively, combined with the Scientific Group Thermodata Europe (SGTE) database have been used to model the formation of PCDD/Fs in thermal processes, such as iron ore sintering process. The predictions using the three different databases are compared, and similar thermodynamic conditions of PCDD/Fs formation are found. The comparison of the calculated values with measured results obtained from industrial iron ore sinter plant indicates that the PCDDs and PCDFs found in practice are not in equilibrium with each other. While within each dioxin and furan homologue equilibrium between the isomers appears to be established in industrial processes, reactions between dioxins and furans seem to be kinetically inhibited. This view has been supported by assuming no reaction at all between PCDFs and PCDDs in the simulation. With this assumption, both PCDFs and PCDDs reached partial pressures between 600 and 800 K in the order of magnitude actually found in practice. Taking this restriction into account, the conditions for PCDD/Fs formation were calculated as a function of oxygen partial pressure; temperature; concentrations of carbon, hydrogen, and chlorine; and C/H ratio.

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Section: Resultsmentioning

confidence: 99%

Thermodynamic Modeling of PCDD/Fs Formation in Thermal Processes

Tan

Hurtado

Neuschütz

et al. 2001

Environ. Sci. Technol.

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“…This may turn out to be difficult in practice, however. Accordingly, various inhibitors have been tested both in the laboratory and in pilot plants ( − ). There is clear evidence that some compounds actually reduce PCDD/Fs in flue gases, although no final solution has been found nor has the mechanism of inhibition been completely resolved.…”

Section: Introductionmentioning

confidence: 99%

Effect of Gaseous Inhibitors on PCDD/F Formation

Ruokojärvi

Halonen

Tuppurainen

et al. 1998

Environ. Sci. Technol.

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Emissions of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) from municipal waste incineration are currently a subject of considerable public concern because of their extreme toxicity. PCDD/F formation in incineration processes is being studied widely, but studies on inhibition are quite sparse, especially in a pilot-plant scale. In this work, the effect of four gaseous inhibitors (sulfur dioxide, ammonia, dimethylamine, and methyl mercaptan) on PCDD/PCDF formation in the combustion of liquid fuel was studied using a pilot-scale plant. The inhibitors were injected into the flue gas stream after the first economizer at a temperature of 670 °C and just before the second economizer at 410 °C. Both the chlorophenol and PCDD and PCDF concentrations decreased when inhibitors were added. Particle-phase PCDD/F concentrations in particular decreased by up to 98%. The results suggest that the formation of PCDD/Fs is hindered in the particle phase at the early stages of the PCDD/F formation chain, probably even before precursors such as chlorophenols have been formed.

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Reducing dioxin formation by adding hydrogen in simulated fly ash

Yang

Meng

et al. 2015

Environ Sci Pollut Res

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In this study, simulated fly ash containing CuO/CuCl2 was heated at 350 °C in a flow of N2 and also in a nitrogen flow containing 10 vol% H2, to evaluate the influence of hydrogen adding on dioxin formation. The total polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) output derived from the CuO sample under N2 and 10 % H2 was 7.382 and 0.708 ng/g, respectively. As for CuCl2, it was 589 and 46.1 ng/g, respectively. The results show that the hydrogen adding has a good inhibition effect on PCDD/F formation; the inhibition rate was higher than 90 % for PCDD/Fs. HCl and NH3 were detected by Gasmet in the flue gas; the probable inhibition mechanism of hydrogen reaction was proposed, based on our measurements and others' researches.

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Development of the Ammonia Injection Technology (AIT) for the Control of PCDD/PCDF and Acid Gases from Municipal Solid Waste Incinerators

Cited by 15 publications

References 0 publications

Thermodynamic Modeling of PCDD/Fs Formation in Thermal Processes

Thermodynamic Modeling of PCDD/Fs Formation in Thermal Processes

Effect of Gaseous Inhibitors on PCDD/F Formation

Reducing dioxin formation by adding hydrogen in simulated fly ash

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