<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans are generally considered the most dangerous chemical substances known to man. Although they have never been the product of purposeful human activity, yet they are formed in many chemical and virtually all thermal processes. Research on the occurrence of dioxins in the environment, their release into the environment, ways of formation and methods of reducing their emissions lasts since the late seventies of the last century. Currently, we know three basic pathways of dioxins formation in thermal processes, the most important of them being the so called de novo synthesis which occurs outside the combustion zone at 200-400°C in the presence of catalysts (<italic>eg</italic> copper) and oxygen from the products of incomplete combustion including carbon black and chlorine or chlorinated compounds. It is well known that some metals like copper catalyze the de novo synthesis, while others decompose dioxins and furans formed previously. The formation of dioxins resulting from the de novo synthesis was studied through analysis of the effect of the type of metal on the course of the de novo synthesis. The influence of the addition of sulfur, nitrogen and alkali metals on this synthesis was also examined because some reports in the literature refer to inhibitory effect of these elements.</p></abstract>

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans are generally considered the most dangerous chemical substances known to man. Although they have never been the product of purposeful human activity, yet they are formed in many chemical and virtually all thermal processes. Research on the occurrence of dioxins in the environment, their release into the environment, ways of formation and methods of reducing their emissions lasts since the late seventies of the last century. Currently, we know three basic pathways of dioxins formation in thermal processes, the most important of them being the so called de novo synthesis which occurs outside the combustion zone at 200-400°C in the presence of catalysts (eg copper) and oxygen from the products of incomplete combustion including carbon black and chlorine or chlorinated compounds. It is well known that some metals like copper catalyze the de novo synthesis, while others decompose dioxins and furans formed previously. The formation of dioxins resulting from the de novo synthesis was studied through analysis of the effect of the type of metal on the course of the de novo synthesis. The influence of the addition of sulfur, nitrogen and alkali metals on this synthesis was also examined because some reports in the literature refer to inhibitory effect of these elements.

Effect of selected additions on de novo synthesis of polychlorinated dioxins and furans

Faculty of Process and Environmental Engineering, Lodz University of Technology, ul. Wólczańska 175, 90-924 Łódź, Poland, phone +48 42 631 37 95, fax +48 42 636 81 33

Faculty of Chemistry, Cracow University of Technology, ul. Warszawska 24, 31-155 Kraków, Poland

Ecological Chemistry and Engineering S

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans are generally considered the most dangerous chemical substances known to man. Although they...

Effect of selected additions on de novo synthesis of polychlorinated dioxins and furans

Pubblicato online: 07 lug 2016

Pagine: 249 - 257

DOI: https://doi.org/10.1515/eces-2016-0017

Parole chiave
dioxins and furans, PCDD/Fs, de novo synthesis, formation and inhibition

© 2016 Grzegorz Wielgosiński et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Effect of selected additions on de novo synthesis of polychlorinated dioxins and furans

Pubblicato online: 07 lug 2016

Pagine: 249 - 257

DOI: https://doi.org/10.1515/eces-2016-0017

Parole chiavedioxins and furans, PCDD/Fs, de novo synthesis, formation and inhibition

© 2016 Grzegorz Wielgosiński et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Parole chiave
dioxins and furans, PCDD/Fs, de novo synthesis, formation and inhibition