Reaction pathways for the formation of polychloro-dibenzodioxins (PCDD) and —dibenzofurans (PCDF) in combustion processes: II. Chlorobenzenes and chlorophenols as precursors in the formation of polychloro-dibenzodioxins and —dibenzofurans in flame chemistry

Ballschmiter, Karlheinz; Braunmiller, I.; Niemczyk, R.; Swerev, M.

doi:10.1016/0045-6535(88)90070-7

Cited by 150 publications

(47 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As far as MSWI which is considered as the major PCDD/Fs emission source is concerned, the precursors for PCDD/Fs come from many paths. Besides the introduction via the MSWI feed, the precursors could be formed through de novo synthesis in incomplete combustion or through heterogeneous catalyzed reaction during the cooling of flue gases in the post-combustion zone (Ballschmiter et al, 1988). Suppressing the PCDD/Fs formation from precursors may be more efficient than end-of-pipe technology for PCDD/Fs in MSWI in the future.…”

Section: Introductionmentioning

confidence: 99%

Influence of metal oxides on PCDD/Fs formation from pentachlorophenol

et al. 2005

View full text Add to dashboard Cite

The total suppressing efficiencies of several metal oxides including CaO, BaO, PbO, Ag 2 O, HgO and SnO which have lower Z/r (charge to radius ratio) <2 are all over 90%. The theories of generalized acid-base and atomic parameter (Z/r) were used to speculate the effecting mechanisms. The factors including time and temperature on suppressing efficiencies of CaO, BaO and PbO have also been studied in the present paper. The results showed that the total suppressing efficiencies of CaO, BaO and PbO increase with the increase of heated time and temperature.

show abstract

Section: Introductionmentioning

confidence: 99%

Influence of metal oxides on PCDD/Fs formation from pentachlorophenol

et al. 2005

View full text Add to dashboard Cite

show abstract

“…These congeners seem to be the most thermodynamically stable in their homologue groups and were found to be dominant in flue gas from municipal waste incinerators (Ballschmiter et al, 1988).…”

Section: Chlorobenzenes Chlorophenols and Bromophenolsmentioning

confidence: 99%

Pollutant emissions during pyrolysis and combustion of waste printed circuit boards, before and after metal removal

García

Conesa

Moltó

et al. 2014

Science of The Total Environment

101

View full text Add to dashboard Cite

The constant increase in the production of electronic devices implies the need for an appropriate management of a growing number of waste electrical and electronic equipment.Thermal treatments represent an interesting alternative to recycle this kind of waste, but particular attention has to be paid to the potential emissions of toxic by-products. In this study, the emissions from thermal degradation of printed circuit boards (with and without metals) have been studied using a laboratory scale reactor, under oxidizing and inert atmosphere at 600 and 850 ºC. Apart from carbon oxides, HBr was the main decomposition product, followed by high amounts of methane, ethylene, propylene, phenol and benzene. The maximum formation of PAHs was found in pyrolysis at 850 ºC, naphthalene being the most abundant. High levels of 2-, *Corresponding author. E-mail: ja.conesa@ua.es. Phone: +(34)965903400 Fax: +(34)965903826 2 4-, 2,4-, 2,6-and 2,4,6-bromophenols were found, especially at 600 ºC. Emissions of PCDD/Fs and dioxin-like PCBs were quite low and much lower than that of PBDD/Fs, due to the higher bromine content of the samples. Combustion at 600 ºC was the run with the highest PBDD/F formation: the total content of eleven 2,3,7,8-substituted congeners (tetra-through heptaBDD/Fs) was 7240 and 3250 ng WHO 2005 -TEQ/kg sample, corresponding to the sample with and without metals, respectively.

show abstract

“…Formation of chlorobenzenes may occur by different ways, according to Ballschmiter et al [23]: (i) direct scission of non-totally dehydrochlorinated PVC chain, (ii) chlorination of benzene or lower chlorinated benzenes by Cl 2 , (iii) cyclization of chloro-C 1 /C 2 units and (iv) pyrolytic isomerization of the chlorobenzenes formed. Lattimer and Kroenke [3] reported that direct scission of PVC chains to form chlorinated-containing compounds is a very minor decomposition pathway because an inappreciable amount of chlorine remains in the polyene after dehydrochlorination.…”

Section: U N C O R R E C T E D P R O O Fmentioning

confidence: 99%

Semivolatile and volatile compounds from the pyrolysis and combustion of polyvinyl chloride

Aracil

Font

Conesa

2005

Journal of Analytical and Applied Pyrolysis

View full text Add to dashboard Cite

Emissions evolved from the pyrolysis and combustion of poly(vinyl chloride) were studied at four different temperatures (500, 700, 850 and 1000 8C) in a horizontal laboratory tubular quartz reactor in order to analyse the influence of both temperature and reaction atmosphere on the final products from thermal and oxidative reactions. It was observed that the CO 2 /CO ratio increased with temperature. Methane was the only light hydrocarbon whose yield increased with temperature up to 1000 8C. Benzene was rather stable at high temperatures, but in general, combustion at temperatures above 500 8C was enough to destroy light hydrocarbons. Semivolatile hydrocarbons were collected in XAD-2 resin and more than 160 compounds were detected. Trends on polyaromatic hydrocarbon (PAH) yields showed that most had a maximum at 850 8C in pyrolysis, but naphthalene at 700 8C. Formation of chlorinated aromatics was detected. A detailed analysis of all isomers of chlorobenzenes and chlorophenols was performed. Both of them reached higher total yields in combustion runs, the first ones having a maximum at 700 8C and the latter at 500 8C. Pyrolysis and combustion runs at 850 8C were conducted to study the formation of polychlorodibenzo-p-dioxins (PCDDs) and polychlorodibenzofurans (PCDFs). There was more than 20-fold increase in total yields from pyrolysis to combustion, and PCDF yields represented in each case about 10 times PCDD yields. #

show abstract

Reaction pathways for the formation of polychloro-dibenzodioxins (PCDD) and —dibenzofurans (PCDF) in combustion processes: II. Chlorobenzenes and chlorophenols as precursors in the formation of polychloro-dibenzodioxins and —dibenzofurans in flame chemistry

Cited by 150 publications

References 13 publications

Influence of metal oxides on PCDD/Fs formation from pentachlorophenol

Influence of metal oxides on PCDD/Fs formation from pentachlorophenol

Pollutant emissions during pyrolysis and combustion of waste printed circuit boards, before and after metal removal

Semivolatile and volatile compounds from the pyrolysis and combustion of polyvinyl chloride

Contact Info

Product

Resources

About