Predictions for isomer distributions of toxic dioxins and furans in selected industrial combustion processes

Tan, Pengfu; Hurtado, I.; Neuschütz, D.

doi:10.1016/s0045-6535(01)00250-8

Cited by 6 publications

(12 citation statements)

References 12 publications

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“…This means that other operating conditions such as the concentrations of reactants (O 2 , CO, CO 2 , H 2 O, Cl, or some chlorinated precursors) have no infl uence on the isomer distribution of PCDD/Fs within each homologue. 19 The calculated isomer distribution of PCDD/Fs could be fi tted to the experimental data for PCDD/Fs in soot from wood combustion. 18 Tan et al 19 also calculated thermodynamic properties using the MNDO method and then obtained the isomer distribution of PCDD/Fs using Eqs.…”

Section: Calculation Of Isomer Distributionmentioning

confidence: 99%

“…19 The calculated isomer distribution of PCDD/Fs could be fi tted to the experimental data for PCDD/Fs in soot from wood combustion. 18 Tan et al 19 also calculated thermodynamic properties using the MNDO method and then obtained the isomer distribution of PCDD/Fs using Eqs. 1 and 2.…”

Section: Calculation Of Isomer Distributionmentioning

confidence: 99%

“…For this reason, discussion of the isomer distribution that is obtained using the computational molecular modeling method can be useful. Therefore, by analogy with Tan et al's report, 19 we also calculated the thermodynamic properties using the MNDO method and then obtained the isomer distribution using Eqs. 1 …”

Section: Calculation Of Isomer Distributionmentioning

confidence: 99%

“…According to the calculations of Tan et al, 19 the isomer distribution of toxic 2,3,7,8-chlorine-substituted isomers varied with temperature. Therefore, it seems possible to give one temperature to each incinerator using the temperature trajectory of the calculated isomer distribution of PCDD/Fs.…”

Section: Isomer Distribution Of Pcdd/fsmentioning

confidence: 99%

“…The isomer distribution of 1,2,3,4,6,7,8-HpCDF and 1,2,3,4,7,8,9-HpCDF within the HpCDF homologues varied considerably with the temperature, whereas that of toxic 2,3,7,8-chlorine-substituted isomers within their respective homologues other than HpCDFs varied less. 19 Moreover, in the analytical method chosen in this study, HpCDFs were analyzed using a nonpolar fused-silica capillary column having a stable stationary phase. All four isomers of HpCDFs were perfectly separated, and so the measured values were more accurate and reliable.…”

Section: Isomer Distribution Of Pcdd/fsmentioning

confidence: 99%

See 4 more Smart Citations

Characteristics of azaarenes and dioxins in gases emitted from waste incinerators

Minomo

Ohtsuka

Nojiri

et al. 2009

J Mater Cycles Waste Manag

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In this study, we propose an analytical method to determine the fourteen of azaarenes present in fl ue gas samples collected according to Japanese Industrial Standard K 0311, which designates the method for the determination of dioxins in fl ue gas. Azaarenes can be analyzed using the acidic water phase after shaking extraction with dichloromethane, which is unnecessary for dioxin analysis. Flue gas samples were obtained from 24 waste incinerators in Japan, and azaarenes were detected in all the fl ue gas samples (0.21-3800 μg/m 3 N ). The most abundant of the detected compounds were quinoline and isoquinoline. The concentration of azaarenes had a tendency to increase with that of polychlorinated dibenzo-p-dioxins and dibenzofurans. The isomer distribution of heptachloro-dibenzofurans (HpCDFs) was calculated using the computed Gibbs energy of formation (ΔG f ) obtained by the semiempirical molecular orbital method at various temperatures. The calculated isomer distribution was fi tted to the measured value of HpCDFs. It seems that the temperature obtained from the fi tting calculations is an indicator of the cooling capacity of the combustion gas in an incinerator. The computed ΔG f also explained the measured isomer distributions of azaarenes. It is suggested that the isomer distribution of azaarenes in the combustion process is thermodynamically controlled.

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Section: Calculation Of Isomer Distributionmentioning

confidence: 99%

Section: Calculation Of Isomer Distributionmentioning

confidence: 99%

Section: Calculation Of Isomer Distributionmentioning

confidence: 99%

Section: Isomer Distribution Of Pcdd/fsmentioning

confidence: 99%

Section: Isomer Distribution Of Pcdd/fsmentioning

confidence: 99%

See 3 more Smart Citations

Characteristics of azaarenes and dioxins in gases emitted from waste incinerators

Minomo

Ohtsuka

Nojiri

et al. 2009

J Mater Cycles Waste Manag

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Thermodynamic Modelling of the Injection of Waste Products into a Blast Furnace

Коробов

Yusfin

Janke

2003

steel research international

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The purpose of this paper is to investigate the possibility to use blast furnaces for recycling of household and industrial wastes. In this respect, recycling conditions and requirements to utilize waste products are considered. The structure of waste products allowable for recycling in the blast furnace has been studied. Their behaviour is simulated at higher temperatures both in the presence (gasification, combustion) and in the absence (pyrolysis) of reactive gases. The possibility of formation of different components and their maximal concentrations, including dioxins and furans, are predicted. The results obtained prove not only the possibility, but highly recommend to use blast furnaces for the recycling of waste products, particularly plastics and other materials with high contents of carbon and hydrogen. This method guarantees not only the destruction but also the maximal effective use of the above‐mentioned chemical components leading to the formation of ecologically safe products. One of the main problems in the recycling of waste products by thermal decomposition is the formation of dioxins and furans. However, the investigations conducted show that concentrations of dioxins and furans in the blast‐furnace gas do not exceed the allowed concentration limits.

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Study on polychlorinated dibenzo-p-dioxin/furan formation in iron ore sintering process

Tan

Neuschütz

2004

Metall Mater Trans B

Self Cite

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In order to understand and control the formation of dioxins and furans (PCDD/Fs) in iron ore sinter plants, a CFD model of iron ore sintering, combined with the kinetic models of 14 relevant chemical reactions and thermodynamic calculations of dioxin formation, has been developed to simulate the concentrations of the gaseous species, temperatures of the gas and solid, velocity of the gas, temperature zones, and residence time of the gas in each temperature zone. The predicted off-gas compositions, the velocities of the gas, and the trends for the gas temperature at the bottom of the bed have been compared with measured data from a sinter plant, and good agreement has been obtained. From the predicted temperature zones of the gas and solid, the predicted residence time of the gas in each zone, and thermodynamic conditions of PCDD/F formation, the PCDD/F formation in sinter plants has been discussed. The dioxins are formed in the critical temperature region of 250°C to 450°C below the combustion zone in the bed, are then carried downward with the gas, and are condensed close to the bottom of the sinter bed. Transported to the discharge end with the solid mixture, they are again released into the gas phase when the flame front approaches the bottom. The dioxins are also formed in the last wind boxes when the hot off-gases cool and reach the critical temperature range. These pathways on PCDD/F formation can explain the industrial observations well. The preceding information may assist in the effective control or elimination of dioxin formation in iron ore sinter plants.

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Predictions for isomer distributions of toxic dioxins and furans in selected industrial combustion processes

Cited by 6 publications

References 12 publications

Characteristics of azaarenes and dioxins in gases emitted from waste incinerators

Characteristics of azaarenes and dioxins in gases emitted from waste incinerators

Thermodynamic Modelling of the Injection of Waste Products into a Blast Furnace

Study on polychlorinated dibenzo-p-dioxin/furan formation in iron ore sintering process

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