The formation of dioxins in combustion systems

Stanmore, B. R.

doi:10.1016/j.combustflame.2003.11.004

Cited by 432 publications

(234 citation statements)

References 177 publications

(366 reference statements)

Supporting

Mentioning

220

Contrasting

Unclassified

Order By: Relevance

“…The mechanisms of PCDD/Fs formation in MSWI have been elucidated as the following three paths: (i) high-temperature pyrosynthesis, (ii) low-temperature de novo synthesis, (iii) formation from different organic precursors such as chlorophenols, chlorobenzenes, etc., and PCDD/Fs formation from (iii) is 10 2 -10 5 times faster than from (ii) (Addink and Olie, 1995;Tuppurainen et al, 1998;McKay, 2002;Stanmore, 2004). Model studies also showed that PCDD/ Fs formation from precursors is likely the predominance of the two proposed pathways (ii) and (iii) (Dickson et al, 1992).…”

Section: Introductionmentioning

confidence: 89%

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: 89%

Influence of metal oxides on PCDD/Fs formation from pentachlorophenol

et al. 2005

View full text Add to dashboard Cite

show abstract

“…The SeCu fly ash was compared with fly ash from other thermal-related processes, and it was found that the Cu concentration was much higher in the SeCu fly ash than in fly ash from a MSWI plant (0.47-0.33 mg g À1 ) (Cobo et al, 2009) and fly ash from an integrated iron and steel facility (0.12-7.95 mg g À1 ) (Tsai et al, 2007). PCNs are usually formed along with PCDDs and PCDFs, and the formation of all of these chemicals is probably favored by the presence of carbon, chlorine, and transition metals, such as Cu, on the surfaces of fly ash particles (Addink and Olie, 1995;Hatanaka et al, 2004;Stanmore, 2004;Chin et al, 2011). Therefore, we speculated that the fly ash we had prepared could lead to the formation of PCNs under favorable conditions.…”

Section: Experimental Designmentioning

confidence: 99%

Fly ash-mediated formation of polychlorinated naphthalenes during secondary copper smelting and mechanistic aspects

2015

View full text Add to dashboard Cite

“…Cl 2 is the most important chlorine source in the reaction [14] . It mainly produced by HCl and O 2 via Deacon Reaction [15] :…”

Section: Inhibition Mechanism Of Pcdd/fs In Pvc Chemical Looping Combmentioning

confidence: 99%

Study on the formation of PCDD/Fs in PVC chemical looping combustion

Zhao

Chen

et al. 2015

Journal of Fuel Chemistry and Technology

View full text Add to dashboard Cite

CaSO4 oxygen carriers with silica sol were prepared and their reaction performances with CH4, CO and H2 were experimentally investigated. The formation characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in PVC combustion by means of chemical looping combustion (CLC) based on CaSO4 oxygen carrier and air were studied in a tube furnace system. The results show that CaSO4 oxygen carriers with silica sol can be completely reduced by CH4, CO and H2. The reaction time of CH4 and H2 is much shorter than CO. The chemical looping combustion of PVC can effectively inhibit the formation of PCDD/Fs.The yield and International Toxicity Equivalent Quantity (I-TEQ) of PCDD/Fs produced in CLC are 2270.9 pg/g and 290.2 pg(I-TEQ)/g, much lower than those in air combustion which are 34172.5 pg/g and 732.8 pg(I-TEQ)/g. It is mainly because fuel doesn't directly contact with O2 in CLC, the oxidative cleavage of large carbon molecule and the conversion from HCl to Cl2 are significantly reduced which will inhibit the low temperature de novo synthesis and precursors reaction of PCDD/Fs. The disposal of combustible solid waste (CSW) is one of the severely environmental problems in the world [1] . Composting, landfill and incineration are the common treatment methods of MSW. Incineration is the main developing direction in combustible solid waste management because of its small occupation area, stable and reliable operation and good reduction [2] . But incineration of CSW is easy to produce PCDD/Fs and other toxic substances, which is harmful to human health. So its development is controversially [3] . Hutzinger et al [4] found that de novo synthesis and precursor reaction are the main generating ways of PCDD/Fs in CSW incineration. O 2 plays an important role in the two reactions [5] . Therefore, avoiding the direct contact of O 2 and fuel is one of the feasible approaches to inhibit PCDD/Fs generation in combustion.Chemical looping combustion (CLC) is a new combustion technology. The oxygen is transferred from air to fuel by means of the circulation of oxygen carriers between air reactor and fuel reactor, which realize the non-contact combustion of fuel and air [6] . The formation of PCDD/Fs may be greatly inhibited by use of CLC to dispose CSW, because there is no direct contact between free oxygen and CSW.Oxygen carriers are the key element in CLC. The metal oxides such as Ni, Cu, and Fe are mainly studied at present [7] . However, metal oxides have strong catalysis on the formation of PCDD/Fs [8] , which may aggravate its generation. By contrast, CaSO 4 oxygen carrier is more suitable to dispose high chlorine CSW because of its high oxygen transport capacity, low cost, environmental friendliness and small catalysis on the formation of PCDD/Fs [9] .Based on this, CaSO 4 oxygen carrier with silica sol is prepared and its reaction characteristics with different fuel gas were experimentally investigated. Finally, the influence of CLC and air combustion on the formation of PCDD/Fs is investigated b...

show abstract

The formation of dioxins in combustion systems

Cited by 432 publications

References 177 publications

Influence of metal oxides on PCDD/Fs formation from pentachlorophenol

Influence of metal oxides on PCDD/Fs formation from pentachlorophenol

Fly ash-mediated formation of polychlorinated naphthalenes during secondary copper smelting and mechanistic aspects

Study on the formation of PCDD/Fs in PVC chemical looping combustion

Contact Info

Product

Resources

About