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Chlorinated Dioxin and Furan Formation,
Control and Monitoring
Presented at
IIIICCCCCCCCRRRR MMMMeeeeeeeettttiiiinnnngggg
RRRReeeesssseeeeaaaarrrrcccchhhh TTTTrrrriiiiaaaannnngggglllleeee PPPPaaaarrrrkkkk
SSSSeeeepppptttteeeemmmmbbbbeeeerrrr 11117777,,,, 1111999999997777
Dr. Brian Gullett
EPA
(919) 541-1534
Dr. Randy Seeker
EER Corporation
(714) 859-8851
ICCR Meeting September 17,1997
AAAAcccckkkknnnnoooowwwwlllleeeeddddggggmmmmeeeennnnttttssss
❏ Jim Kilgroe, EPA Office of Research and Development
❏ Steve Lanier, EER Corporation, North Carolina
❏ Glenn England, EER Corporation, Irvine, CA
ICCR Meeting September 17,1997
OOOOuuuuttttlllliiiinnnneeee ooooffff TTTTaaaallllkkkk
❏ Structures
❏ Concentrations of interest
❏ Measurement Techniques and Issues
❏ Fundamental Principles
❏ Dioxin and Furan Formation Chemistry
❏ Control Technologies
❏ Formation Conditions
❏ Monitoring Technologies
❏ Conclusions
❏ Recommendations
ICCR Meeting September 17,1997
DDDDiiiiooooxxxxiiiinnnn aaaannnndddd FFFFuuuurrrraaaannnn SSSSttttrrrruuuuccccttttuuuurrrreeee
2,3,7,8 — Tetrachlorodibenzo(p)dioxin
OCl
Cl
Cl
Cl
5
2
3
98
7
6
10 1
4O
O
2,3,7,8 — Tetrachlorodibenzofuran
O
OCl
Cl
Cl
Cl
Dioxin
Furan
❏ There are 210 different congener configurations.
O1
2
346
7
89
ICCR Meeting September 17,1997
CCCCoooonnnnggggeeeennnneeeerrrrssss TTTTooooxxxxiiiicccc EEEEqqqquuuuiiiivvvvaaaalllleeeennnntttt FFFFaaaaccccttttoooorrrr
Congener NATO Toxic Equivalent Factors (I-TEQ)
2378 TCDD 112378 PeCDD 0.5123478 HxCDD 0.1123678 HxCDD 0.1123789 HxCDD 0.11234678 HpCDD 0.01OCDD 0.0012378 TCDF 0.112378PeDF 0.0523478 PeCDF 0.5123478 HxCDF 0.1123789 HxCDF 0.1123678 HxCDF 0.1234678 Hx CDF 0.11234678 HpCDF 0.011234789 HpCDF 0.01OCDF 0.001
❏ 17 out of the 210 have toxic equivalency factors
World Health Organization (TEF)
“-” indicates no TEF because of lack of dataa) limited data setb) structural similarityc) QSAR modelling prediction from CYP1A induction (monkey, pig, chicken, or fish)d) no new data from 1993 reviewe) in vitro CYP1A inductionf) in vivo CYP1A induction after in ovo exposureg) QSAR modelling prediction from class specific TEFs
ICCR Meeting September 17,1997
Relating TEQs to Total PCDD/PCDFT
EQ
(ng
/dsc
m @
7%
O2)
1 10 100 1000 10000
SD/FFSD/ESPESP
1000
100
10
1
0.11 10 100 1000 10000
FFESP
100
10
1
0.1
0.01
100
10
1
0.1
0.01
0.0010.1 1 10 100 1000 10000Total PCDD/PCDF (ng/dscm @
7% O2)
100
10
1
0.1
0.010.1 1 10 100 1000Total PCDD/PCDF (ng/dscm @
7% O2)
TE
Q (
ng/d
scm
@ 7
% O
2)
Hazardous Waste Incineratorsand Boilers
Medical Waste IncineratorsMunicipal Waste Incinerators
Cement Kilns
Data From Combustion Emissions Technical Resource Document
(CETRD) EPA 530-R-94-014, May 1994
ICCR Meeting September 17,1997
OOOOuuuuttttlllliiiinnnneeee ooooffff TTTTaaaallllkkkk❏ Structures
❏ Concentrations of interest
❏ Measurement Techniques and Issues
❏ Fundamental Principles
❏ Dioxin and Furan Formation Chemistry
❏ Control Technologies
❏ Formation Conditions
❏ Monitoring Technologies
❏ Conclusions
❏ Recommendations
ICCR Meeting September 17,1997
LLLLeeeevvvveeeellllssss ooooffff DDDDiiiiooooxxxxiiiinnnn ooooffff IIIInnnntttteeeerrrreeeesssstttt❏ Currently levels in standards or proposed
standards➮ New Large Municipal Solid Waste Combustors
• 13 ng/dscm total or 0.2 TEQ (@7 % O2 )
➮ New Large (500lb/hr) Medical Waste Combustors
• 25 ng/dscm total or 0.6 TEQ
➮ New Large Hazardous Waste Incinerators (proposed)
• 0.2 ng/dscm TEQ
❏ What is a ng/dscm?➮ nanogram (10 -9 gram) per dry standard cubic meter
➮ 10 ng/dscm of PeCDD corresponds to .6 parts per trillion
• one person out of 100 world populations
➮ If room size of 100 x 100 x 10 ft
• if dioxin concentration is 1 ng/dscm there are approximately 0.000003 gm of dioxin in the room
ICCR Meeting September 17,1997
OOOOuuuuttttlllliiiinnnneeee ooooffff TTTTaaaallllkkkk❏ Structures
❏ Concentrations of interest
❏ Measurement Techniques and Issues
❏ Fundamental Principles
❏ Dioxin and Furan Formation Chemistry
❏ Control Technologies
❏ Formation Conditions
❏ Monitoring Technologies
❏ Conclusions
❏ Recommendations
ICCR Meeting September 17,1997
PPPPCCCCDDDDDDDD////PPPPCCCCDDDDFFFF MMMMeeeeaaaassssuuuurrrreeeemmmmeeeennnnttttssss❏ Manual Sampling -> Laboratory Analysis
➮ Collect on filter & resin using Modified Method 5 train
• Glass probe and sample system components
➮ Complex & sophisticated laboratory analysis
❏ Cleanliness and QA/QC is essential
❏ Labor and time intensive = $$$$$➮ 3-5 days in the field to collect samples, 3-6 weeks
typical lab turnaround time
➮ Typically 3 months from start to finish
❏ Variations in the reference methods➮ EPA (23, 23A, 0010/8290) , California(428) , Canada
➮ EPA Methods can be found on Internet: http://134.67.104.12/html/emtic/cfr prom.htm
ICCR Meeting September 17,1997
Overview Measurement TechniquesSampling onto Particle
Filter and Organic Resin (XAD-2) to concentration
from flue gas
Recovery from Probe, filter, and
resin
Concentrate field rinses and impingers
Solvent extract filter, resin, field rinses and
concentrate
Column cleanup and concentrate
Reporting
Analyze extract by high resolution gas
chromatography/high resolution mass spectrometry with selective ion monitoring
QA/QC spiking
ICCR Meeting September 17,1997
FFFFiiiieeeelllldddd SSSSaaaammmmpppplllliiiinnnngggg
❏ QA/QC samples (field train blanks, field reagent blanks)
❏ Typically 4 to 5 complete samples, 4-6 field fractions each -> 16-30 samples shipped to the laboratory
Three test runs: typically three 10-12 hour days (4-6 hours sampling plus setup and sample recovery for a crew of 3-4)
Glass fiberfilter with
Teflon support
Filteroven
InclineManometer
Flow OrificeMeter
TTV
T
1 1 1
Condenser
XAD-2Sorbent Trap
RecirculationPump
Pump
DryGas
Meter
EPA Method 23
Thermocouple
Heated QuartzProbe Liner
SampleNozzle
T T T
PitotTube Incline
Manometer
ICCR Meeting September 17,1997
RRRReeeeppppoooorrrrttttiiiinnnngggg ooooffff DDDDiiiiooooxxxxiiiinnnn DDDDaaaattttaaaa❏ Treatment of detection limits
➮ zero, half detection, or at detection limit
❏ TEQ treatment ➮ selection of TEF protocol
❏ Measurement technique➮ details of sampling and analysis procedures can
significantly influence the results
➮ can make data comparisons difficult
❏ Emissions Concentrations➮ Percent Oxygen (7% in U.S. vs. 11% in Europe)
• Rule of Thumb: Multiply European Data by 1.404 to compare with North American Data
➮ Different Rounding Procedures
❏ Reporting and treatment of blank and recovery results
ICCR Meeting September 17,1997
MMMMeeeeaaaassssuuuurrrreeeemmmmeeeennnntttt LLLLiiiimmmmiiiittttssss❏ Field data often have large variability
➮ Rule of thumb: PCDD/PCDF data has ± factor of two variability
❏ Controlled emission concentrations data frequently below field blanks
❏ Sources of Variability➮ Process Variations
➮ Sampling Variations
• Sampling Conditions Variability
• Field sampling team
• Sample recovery
➮ Analytical Variations
• extraction and spike recovery
• matrix effects
• hysteresis effects
ICCR Meeting September 17,1997
PPPPrrrraaaaccccttttiiiiccccaaaallll lllliiiimmmmiiiitttt ooooffff qqqquuuuaaaannnnttttiiiittttaaaattttiiiioooonnnn ((((PPPPLLLLQQQQ''''ssss))))
❏ Definitions➮ "PLQ is the lowest level above which quantitative
results may be obtained with an acceptable degree of confidence"
• Federal Register, V57, No. 250, December 29, 1992.
➮ EPA Method 301- " The PLQ is defined as 10 times the standard deviation, at the blank level. This corresponds to an uncertainty of ±30 percent at the 99-percent confidence level"
• analytical process variability
• does not address accuracy and precision from source variation, field sampling and site specific matrix effects.
ICCR Meeting September 17,1997
PPPPrrrraaaaccccttttiiiiccccaaaallll lllliiiimmmmiiiitttt ooooffff qqqquuuuaaaannnnttttiiiittttaaaattttiiiioooonnnn ((((PPPPLLLLQQQQ''''ssss))))
❏ Significant controversy over how a PLQ should be defined for trace species
➮ What level can be routinely be measured with defined accuracy?
➮ What standard can be enforced with the currently available sampling and analysis procedures?
➮ Some studies have indicated that sampling and analytical variations are significant for PCDD/PCDF and that PLQ can be higher than established standards.
➮ Method 23 data are not corrected for spike recovery or blank levels
ICCR Meeting September 17,1997
OOOOuuuuttttlllliiiinnnneeee ooooffff TTTTaaaallllkkkk❏ Structures
❏ Concentrations of interest
❏ Measurement Techniques and Issues
❏ Fundamental Principles
❏ Dioxin and Furan Formation Chemistry
❏ Control Technologies
❏ Formation Conditions
❏ Monitoring Technologies
❏ Conclusions
❏ Recommendations
ICCR Meeting September 17,1997
FFFFuuuunnnnddddaaaammmmeeeennnnttttaaaallll PPPPrrrriiiinnnncccciiiipppplllleeeessss
❏ Organics➮ Under combustion conditions (high temperatures
and with available oxygen),
• thermodynamic equilibrium levels of organics are negligible
• flame/oxidation chemistry of destruction is fast
➮ Formation results from poor mixing, quenches, cool temperature pathways, gas-particle interactions, lack of particle burnout, sooting.
ICCR Meeting September 17,1997
TTTThhhheeeerrrrmmmmooooddddyyyynnnnaaaammmmiiiiccccssss
Fraction Theoretical Air
10-10
10-2
10-4
100
10-6
10-8
10-12
.01 .1 1
Mole Fraction
x x x xx
x
x
Methyl Chloride
Benzene
Biphenyl
Napthalene
CO
THC
Toluene
❏ Equilibrium levels very low except for very rich conditions
ICCR Meeting September 17,1997
OOOOrrrrggggaaaannnniiiicccc KKKKiiiinnnneeeettttiiiiccccssss
Fraction Theoretical Air
10-10
10-2
10-4
100
10-6
10-8
10-12
.01 .1 1
Mole Fraction
❏ Rapid Destruction Kinetics ( modeling data 1227°C, 2240°F for 10 msec in stirred reactor, after W.J. Pitz et al, 1997)
Anthracene
Phenanthrene
Naphthalene
Benzene
Toluene
ICCR Meeting September 17,1997
DDDDeeeessssttttrrrruuuuccccttttiiiioooonnnn KKKKiiiinnnneeeettttiiiiccccssss❏ Rapid Destruction Kinetics (Flow Reactor Data, After
Dellinger et al 1977)
100
.1
1
10
1000 160015001400130012001100
Per
cent
Rem
aini
ng
Temperature (°F)
Hexachlorobenzene
Dichloro-methane
Benzene
DioxinFurans
700Temperature (°C)
800600 900
ICCR Meeting September 17,1997
SSSSoooouuuurrrrcccceeeessss aaaannnndddd CCCCoooonnnnddddiiiittttiiiioooonnnnssss ffffoooorrrr OOOOrrrrggggaaaannnniiiicccc HHHHAAAAPPPPssss ❏ From Unburned Fuel
➮ e.g., Benzene, Toluene, Ethylbenzene and Xylene (BTEX), hexane, naphthalene
❏ From Quenches➮ e.g., acetaldehydes, formaldehydes, acrolein
➮ also CO
❏ From By-product Chemistry in Rich Packets
➮ e.g., benzene and toluene
➮ e.g., polyaromatic hydrocarbons
❏ From Gas-Particle Interactions➮ e.g., chlorinated dioxin
ICCR Meeting September 17,1997
OOOOuuuuttttlllliiiinnnneeee ooooffff TTTTaaaallllkkkk❏ Structures
❏ Concentrations of interest
❏ Measurement Techniques and Issues
❏ Fundamental Principles
❏ Dioxin and Furan Formation Chemistry
❏ Control Technologies
❏ Formation Conditions
❏ Monitoring Technologies
❏ Conclusions
❏ Recommendations
ICCR Meeting September 17,1997
DDDDiiiiooooxxxxiiiinnnn FFFFoooorrrrmmmmaaaattttiiiioooonnnn MMMMeeeecccchhhhaaaannnniiiissssmmmm
❏ 1. Undestroyed PCDD/PCDF originating with waste or fuel
❏ 2. Gas Phase Formation (Furnace to 500°C)
➮ From Related Chlorinated Precursors and from Simple Organics and Chlorine Donors (ca. 700°C)
➮ Formation of Dioxin or Precursors from Complex Organics and Chlorine Donors
❏ 3. Solid Phase Particle Mechanisms (< 500°C )
➮ de novo synthesis
➮ Catalyzed Precursor Mechanisms
➮ Condensation of Precursors and surface chlorination
ICCR Meeting September 17,1997
DDDDiiiiooooxxxxiiiinnnn FFFFoooorrrrmmmmaaaattttiiiioooonnnn MMMMeeeecccchhhhaaaannnniiiissssmmmmssss
O
OCl
Cl
Cl
Cl
❏ 1. Undestroyed PCDD/PCDF originating with waste or fuel
Dioxin in Waste or Fuel or other feed materials
Failure Modes e.g.,flame bypasslow temperaturepoor mixingparticulate burnoutquenches
O
OCl
Cl
Cl
Cl
Dioxin remaining after combustion
ICCR Meeting September 17,1997
DDDDiiiiooooxxxxiiiinnnn FFFFoooorrrrmmmmaaaattttiiiioooonnnn MMMMeeeecccchhhhaaaannnniiiissssmmmmssss❏ 2. Gas Phase Formation
➮ from Related Chlorinated Precursors and from Organics and Chlorine Donors (ca. 700°C)
O
OCl
Cl
Cl
Cl
OHClCl
Chlorophenols
Cl
Cl
Cl
Cl
PCBEvidence: PCDD/PCDF on soot from PCB fires
Lab and Bench Scale Studies of PCB, Chlorinated Benzene, Chlorinated Phenols, C
2 aliphatics have yielded PCDD/PCDF (e.g.,
Schaub and Tsang, Sidhu and Dellinger, Grotheer and Louw, Akki and Mulholland, Weber)
OHClCl
+
Precursors for downstream
formation
ICCR Meeting September 17,1997
GGGGaaaassss PPPPhhhhaaaasssseeee MMMMeeeecccchhhhaaaannnniiiissssmmmmssss❏ An example of the current
thinking about the gas phase mechanisms (After Sidhu and Dellinger 1997)
R• +
OH
Cl
ClClOH
Cl
ClCl+
O•
Cl
ClCl
-OH-Cl
Cl
Cl
OHCl
ClO
Cl
Cl
Cl
ClO
Cl Cl
Cl
Cl
OCl
ClO
-Cl+H
Cl-HCl
RH
Cl
Cl
OHCl
ClO
•
Cl
Cl
O•Cl
ClO
Cl-Cl-Cl
Cl
Cl
OCl
ClO
Cl O
Cl
Cl
O
1,3,6,8 TCDD 1,3,7,9 TCDD
1,3,6,8 TCDD
Cl
-Cl2
Cl
Cl
Cl
ClO
2,4,6,8 TCDF
+R• -Cl
Cl
Cl
Cl
ClO
• Cl
Cl
Cl
Cl
ClO
2,4,6,8 TCDF
-Cl
1,3,6,8 TCDF
Cl
Cl
Cl
ClO
-OH -Cl
ICCR Meeting September 17,1997
DDDDiiiiooooxxxxiiiinnnn FFFFoooorrrrmmmmaaaattttiiiioooonnnn MMMMeeeecccchhhhaaaannnniiiissssmmmmssss❏ 2. Gas Phase Mechanisms
➮ Formation of Dioxin or Precursors from Organics and Chlorine Donors
Complex Organic Structure
LigninWoodPaper
Plastics
Chlorine DonorPVCNaCl
HCl/Cl2
O
OCl
Cl
Cl
Cl
+
Evidence: Lab scale tests of vegetable matter, wood, lignin, coal with chlorine source have yielded PCDD/PCDF
Lab scale studies on fuel rich, simple hydrocarbon flames yielded PAH ( e.g., Marinov, et al and Senkan et al)
Precursors for
downstream formation
ICCR Meeting September 17,1997
Fuel Rich Formation Pathways for Aromatics
H2CCCH+CH3
C3H4 (allene)
C3H5 (allyl)
C2H3+CH3
-H
-H2 +H
+H2CCCH
CH2(S)+C2H2C2H4+C2H3
CH2CHCHCH2
-H2
+H
CH2CHCCH2 H2CCCH3
Branched Aromatics
+H2CCCH or
+H2CCCH3
+H
-H
+H
-H
-H
+H-H
2
(C=C-C=C and C-C=C=C)
-H
H2C=C=CR H
2C-C=CR
R=H (propargyl)
R=CH3 (1-methylallenyl)
+H
CH3 CH
3
CH3
Benzene
After Marinov, Pitz, Westbrook, Castaldi and Senkan, 1996
ICCR Meeting September 17,1997
Fuel Rich PAH Formation PathwaysPropargyl Radical Self-combine
H2C=C=CH
(phenyl)
(phenoxy)
(naphthalene)
(naphthyl)
(phenanthrene)(anthracene)
+ H
O+O
2
+ O
+ +H+H
+H+H+
O
-CO
-CO
+O2
-O
•
• •
+H
•
PAH+C2H
2
(naphthoxy)
After Marinov, Pitz, Westbrook, Castaldi and Senkan, 1996
Thermal Decomposition of Aliphatic Compounds
C2H6 C2H4 C2H2 •C2HCnH2n+2CnH2n
CnH2n-2
CH4 2•CH4 •C2H5 •C2H3
I II
1) Aromatic formation2) Chlorination
1) Aliphatic chlorination2) Cl-aromatic formation
Al2O CuO,
•C4H5C4H6C2H2
•C3H3•C4HxCly
•C3HxClyC4Cl6
(C4HxCly)
C2HClC2Cl2
Radical Propagation/Condensation
RadicalPropagation/Condensation
Diels-Alder Diels-
AlderCatalyticTrimerisation/
Fischer-Tropsch CatalyticTrimerisation/
Fischer-Tropsch
Clx
Clx
Clx
•Cl
•Cl
Clx
O
Clx
O
Clx
•Cl
PCDD/F
PAHbiphenyl
alkylbiphenyl
Gas Phase Mechanisms
Heterogeneous combustion reactions of C2 aliphatics (ca 600°C)(After Froese and Hutzinger, 1997)
ICCR Meeting September 17,1997
DDDDiiiiooooxxxxiiiinnnn FFFFoooorrrrmmmmaaaattttiiiioooonnnn MMMMeeeecccchhhhaaaannnniiiissssmmmmssss❏ 3. Solid Phase Particle Mechanisms (< 500 °C )
Entrained or Captured Particulate
Matter
O
OCl
Cl
Cl
Cl
Low
Temperature
Precursors on Fly Ash Surface
Gas Phase Formation
of Precursors
ICCR Meeting September 17,1997
DDDDiiiiooooxxxxiiiinnnn FFFFoooorrrrmmmmaaaattttiiiioooonnnn MMMMeeeecccchhhhaaaannnniiiissssmmmmssss
❏ 3a. de novo synthesis➮ fly ash can be source of carbon, catalysts and
chlorine as reagent for low temperature formation (ca. 300 °C)
➮ oxidative gasification reactions with carbon in particles to cleave dioxin/furan structures
O
OCl
Cl
Cl
Cl
Evidence: Laboratory scale tests of heated fly ash can generate PCDDPCDF
OxygenMoisture
ca. 300°C
ICCR Meeting September 17,1997
DDDDeeee nnnnoooovvvvoooo FFFFoooorrrrmmmmaaaattttiiiioooonnnn❏ Effect of Temperature on de novo formation rates of
tetra- to octa- PCDD/PCDF (Schwartz 1990)
ICCR Meeting September 17,1997
DDDDiiiiooooxxxxiiiinnnn FFFFoooorrrrmmmmaaaattttiiiioooonnnn MMMMeeeecccchhhhaaaannnniiiissssmmmmssss❏ 3b. Catalyzed Precursor Mechanisms (< 500 °C)
O
OCl
Cl
Cl
Cl
Chlorinated Precursors (e.g., Chlorophenols)
NonChlorinated Precursors (e.g., Aliphatics, Aromatices, Propene, BenzeneC2 hydrocarbons, Methane)
Evidence: Lab Scale data where PCDD/PCDF has been generated at low temperatures when different organics have been burned in the presence of chlorine sources and metals (e.g., Gullett, Froese, Addink)
Metal Catalyzed
Chlorine Source
+
ICCR Meeting September 17,1997
CCCCaaaattttaaaallllyyyyzzzzeeeedddd PPPPrrrreeeeccccuuuurrrrssssoooorrrr MMMMeeeecccchhhhaaaannnniiiissssmmmmssss
TEMPERATURE (°C)
pg P
CD
D/2
µL IN
JEC
TIO
N2,500,000
2,000,000
1,500,000
1,000,000
500,000
0
150 200 250 300 350 400 450 500 550
Tetra-CDD
Penta-CDD
Hexa-CDD
Hepta-CDD
Octa-CDD
H
H
H
H
❏ Effect of Temperature on production with Cu(II) with chlorophenol
ICCR Meeting September 17,1997
CCCCaaaattttaaaallllyyyyzzzzeeeedddd PPPPrrrreeeeccccuuuurrrrssssoooorrrr MMMMeeeecccchhhhaaaannnniiiissssmmmmssss
Tetra-CDD Penta-CDD Hexa-CDD Hepta-CDD Octa-CDD
CONGENER CLASS
pg P
CD
D/2
µL IN
JEC
TIO
N
10,000,000
1,000,000
100,000
10,000
1,000
100
CuO Fe2O3 ZnO NiO Al2O3 Blank
❏ Effect of various metals on dioxin formation from chlorinated phenol
ICCR Meeting September 17,1997
CCCCaaaattttaaaallllyyyyzzzzeeeedddd PPPPrrrreeeeccccuuuurrrrssssoooorrrr MMMMeeeecccchhhhaaaannnniiiissssmmmmssss❏ Effect of iron oxidative state on PCDD with chlorophenol
10,000,000
1,000,000
100,000
10,000
1,000
100Tetra-CDD Penta-CDD Hexa-CDD Hepta-CDD Octa-CDD
Fe2O3Fe (III)
Fe2O4Fe (II, III)
FeFe (0)
BlankNo Fe
CONGENER CLASS
Pg
PC
DD
/2µL
INJE
CT
ION
ICCR Meeting September 17,1997
DDDDiiiiooooxxxxiiiinnnn FFFFoooorrrrmmmmaaaattttiiiioooonnnn MMMMeeeecccchhhhaaaannnniiiissssmmmmssss❏ 3c. Condensation of Precursors and
Surface Chlorination (< 500°C)➮ Surface condensation of precursors followed by
direct chlorination of adsorbed hydrocarbons
Entrained or Captured Particulate
Matter
+Surface
Chlorine Donor O
OCl
Cl
Cl
Cl
Evidence: Studies of passing combustion effluents with oxygen and HCl over fly ash (Altwicker) and entrained flow studies (Gullett et al)
Low
Temperature
Precursors condense on Fly Ash Surface
ICCR Meeting September 17,1997
IIIInnnn FFFFlllliiiigggghhhhtttt FFFFoooorrrrmmmmaaaattttiiiioooonnnn800
0
200
400
600
1 1.5 3.532.520
200
500
400
300
100
Tem
pera
ture
(°C
)
Residence Time (sec)
D+F
Yie
ld (n
g/ds
cm)❏ Pilot Scale RDF
Combustion Tests (After Gullett, 1997)
❏ PCDD/PCDF has formed by 325 °C
❏ Levels decline with time
❏ Long residence times in APCD are not necessarily required for formation
ICCR Meeting September 17,1997
OOOOuuuuttttlllliiiinnnneeee ooooffff TTTTaaaallllkkkk❏ Structures
❏ Concentrations of interest
❏ Measurement Techniques and Issues
❏ Fundamental Principles
❏ Dioxin and Furan Formation Chemistry
❏ Control Technologies
❏ Formation Conditions
❏ Monitoring Technologies
❏ Conclusions
❏ Recommendations
ICCR Meeting September 17,1997
Dioxin Formation Mechanism Regions
Catalytic formation of PCDD/PCDF on fly ash
PCDD/PCDF in waste stream
PCDD/PCDF formed from gas
precursors
PCDD/PCDF formed on particles
o
oCl
Cl
Cl
Cl
ESP
ICCR Meeting September 17,1997
Parameter Observation Source
Entrained PM Increase Stack PCDD/F
Furnace formed PCDD/F associated with Particles
Quebec City,MWC
Montgomery Cty, MWC
CO Emissions Increase uncontrolled PCDD/F Mid-Conn, MWC
Low CO (<200 ppm) not sufficient to assure low stack PCDD/F
Mid-Conn & Mont. Cty MWCsVarious MWIs
High CO (>200 ppm) not sufficient to assure high PCDD/F
Cement kilnsUtility boilers
Carbon inFly Ash
Increase total PCDD/F formationAbsorbs PCDD/FDiverts PCDD/F from stack to fly ash
Borgess Med CtrQuebec CityDavis County
SIGNIFICANT PARAMETERS - FIELD STUDIES
ICCR Meeting September 17,1997
SSSSIIIIGGGGNNNNIIIIFFFFIIIICCCCAAAANNNNTTTT PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS ---- FFFFIIIIEEEELLLLDDDD SSSSTTTTUUUUDDDDIIIIEEEESSSS
Parameter Observation Source
APCD Temp. PCDD/F Formation Increases Exponentially
Montg. Cty, MWCBorgess, MWIAsh Grove , Ck
Effects solid/vapor phase partitioning Montg. Cty, MWC
Quench Rate Rapid Quench decreases PCDD/Fformation rate
MWIs & HWIs withwet scrubbers compared to units with heat recovery & dry APCD
Cl in Fuel Negligible observed impact on PCDD/F stack emissions
Ash Grove CementPPG HAFWurtzberg, MWCHWIs with wet APCD
Catalytic Metals in fuel
Stack PCDD/F emissions impact not clearly defined
Quebec City, MWCAsh Grove Cement
ICCR Meeting September 17,1997
PPPPiiiillllooootttt SSSSccccaaaalllleeee PPPPaaaarrrraaaammmmeeeetttteeeerrrr SSSSiiiiggggnnnniiiiffffiiiiccccaaaannnncccceeee
❏ Ability of specific parameters to account for observed PCDD/PCDF yields while holding all other parameters constant ( semi-partial correlations from two separate pilot scale programs)
Parameter RDF/Coal FlyAsh/Cl Injected intoCo-Combustion Natural Gas
RDF Feedrate 0.764 Not ConsideredQuench Rate 0.762 0.271Sorbent Injection 0.299 0.497SO
2 Conc. 0.234 Not Considered
HCl Conc. 0.132 0.380Sampling Temp. 0.016 Not Statistically SignificantOxygen Conc. Not Considered 0.092Cl
2 Conc. Not Considered 0.131
Duct Temp. Not Considered 0.614Residence Time Not Statistically sig. 0.271
ICCR Meeting September 17,1997
IIIImmmmppppoooorrrrttttaaaannnntttt CCCCoooonnnnttttrrrroooolllllllliiiinnnngggg PPPPaaaarrrraaaammmmeeeetttteeeerrrrssss
❏ Combustion conditions as indicated by ➮ CO and Total Hydrocarbon
➮ Soot formation
➮ Particle entrainment and burnout
❏ Quench Rate and Air Pollution Control Temperature
❏ Fuel/waste parameters➮ Chlorine
➮ Sulfur
➮ Metals
ICCR Meeting September 17,1997
RRRRoooolllleeee ooooffff CCCCoooommmmbbbbuuuussssttttiiiioooonnnn PPPPrrrraaaaccccttttiiiicccceeee
300 120 300 1200
5000
10000
15000
20000
25000
30000
PCDD/PCDF ( ng/dscm )
Furnace Formation
Downstream Formation
Furnace Formation
Downstream Formation
"Poor" Combustion Conditions
"Good" Combustion Conditions
Particulate Filter Temperature ( °C)
❏ Pilot Scale data after EER Corp., 1994)
ICCR Meeting September 17,1997
Role of Combustion Practice
2000
0
500
1000
1500
0 200 800600400 1000
Good operationPoorPoor operation operation
R2=0.70
PC
DD
/PC
DF,
ng/
Sm 3
CO at 12% CO2, ppm
ICCR Meeting September 17,1997
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❏ Laboratory Data- CO, THC and HAP
❏ Good Combustion Conditions as indicated by low CO and Total hydrocarbons leads to low HAP emissions
❏ After PERF, 1997
ICCR Meeting September 17,1997
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❏ Boiler tube simulation with #2 fuel oil, copper napthenate, dichlorohexane
❏ Significant PCDD/PCDF formation
❏ Required all 3
➮ Soot
➮ Copper
➮ Chlorine
❏ Formation even at low Cl (10ppm)
❏ Sulfur Dioxide suppresses PCDD/PCDF
1,000,000
100,000
10,000
1,000
100
10
1
Cl=500
Cl=10Cl=500
SO2=0SO2-600
PC
DD
+P
CD
F (ng
/dsc
m)
Data after Raghunathan, Lee & Kilgroe, 1997
ICCR Meeting September 17,1997
After Soot Deposits
Before Sooting
Combustion AirNatural gas or fuel oil
dichloro-hexane
Dioxin Sampling
end plate
furnace
Duct
to CEM
Sampling Temperature 240 °C, [HCl]= 500 ppm
Impacts of Soot Formation
Data after Raghunathan et al, 1997
ICCR Meeting September 17,1997
Role of ParticlesQuebec City MB/WW MWC
CD
D/C
DF
Em
itted
/Ref
use
Fed
(µm
ole/
tonn
e)
Uncontrolled Ash/Refuse Fed(kg/tonne)
10
0
2
4
6
8
4 86 16141210
Data after Barton et al, 1990
ICCR Meeting September 17,1997
RRRRoooolllleeee ooooffff PPPPaaaarrrrttttiiiiccccuuuullllaaaatttteeee CCCCaaaappppttttuuuurrrreeee TTTTeeeemmmmppppeeeerrrraaaattttuuuurrrreeee
1
10
100
1000
0.0018 0.002 0.00221/[ESP Temperature (K)]
Stack - Inlet Total PCDD+PCDF(ng/dscm @ 7% O2)
Electrostatic Precipitator Temperature (°C)
250 225 200 175
❏ Dioxin formation very sensitive to the temperature of the Particulate Collection Device
ICCR Meeting September 17,1997
LLLLoooowwww TTTTeeeemmmmppppeeeerrrraaaattttuuuurrrreeee FFFFoooorrrrmmmmaaaattttiiiioooonnnn❏ Data after Swartz et al (1990)
ICCR Meeting September 17,1997
Role of Particulate Capture Temperature
100%
-100%
-50%
0%
50%
-250%
-200%
-150%
420 600580560540520500480460440
Con
trol
Effi
cien
cy %
ESP Inlet Temperature (°F)Pinellas County-MB Peekskill-MB Peekskill-MB Oswego-
Stack air emission =Inlet emission
300250 275225ESP Inlet Temperature (°C)
ICCR Meeting September 17,1997
Mechanisms in Particle Collection Devices
PARTICULATE MATTER -WITH ABSORBED ORGANICS INCLUDING CDD/CDF
GAS PHASE ORGANICSCDD/CDF & PRECURSORS
APCD
SURFACE CATALYZED REACTIONS
ORGANICS DESORBED
FROM SURFACES
PARTICLES ESCAPING
PARTICLES COLLECTED
GAS PHASE ORGANICS
AND CDD/CDF
PARTICLES MAY
CONTAIN CDD/CDF
PARTICLES CONTAINING CDD/CDF
ICCR Meeting September 17,1997
CCCChhhhlllloooorrrriiiinnnneeee IIIImmmmppppaaaaccccttttssss❏ ASME Field
Correlations
➮ Lack of Relationship between Percent Chloride Feed and Mass of PCDD/F Emitted.
➮ Other parameters are controlling
215219220224227230231234235238239246251252253258270271272273274281282283284382388389396398399400
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✕
L
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✕
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-1
0
1
4
3
2Lo
g ng
PC
DD
/PC
DF
per
dscm
7%
02
Percent Chlorine in the Feed100
ICCR Meeting September 17,1997
EEEEffffffffeeeecccctttt ooooffff HHHHCCCCllll CCCCoooonnnncccceeeennnnttttrrrraaaattttiiiioooonnnn❏ Pilot scale RDF data (after Gullett, 1997) indicate
that HCl concentration effect is dependent on quench rate
3500
500
1000
1500
2000
2500
3000
0 654321HCl, g/min
Tota
l, ng
/min
RDF,kg/min
HCl,g/min
SO2,g/min
QU, °C/s TS, °C Ca,g/min
1.12 X-Axis 338 00.011 Legend
426426°°C/sC/s 304304°°C/s C/s 531 531°°C/sC/s
Total PCDD/PCDF
ICCR Meeting September 17,1997
RRRRoooolllleeee ooooffff AAAAmmmmbbbbiiiieeeennnntttt CCCChhhhlllloooorrrriiiinnnneeee❏ Ambient levels of chlorine in atmospheric
particulate ➮ from World Meteorological Organization
➮ Total global tropospheric Cl concentration
• organic bound 3.8 ppb (e.g., long lifetime CFCs, carbon tetrachloride, methylchloroform, )
• HCl 1.4 ppb
• particulate bound <0.23 ppb
➮ elevated near coast
• some measurements indicate levels of 35 ppb
• acidification of salt spray
❏ Chlorine levels in ambient air (ppb) can be orders of magnitude greater than required to generate ppt levels of PCDD/PCDF
ICCR Meeting September 17,1997
SSSSuuuullllffffuuuurrrr IIIImmmmppppaaaaccccttttssss❏ Pilot scale RDF data indicate that SO2 lowers dioxin
formation
8000
0
2000
4000
6000
0 87654321
Tota
l, n
g/m
in
SO2, g/min
1.12 kg/min1.12 kg/min 1.93 kg/min1.93 kg/min 0.5 kg/min0.5 kg/min
RDF,kg/min
HClg/min
SO2,g/min
QU, °C/s TS, °C CA,g/min
Legend 1.9581 X-Axis 428 338 0
Total PCDD/PCDF
ICCR Meeting September 17,1997
EEEEffffffffeeeeccccttttssss ooooffff CCCCooooaaaallll CCCCooooffffiiiirrrriiiinnnngggg wwwwiiiitttthhhh RRRRDDDDFFFF ((((EEEEffffffffeeeeccccttttssss ooooffff SSSSuuuullllffffuuuurrrr))))
❏ Cofiring of high sulfur coal suppresses RDF's PCDD/PCDF formation (>73%)
❏ PCDD/PCDF decreases with cofiring cycles, suggesting build up of sulfur effect
❏ Return to PCDD/PCDF RDF baseline is slow
120
0
20
40
60
80
100 RDF
+Coal
RDF
RDF
RDF
+Coal
Avg
. D/F
Yie
ld (
ngT
EQ
/dsc
m)
Full Scale RDF Data prior to APCD ( After Gullett, 1997)
ICCR Meeting September 17,1997
OOOOuuuuttttlllliiiinnnneeee ooooffff TTTTaaaallllkkkk❏ Structures
❏ Concentrations of interest
❏ Measurement Techniques and Issues
❏ Fundamental Principles
❏ Dioxin and Furan Formation Chemistry
❏ Control Technologies
❏ Formation Conditions
❏ Monitoring Technologies
❏ Conclusions
❏ Recommendations
ICCR Meeting September 17,1997
DDDDiiiiooooxxxxiiiinnnn ccccoooonnnnttttrrrroooollll❏ Good Combustion Practice
➮ Uniform high temperature
➮ Good mixing with sufficient air
➮ Minimize entrained, unburned particulate matter
➮ Feed rate uniformity
➮ CO and Total Hydrocarbons Emissions as indicators
➮ Temperature at particulate control device
❏ Air Pollution Control➮ Spray Dryer/fabric filter
➮ Wet Scrubbers
➮ Carbon injection
➮ Carbon beds
➮ Catalysts poisoning agents and inhibitors
➮ Catalytic Oxidations
ICCR Meeting September 17,1997
CCCCoooonnnnddddiiiittttiiiioooonnnnssss MMMMoooorrrreeee LLLLiiiikkkkeeeellllyyyy ttttoooo LLLLeeeeaaaadddd ttttoooo PPPPCCCCDDDDDDDD////PPPPCCCCDDDDFFFF FFFFoooorrrrmmmmaaaattttiiiioooonnnn
❏ Poor Combustion Conditions ➮ Mixing, Temperature, Quenches, Transients
➮ Sooting conditions
➮ High CO and Total hydrocarbons
❏ High particulate entrained from combustion process with poor burnout (high carbon)
❏ Particulate holdup in critical temperature window (150-450°C)
❏ Particulate matter which contains metal that can catalyze formation of dioxin
❏ Waste or fuel with complex organics and/or lignin like structure
❏ Sufficient Chlorine
Listed in Order of Relative Importance
ICCR Meeting September 17,1997
CCCCoooonnnnddddiiiittttiiiioooonnnnssss ttttyyyyppppiiiiccccaaaallllllllyyyy aaaassssssssoooocccciiiiaaaatttteeeedddd wwwwiiiitttthhhh lllloooowwww PPPPCCCCDDDDDDDD////PPPPCCCCDDDDFFFF FFFFoooorrrrmmmmaaaattttiiiioooonnnn
❏ Low Particulate Matter ❏ Low Temperature or no Particulate Control
Device❏ Rapid Quenches through dioxin
reformation window❏ Good Combustion Practice❏ Low "catalysts" Metals❏ High Sulfur❏ Insufficient Chlorine
Listed in Order of Relative Importance
ICCR Meeting September 17,1997
OOOOuuuuttttlllliiiinnnneeee ooooffff TTTTaaaallllkkkk❏ Structures
❏ Concentrations of interest
❏ Measurement Techniques and Issues
❏ Fundamental Principles
❏ Dioxin and Furan Formation Chemistry
❏ Control Technologies
❏ Formation Conditions
❏ Monitoring Technologies
❏ Conclusions
❏ Recommendations
ICCR Meeting September 17,1997
MMMMoooonnnniiiittttoooorrrriiiinnnngggg aaaannnndddd CCCCoooonnnnttttiiiinnnnuuuuoooouuuussss PPPPeeeerrrrffffoooorrrrmmmmaaaannnncccceeee
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❏ No direct real time monitors exist➮ Emerging technologies (REMPI) hold some promise
for more direct measurement
❏ Currently must rely on periodic manual sampling and analysis and monitoring of parameters that are known to impact formation and emissions e.g.,
➮ combustion parameters
➮ CO/THC indicators of combustion conditions
➮ PM control device temperature
ICCR Meeting September 17,1997
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❏ Carbon monoxide is a stable combustion intermediate
❏ It can be continuously and reliably monitored
❏ It can be used as an indicator ➮ that conditions are same as compliance tests
➮ that conditions are good combustion conditions
❏ But not as a direct indicator of trace organic emissions
ICCR Meeting September 17,1997
Laboratory Data- CO,
THC and HAP
ICCR Meeting September 17,1997
CO and PCDD/PCDF in MWCs
2000
0
500
1000
1500
0 200 800600400 1000
Good operationPoorPoor operation operation
R2=0.70
PC
DD
/PC
DF,
ng/
Sm 3
CO at 12% CO2, ppm
ICCR Meeting September 17,1997
CO and PCDD/PCDF in Hazardous Waste Incinerators
ICCR Meeting September 17,1997
THC and PCDD/PCDF in Hazardous Waste Incinerators
ICCR Meeting September 17,1997
AAAAddddvvvvaaaannnncccceeeedddd MMMMoooonnnniiiittttoooorrrriiiinnnngggg TTTTeeeecccchhhhnnnniiiiqqqquuuueeeessss
❏ Resonance Enhanced Multi-Photon Ionization "REMPI"
❏ Principles➮ Molecules have characteristic energies of their
intermediate vibrational states
➮ Selection of laser wavelength in resonance with that vibrational state causes photoionization
➮ Ionization yields are very high
➮ Ionization is selective, molecule specific
➮ Coupled with Time-of-Flight Mass Spectrometer yields 2D analytical tool
ICCR Meeting September 17,1997
REMPI ApparatusGas
Probe Gated Valve
ISTriggerGate
Reflectron-TOF-MS
SHG + PS
LambdaOPPO
COHERENTInfinityNd-YAG
1 mJZ ns0.15 cm-1
Trigger
Controland Data
Acquisition
DSO108/s
Preamplifier
Signal
ICCR Meeting September 17,1997
Correlations of mono, di, tri dioxins with TEQ
No. of R2 SS Variables in ModelIsomers1 0.729 66.55 2,3,7-TrCDD1 0.537 112.501 2,6-DiCDD1 0.501 122.515 2-MCDF2 0.736 66.040 2,3,7-TrCDD 2,4-DiCDD2 0.733 65.377 2-MCDD 2,3,7-TrCDD2 0.733 65.467 2,3,7-TrCDD 2-MCDF3 0.767 57.136 2-MCDD 2,3,7-TrCDD 2,4-DiCDF3 0.760 68.068 2,8-DiCDD 2,3,7-TrCDD 2,4-DiCDF3 0.757 69.038 2-MCDD 2,3,7-TrCDD 2-MCDF4 0.770 56.535 2-MCDD 2,3,7-TrCDD 2,4-DiCDF4 0.769 56.639 2-MCDD 2,8-DiCDD 2,3,7- TrCDD 2,4-DiCDF4 0.760 58.807 2,8-DiCDD 2,3,7-TrCDD 2-MCDF 2,4-DiCDF5 0.771 58.189 2-MCDD 2,8-DiCDD 2,3,7-TrCDD 2-MCDF
2,4-DiCDF
Predictive Models of TEQ with Low Chlorinated Congeners
ICCR Meeting September 17,1997
CCCCoooonnnncccclllluuuussssiiiioooonnnnssss❏ Dioxin levels of interest
➮ very low concentrations
➮ difficult to measure
➮ care must be taken when comparing measurements due to differences in measurement and reporting techniques
➮ levels near analytical detection limits and practical quantitation limits
❏ Monitoring➮ No direct real time monitors exist
➮ Must rely on Parameter monitoring e.g.,
• CO/THC indicators of combustion conditions
• PM control device temperature
➮ Emerging technologies (REMPI) hold some promise for more direct measurement
ICCR Meeting September 17,1997
CCCCoooonnnncccclllluuuussssiiiioooonnnnssss❏ Formation Mechanisms
➮ Major pathways are defined
➮ Different pathways dominant under different conditions involving both combustion and post combustion regions
• Gas Phase mechanisms
• Solid Phase mechanisms
➮ Kinetics of mechanisms are not established
• Cannot a priori predict PCDD/PCDF formation levels
➮ Key importance of
• Good Combustion Practice
• Particulate matter
• PM control Device Temperature
ICCR Meeting September 17,1997
CCCCoooonnnnddddiiiittttiiiioooonnnnssss MMMMoooorrrreeee LLLLiiiikkkkeeeellllyyyy ttttoooo LLLLeeeeaaaadddd ttttoooo PPPPCCCCDDDDDDDD////PPPPCCCCDDDDFFFF FFFFoooorrrrmmmmaaaattttiiiioooonnnn
❏ Poor Combustion Conditions ➮ Mixing, Temperature, Quenches, Transients
➮ Sooting conditions
➮ High CO and Total hydrocarbons
❏ High particulate entrained from combustion process with poor burnout (high carbon)
❏ Particulate holdup in critical temperature window (150-450°C)
❏ Particulate matter which contains metal that can catalyze formation of dioxin
❏ Waste or fuel with complex organics and/or lignin like structure
❏ Sufficient Chlorine
ICCR Meeting September 17,1997
RRRReeeeccccoooommmmmmmmeeeennnnddddaaaattttiiiioooonnnnssss❏ Examine source design and operation for conditions
potentially favoring dioxin formation
❏ Examine existing dioxin emissions data bases for similar sources
❏ Support research leading to screening and predictive models for PCDD/PCDF from practical combustion systems
❏ Field test on sources
➮ If funds limited focus on more likely sources based upon current understanding of PCDD/PCDF mechanisms
➮ Data collection should include parameters known to influence PCDD/PCDF formation and control
➮ Data engineering analysis to interpret and generalize to other configurations
➮ Address practical quantitation limit
❏ Emphasis on continuous performance assurance and advanced monitoring techniques
Testing RecommendationsSource Fuel Potential Rationale/parameters
Incinerators Waste High Complex organic, Entrained PM, PM Control, metals & Cl, PM Control Temp
Boilers Wood/biomass Mod-High Complex Organics, entrained PM, PM control, Cl, Metals, PM Control Temp
Boilers Landfill gas Moderate Transients, Complex HC, Cl, Low PM
Boilers Residual Oil Mod-Low Sooting, metals, S/Cl, PM control TempIC Engines Landfill gas Moderate Transients, Complex HC, Cl,
Low PMBoilers Coal Low-mod S/Cl ratio, GCP, Entrained PM, PM
Control, C in ash, metalsHeaters Process gas Low GCP, transients, potential catalysts, low
PMFlares Waste Gas Low No PM control, rapid quenchBoilers Distillate Oil Low Sulfur, GCP, low ClIC Engines Diesel Low PM present,Low Cl, Temp ProfileTurbines Distillate Oil Low GCP, no PM control, thermal
quenchBoilers Natural Gas Very Low GCP, very low PM, Low metals andClIC Engines Natural Gas Very Low Very low PM, GCP, Low metals and ClTurbines Natural Gas Very Low GCP, very low PM, Rapid
Quench, Low metals and Cl