-------
excess air were used and minimizes entrainment of fuel particles and ash in
the flue gas. The incomplete combustion products pass into the secondary
combustion chamber where excess air is added and combustion is completed. The
auxiliary burner is fired if the secondary chamber temperature falls below a
specified level. The resulting hot gases can be passed through a heat-
recovery boiler for energy recovery. Although several existing modular
combustors do not have heat recovery, almost all new and planned modular
combustors are expected to incorporate heat recovery.
The modular unit described above typically is called a controlled air or
starved air combustor. Another type of modular combustor uses excess air in
the primary chamber, and no additional air is added In the secondary chamber.
In this design the secondary chamber simply provides additional residence time
for the completion of combustion. This type of design is functionally similar
to larger, mass burn units.
A third major class of municipal waste combustor burns refuse-derived
fuel (RDF). Figure 2-3 shows an RDF facility. The types of boilers used to
combust RDF can include suspension, stoker, and fluidized bed designs. RDF
may be co-fired with a fossil fuel (usually coal), but co-firing is not
prevalent and information generated during this study does not include
information about co-firing.
The degree of processing of refuse to yield RDF can vary from simple
removal of bulky items accompanied by shredding to extensive processing to
produce finely divided fuel suitable for ccMFtHingMn pulverized coal-fired
boilers. Processed municipal waste, regardless of the degree of processing
t
performed, is broadly referred to as RDF. \
2.3.2 Description of the Industry
The population of municipal waste combustors in the United States (both
existing and projected) is described in terms of 1) throughput or capacity, 2)
number of facilities or combustor sites, 3) type of combustor, and 4) location
of facilities. Throughput or capacity may be aggregated in several ways: by
type of combustor, by number of facilities in a state or region of the
United States, or by facility or unit. A facility may consist of one or more
combustors. Capacity refers to the amount of municipal waste a facility,
unit, or group of facilities is designed to combust.
12
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Slab Receiving
& Storage Are*
Primary
Shredder
Residue Aluminum Heavy Light
Ferrous Ferrous
RDF Combustion
Secondary
Shredder
Air Classifier may b« reoiaced
tty Trommel Screen
RDF
Distributors
Grata Surface
Drive
Shaft ~~-4
Underrate
Air Compartment
Tangantlal
Overflre Air
Sifting Screw
Conveyor
Figure 2 - 3. Diagrams of RDF Processing and Combustion
13
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In this report, the existing and planned combustor populations will be
described first by typr, then by location. In both descriptions,
distributions of the population are presented by number of facilities and by
capacity.
*
2.3.2.1 Distribution of combustors by type. There are 111 municipal
waste combustion facilities currently in operation in the United States.
Table 2-1 presents a summary of these existing facilities. They are ground
by three design types: mass bur ' modular, and facilities that produce and
combust RDF. These design types were previously described in Section 2.3.1.
The total design capacity for the 111 existing municipal waste combustion
facilities is approximately 49,000 tons per day of municipal waste input.
Table 2-1 and Figure 2-4 show the distribution of total U.S. capacity among
the three design types. Figure 2-4 shows that the mass burn facilities have
the largest share of the installed U.S. capacity, 68 percent of the total.
The RDF facilities represent 23 percent of the total capacity, and modular
represent 9 percent. Though they represent a small amount of the total
installed capacity, the number of facilities using modular combustors to
combust municipal waste is greater than the number of mass burn facilities (56
facilities with modular combustors compared to 45 mass burn facilities).
There are only ten RDF facilities in operation.
Table 2-1 also shows the size distribution of municipal waste combustion
facilities in the U.S. The majority of the facilities with modular combustors
(54 of the 56 facilities) have design capacities of less than 250 tons per
day. There is no typical design capacity for the mass burn facility. The
data indicate that mass burn facilities are designed to meet a variety of
capacity requirements, unlike the modular units which are specifically
designed for a smaller combustion demand. Twelve mass burn facilities have
design capacities less than 250 tons per day, 6 facilities have capacities in
*
The information in this section is a summary of information presented in
Reference 6, Municipal Waste Combustion Study: Characterization of the
Municipal Waste Combustion Industry.
14
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TABLE 2-1. SUMMARY OF OUSTING MWC FACILITIES
Total
Number of
Capacity
Range
Design Type (tons per day)
Mass Burn <250
Modular
RDF
Mass Burn 250 to <500
Modular
RDF
Mass Burn 500 to <1000
Modular
RDF
Mass Burn >1000
Modular
RDF
Totals
Installed
With
Heat
Recovery
8
37
1
4
2
3
4
0
1
8
0
5
73
Facilities
Without
Heat
Recovery
4
17
0
2
0
0
11
0
0
4
0
0
38
Installed
(tons
With
Heat
Recovery
1,291
3,292
200
1,820
570
1,100
2,740
0
600
14,250
0
9,500
35,363
Capacity
per day)
Without
Heat
Recovery
748
610
0
900
0
0
7,150 "
0 "
0
4,200
0
0
13,608
111
48,971
15
-------
Modular (9%)
Mass Burn (68%)
RDF (23%)
Total Design Capacity = 49,000 tons per day
s
ao
Figure 2 • 4. Distribution of Existing Installed Municipal Waste
Combustion Capacity by Design Type
16
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the 250 to 500 tons per day size range, 15 facilities have «apacities in the
500 to iOOC •'ze range, and 12 facilities'have capacities iqual to or greater
than 1000 U is per day. Five of the ten RDF facilities are designed to
process more than 1000 tons per day of municipal waste.
Of the 111 existing municipal waste combustion facilities, 73 are"
designed with heat recovery boilers. Thirty-nine of the 56 facilities with
modular combustors (70 percent) and all of the RDF facilities (53 percent) are
designed with heat recovery boilers. Heat recovery boilers are prevalent at
facilities with modular combustors, because many of these facilities have been
built more recently than mass burn facilities, and heat recovery boilers are
an integral part of newer designs.
The EPA has information concerning 210 planned municipal waste combustion
facilities. Planned facilities are those which are not yet operating, but are
either under construction, planned for construction, under negotiation, or
have been formally proposed. Table 2-2 presents a summary of these planned
facilities. They are grouped by the same design types that were used to group
the existing facilities. One hundred and eighteen of the 210 identified
planned facilities are mass burn facilities, 24 are facilities planning to
install modular combustors, and 31 are RDF facilities. For 37 facilities,
data on the design type were either unavailable, or a design type had not been
chosen. The total design capacity for the 210 facilities is projected to be
approximately 190,000 tons per day, or approximately four times the total
design capacity of existing municipal waste combustion facilities. Some of
these planned units are in the early stages of planning. Not all of the
planned projects will proceed to completion. On the other hand additional new
municipal waste combustion projects are being considered every day. The
ultimate capacity expected to come on line is obviously uncertain.
Figure 2-5 shows, for planned facilities, the expected distribution of
total U.S. capacity among the three primary design types. The mass burn
facilities are expected to account for 59 percent of the total design
capacity. The RDF facilities are expected to account for 20 percent, and
facilities planning to install modular combustors are expected to account for
only 3 percent. The remaining 18 percent of planned capacity includes
facilities where the design technology is either undecided or not available.
All of the planned facilities are expected to incorporate energy recovery.
17
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TABLE 2-2. SUMMARY OF PLANNED MUNICIPAL WASTE COMBUSTION FACILITIES
Design Typee
Design
Capacity
Range
(tons per day)
Number of
Planned Facilities
Total
Planned Capacity
(tons per day)
Mass Burn <250
'-odul ar
RDF
DNA
Mass Burn 250 to <500
Modular
RDF
DNA
Mass Burn 500 to <1000
Modular
RDF
DNA
Mass Burn >1000
Modular
RDF
DNA
18
14
3
7
17
10
2
9
33
0
11
6
50
0
15
15
3,055
1,377
450
1,225
6,155
3,730
730
3,220
21,653
0
8,544
3,700
82,532
0
29,150
27,850
Totals
210
193,371
DNA indicates that data on design type are not available or the technology
is undetermined at this time.
18
-------
Modular (3%)
Mass Burn (59%)
RDF (20%)
Undecided/Not Available (i8°/
Total Design Capacity = 190,000 tons per day
00
Figure 2 - 5. Distribution of Planned Municipal Waste Combustion
Capacity by Design Type
19
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Table 2-2 shows the expected size distribution among planned facilities.
Fourteen of the 24 facilities with moo .ar •. nmbustors are planned with
capacities of less than 250 tons per day. « a remaining ten facilities
planning modular combustors are expected to fall into the 250 to 500 tons per
day capacity size range. Fifty of the 118 i.iass burn facilities are planned
with capacities equal to or greater than 1000 tons per day. Fifteen of the 31
RDF facilities are planned with a capacity equal to or greater than 1000 tons
per day.
2.3.2.2 Distribution of Municipal Waste Combustors bv Location.*
Table 2-3 lists the states with the largest existing capacity to combust
municipal waste. New York State has the largest existing capacity with
approximately 9,000 tons per day (at 12 facilities). The 6 states listed in
Table 2-3 account for a combined capacity of 32,000 tons per day, or nearly 66
percent of the total capacity in the United States. The remaining 29 states
and the District of Columbia account for a combined capacity of nearly
17,000 tons per day, or 34 percent of the total capacity. Figure 2-6 shows
the geographic distribution of municipal waste combustion facilities in the
United States. The figure shows that municipal waste combustion facilities
are concentrated on the east coast. A complete list of existing municipal
waste combustion facilities is included in Appendix B.
Table 2-4 lists the States with the planned growth in municipal waste
combustion of greater than 5000 tons per day capacity. California's planned
growth in combustion capacity of approximately 43,000 tons per day (at 36
facilities) is the largest. The 9 states listed in Table 2-4 account for a
combined planned capacity of approximately 150,000 tons per day, or nearly 80
percent of the planned capacity in the United States. The remaining 34 states
account for a combined planned capacity of nearly 40,000 tons per day, or 20
percent of the total planned capacity for the United States. Figure 2-7 shows
the distribution of planned municipal waste combustion facilities in the
The information presented in this section is a summary of information
presented in Reference 2, Municipal Waste Combustion Study: Characterization
of the Municipal Waste Combustion Industry.
20
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TABLE 2-3. STATES WITH THE LARGEST EXISTING CAPACITY TO
PROCESS MUNICIPAL SOLID \STE
State
New York
Florida
Massachusetts
Ohio
Maryland
Pennsylvania
Subtotal
Remaining States
Total
Number of
Facilities
12
5
6
5
Z
3
33
78
111
Existing Capacity
(tons per day)
9,025
7,498
5,640
4,400
3,450
2,220
32,233
16,738
48,971
aRanked in descending order by capacity.
Each of the remaining States has a total existing capacity less than
2000 tons per day. New Hampshire has 12 modular facilities with a total
capacity of 517 tons per day.
21
-------
r>o
ro
Figure 2 - 6. Regional Distribution of Existing Municipal Waste
Combustion Facilities
-------
PR
Figure 2 - 7. Regional Distribution of Planned Municipal Waste
Combustion Facilities
-------
TABLE 2-4. STATES WITH PLANNED GROWTH IN MWC CAPACITY
EXCEEDING 5000 TONS PER DAY3
State
California
New York
New Jersey
Pennsylvania
Florida
Massachusetts
Connecticut
Virginia
Washington
Subtotal
Remaining States
Total
Number of
Facilities
36
'23
6
26
13
11
11
4
5
149
61
210
Planned Capacity
(Tons Per Day)
42,522
22,853
23,955
18,472
14,420
10,060
8,520
8,375
5,150
154,327
39,044
193,371
Ranked in descending order by capacity.
24
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United States. The figure shows increasing activity in municipal waste
combustion on botn the east and west coasts. A list of planned municipal
waste combustion facilities known to the EPA is shown in Appendix B.
2.3.2.3 Projections through the Year 2000. Most of the facilities
identified by EPA as planned will be constructed by 1990 if there are not
serious delays in implementation. The EPA has also made projections of the
growth of the municipal waste combustion industry through the year 2000.
These projections are largely based on market surveys and projections in the
increase in the generation of municipal waste.
Market analys.'s from several sources indicates substantial growth in the
total number and capacity of facilities out to the year 2000; although, the
extent of the growth predicted varies with the different analyses. Estimates
indicate that over 300 facilities will be on-line and operating by that time.
The total projected capacity is expected to be between 113,000 and 260,000
tons per day by the year 2000.
Based on the capacities of existing and planned facilities, mass burn
facilities are expected to account for between 60 and 70 percent of the total
projected capacity by the year 2000. Facilities that combust RDF will
constitute between 20 and 30 percent, and facilities with modular combustors
will account for approximately 10 percent of the total projected capacity by
the year 2000.
The net growth in the number of municipal waste combustors by the year
2000 is dependent on the growth in the number of new facilities minus the
closing of existing facilities. The EPA estimates that the number of existing
facilities to be retired or closed over the next 15 years will be small in
number. This projection results from the fact that the majority of existing
municipal waste combustors were built since 1970 and, therefore, will have
less than 30 years in operation by the year 2000. Some refurbishing of
facilities currently shut down may also occur, adding to the projected
capacity.
The information in this section is a summary of information presented in
0
Reference 6, Municipal Waste Combustion Study: Characterization of the
Municipal Waste Combustion Industry.
25
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3. ENVIRONMENTAL ISSUES
Converging with the shift in waste management strategies and the
resultant growth in municipal waste combustor population is rising concern
about the environmental effects of municipal waste combustion. Environmental
concern has been raised about solid residues as well as pollutants emitted to
the atmosphere. Particular concern exists, as mentioned previously, with the
confirmation of the presence of CDD and CDF in emissions and residues.
3.1 SOLID RESIDUES
The Resource Conservation and Recovery Act applies to disposal of the
bottom ash and collected fly ash from municipal waste combustion facilities.
These residues generally contain metals such as lead and cadmium.
EPA has reviewed data from the literature concerning results of EP
toxicity tests (as described in 40 CFR 261.24) on ash. The Agency has no
information to indicate the reliability of these data. A majority of the fly
ash tests reported indicate levels of lead or cadmium above those indicative
of EP toxicity. Few tests of bottom ash or combined fly and bottom ash
indicate levels of metals above such levels. EPA is in the process of
obtaining more reliable data on ash characteristics and Teachability.
If the ash generated by a municipal waste combustion facility were to be
managed as a hazardous waste, the cost of managing that ash would be expected
to increase substantially.
The EPA's findings concerning ash disposal will be issued as they are
completed. Unfortunately, they were not available for inclusion in this
report. Therefore, the remainder of this report and the documents published
with it focus on potential environmental effects of emissions from municipal
waste combustors to the atmosphere.
26
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3.2 EMISSIONS TO THE ATMOSPHERE*
Recently, concerns have been raised about emissions of pollutants to the
atmosphere from municipal waste combustors. As discussed in the Introduction,
much of this concern was over emissions of CDD and CDF, but other pollutants
of concern have also been cited. As part of the integrated study of municipal
waste combustion, EPA attempted to collect as much data on emissions from
municipal waste combustors as was available. Summary matrixes showing
emissions data collected by the EPA are shown in Tables C-l and C-2 in
Appendix C. The first summary table shows almost 50 facilities for which the
EPA has documented test reports to support the test data. The second
compilation is of data from emission tests about which the agency has little
supporting information. These data include emission tests conducted in North
America, Western Europe, and Japan.
Comparison of the data from different tests is difficult because the
facilities vary widely in design and operating conditions, the tests were
conducted with different objectives and different protocols, and the level of
detail of the reported data varies. Further, the specific sampling and
analysis methods were not the same for all tests. These differences make it
difficult not only to make comparisons among combustors tested but also to
draw conclusions about the entire population of combustors.
To make the most of existing emissions data, a compilation of test data
has been assembled as a part of this effort to address environmental effects
of municipal waste combustion. The compilation is presented in the document
titled "Municipal Waste Combustion Study: Emissions Data Base for Municipal
Waste Combustors." Information concerning the units tested, operating
conditions, and sampling and analytical protocols has also been included with
the emissions measurement data.
The emissions data gathered to date from municipal waste combustors show
a variety of pollutants emitted from their stacks at widely varying
concentrations. A summary of the ranges measured for various pollutants
*The emissions data presented in this chapter are from Reference 16, Municipal
Waste Combustion Study: Emissions Data Base for Municipal Waste Combustors.
All data are shown on the basis of 12% COg.
27
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exiting the plants is shown in Table 3-1. The da*a are shown for the three
ir; classes of municipal waste combustion units, mass burn, modular, and
RL -fired. These data were collected from about 30 full-scale facilities for
which documented test data and sampling and analytical methodologies were
available. All emissions data have been normalized to 12 percent C02-
The emissions numbers shown in Table 3-1 comprise emissions measured from
municipal waste combustors that are equipped with widely varying control
devices. The effects of different control devices on emissions of a given
pDllutant can be seen in widely varying stack emissions, contributing to the
wide range shown in the table. The numbers shown do not distinguish among
control devices in use. Existing municipal waste cowbustors are generally
equipped with particulate matter control devices only, if they are equipped
with control devices of any kind. Virtually all existing mass burn units
(which tend to be larger) are equipped with some sort of particulate matter
collection device. Thirty-six of 56 existing modular facilities now operating
in the U. S. (which tend to be smaller and carry over fewer particulate
emissions because of their design) are equipped with no add-on control
devices. However, all new, mass burn and RDF facilities and most new modular
facilities are expected to be equipped with efficient particulate matter
control devices. Only two existing facilities currently are equipped with
scrubbers in addition to particulate matter control devices, but many new
facilities are expected to incorporate some type of gas scrubber for control
of other pollutants.
These control devices are being incorporated in response to regulatory
strategies at both the Federal and State levels. The control of particulate
emissions from new municipal waste combustors is required by Federal
standards. Some states, particularly those with the largest numbers of new
units, are also requiring control of a variety of pollutants through the use
of add-on control equipment and, in some cases, (e.g., California and in New
York) furnace operating requirements.
Remembering all the previous comments on the difficulty of comparing the
emissions data, it may be useful to look more closely at the emissions test
data for selected pollutants. Looking for trends or patterns, the facilities
associated with the extremes of the ranges shown in Table 3-1 have been
28
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TABLE 3-1. SUGARY OF EMISSIONS MEASURED FROM THE THREE
MAJOR CLASSES OF MUNICIPAL WASTE COMBUSTORS*
Pollatent
Mass Burn
Modular
RDF-Fired
to
Part leu late witter 5.5 -
(0.002
Sulfur dloxld* 0.04
Nitrogen oxld** 39
Carbon Monoxide 16.5 <
Hydro0*n chloride 7.5
Hydrogen fluoride 0.62
Arsenic 0.452
Beryl lluei 0.0005
Cad»1u* 6.2 •
Cnro»1u* 21 -
Lead 25 -
Mercury 9 -
Nickel 230 •
TCOO 0.20 •
TCDF 0.32 •
PCOO 1.1 -
PCOF 0.423 -
1.530 wj/N*3
- 0.669 gr/d*cf)
- 401 ppwlv
- 380 ppwfv
- 1.350 ppwlv
- 477 ppwlv
- 7.2 ppwlv
- 233 ug/N*3
- 0.33 ug/N*3
• 500 ug/N*3
1.020 ug/N*3
15.000 ug/N*3
2.200 ug/N*3
• 480 ug/N*3
• 1.200 ng/N*3
> 4.600 ng/N*3
11.000 no/N*3
15.000 ng/N*3
23-300 ng/M*3
(0.012 • 0.13 gr/d»cf)
61 - 124 ppwlv
260-310 ppwlv
3.2 - 67 ppwlv
160 • 1270 ppwlv
1.1 - 16 ppwlv
6.1 - 119 ug/N*3
0.096 - 0.11 ug/N*3
21 - 942 ug/N*3
3.6-390 ug/N*3
237 - 15.SCO ug/N*3
130 - 705 tig/Me3
<1.92 - 553 ug/Na3
1.0 - 43.7 ng/N*3
12.2 - 345 ng/N*3
63 - 1540 ng/N*3
97 - 1810 ng/N*3
220 - 530 WJ/MM3
(0.096 - 0.230 gr/dscf)
55 - 188 ppwlv
' 263 ppwlv6
217 - 430 ppwlv
96-780 ppwlv
2.1 ug/N*3 b
19-160 ug/N*3
21 ug/N*3 b
34 - 370 ug/N*3
490 - 6.700 ug/N*3
970 - 9.600 ug/N*3
170 - 440 ug/N*3
130 - 3.600 ug/N*3
3.5 - 260 ng/N*3
32 - 680 ng/N*3
54 - 2,840 ng/N*3
135 - 9.100 ng/N*3
•See Appendix C for iu**iry of facilities represented In Missions data for each pollutant category. Results
su**ar1zed are fro* full scale co**arc1a1 facilities only.
Only one test.
-------
identified arJ are discussed in the following sections. Supporting detail
concerning unit types and test conditions may be found in the volume titled
"Municipal Waste Combustion Study: Emission Data Base for Municipal Waste
Combustors."16
It should be noted that the concentration ranges reported were measured
during relatively short duration tests, usually compliance tests, performed
under optimum conditions. In particular, the levels at the low end of the
ranges may not be achievable at all combustors and may not be achievable on a
continuous basis even by the specific combustors tested.
In addition, the levels at the low end of the ranges have not been found
at the same facility for all pollutants. In some cases, achieving a low level
of one pollutant is likely to make it more difficult to achieve a low level of
others, e.g., achieving low levels of organic emissions through combustion
optimization will make it more difficult to achieve low levels of nitrogen
oxide emissions. Thus, the levels at the low end of the ranges are not all
likely to be achievable at the same facility.
3.2.1 Particulate Matter
A benchmark against which the particulate matter concentrations measured
in stack gases from municipal waste combustors can be compared is the NSPb of
0.08 gr/dscf (183 mg/Nm ), established in 1971. Also, the newly promulgated
NSPS for industrial boilers, which would apply to units of 100 million
Btu/hour (270 tons per day of municipal waste) or larger that generate steam,
limits particulate emissions to 0.1 ID/million Btu (43 ng/Joule) of heat
input, which is equivalent to about 0.04 gr/dscf (92 mg/Nm ), assuming the
composition of waste shown in Appendix D.
As noted generally about all the emission test data, the range of
particulate matter concentrations measured in combustor stack gases is large,
especially for mass burn units, covering several orders of magnitude. Even
though the range is large, the measured particulate concentrations tend to
reflect the age of the technology in use and the type of control device in
use.
The lowest concentrations were measured from two relatively new units,
one equipped with a high efficiency (99.9%) electrostatic precipitator (ESP)
30
-------
and one equipped with a scrubber/fabric filter system. The lowest value for
particulate concentrations from mass burn units (5.49 mg/Nm ) was measured at
Unit 1 of the Baltimore, Maryland, facility, a large, recently constructed
facility. The Baltimore facility achieved an emission level of 6.2 mg/Nm at
Unit 2 during a test program conducted by the EPA later in the same year
(1985). Another low particulate matter concentration (9.15 mg/Nm ) was
reported from a combustor in Wurzburg, Germany. This new facility is equipped
with a dry scrubber/fabric filter. Other facilities equipped with ESPs or dry
scrubber/fabric filter combinations have reported particulate matter
concentrations in the range of 11 to 30 mg/Nm . (Marion County, Oregon;
Tulsa, Oklahoma; Tsushima, Japan; Malmo, Sweden; and Munich, Germany.)
At the high end of the range of particulate matter concentrations, two
refractory mass burn combustors reported high levels. The highest
(1530 mg/Nm ) was reported from the combustor at Mayport Naval Station in
1980. The particulate matter emission control device in use was a
multiple-cyclone dust collector. This type of dust collector is not as
effective as newer particulate emission control technologies. Another high
•a
value for particulate matter concentrations (1330 mg/Nm ) was measured from
Unit 2 of the Philadelphia Northwest facility, where particulate matter
emission control is accomplished with an ESP.
This high concentration reported from one unit of the Philadelphia
facility may be anomalous. The value of 1330 mg/Nm is the average of three
determinations of which one was extremely high. During the same series of
tests, the average for Unit 1 of the same facility was 252 mg/Nm . The other
two measurements for Unit 2 were nearer the levels measured for Unit 1. Of
the waterwall mass burn combustors, the highest value (917 mg/Nm ) was
reported from Hampton in 1981. The Hampton facility is equipped with an ESP
for control of particulate matter emissions. This combustion facility has
been noted for several design and operational problems. Those problems are
analyzed in more detail in the volume titled, "Municipal Waste Combustion
Study: Combustion Control of Organic Emissions."
Measured particulate matter stack gas concentrations for modular units
are available from only six facilities. The data from these units show a much
narrower range of values than those measured for mass burn units. The modular
31
-------
combustors for which stack gas particulate concentration data are available
are of the starved air, Consuimt design. Uncontrolled particulate matter
concentrations in stack gases from these units are generally lower than
uncontrolled concentrations from mass burn units because of lower air
velocities, resulting in less carry-over of ash. Uncontrolled particulate
concentrations measured at modular units range from 170 to 300 mg/Nm compared
with uncontrolled concentrations of 2,200 to 8,500 mg/Nm measured at mass
burn units. Ultimate stack concentrations from existing modular combustors
may be higher, however, because they generally are not equipped with
particulate matter emission control devices, while the mass burn units usually
have them. Even so, because modular units are smaller, their total mass
emissions of particulate matter generally are lower than the totals from mass
burn facilities. Additionally, new modular combustors are generally expected
to be equipped with particulate matter control devices.
The low value for modular units (23 mg/Nm ) was measured at Barron
County, Wisconsin, an ESP-controlled facility. Another facility, the
Tuscaloosa facility, is also equipped with an ESP. Particulate matter
concentrations measured at Tuscaloosa were HO mg/Nm . However, this
controlled particulate matter concentration is not considered representative
of normal levels because of noted problems with the control equipment during
the test. The high particulate matter concentration for modular units
(300 mg/Nm ) was measured at the 90 Mg/day combustor in Dyersburg in 1982.
Testing was performed at a feed rate of 45 Mg/day, and the feed during the
test was about 30 percent industrial and 70 percent municipal waste. The
remaining particulate matter emissions data were gathered from testing under
several different operating conditions at the Prince Edward Island combustion
facility and range from 173 to 255 mg/Nm . The value obtained under normal
conditions was 214 mg/Nm. Neither Dyersburg nor the Prince Edward Island
facility have add-on air pollution control systems.
As with the modular units, the amount of data available for RDF-fired
units is limited. The low particulate matter emission value for RDF units
(220 mg/Nm ) was measured at the Niagara facility. The facility fires
shredded waste from which ferrous metals have been removed. Particulate
matter emissions are controlled using ESPs. A particulate matter
32
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concentration of 89 mg/Nm was measured at thi Hamilton-Wentworth facility in
Ontario, Canada, during normal load usini, only the lower overfire air port.
This concentration was measured during one test run only. Emission test data
taken under normal conditions showed 518 mg/Nm . The high particulate matter
concentration for RDF-fired units (530 mg/Nm ) was measured at the Akron"
facility in 1981. At Akron, processing of RDF includes shredding, air
classification, and magnetic separation. Particulate matter emissions are
controlled by an ESP.
The lowest uncontrolled particulate matter concentration from RDF-fired
facilities was measured at Malmo, Sweden. A concentration of 4330 mg/Nm
particulate matter was measured upstream of very efficient control equipment.
It should be noted that this unit is a relatively new unit designed as a mass
burn unit and differs from typical RDF designs. When the unit was fired with
unprocessed refuse, uncontrolled particulate matter concentrations were 4,450
mg/Nm , nearly the same as the RDF-fired concentration. Controlled levels
measured while operating in the mass burn mode were 23.2 mg/Nm .
3.2.2 Sulfur Dioxide
The concentration of S02 measured in stack gases from municipal waste
combustors depends directly on the amount of sulfur in the feed. Although it
can be highly variable, a typical value for sulfur content of municipal waste
is about 0.12 percent, and 30-60 percent of that is converted to SO-. The
balance remains with the bottom ash or is absorbed on fly ash. Sulfur is
associated with such items as asphalt shingles, tires and other miscellaneous
items in the waste feed.
For purposes of comparison, the sulfur content of coal being burned in
the U. S. ranges from about 0.5 to about 5 percent. If high sulfur coal were
burned in utility boilers without S02 controls, the resulting uncontrolled
concentrations of S02 in stack gases could be as high as 3,000 ppm or higher.
Another comparison point, the 1978 NSPS for S02 emissions from utility
boilers, allows S02 emissions concentrations of 100 to 500 ppm S02, depending
on the sulfur content of the coal. These controlled S02 levels generally are
higher than uncontrolled concentrations in stack gases from municipal waste
33
-------
combustors, but as shown in the table, the high end of the range for mass burn
un-us if -omparable to the controlled level for coal-f;red utility boilers.
AH ough the sulfur content in the waste is the ultimate determinant and
major cause of variability in SO- concentrations measured, the emissions test
data indicate that the control equipment in use is a major factor in the S02
concentrations measured in the combustor exhaust. As might be expected,
combustors equipped with alkaline scrubbers tend to have lower levels of SO-
in their stack gases. The low e1"-4 of the range of sulfur dioxide stack g^
rf-.
concentrations for mass burn mm* was measured at a Japanese unit in Tsushima
in 1983. The Tsushima facility is controlled with a Teller dry scrubber/
fabric filter system. The SO- concentration upstream of the control system
was 12.7 ppm; the concentration measured downstream of the control system was
0.040 ppm. The reduction across the control device represents a control
efficiency of greater than 99.7 percent. The data reported for the
composition of the waste feed at Tsushima showed that the average sulfur
content of the waste is 0.38 percent on a wet basis. This is comparable to
the sulfur content of municipal waste generated in North America; however, the
uncontrolled SO- concentrations are about an order of magnitude lower than
those at any other facility tested. Moreover, outlet SO- concentrations are
more than two orders of magnitude less than any other reported values,
including those from other facilities using dry scrubbing. These
discrepencies make comparisons to S02 concentrations measured at other units
questionable. The next lowest S02 concentrations were measured at a Quebec
City pilot-scale test on a slip stream from a full-scale waterwall combustor.
The temperature of the inlet gas to a scrubber/fabric filter system was varied
during the test; the lowest concentration (4.86 ppm S02) was measured at the
lowest temperature (110°C). The S02 concentration measured during the
pilot-scale test increased with increasing temperature up to 90.3 ppm at
200°C. Another low S0« value, 13.5 ppm, was reported from a unit in Kure,
Japan, equipped with two 75 Mg/day rotary combustors and an ESP followed by a
wet scrubber. The next lowest SO- concentration, 41.5 ppm, was measured in
1986 at the Marion County unit in Brooks, Oregon. The Marion County facility
is a new facility equipped with a dry scrubber/fabric filter system.
The high SO- emission measurement, 401 ppm, was obtained at the
Philadelphia Northwest facility, equipped with an ESP and no additional
34
-------
control devices. This level and the other, value for Philadelphia }f 375 ppm
are inexplicauly ^ ""her than the SO- concentrations measured ••.t the other mass
burn units. SO- c ncentrations in exhaust gases from mass burn units equipped
with ESPs or other particulate matter control devices are about the same as
SO- concentrations measured in the inlets to the control devices for those
combustors equipped with scrubbing systems. This is to be expected because
ESPs do not remove S02» nor do cyclones. These uncontrolled SO-
concentrations generally range between about 80 and 140 ppm, levels
significantly lower than controlled levels required for fossil fuel-fired
boilers.
Modular unit SO- concentration data compiled in the EPA's emission data
base are taken from only two facilities, Prince Edward Island (under a variety
of conditions) and Red Wing (under normal conditions). The low value of 61
ppm was obtained under "normal" conditions at Prince Edward Island. The
highest value obtained at Prince Edward Island of 87 ppm was measured under
low secondary chamber temperature conditions. The highest level of 124 ppm
was achieved at the Red Wing facility under normal conditions. The
concentrations are roughly comparable to the uncontrolled concentrations
measured for mass burn units. A concentration of <29.3 ppm was reported at
North Little Rock, Arkansas; however, data were not available to correct the
reported value to a dry basis, so it cannot be compared.
Sulfur dioxide emissions data for RDF-fired combustors are available for
only three facilities. The low value of 55 ppm was measured in 1984 at the
Hamilton-Wentworth, Ontario facility which was equipped with an ESP for
control of particulate matter emissions. The high value of 188 ppm, was
measured at the Albany, New York facility in 1984. Although it is difficult
to make any meaningful comparisons with this small amount of data, the SO-
concentrations are again consistent with uncontrolled SO- concentrations
measured at mass burn units.
3.2.3 Hydrochloric Acid
The concentration of HC1 in stack gases from municipal waste combustors
is related to the chlorine content of the feed. Major chlorine sources in
municipal waste are plastics and paper, materials that also provide the
35
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largest heating value in the waste. By way, of comparison to the ranges shown
in Table 3-1, typical ui.-ontir lied HC1 concentrations in stack gases from
coal-burning utility boilers ould range from about 60 ppm for average
chlorine content coal to 120 ppm for high chlorine content coal. These HC1
concentrations considered with the previous discussion of S02 concentrations
indicate that the acid gas of primary concern with municipal waste combustors
is usually HC1, while with fossil fuel-fired boilers the primary acid specie
is usually SCL.
The major determinant of the ultimate concentration of HC1 in stack gases
exiting a municipal waste corabustor, other than feed composition, is the
control device in use. It is logical to expect facilities equipped with
scrubbers have significantly lower HC1 concentrations because HC1 is easily
removed with scrubbing. This expectation is borne out by the EPA's emission
test data.
For mass burn combustors the lowest stack gas concentration for
hydrochloric acid was measured at the Quebec City scrubber/fabric filter pilot
scale testing in 1985-1986. The lowest HC1 concentration (3.99 ppm) was
measured at the lowest temperature (110°C) test condition. Measured HC1
concentrations leaving the fabric filter increased with increasing temperature
to 104 ppn> at 200°C. The next lowest HC1 concentration (7.5 ppm) was measured
at the Tsushima facility. The lowest concentration achieved at a
commercial-scale North American facility (12 ppm) was measured during the
recent test of the Marion County facility equipped with a dry scrubber/fabric
filter system. The high end of the range for mass burn units (477 ppm) was
measured upstream of air pollution control equipment at the Gallatin,
Tennessee facility in 1983. Emission control equipment consisted of a cyclone
and an electrostatically assisted fabric filter, neither of which is designed
to reduce HC1 stack gas concentrations. Another high HC1 concentration was
measured at a new mass burn combustor in Tulsa. Stack gas concentrations of
402 and 421 ppm were measured downstream of an electrostatic precipitator.
This facility is notable because CDD/CDF concentrations measured there were
very low, a condition attributable to optimized combustion.
Hydrochloric acid emissions test data are available for only four modular
facilities; all are Consumat, starved air units, and two of these modular
36
-------
facilities are equipped with post combustion controls. The low value of 160
ppm was measured at the Dyersburg '"cilUy .during testing in 1982. The high
value (1270 ppm) was measured at the Re Ving facility. The second highest
value (768) was obtained under high temperature secondary chamber conditions
at Prince Edward Island. Under "normal" conditions at Prince Edward Island
716 ppm HC1 was measured in the stack gas. The Barren County facility
reported an intermediate concentration of 460 ppm. The Red Wing HC1
concentration is noticeably higher.
None of the available HC1 emissions data for RDF-fired combustors were
obtained from measurements downstream of acid gas control devices; therefore,
they essentially represent uncontrolled HC1 stack gas concentrations. The
lowest level of HC1 concentration (96 ppm) from an RDF unit was measured at
Wright Patterson Air Force Base in 1982. The combustor there is an 11,000
MJ/hr boiler designed to burn coal. During the test the boiler was fired with
densified RDF. Particulate matter emission control equipment at the Wright
Patterson facility consists of a multicyclone followed by an ESP. The high"
value of 780 ppm was reported in 1983 from a combustor in Malmo, Sweden. The
Malmo facility was designed as a mass burn unit. These emissions were
measured during a test in which RDF was fired in the combustor designed to
fire unprocessed waste. Although this plant is equipped with a cyclone/dry
scrubber/ESP/fabric filter combination which should control HC1 emissions, the
measurement reported was upstream of the control device, representing an
uncontrolled HC1 stack gas concentration. Other HC1 concentrations measured
from RDF-fired plants range from 350 ppm measured at the Albany facility to
450 ppm measured at the Akron facility in 1981. These values are typical of
the expected range of uncontrolled HC1 stack gas concentrations.
3.2.4 Metals
Metals and metallic compounds are found distributed throughout municipal
refuse, not just associated with large metallic objects. Many metals, such as
silver, chromium, lead, tin, and zinc, are used in metallic surface coatings,
galvanizing, and solders. These metals may volatilize during the combustion
process. PJUitjc^objects contain metallic compounds (cadmium, in particular)
~~* as stabilizers and other additives. Metals, such as cadmium, chromium, and
37
-------
lead, are also found in inks and paints associated with paper, fabric, and
plastic substrates. Discarded batteries are sourc of mercury, nickel, and
cadmium. Metals and metallic compounds may change phases or may form new
metallic compounds, but they are not destroyed in the combustion process. The
metals and metallic compounds will leave the combustor in the stack gas er in
the ash residues. Operating temperature affects metals emissions by affecting
the partitioning between phases. Thus one would expect stack gas
concentrations of metals to be related to feed concentration and operating
conditions. But the data also tend to show a strong effect of control
devices.
Table 3-2 shows the facilities associated with the extremes of the
concentration ranges for a few selected metals measured in stack gases from
mass burn combustors. As the table shows, the Quebec City facility is
associated with the low end of the range for the four metals shown. As
mentioned before, the Quebec City data were generated just recently on a slip
stream from a full-scale combustor. A dry scrubber/fabric filter system was
tested at several fabric filter operating temperatures, thus, the ranges shown
for Quebec. The Malmo, Wurzburg, and Munich facilities are all equipped with
dry scrubbers. The Kure facility, however, is equipped with an ESP/wet
scrubber combination. While the scrubber-equipped combustors show lower
metals concentrations in the stack gases, the data also indicate that ESPs may
be operated as effective control devices for some metals. For example,
arsenic concentrations measured downstream of the ESP at Baltimore were
3
6.29 ug/Nm ; this represents 97 percent reduction in the uncontrolled level of
240 ug/Nm . The Baltimore facility's ESP also achieved 99 percent reduction
of chromium. The controlled concentration levels measured at Baltimore are
higher than those measured at facilities equipped with scrubbers, but they are
lower than those measured at other ESP-equipped facilities.
The high end of the range of stack gas concentrations at mass burn units
for these selected metals is associated with the Hampton and Braintree
facilities. The Hampton facility, as previously noted, has been notable for
several design and operational problems. Those problems are discussed in more
detail in the report titled "Municipal Waste Combustion Study: Combustion
Control of Organic Emissions." Like Hampton, the Braintree system was
equipped with an ESP for particulate removal.
38
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Conclusions drawn from these data must be drawn with caution. A serious
complicating factor involved in the metals emissions data may prevent de :nite
conclusions from being drawn. Sampling and analytical methods used duri g the
testing reported here were not constant. In some emissions tests only metals
in the form of participate matter were measured. In other tests both
particulate matter and the condensibles were analyzed for metals. Moreover,
sampling and analytical techniques used for measuring metals in either or both
phases differed among the emissions tests, as shown in the table. The
complications these differences introduce are clear. While it is unlikely
that the differences in the metals concentrations reported are due totally to
different sampling and analytical protocols, the contributions to the
differences are unknown. The EPA is investigating the issue of data
comparability.
The data for mercury concentrations in combustor stack gases, with the
exception of the Quebec City data, do not show outstanding control with the
use of either ESPs or scrubber/fabric filter systems. Mercury concentrations
measured at inlet and outlet to scrubber/fabric filter systems at Malmo and
Tsushima show only 30 to 40 percent reduction, while ESP data showed no
control. Metallic mercury is generally thought to volatilize, so control
might be accomplished through cooling and condensation. Research in Germany
18
has also indicated a possible chemical reaction with alkaline sorbents.
Moreover, the data gathered at Quebec under varying temperature conditions
indicate that it may be possible to optimize mercury control through cooling.
This is a subject of continuing study. With respect to mercury, it should
also be noted that the high end of the range of stack gas concentrations for
mass burn facilities is an order of magnitude higher than such concentrations
measured at other facilities.
Metals emissions data are available for only five modular units, Prince
Edward Island, Dyersburg, Barren County, Tuscaloosa and Red Wing; all are
Consumat systems. Three (Barron County, Tuscaloosa and Red Wing) are equipped
with particulate matter control devices. Those facilities reporting the
highest and lowest concentrations for the four metals being discussed here are
shown in Table 3-3. The table shows that the stack test data from Dyersburg
showed the lowest of the mercury concentrations. This concentration is lower
40
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TABLF 3-3. MODULAR FACILITIES FOR WHICH HIGHEST ANf) LOWEST
EMISSION LEVELS WERE MEASURED FOR SELECTED METALS
Facilities Shotting
LOB Concentrations
Sampling
and
Emission Analytical Facilities Shoving
Concentration Method High Concentrations
Sampling
and
Analytical Emission
Method Concentration
As
Cd
Pb
Hg
Prince Edward Island*
Barren Count yb
Barren Countyb
Dyersburga
6.09 ug/N*3
21 ug/N*3
240 ug/N«3
130 ug/N*3
d Oyersburg*
Prince Edward Island*
Prince Edward Island*
e Prince Edward Island*
c
d
d
d
116 ug/Nm3
942 ug/N*3
15,500 ug/Nm3
705 ug/Nm3
•Both phases analyzed.
''Unknown which phases were analyzed.
cArsen1c concentrations were measured by EPA Method 108. The filter and solids contained In the O.I N NaOH
rinse of the front half of the sailing train were analyzed by atonic absorption. The Implngers and
0.1 N NaOH rinse were analyzed by atoxic absorption.
dSample train similar to that of Method 5. First two Implngers contain 5 percent aqua regla. third Implnger
contained 2X KMn04 1n IQ* H2S04. Analysis generally by direct current plasma Mission spectrometry.
•Volatile trace elements trapped In liquid Imptnger train which contains H
amnnluM persulfate In the fo
(manual cold vapor technique)
-------
than concentr?cions measured at some of the .mass burn units equipped with
alkaline -crubbers. Barren County reported the lowest measured concentrations
for lead and cadmium. Prince Edward Island's stack test data were lowest for
arsenic; the highest arsenic concentration was reported from Dyersburg. The
highest cadmium and lead concentrations were measured at Prince Edward Island.
The high cadmium concentration was measured under "normal" conditions. The
high lead concentration was measured during a test run of a long feed cycle,
but a similarly high concentration (14,400 ug/Nm ) was measured under "normal"
conditions. The highest mercury concentration (705 ug/Nm ) was also measured
at Prince Edward Island under "nornal" conditions.
Metals data for two plants designed to fire RDF were available for
comparison. The Albany and Akron facilities were both equipped with ESPs for
particulate matter control. The metals analyses for Akron and Albany included
both particulate matter and condensibles. Test data from the Albany facility
showed stack gas concentrations an order of magnitude lower for arsenic,
cadmium, and lead, than levels measured at the Akron facility. The mercury
concentrations measured at Akron were somewhat lower, however. With only two
units, it is hard to draw any firm conclusions. However, there is no
indication that these units exhibit significant differences from the mass burn
units in metals stack gas concentrations. The Mai mo plant, a new mass burn
unit fired with RDF, reported mercury and lead concentrations upstream of the
control device similar to the concentrations reported for the Akron facility.
But the cadmium emission:
those measured at Akron.
But the cadmium emissions measured at Maimo were higher (488 ug/Nm } than
3.2.5 CDD and CDF
As pointed out in the beginning of Section 3.2, the test data available
for CDD and CDF were not gathered with a statistically designed sampling plan
for the industry, and the data assembled in this study are averages of test
data from diverse facilities. Nevertheless, for purposes of this report
these data are the best available to characterize potential emissions of CDO
and CDF from municipal waste combustors.
The variability associated with measured CDD and CDF stack gas
concentrations is the most noticeable observation about the emissions data.
42
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These data have been sur-.uarized in Table 374 and graphically in Figures 3-1
and 3-2. As shown, th* stack gas concentrations of COD cover several orders
of magnitude, showing the largest range for mass burn facilities for which
there are the most data points. Another indication from the test data
assembled by EPA is that alkaline scrubbing systems combined with fabric
filters are effective at reducing CDD/CDF concentrations in stack gas. As
shown in Table 3-4 and in Figures 3-1 and 3-2 and in the data summarized in
the volume titled "Municipal Waste Combustion Study: Emission Data Base for
Kunicipal Waste Combustors,1 those facilities equipped with alkaline
scrubbers tend toward the lower end of the range of CDD concentrations.
However, the data shown tor facilities without alkaline scrubbers include some
older units, while the units with alkaline scrubbers are all fairly new.
Table 3-5 shows which mass burn facilities are associated with the end
points of the ranges shown for stack gas concentrations of selected CDD and
CDF. As the table shows, the ranges cover five orders of magnitude. Marion_
County data were the lowest for four of the six classes shown in the table.
Those measured at Quebec City and Wurzburg were the lowest for the other two.
The Marion County combustion facility is a new facility, also equipped with a
dry scrubber/fabric filter system. The Wurzburg facility is also equipped
with an alkaline scrubber/fabric filter system. Both the Marion County and
Wurzburg facilities are of Martin design. It should be noted that the Quebec
City test data are pilot plant data, and it is not clear how the test results
can be extrapolated to the population of full-scale combustors.
These low values show that alkaline scrubber/fabric filter control
systems can effect good control of organic compounds like CDD and CDF. Low
levels have also been achieved without a scrubber. Recently obtained data
from Tulsa show that low concentrations might also be expected from municipal
waste combustors with good combustion. The Tulsa facility is a new mass burn
waterwall combustion facility. Particulate matter emissions are controlled by
ESPs, but no additional control equipment is in use. It is currently unclear
what contribution ESPs may make with respect to control of organic emissions,
but most ESPs are run at temperatures high enough that little organic control
43
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TABLE 3-4. SUMMAR' JF CDO/CDF EMISSIONS FROM
MUNICIPAI WASTE COMBUSTORS
Emissions, ng/Nm .
at 12 percent CO,
Facil ity
Chicago NWC
Hampton (1981)
Hampton (1983)
Hampton (1984)
Tulsa
North Andover
Saugus
Umea (Fall)
Umea (Spring) .
Marion County (DS)
Quebec (DI)
Quebec (SO)
Wurzburg (DS)
Philadelphia (NW1)
Philadelphia (NW2)
Cattaraugus
Red Wing
Prince Edward Island
Albany
Hamilton Wentworth
Wright Patterson
Test Condition*
Normal
Nc ., 1
No ,dl
Normal
Normal
Normal
Normal
Normal
Low temperature
Normal
Normal
110
125
140
200
140
140 & R
Normal
Normal
Normal
Normal
Normal
Normal
Long
High
Low
Normal
F/None
F/Low back
F/Back
F/Back, low front
H/None
H/Low back
Normal
CDO/CDF
258
16,800
9,630
25,500
34.4
348
580
501
745
492
1.55
2.65
BD
1.03
7.61
BD
1.33
49.9
11,300
5,620
258
3,310
395
428
195
413
578
9,230
10,900
12,000
20,900
14,100
11,500
228
i.
TCDD
°.39
800
214
1,160
1.61
8.38
31.9
51.6
64.8
<12
0.195
BD
BD
BD
BD
BD
0.0639
1.91
378
365
8.1
43.7
3.05
5.09
1.02
3.05
19.9
590
560
570
3,500
1,200
700
3.47
aTest conditions defined in Reference 9, Municipal Waste Combustion Study
Emission Data Base for Municipal Waste Combustors.
BD * Below detection limit.
cNo Penta CDD or Penta CDF measured. Values for CDD/CDF biased low.
Values not corrected to 12 percent CO*.
44
-------
• No Control
• ESP Only
A Dry Scrubbing
x Other
10,000
1,000-
-a
8
100-
z
o>
co
c
o
'35
—
LU
10
1.0-
0.1-
0.01
1
2,3,7,8
TCDD
PCDD 2,3,7,8
TCDO
PCDD 2,3,7,8 PCDD
TCDD
CM
O
TCDD
Mass Burn
TCDD
Modular
TCDD
RDF
Figure 3-1. Summary of CDD Stack Gas Emissions Test Data.
-------
• No Control
• ESP Only
A Dry Scrubbing
x Other
10,000 -
O
O
•S
V)
c
O
"55
w
in
1,000-
100-
10-
1.0-
0.1-
0.01
I
2,3,7,8 PCOF 2,3,7,8 PCDF 2,3,7,8 PCOF
TCDF I TCDF I TCOF I
TCDF TCDF TCDF
Mass Burn Modular RDF
fM
O
r^
s
Figure 3-2. Summary of CDF Stack is Emissions Test Data.
46
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TABLE 3-5. MASS BURN FACILITIES FOR WHICH HIGHEST AND LOWEST STACK GAS
CONCENTRATIONS WERE MEASURED FOR SELECTED GROUPS OF CDD AND CDF
Number of . Fadllty(s) Showing Concentration Faclllty(s) Showing Concentration
Pollutant Facilities Low Concentration (ng/Nm ) High Concentration ' 'Nm )
2,3,7,8-TCDD 8
TCDD 9
2,3,7,8-TCDF 7
TCDF 9
CDD 10
CDF 10
Wurzburg
Marlon County
Marlon County
Marlon County
Quebec City (140° and
Recycle) a
Quebec City (110°)a
Marlon County
Marlon County
Quebec City (140° and
Recycle)4
0.016
0.20
0.17
0.32
0.13
0.165
1.13
0.423
0.947
Hampton (1982) 63
Hampton (1984) 1,200
Hampton (1984) 450
Hampton (1981) 4,600
Hampton (1984) 11,000
Hampton (1984) 15,000
aThese data are from a pilot scale test of a dry scrubber/fabric filter system. The control equipment 1n use
under ordinary circumstances 1s an ESP.
^Number of facilities for which documented test data available.
-------
would be expected. Con- itra*ions of COD and CDF were measured at Tulsa as
follows:
TCDD 1.61 ng/Nm3
PCDD 18.9 ng/Nm3
TCDF 7.31 ng/Nm3
PCDF 15.5 ng/Nm3
These values are the lowest CDD/CDF values in the emissions data base for mass
burn facilities not using alkaline scrubbers. Moreover, because the ESP is
not thought to contribute a significant amount of organic control, the
concentrations measured are thought to result from relying on optimized
combustion only. Note that these concentrations are similar to those measured
at Wurzburg, a facility equipped with a dry scrubber/fabric filter system.
The combustion facility at Hampton was associated with each of the upper
bounds of these classes of dioxins and furans. As mentioned previously, that
unit is equipped with an ESP and has known design and operational problems.
More information about the Hampton facility may be found in the volume titled
"Municipal Waste Combustion Study: Combustion Control of Organic
Emissions."
There are only a few modular units for which the stack gas concentrations
of CDO and CDF can be compared. In general, the concentrations measured at
the modular units fall in the mid-range. They are higher than those measured
at facilities equipped with alkaline scrubbers, but lower than the high values
measured at mass burn units. The modular facilities represented in the data
base are equipped with Consumat combustors. Two of them are equipped with
ESPs. The high and low values for some of the classes of CDD and CDF are
shown in Table 3-6. As the table shows, Prince Edward Island dominates the
low end of the ranges, the Red Wing facility dominates the high end. The low
values reported for Prince Edward Island were measured under high secondary
chamber temperature conditions.
The range for RDF-fired facilities is very large, even though there are
only 3 or 4 facilities available for analysis. This makes looking for trends
or drawing conclusions particularly difficult. The low end of the range of
TCDD concentrations shown was measured at Wright Patterson Air Force Base.
The high concentration was measured at Akron. The concentrations measured for
48
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VO
TABLE 3-6. MODULAR FACILITIES FOR WHICH HIGHEST AND LOWEST
STACK GAS CONCENTRATIONS MERE MEASURED FOR SELECTED
GROUPS OF COD AND CDF
Pollutant
1COO
TCDF
COO
COT
Facility Shoving Concontratlon Facility Shoving Concentration
Low Concontratlon (ng/htr) High Concentration (ng/ltar)
Prlnco Edward Island 1.0* Rod King • 44
Prlnco Edward Island 12* Rod King 350
Prlnco Edward Island 63* Rod Ming 1500
Prlnco Edward Island 97 • Rod King 1000
Sloasurod undor high secondary chsoftor toaporaturos
-------
TCDF again were lower at the Wright Patterson facility {32 ng/Nm ) and higher
at the Akron facility (680 ng/Nm ). For PCD,.. ste'k gas concentration data
were available for a few additional units. As bet ,e, the low end of the
range (54 ng/Nm ) was measured at Wright Patterson, but for this class of
compounds, the high value (2,840 ng/Nm ) was measured at the Hamilton- •
Wentworth facility under normal load with both back overfire air ports in
operation. Consistent with the other classes of COD and CDF, the low value in
the emission data base for PCDF concentration was measured at the Wright
Patterson facility. The high value of 9,100 ng/Nm was again measured at
Hamilton-Wentworth under normal load with both back overfire air ports in
operation. All of the ROF-fired facilities tested are equipped with ESPs.
50
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4. OPTIONS FOR CONTROLLING EMISSIONS TO THE / 10SP"ERE
The pollutants shown in the summary emissions table (Table 3-1) include
several major classes of substances for which control may be possible:
particulate matter, organics, acid gases, metals, and NO . There are
^
basically two^apjproaches _tg_control 1 i ng emissions from municipal waste
combustors. One approach is to alter the combustion process to reduce
emissions, sometimes called combusJijpJXjLOJitroJ . The other is adding pollution
control equipment to clean the combustion gases. This approach may be called
flue gas cleaning, or flue gas treatment. These two
approaches are not exclusive, and are often used together for a comprehensive
control strategy.
For municipal waste combustors the control problem involves a slate of
pollutants. Moreover, application of control technology for one pollutant or
class of pollutants may have positive or negative effects on control of other-
pollutants. For example, enhanced combustion should reduce the emissions of
other organic pollutants in addition to COD and CDF. Moreover, alkaline
scrubbers, when combined with particulate control devices, can reduce not only
acid gases but also some organic species and volatile metals. On the other
hand, maximizing the combustion efficiency may Increase the potential to form
NO . Devising a control strategy, then, involves consideration of control
^
techniques for each of the classes of pollutants present, but also requires
consideration of the effects of a selected control technique on the whole list
of pollutants.
In addition to considering positive and negative effects of air pollution
control equipment on different air pollutants, another important consideration
concerns cross-media effects. Some pollutants, notably metals, may be
captured and prevented from being emitted to the atmosphere, but they are not
destroyed. Increased capture means that the ash residues contain more metals.
The following sections describe available control techniques for each
pollutant class. Then optimum strategies for controlling the whole list of
51
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pollutants from the stack gases of municipal 'waste combustors are cr Mde-ed.
More complete discussions of combustion optimization and flue gas treatme
may be found in two volumes: "Municipal Waste Combustion Study: Combustion
;ion<
,,19
Control of Organic Emissions and "Municipal Waste Combustion Study: Fl-ue
Gas Cleaning Technology.
4.1 ORGANICS
The municipal waste combustion process essentially is designed to convert
organic materials to CO- and water. Nonetheless, some organic materials are
emitted. The presence of organics in the exhaust gas is a sign of incomplete
combustion. Incomplete combustion can also be indicated by high levels of CO,
so one would expect high levels of CO to be accompanied by high levels of
organics.
This expectation is validated by a simple look at CDO/CDF concentrationsr
particular group of organic compounds, versus CO concentrations measured in
stack gases from municipal waste combustors. Figure 4-1 shows average CDD/CDF
and CO data gathered in the course of this study. Keeping in mind that these
data represent averages of tests made using different methods from different
types of combustors, using different types of control equipment, and noting
that the variability is large, regression analysis is not advisable.
Moreover, the data used are not adequate to establish a functional
relationship between variables. Nevertheless, the trend toward higher CDD/CDF
emissions with higher CO emissions is clearly evident. Further validation of
trends between CDD/CDF and CO concentrations is seen in Table 4-1 which
summarizes Spearman Rank Order Correlation results, a statistical test for
monotonic relationships. This analysis is not a rigorous analysis for
statistical correlation and, therefore, caution should be used in drawing
conclusions. However, the graph and the Spearman Rank Order Analyses indicate
that, in general, high CDD/CDF are associated with high CO concentrations and
low CDD/CDF concentrations are associated with low CO concentrations.
Several theories have been postulated concerning ways that organic
compounds, including CDD and CDF, may appear in stack gases from municipal
waste combustors. The best supported theories for the formation of CDD/CDF
17
are summarized in Figure 4-2.
52
-------
10,000
_ 1000
(Of
o
o
£
CM
z
"Sb
m
n
01
u_
Q
O
O
a
o
100
10 -
1.0 -
0.1
10
o o
• Man Burn/ESP
• Man Burr/Dry Scrubber
A Modular
O RDF-Fired
100 1000
Average CO Concentration (ppm)
Figure 4 • 1. Comparison of CDD/CDF Stack Gas Concentrations to
CO Stack Gas Concentrations
53
-------
TABLE 4-1. RANK ORDER CORRELATION,RESULTS FOR CO vs. CDD/CDF
Combustor Type
Mass burn
Modular
RDF-fired
Total
No. of Tests
14
6
7
25
rs
0.52a
-0.4:
0.07
0.69b
r = Spearman's rank order correlation coefficient.
aA positive relationship is indicated at the 0.05 level of significance.
A positive relationship is indicated at the 0.001 level of significance.
54
-------
I. CDD in Refuse
X Combustion \
V Zone /
Cl
Unreacted
CDD/CDF
Evidence: Occasional CDD/CDF contamination in refuse
II. Formation from Related Chlorinated Precursors
Chlorophenois
Cl
Cl
Cl
PCB
Evidence: CDD/CDF on soot from PCB fires
Lab and bench studies of PCB, Chlorinated Benzene and Chlorinated Phenols yielded CDD/CDF
HI. Formation from Organics and Chlorine Donor
PVC ( i Chlorine donor
Lignin j ^ NaCL,HCI,CI2
CDD/CDF
Evidence: Lab scale tests of vegetable matter, wood, lignin, coal with chlorine source yielded CDD/CDF
IV. Solid Phase Fly Ash Reaction
Precursor
-f- Cl Donor
Low
Temp
CDD
Evidence: Lab scale demonstrating potential for ash catalysis reactions of CDD's to other homologues
8
r^.
3
Figure 4 - 2. Summary of Theories for CDD/CDF Municipal Waste
Combustor Stack Gas
55
-------
The first possible mechanism shown in Figure 4-2 involves breakthrough of
unreacted organic species preseni. in the refuse. A second theory involves the
reaction of organic precursors in the waste. For example, relatively simple
reactions can convert chlorophenols and polychlorinated biphenyls to CDD/CDF.
These precursors can be in the refuse and can be produced by pyrolysis in
oxygen-starved zones.
A third mechanism involves the synthesis of CDD/CDF from a variety of
organics and a chlorine donor. Again, the simplest mechanisms involve those
species that are structurally related to CDD/CDF; however, a full spectrum of
plausible combustion intermediate chemistry could be proposed to lead to
precursors and eventually to CDD/CDF.
The final possible mechanism shown involves catalyzed reactions of
organic precursors escaping the combustion zone on fly ash particles at low
temperatures. These hypothesized mechanisms can be broadly classed into three
main ways that organics may appear in the exit gases from combustors:
o Lack of destruction of organics originally present in the feed
refuse,
o Conversion of precursors present in the feed or formed in the
combustion processes to organic compounds emitted from the stack,
and
o Lack of destruction of precursors in the combustion system and
conversion of the precursors to other organic substances
downstream of the combustion zone at low temperatures.
While it is not certain which, if any, of these basic mechanisms
dominates, all three basic formation mechanisms would be minimized by
achieving complete combustion, thereby converting all organic species to C02-
Thermodynamic considerations indicate that under excess air conditions
and temperatures characteristic of municipal waste combustors, there is no
theoretical barrier to achieving essentially zero emission levels for these
species. In spite of this, emission measurements have shown the presence
of significant quantities of organic species in exit gases from some municipal
waste combustors. Existence of these species (either in the flame or in the
exhaust) iQdjc_3ie_s_a failure in the combustion process caused by insufficjLejvt
mixing and characterized by escape of local fuel-rich pocketsjvfjgas. This
perplexing formation may be more easily understood when the heterogeneity of
56
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municipal refuse is considered. The collection of discarded materials known
•s municipal refuse forms a highly variable, heterogeneous fuel containing
items of all sizes and shapes, composed of all sorts of materials. Solid
pieces of the waste may volatilize and/or pyrolyze unevenly, causing fuel-rich
pockets of gas to form in the furnace. If these fuel-rich pockets are not'
sufficiently mixed with air, incomplete combustion will result and organic
materials may be emitted to the atmosphere.
However, theoretical kinetic and equilibrium considerations indicate that
the destruction of organic species can be rapidly achieved in the presence of
sufficient oxygen at elevated temperatures. ' Therefore, control of
organic emissions requires development of a combustion control strategy that
ensures that all organic materials, down to the molecular level, are exposed
to enough air and to a high enough temperature for enough time to destroy
them.
Conditions within the municipal waste combustor that would satisfy the
above goals are:
o Mixing of fuel and air to prevent the existence of fuel-rich
pockets in the combustion gases,
o Sufficiently high temperatures in the presence of sufficient
oxygen for destruction of organic species, and
o Prevention of quench zones or low temperature pathways that would
allow partially reacted or unreacted fuel from exiting the
combustion zone of the furnace.
4.1.1 Combustion Controls*
To achieve the thorough combustion required to minimize emissions of
organic species, manufacturers of municipal waste combustion equipment are
paying a great deal of attention to three combustion parameters: time,
temperature, and mixing (turbulence). However, the simplistic view of
optimization of combustion by the "three Ts" (time, temperature and
*The information presented in this section is a summary of information
presented in Reference 17, Municipal Waste Combustion Study: Combustion
Control of Organic Emissions.
57
-------
turb'^ence) is not directly valid in this context. For evample, the gas phase
residence ,me should not be considered solely a neceisa»y reaction time, but
should also be considered a mixing time. Time is required for air and
intermediates to mix, but once mixed at sufficient temperature, the
destruction reaction takes place virtually instantaneously. There is no need
to hold the mixed gases at this temperature for a longer time. Further,
turbulence on its own is not sufficient to ensure the necessary mixing. Two
separate, highly turbulent stream tubes in the furnace will not mix despite
their high turbulence level unless they come into contact. Thus, mixing of
the furnace gases with air requires that the turbulent jet? be dispersed
throughout the combustion gases. Finally, the definition of a mean
temperature must be made with the minimum required temperature and expected
variability around the mean in mind.
With the goal of complete combustion in mind the EPA has developed a set
of combustion strategy elements termed "good combustion practices."
These control strategy elements are summarized in Table 4-2 for mass burn,
modular and RDF units, respectively. Also shown are preliminary
specifications for each of the elements.
Detailed information concerning the selection of each of these
preliminary specifications is presented in the volume titled "Municipal Waste
Combustion Study: Combustion Control of Organic Emissions." In general,
they were derived from theory and expert opinion. They have been reviewed by
EPA; trade and professional organizations such as the American Society of
Mechanical Engineers and the American Boiler Manufacturers Association, and
others.
Several cautionary notes are associated with these specifications.
First, these recommendations are preliminary and have not been verified in
field tests. There are no test data that explicitly show the effects of these
practices on emissions. Moreover, as with any general principles, the
specific designs of individual systems must be considered. In particular,
several combustion systems, such as the mass burn refractory technologies of
Volund and Enercon/Vicon and the mass burn rotary technology of Westinghouse/
O'Connor incorporate differences from the typical of the practices described
in Table 4-2. For such systems, parameters such as "fully mixed height" will
have to be defined based on technology-specific engineering analysis rather
58
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TABLE 4-2. GOOD COMBUSTION PRACTICES FOR THE MINIMIZATION OF ORGANIC EMISSIONS FROM MUNICIPAL WASTE COMBUSTORS
en
«O
Practice
Mass Burn
Prellninary Target
RDF
Preliminary Target
Design temperature at fully Mixed height
Underflre air control
Overfire air capacity
(not an operating requirement)
Overftre air Injector design
Auxiliary fuel capacity
Excess Air
Turndown restrictions
Start-up procedures
Use of auxiliary fuel
Oxygen In flue gas (continuous eonItor)
CO In flue gas (continuous Monitor)
Furnace temperature (continuous Monitor)
Adequate air distribution
18000f at fully nixed height
At least four separately
adjustable plenums. One each
under the drying and burnout zones
and at least two separately
adjustable plenum under the
burning >one.
401 of total air
That required for penetration
and coverage of furnace cross-
section
That required to eeet start-up
temperature and IdOOOf criteria
under part-load operations
18000F at fully Mixed height
As required to provide uniform
bed burning stolchloMetry
40f of total air
That required for penetration
and coverage of furnace cross-
section
j
That required to Meet start ..p
temperature and 18000F criteria
under part-load operations
6 - 12* excess oxygen (dry basts) 9-91 excess oxygen (dry basis)
80 - 110S of design - lower ItMlt
My be extended with verification
tests
On auxiliary fuel to design
temperature
On prolonged high 00 or low
furnace temperature
6 -
dry
SO ppn on 4 hour average -
corrected to 12* CO.
MlnlMUM of iaOO°F (Mean) at fully
Mixed height across furnace
Verification test*
00 - 1101 of design - lower Melt
May be extended with verification
tests
On auxiliary fuel to design
temperature
On prolonged high 00 or low
furnace temperature
3 - M dry
50 ppM on 4 hour average -
corrected to 12* CO?
MlnlMUM of iaOO°F (e»an) at fully
Mixed height
Verification test1
Starved-alr
Preliminary Target
18000F at fully nixed height
80S of total air
That required for penetration
and coverage of furnace
cross-section
That required to Meet start-up
temperature and 1800°F criteria
under part-load conditions
6 - 121 excess oxygen
(dry basis)
80 - 110* of design - lower
limit May be extended with
verification tests
On auxiliary fuel to design
temperature
On prolonged high CO or low
furnace temperature
6-121 dry
50 ppM on 4 hour average -
corrected to 12k CO->
MlnlMUM of 1800°F (Mean) a
fully Mixed plane (secondary
chanter)
Verification test*
•See text Section 4 and "Municipal Waste Combustion Study: Combustion Control of Organic Enlsslons." Chapter 9.
-------
than on the general one-nv )r r le suggested for traditional mass burn
systems. However, it is import, t for permit writers and those applying for
permits to be aware of the conditions that promote achievement of complete
combustion. Those planning to construct municipal waste combustion facilities
should also be aware of good combustion practices and their implications for
design practices. For example, one implication of turndown restrictions is
design for fairly constant load. Sizing for a fairly constant load becomes a
critical part of the design, and load leveling constraints may increase the
benefits of designs using multiple combustion units, for example.
Of course, the final determinant of the performance of each system is the
measured level of trace organics emitted. Whether these levels indicate
acceptable performance will depend on emission levels established in the
facility's permits, state standards or guidance, and any federal guidance or
regulation that may be established in the future.
Recent test data obtained from the new municipal waste combustor in Tulsa.
show that low concentrations of organics may be achieved by optimizing
combustion conditions even though the design and operating conditions cannot
be directly related to the preliminary targets in Table 4-2. Although no post
combustion control devices were installed specifically for removal of organic
species, the organic concentrations are lower than those measured in any
similarly equipped facility, indicating thorough optimization of the
combustion process. The only lower values for mass burn units in the EPA's
Emissions Data Base were measured in units equipped with alkaline
scrubber/fabric filter systems, as discussed in the section on CDD and CDF
emissions. In fact, the concentrations of TCDD, TCDF, PCDD, and PCDF were on
the same order but lower than the concentrations measured at the Wurzburg
facility which is equipped with a dry scrubber/fabric filter system.
Another illustration of the possibility of decreasing organic emissions
through combustion optimization is the municipal waste combustor in Quebec.
In Quebec, an older facility was modified to reflect current low emission
design philosophy. Concentrations of CDD and CDF were measured before and
21
after the modifications as follows:
Before After
CDD 800 - 3980 ng/Nm3 12 - 205 ng/Nm3
CDF 100 - 1100 ng/Nm3 49 - 336 ng/Nm3
60
-------
These data are preliminary and corrected to 12% CO-. These data indicate the
possibility of using a combination of com' :tion system design and operational
tuning to significantly reduce CDD and CDl emissions. However, the specific
changes appropriate for a specific facility and the likely effectiveness of
those changes in reducing organic emissions must be determined on a
case-by-case basis.
An important factor in operation of an optimally designed and tuned
municipal waste combustor in a continuously optimized manner is operator
training. The Northeast States for Coordinated Air Use Management (NESCAUM)
and the American Society of Mechanical Engineers (ASME) have developed a
training course for resource recovery facility operators. NESCAUM plans to
offer the course in the fall of 1987. In addition, NESCAUM is working with
ASME to develop a fonnaJ^c^rjdiUiion^^ training and certification
of operators of resource recovery facilities, to be administered by ASME.+
Certification of operators has now been included in the requirements for
operating permits in Connecticut, New Jersey, New York, and Vermont.
4.1.2 Flue Gas Treatment*
The previous discussion has dealt exclusively with destruction of organic
materials to minimize organic emissions through design and operation of the
combustion process. Control of organic emissions may also be accomplished
through post combustion control techniques. In fact, the secondary combustion
chambers on many modular combustors can be thought of as afterburners.
Although no conventional mass burn facilities employing afterburners have been
identified, this type of control device might be used to control organic
emissions. Direct flame afterburners operating at 2,000°F for a 1.0 second
residence time have demonstrated the ability to achieve greater than
4.
Thomas Allen, Associate Director of the Division of Air, New York Department
of Environmental Conservation, is the Acting Chairman of the ASME
Accreditation Committee. Arlene Spadafino, a Director in ASME's Codes and
Standards Division, may be contacted for further information at
(212) 705-7030.
information presented in this section is summarized from Reference 19,
Municipal Waste Combustion Study: Flue Gas Cleaning Technology.
61
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98 percent destruction of hazardous wastes, eve" for chlorinated
22 23
organics. '
Recent tests have indicated that alkaline scrubt ng systems can achieve
significant control of organic emissions. There are several different types
of alkaline scrubbers and the terminology describing them can be confusing.
In the United States scrubbers have been classified as either wet or dry,
depending on whether the cleaned flue gas leaving the scrubbing system is
saturated. Using this classification, a wet scrubbing system emits a
saturated gas, while a dry scrubber has a gaseous effluent which is
unsaturated. Scrubber terminology in other countries often includes
"semi-dry" or "wet/dry" and "dry" scrubber. The terms "semi-dry" and
"wet/dry" apply to a spray dryer and fabric filter or ESP system in which the
sorbent enters the spray dryer as a slurry or solution and the cleaned flue
gas leaves the particulate collector unsaturated. The terms "dry scrubber" or
"dry injection", as often used in the same countries, refer to a dry powdered^
sorbent being injected into the flue gas upstream of the particulate
collector. In the United States, scrubbing systems using either spray drying
or dry injection of sorbent upstream of particulate collectors are commonly
called "dry" scrubbers.
The mechanism of organic pol'ijtant capture by alkaline scrubbers is not
clear. It is likely that condensation and capture in the physical form of
particulates or aerosols is an important mechanism, but chemical reaction with
caustic reagents is also a possibility. To take advantage of these collection
phenomena, a control strategy could include steps to lower the flue gas
temperature, subject it to caustic sorbents, and collect the particles with an
efficient particle collector. Combinations of equipment would be required to
implement this strategy; spray drying combined with an ESP or spray drying
combined with a fabric filter would be the probable choice. A few data are
available showing the effectiveness of the combination of alkaline scrubbing
with a fabric filter for control of ODD. Data showing the effectiveness of an
alkaline scrubber with an ESP are more limited. Data from two sets of pilot
plant tests are shown in Table 4-3. The combination of alkaline scrubbing
with fabric filtration also may be used to control emissions of acid gases and
metals. This cooperative effect is discussed more fully in the section on
multipollutant control strategies.
62
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TABLE 4-3. CONTROL EFFICIENCY DATA FOR CDD
Efficiency
Spray Dryer + ESP2
reported by manufacturer
48 - 89*
Spray Dryer + Fabric Fi1ter24
tested by manufacturer
High T
Low T
52 - 93*
97 - 99.8*
Spray Dryer + Fabric Filter
Environment Canada
25
>99.9
Dry Injection + Fabric Filter
Environment Canada
25
200°C
110° - 140°C
99.4
>99.9
*Range for different homologs.
63
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4.2 ACID GASES*
Control of acid gases (HC1, HF and SO-) requires Drubbing or devices for
gas/liquid or gas/solid contact. Water alone is a reasonably effective
sorbent for very reactive acid gases such as HC1 and HF, but an alkali sorbent
is necessary for substantial SO- control.
Effective acid gas control is possible with dry, semi-dry and wet
scrubbers. HC1 and HF are relatively easy to control, while SO- control is
favored by wet or semi-dry system-* ith lower flue gas temperatures. Alkaline
scrubbing systems combined with particulate capture devices may be used to
control other pollutants such as some organic species and metals. This
synergy is discussed more fully in the section on multipollutant control
strategies. Spray drying or semi-dry injection of sorbent is more effective
than dry injection of sorbent. The most effective control of acid gases is by
wet alkali scrubbers, but wet scrubbing produces waste water that must be
treated.
Combination dry, semi-dry scrubbers may control acid gases more
effectively than once-through spray drying and may be similar in effectiveness
to spray drying with recycle. Combination wet-dry systems may be the most
effective system for acid gas control but are increasingly complex. Table 4-4
summarizes the scrubber options for acid gas control and shows expected
control efficiencies. It should be noted that any of these techniques may be
enhanced by the use of more reactive sorbents or by operation at more
favorable temperatures. Table 4-5 shows acid gas control efficiency data
included in the EPA's Emissions Data Base. These data are supported with
emission test reports (Municipal Waste Combustion Study: Emission Data Base
for Municipal Waste Combustors).
*Information presented in this section is summarized from Reference 19,
Municipal Waste Combustion Study: Flue Gas Cleaning Technology.
64
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TABLE 4-4. EXPECTED EFFECTIVENESS OF ACID GAS CONTROLS (% P *OVAL)19
Control System
Dry Sorbent Injection + Fabric Filter3
Dry Sorbent Injection + Fluid Bed
Reactor/ESPD
Spray Dryer - ESP
(Recycle)0
Spray Dryer Baghouse
(Recycle)0
Spray Dryer + Dcy Sorbent Injection +
Fabric Filter
Wet Scrubber6
Dry/Wet Scrubber6 'f
aT - 160 - 180°C. T is the temperature
bT - 230°C
HC1
80
90
95+
(95+)
95+
(95+)
95+
95+
95+
at the exit
Pollutant
HF S02
98 50
99 60
99 50 - 70
(99) (70 - 90).
99 70 - 90
(99) (80 - 95)
99 90+
99 90+
99 90+
of the control device.
CT - 140 - 160°C
dT - 200°C
eT » 40 - 50°C
Consists of a spray dryer which atomizes spent scrubber liquor from two
venturi scrubbers, one for HC1 control and the other for SO- control, to
dispose of liquid wastes. The venturi scrubbers are in series and follow the
particulate control device which is just downstream of the spray dryer. This
system, by proper selections of feed stream compositions to the Venturis, can
also be used for NO control.
65
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TABLE 4-5. CONTROL EFFICIENCY DATA FOR ACID GASES16
Control Efficiency (%}
Facility
Gallatin
Kure
Quebec
Tsushima
Munich
Mai mo
Control Device
Cyclone/fabric filter
ESP/water scrubber
Dry injection/fabric filter
110°C
125°C
140°C
200°C
Spray dryer/ fabric filter
140°C
140°C with recycle
Spray dryer/dry injection/fabric filter
(Teller system)
Dry scrubber/ESP
Cyclone/dry scrubber/ESP/fabric filter
HC1
79
99
98
93
77
91
91
98
9b
72
HF S02
0
68 87
96
92
78
23
67
60
48 99.7
66
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4.3 NJ.ROGEN OXIDES
Control of nitrogen oxides may be accomplished through post-combustion
flue gas treatment processes. Selective catalytic reduction (SCR) is the most
advanced process. In the selective catalytic reduction process NO is reduced
^
to nitrogen and water vapor with the addition of ammonia in the presence of a
catalyst. Although not specifically applied to municipal waste combustion,
SCR is being applied to sludge combustors in Japan and the technology is
expected to be readily transferable.
Impurities such as HC1 and metals degrade the SCR catalyst, so municipal
waste cunbustor gases are typically subjected to cleaning processes before
they contact the special ^itaniurn-based honeycomb catalyst system. Design
data show 80 to 90 percent reduction of NO , but performance data are
A
unavailable.
Another NO control system, thermal DeNO , involves injection of ammonia
A A
in the upper furnace to achieve selective reduction of NOX- This system is
currently installed on at least one municipal waste combustor in California.
The effects of thermal DeNO systems on other pollutants in the flue gas from
^
municipal waste combustors have not been established.
4.4 PARTICULATE MATTER*
Control of particulate matter emissions is currently practiced to a large
extent among existing municipal waste combustors. Electrostatic precipitators
(ESPs), fabric filters, and wet scrubbers are all systems used to control
particulate matter emissions. Newer units are equipped with ESPs and fabric
filters. Modern ESPs can achieve very high removal efficiencies for
particulate matter (>99%). There are currently nearly 40 U.S. municipal waste
combustion facilities equipped with ESPs, some of which are combined with
other flue gas treatment technologies. Also, a trend can be seen toward
higher particulate matter collection efficiencies with newer installations.
"Information presented in this section is summarized from Reference 19,
Municipal Waste Combustion Study: Flue Gas Cleaning Technology.
67
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Fabric filters have not generally been applied directly to flue gas from
municipal waste combustors, but they have been used as sorbent collectors and
secondary reactors for dry and semi-dry scrubbers. Three reasons that fabric
filters have-not Jaeen appliedjJirectly to municipal waste combustor flue gas
are: (1) attack by acid gases upon fabric, (2) fabric~BTTndTng by ^sticky"
particles, and (3) baghouse fires caused by unstable combustion and carryover
of sparks into the flue. Electrostatic precipitators and wet scrubbers are
somewhat more forgiving of these phenomena and have generally been preferred.
« ^-^•"^^i—"™^™™^^^^^^^^" ™ —
However, upstream scrubbing of acid gases with sorbent accumulation on fabric
materials can address the problems mentioned above, so that fabric filters
become an attractive choice for control of particulate matter emissions.
Fabric filters used in this way with upstream sorbent injection are capable of
particulate matter control to concentrations of less than 0.02 gr/dscf.
Wet scrubbers are not likely to be applied to municipal waste combustors
for__£ontro1 of particulate matter^emissions in the future. Although wet
scrubbers account for nearly one-fifth of existing particulate matter control
systems in the United States, they hayedisadvantages which are likely to
eliminate them from future selection. First, used alone, without additional
particulate matter controls, they are not as effective in controlling
particulate matter as other control equipment. It is unlikely that wet
scrubbers can meet current or future particulate matter emission requirements
without very high pressure losses accompanied by erosion and increased
maintenance requirements. Second, wet scrubbers will absorb acid gases
including HC1 and, if they are not designed to handle the accumulating acids,
will have significant operating problems.
Efficient particulate matter capture devices also provide enhanced
capture of other pollutants in the flue gas in solid or aerosol form,
e.g., metals and large organic molecules. These captured materials then
become part of the ash residue from the process.
4.5 METALS
Effective control of particles and low flue gas temperatures are major
factors in the control of metals emissions. Sorbents are not suspected of
68
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playing a major role. Nevertheless, scrubber, systems combined with
participate control devices have achieved effective metals removal because
they cool the incoming flue gas. Hetals and metallic compounds enter the
combustor in the solid waste material and are not destroyed in the combustion
process, although they may change phase or react to form other metallic
compounds. Because they are not destroyed, they must leave the combustion
process in the bottom ash, fly ash, or stack gas. Metals and metallic
compounds carried by the flue gas «-ter particulate matter collectors as
solids, liquids, and vapors, and as the flue gas cools, the vapor portion
converts to collectible solid" and liquids.
Based on theoretical vapor pressure considerations, reduction of flue gas
temperatures to below 200°C (392°F) in combination with high efficiency
particulate collection should result in 99 percent reduction of metals, except
for mercury (Hg), arsenates (AsO^) , and selenium (SeO- and Seg). Increased
reduction in concentrations of these compounds occurs as temperatures are
\ increasingly lowered.
Recently collected metals data from a pi lot-scale test in Quebec are
summarized in Table 4-6. The inlet and outlet concentrations data show that
the alkaline scrubber/fabric filter system effected greater than 99.9% removal
efficiency for all metals except mercury. The collection efficiency for
mercury ranged from 91 to 97 percent except for the high temperature (209°C)
test in which a negative control efficiency was measured. Environment Canada
characterized this result as indicative of no mercury removal. It is also
important to note that measurements of metals in the ash residues showed that
25
the solids collected by the fabric filter were enriched with metals. The
fabric filter solids contained by far the highest concentration and the
highest quantities of total metals.
In other tests, metals control efficiency data show 95-98 percent control
or greater for heavy metals except mercury. Seventy-five to 85 percent
control of mercury vapor has been reported with a spray dryer combined with a
baghouse; 35 to 45 percent control has been reported with a spray dryer plus
ESP.
69
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TABLE 4-6. INLET/OUTLET METAL JONCENTRATIONS FROM QUEBEC PILOT
PLANT TESTING (ug/Nra3 0 8% 02)25
Drv Injection
Sorav Drver
140°C
Metal
Zinc
(Zn)
Cadmium
(Cd)
Lead
(Pb)
Chromium
(Cr)
Nickel
(Ni)
Arsenic
(As)
Antimony
(Sb)
Mercury
(Hg)
Location
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
110°Ca
99,000
7
1,300
0.4
41,000
4
3,100
0.4
1,000
1.3
150
0.02
2,000
0.2
440
40
125°Ca
108,000
.5
1,300
0.4
44,000
3
1,900
0.4
1,800
0.4
100
0.04
800
0.4
480
13
140GC
93,000
6
1,500
ND
34,000
5
2,000
1
1,300
0.7
130
0.04
1,000
0.6
320
20
>200°C
91,000
10
1,000
0.6
35,000
6
1,900
0.5
800
2
80
0.07
1,500
0.5
450b
610
140°C
77,000
5
1,200
NO
36,000
1
1,400
0.2
700
1.3
110
0.04
1,000
0.3
190
10
+Recycle
88,000
6
1,100
NO
34,000
6
1,700
0.7
2,500
2
130
0.03
2,200
0.6
360
19
Note: Concentrations rounded off for simplicity.
NO - Not detected
aBased on one test run, except for mercury, which is based on two test runs.
Negative control efficiency; no capture of mercury occurred.
70
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4 6 MULT I POLLUTANT CONTROL STRATEGIES
In devising a control strategy for fflinimizlng emissions to the atmosphere
from municipal waste combustors, a starting place is alteration of design .or
operating practices that may cause or exacerbate pollutant formation; i.e.,
combustion controls. With the potential for pollutant formation in the
process minimized, the next logical step would be the use of post combustion
flue gas cleaning equipment to remove remaining pollutants from the flue
gases. However, this straightforward approach is complicated because the
control problem consists of many different polluta,,ts emitted together, so the
effects of the various control options on other pollutants must be considered.
In the previous discussion on control options, the potential for
minimizing organic emissions through a combustion optimization strategy was
presented. The combustion strategy may do little for the control of other
pollutants, however. In fact, while combustion optimization is expected to -
have little impact on acid gases and particulate matter, it may increase
emissions of NOX and some metals.
The preliminary combustion control strategy is probably most incompatible
with NO emissions minimization. High-temperature, well -mixed, excess air
^
conditions favor the formation of NO from both thermal fixation of molecular
nitrogen and the conversion of fuel nitrogen. Traditionally, NOX emissions
from municipal waste combustors have not been controlled, and the need to
control NO emissions has been confined to fairly localized areas. As
previously pointed out, NOX emissions can be reduced by flue gas cleaning
processes. It is not clear what effect NO control systems may have on other
A
pollutants, but they are not expected to provide significant removal potential
for other pollutants.
Metal concentrations in uncontrolled stack gases may also be exacerbated
by the recommended combustion strategy. The^jvaxtitiioning of metalsjamong
phase depends on the temperature and oxygen
levels experienced by the metal -bearing refuse. For example, higher air
velocities through the bed will increase the entrainment of particles. Also,
changes in stoichiometry for proper air distribution will influence the
vaporization of volatile metals. And, temperature increases favor the
vaporization of volatile metals. As in the case with NOX control, metal
emissions may also be removed in flue gas cleaning processes.
71
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Hi-h efficiency participate collection devices, such as ESPs and fabric
filters, hav the potential for collection of metals and organics that exist
in the stack gases in particulate or aerosol form. Furthermore, when combined
with cooling to promote condensation, this collection potential is further
enhanced. Adding to these possible processing steps, the use of alkali
sorbents enhances the collection still further by increasing the potential for
collecting organic materials such as COD and CDF and acid gases.
An approach to minimizing a w*-"le list of emissions to the atmosphere •
from municipal waste combustors woufd be:
optimization of the combustion process,
flue gas treatment using alkaline scrubbers in conjunction with ESPs
or fabric filters at a temperature conducive to promoting
condensation, and
flue gas treatment for NO control, if necessary.
A
With respect to cooling the stack gases, there are practical limits with the
use of ESPs alone. Very low exit temperatures may not be feasible without
additional gas conditioning because of acid condensation and corrosion
problems. To operate with low exit gas temperatures, it may be necessary to
use an alkaline scrubber upstream of an ESP.
Testing of control equipment designed for multipollutant control is now
beginning and results are just becoming available. Tables 4-7, 4-8 and 4-9
contain summary results of such emissions testing. The first table is a very
simplified representation of an extensive series of tests performed by
Environment Canada at Quebec. Tests were performed at a pilot plant by
testing control device efficiency on a slip stream from a commercial-scale
municipal waste combustor. Tests were run at several flue gas temperatures on
two scrubbing systems, dry lime injection/fabric filter and lime spray dryer/
fabric filter. In general, high removal efficiencies were seen in both
systems for all pollutants of concern, but cooling of the flue gas below 200°C
was seen as key to the control of hydrogen chloride, sulfur dioxide, and
mercury.
72
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TABLE 4-7. 'UMK'RY OF TESTING OF MULIIPOLLUTANT CONTROL STRATEG,
AT QUEBEC CITY25
Range of Removal
Pollutant Efficiencies Measured (%)
PCDD 99.4 to > 99.9
PCDF 99.3 to > 99.9
Chlorobenzenes 62a to > 99
Polychlorinated biphenyls 54a to > 99
Polycyclic aromatic hydrocarbons 79 to > 99
Chlorophenols 56a to 99
Zinc > 99.9
Cadmium > 99.9
Lead > 99.9
Chromium > 99.9
Nickel > 99.9
Arsenic > 99.9
Antimony > 99.9
Mercury Oa to 97
Hydrogen Chloride 77a to 98
Sulfur dioxide 29a to 96
Measured at highest test temperature (209°C)
Measured in recycle test.
73
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TABLE 4-8. SUMMARY 0, TEST NG OF MULT1POLLUTANT CONTROL STRATEGY
PERFUMED BY NIRO26
Pollutant
Emissions Data
Particulate matter
HC1
HF
so2
so3
Cd
Hg
Dioxins/furans
5 to 10 mg/Nnr
5 to 15 mg/Nm3
0.3 mg/Nra3
20 to 70 mg/Nm3
1 mg/Nm3
0.01 to 0.03 mg/Nm3
0.03 to 0.1 mg/Nm3
90 to 99% removal
74
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TABLE 4-9. COMPARISON OF PIL -SW £ TESTS OF MULT I POLLUTANT
CONTROL EQUIPK-.1T18
Pollutant Removal Efficiency
Pollutant
Hga
Pb
Cd
As
Particulate Matter
CDD
CDF
aVapor only
bAt 110°C
Spray
35
65
95
93
dryer/ESP
- 40%
- 75%
- 97%
- 98%
>99%
48
64
- 89%
- 85%
Spray dryer/
fabric filter
75 - 85%
95 - 98%
95 - 97%
95-98%.
>99%
>99%b
>99%b
75
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The second table contains data provided by Niro atomizer on their spray
dryer combined with a "dust collector." Table 4-^ sh' 's results of
pilot-scale testing of a spray dryer/ESP system and a s-,- ay dryer fabric
18
filter system. Results of additional tests of these multipollutant control
systems are now being released and will provide additional information with
which they may be evaluated.
76
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5. IMPACTS OF POTENTIAL CONTROL STRATEGIES
A major concern voiced by the public in communities where nut. ipal
combustors are being considered is the heaHh risk from emissions of
pollutants to the atmosphere. In the following analysis, health risks due to
direct inhalation of pollutants and due to other indirect exposure routes are
discussed for the existing and the projected future combustor populations,
under two different levels of pollution control. Costs and other effects are
also considered.
5.1 ESTIMATED HEALTH RISK UNDER TWO CONTROL SCENARIOS
The risk analysis seeks to answer the questions of what are the health
risks associated with municipal waste combustion, and how might they be
reduced by applying emission controls? To address these questions, EPA
analyzed exposures to pollutants directly emitted to the atmosphere from
municipal waste combustors and indirect exposures from deposited pollutants.
Health risks from carcinogens and non-carcinogens were considered. And, to
capture the risk from municipal waste combustors as they exist today and as
they may exist in the future, the risk analysis was extended to the projected
population. Thus, the analysis consists of many parts defined by route of
exposure, combustor population, emission control scenario, and the type of
health effect being considered. Results of these risk analysis elements were
generated for several organic pollutants (COD, CDF, chlorophenols,
chlorobenzenes, formaldehyde, polychlorinated biphenyls, polycyclic aromatic
hydrocarbons) and for inorganic pollutants (arsenic, beryllium, mercury, lead,
cadmium, and hexavalent chromium, and hydrochloric acid).
5.1.1 Methodology
The methodology for performing this complex analysis is described in
detail in "Municipal Waste Combustion Study: Assessment of Health Risks
27
Associated with Municipal Waste Combustion Emissions." In its evaluation
77
-------
of the potential health risks from combustion sources, EPA traditional!^ has
focused on air emissions from the source and on the carcinogenic risks from
direct inhalation of predicted ambient air concentrations of pollutants. Tht
risk analysis for municipal waste combustors represents an expansion of the
analytical scope to include consideration of multiple exposure pathways, .
carcinogenic and non-carcinogenic risks posed to humans, and potential adverse
effects to the natural environment.
5.1.1.1 Emissions and Control Scenarios. The risk analysis was constructed
to include existing and projected combustors under a baseline control scenario
and a controlled scenario. The baseline scenario was designed to reflect the
status quo in add-on control technology (ESPs), while the controlled scenario
was designed to reflect uniform application of dry scrubbing combined with
very efficient particulate collection devices. In terms of combustion
efficiency the models assumed existing units under both control scenarios
would have combustion efficiencies reflective of currently operating
combustors. The projected population, however, was assumed to incorporate
very efficient combustion under both control scenarios.
The existing and projected populations of combustors used in the risk
analysis are described in "Municipal Waste Combustion Stuay: Characterization
of the Municipal Waste Combustion Industry." Since the risk analysis and the
development of the emissions data base proceeded in parallel, emissions
estimates were developed from test data compiled and presented in a publicly
released draft of the volume titled "Municipal Waste Combustion Study:
Emission Data Base for Municipal Waste Combustors. (January 1987)" Tables
5-1 and 5-2 indicate from which units test data were derived. Details about
the facilities tested and testing procedures used to generate the emissions
test data also may be found in the EPA's Emissions Data Base ' . For each
pollutant, emissions data from the facilities listed in the tables were
averaged to obtain an overall emission factor.
As the tables show, for some pollutants the emissions estimates are based
on very little data, especially for the organic pollutants. Another
observation from Table 5-2 is the different lists of facilities chosen to
represent existing and planned facilities. An attempt was made to use the
most appropriate data to represent emissions from different types of
78
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TABLE 5-1. METALS EMISSION FACTOR DATA SUMMARY
POUUTAMT
METALS
Arsenic
Beryl 1 Ilia
CaMlun
Chro»'u»
LMd
Mercury
Nickel
FACILITY TYPE
MB Water Wall
MB Refractory
RDF
Modular
MB Water Wall
MB Refractory
ROF
Modular
MB Water fall
MB Refractory
RDF
Modular
MB Vater Wall
MB Refractory
ROF
Modular
MB vater Vail
MB Refractory
ROF
Modular
MB Vater Mil
MB Refractory
ROF
Modular
MB Vater Mil
MB Refractory
ROF
Nodular
MK FACILITIES TESTED
Baltlwre. Bralntree, Haapton, Munich* Murzfeurg
TM*MM
Akron. Albany
Tuecaloosa. Oyeriburg^ Prince Eduard Island
Bralntree. Hampton. Tulsa. Munich
TtushlM
Albany
Dyerafeurg
Bralntree. Haopton, Munich. Malao, Vurzvurg
Vaanlngton. Alexandria. Nicosia. TauanlM
Albany
Dyertburg, Prince EdMrd IslMd
Balttaore. Bralntree. Haaeton, Munich. Vurzburg
WatMngton. Alexandria. Nicosia. TaushlM
Akron. Albany
Oyeroburg. Prince Eduard Island
Bralntree. Maaaton* Tulaa. Munich. Malen. Vurtturg
Washington. Alexandria. Nicosia. Tsushlas
Akron. Albany
Oyersburg. Prince Eduard Island
Bralntree. HaapTim T«l»a, Mtlao
TsushlM
•kron. Albany
Oyersburg. Prince EdMrd Island
Hasten. Munich. Vuriturg
Washington. Alexandria. Nicosia. TsushlM
Akron. Albany
Oyersburg. Prince Edward Island
79
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TABLE 5-2. MUNICIPAL WASTE COMBUSTION FACILITIES FROM WHICH TEST DATA WERE
USED FOR ORGANIC EMISSION FACTORS
EXISTING MC
1 M»C Tested
1 Man Burn
Non Heat Recovery
6 Mas* Burn
Meat Recovery
6 Modular
5 RDF
fWUKTHJ Me
7 Mm Burn
5 RDF
6 Modular
COO/CDF fl(a)P PCS
Philadelphia Ml Haapton Heapton
Quebec Haapton Chicago Ml
Saugus Haapton
Chicago
Peek Mil
TulM
Haapton
N. Andover
PEI. Oyersburg Cattarauguf PEI
N. Little Rock Cattaraugus
Mayport. One Ida
Cattaraugus
Sieru Albany Albany
Akron S»ani
•right Patterson
Albany
Niagara Falli
•urxburg Haapton Chicago Ml
N. Andover
Saugus
Peek skill
TulM
Marlon Co.
Seam* Albany Albany
Akron Seant1
•right Patterson
Albany
Niagara Falls
PEI. Oyers»erg Cattaraugus PEI
N. Little Mock Cattarangvs
Mayport. Owe lea
•
fonatldehyde Chlorobenzenes Chlorophenols
Haapton Chicago Ml Chicago Ml
Poeksklll Haapton Haapton
Haapton Chicago Ml Chicago Ml
Peek skill Haapton Haapton
Dyersburg PEI PEI
Cattaraugus
Albany Vrlght Patterson Vrlght Patterson
Akron Siaru Snani
Niagara Falls
Peek*m Chicago Ml Chicago NH
Albany "right Patterson Vrlght Patterson
Akron Searu* S»ani
Niagara Falls
Oyerskerg PEI PEI
Cattaraugus
*A«jMtte4 to reflect J
•sel f Icattees.
80
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combustors and for different "cenarios. Some of the existing facilities, for
example Hampton (mass birn), may not represent performance levels expected of
new facilities. Test data from this facility were, therefore, excluded when
computing average emission factors for COO and CDF for the projected
population of mass burn heat recovery facilities. For some other organic -
pollutants, for example B(a)P, there were no state-of-the-art data available,
so the data from Hampton were used, even though they may not be considered
representative of new facilities. The paucity of data introduces considerable
uncertainty, because there is significant variation among emissions measured
at different facilities. The variability is due in part to differences in
feed materials and design and operating characteristics of municipal waste
combustors and air pollution control equipment.
Control efficiencies for the baseline and controlled scenarios were
developed as follows. For the existing combustor population, the baseline
scenario organic emissions estimates are reflective of uniform use of ESPs
because test data were collected from ESP-controlled units. A variety of
particulate matter emission controls, however, are actually used at existing
facilities. (See Table 5-3.) The baseline scenario for existing units
incorporates particulate matter and metals control efficiencies reflective of
actual particulate matter control devices in use. The controlled scenario for
existing combustors was constructed by assuming 99.5% control of particulate
matter emissions, including metals, and 95 percent control of organic
emissions. HC1 emissions were assumed controlled by 90 percent, and S02 was
assumed controlled by 70 to 90 percent. These control levels reflect the
efficiencies achieved by the combination of dry scrubbers and fabric filters
tested at pilot-scale facilities by Environment Canada and others. (See
19
Municipal Waste Combustion Study: Flue Gas Cleaning Technology. )
For the projected population, control efficiencies for the baseline
scenario were assumed to be 20 percent for organics and 99 percent for
particulate matter and metals, reflecting application of particulate matter
controls only. This is a conservative assumption for organics because many
planned facilities are expected to incorporate dry scrubbers, as in the
controlled scenario. Little data are available on the performance of ESPs
alone in controlling organics. However, preliminary results from recent tests
indicate a range of 0 to 50 percent for control of CDD and CDF, and data from
81
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TABLE 5-3. EMISSION CONTROLS ON EXISTING SOURCES
TECHNOLOGY
(I FACILITIES)
COMBUSTION
CONTROLS
GOOD/FAIR/POOR
FLUE GAS TREATMENT CONTROLS
WET FABRIC
SCRUBBER ESP FILTER DS/FF OTHER NONE
CD
fN>
MASS BURN
(45)
REFUSE
DERIVED FUEL
(10)
Good-Poor
Many older units are
deficient In design*
operation, and
maintenance
Not well understood
33
MODULAR
(56)
Good-Fair
- starved air
- secondary combustion
10
3 36
-------
earlier tests at the Chicago NW facility indicated approximately 20 percent
cor ol of chlorophenols. In consideration of thtse limited data points,
20 percent control was assumed. Particulate matter control of 99 percent
efficiency reflects the performance of a modern ESP. However, it is possible
that some facilities way consider control devices designed to meet current
standards of 95% for municipal waste combustors or about 97 to 98 percent for
industrial boilers. No control of HC1 by ESPs was assumed.
Control efficiencies for the controlled scenario were assumed to be the
same as for the existing facility population: 99.5 percent for particulate
matter including metals, 95 percent for organics, and 90 percent control of
HC1 and 70 to 90 percent control of sulfur oxides. This scenario is
reflective of uniform application of dry scrubbers and particulate matter
control devices to the entire population.
5.1.1.2 Exposure Modeling. Exposure potential due to the direct inhalation -
28
route was modeled using EPA's Human Exposure Model , which links a dispersion
model and population data to estimate exposure levels. Deposition of
29
pollutants was modeled using the ISC-ST model. The Terrestrial Food Chain,
Surface Runoff, Groundwater and Dermal Exposure models have been developed to
analyze possible human exposure associated with indirect exposure pathways for
the deposited emissions. Potential exposure to terrestrial and aquatic
organisms exposed to deposited municipal waste combustion emissions have also
been addressed in the indirect exposure modeling.
The actual locations and sizes of the facilities were used to model
direct inhalation exposure from the existing population. For the projected
facilities, two different sets of model facilities were used to project
maximum individual risks and annual incidence.
Maximum individual risk estimates were obtained from modeling 3000 ton
per day mass-burn, 3000 ton per day RDF, and 250 ton per day modular units.
These units were located in urban and suburban areas and represent large
planned facilities. From these results, the maximum modeled individual
lifetime risk was estimated for projected facilities.
To estimate annual incidence from projected sources, risk estimates were
obtained using average-sized model plants of 1000 ton per day mass-burn and
1500 ton per day RDF facilities, each located in hypothetical urban and
83
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suburba* ""oca^ions. The average values for the urban and suburban estimates
were then SCL d up in proportion to the capacity projected for each type of
technology in 1993. Risk estimates were also obtained froir a 250 ton per day
modular facility in two setsn-rural locations, and a similar procedure was .used
to scale up the estimates.
Given the complexities involved in modeling both the environmental fate
and transport of specific emitted chemicals and the multiple routes of
indirect human exposure to specific chemicals, it is currently not practical
to analyze the indirect exposure due to every existing or planned municipal
waste combustor. The analysis instead was designed to test th^ hypothesis of
whether indirect exposure routes could contribute significantly to the total
exposure due to municipal waste combustors. To examine this possibility,
reasonable worst case estimates of long-term indirect exposure were compared
against reference levels for health effects. These reference levels are based
on either carcinogenic risk or "Risk Reference Doses" (RfDs). The methodology
used to analyze indirect exposures evaluated a facility using technologies
thought to be representative of those being planned, but under reasonable
worst-case environmental conditions in which hydrogeological and
meteorological factors combine to enhance the opportunity for exposure. The
methodology also evaluated a facility thought to represent worst-case
emissions from existing facilities. The methodology evaluated long term
deposition and included exposure scenarios over 30 years and over 100 years.
5.1.1.3 Risk Measures. Two types of health risk were addressed: carcinogenic
health effects and non-carcinogenic health effects. Unit risk factors
representing the lifetime (70 year) upper limit estimate of cancer risk for an
individual continuously exposed to 1 ug/m of a particular pollutant over 70
years, developed by EPA's Carcinogen Assessment Group were used to estimate
the risk of cancer. Cancer risks have been expressed both in terms of annual
cancer incidence to the entire exposed population, and risk to a hypothetical
individual or subpopulation exposed to the highest modeled ambient levels of
each pollutant in the nation - the maximum individual lifetime cancer risk.
Risks from exposure to carcinogens were considered additive in conformance
with EPA guidelines. Non-carcinogenic health effects were evaluated by
comparison with concentrations predicted in the environment to established
Risk Reference Dose values for the pollutants.
84
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5.1.1.4 Assumption Ii the previous methodology discussion several
uncertainties and assump ons have been noted. In addition, there are a few
other points to note about the risk analysis. Risk estimates are based on
calculations incorporating a cancer potency estimate and exposure estimate.
The estimate of cancer potency is based on a conservative extrapolation of- the
results of epidemiological studies and studies with laboratory animals. The
exposure estimate is based on mathematical models of pollutant dispersion.
While both of these approaches are traditionally used in risk calculations,
each incorporates uncertainties and assumptions.
Emissions have been modeled as a constant rate over long periods of time.
Implicit in this assumption is that average emission levels are equal to those
found in the reported tests; therefore, these estimates do not reflect what
may occur during start-up, shutdown, or upset conditions. Furthermore, the
risk estimates for direct inhalation assume that persons are continually
exposed to pollutants for 70 years, and that the population is constant and -
fixed.
5.1.2 Risks from Direct Inhalation
The risk estimates from direct inhalation exposure are shown in
Tables 5 4 through 5-6. Tables 5-4 and 5-5 show cancer risk estimates for
the direct inhalation route of exposure, disaggregated into risk estimated
from metals and organics. Table 5-4 shows risk under the baseline control
scenario, while Table 5-5 shows risk under the controlled scenario, as
discussed in Section 5.1.1. Table 5-6 shows the contribution to risk made by
the individual species modeled.
5.1.2.1 Ranges and Uncertainties. The risk ranges shown in the tables
reflect several areas of uncertainty in the analysis. First, recovery of
CDD/CDF from the Modified Method 5 stack sampling trains in some cases has
been reported to be as low as 10 percent. Thus, actual emission levels could
be higher than reported emissions by an order of magnitude. However, recovery
has also been reported to be significantly higher. The ranges shown
incorporate recovery levels of 10 to 100 percent to account for variation in
sampling methods.
85
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CO
e
TABLE 5-4. ESTIMATED CANCER RISK FROM INHALATION NATIONWIDE
(Basel1n« Scenario)
Organ Ics
b
Metals Combined
Ann. Incld. c Max. Ind1v.d
Existing SoyrCM < !**•£!
Mass Burn (Non-heat)
Mass Burn (Heat Rec)
RDF
Modular
f
EXISTING TOTAL
Mass Burn (Heat Rec)
RDF
Modular
f
PROJECTED TOTAL
f
COMBINED TOTAL
1-30 10'4 -
.2-4 10'4 -
.1-3 10"5 -
.oooa-.oi io~* -
2-40 10"4 -
.3-7 10"6 -
.a - 10 io~5 -
.04 - .9 10"* -
1 - 20 IO"5 -
3-60 10"4 -
ID'3
ID'3
ID'3
ID'4
ID'3
ID'5
ID'4
ID'5
ID'4
ID"3
Ann. Incld.
.2
.04
.2
.01
.5
.3
.1
.01
.4
.9
Max. Indiv. Ann. Incld.
10"5 1 - 30
10"4 .2-4
10"5 .3-3
10"4 .01 - .02
10"4 2-40
10"6 .6-7
10~7 .9 - 10
10"* .05 - .9
10"6 2-20
10~4 4-60
Max. Indtv.
io-4-
Hf4-
10"5 -
io-4-
10 -
10-*-
10-5-
lo-6-
lO'5-
io-4-
10"3
IO"3
io-3
ID'4
ID'3
ID'5
ID'4
10'S
io'4
ID"3
*CDO. cMorophenols. cklorobw»en««> fomaldehyde. PCS. PAH. Risk ranges for organtcs result fro* assumptions about
.the carcinogenic Ity of pollutants classes and the recovery efficiency for COO/CDF tn stack tests.
^Arsenic, beryl HIM, cad*1un> chroalu* 46
Annual Incidence Is the Modeled number of cancer cases per year In populations within SO k« of all Municipal waste
.coattustors In the U.S.
aMaxlMi Individual risk Is the eodeled probability that a person exposed to the highest Modeled concentration of
oollutants fro* a Municipal waste co«bustor will develop cancer over his or her 70-year llfespan.
^Rounded to one significant figure. See text for assumptions Involved In producing these estimates.
Totals do not add due to rounding.
-------
TABLE 5-5. ESTIMATED CANCER RISK FROM INHALATION NATIONWIDE
(Controlled Scenario)
00
Existing SfiUrC.ll (19*5)
Mass Burn (Non-neat)
Mass Burn (Heat Rec)
RDF
Modular
g
EXISTING TOTAL
Projected Sources (1993)
Mass Burn (Heat Rec)
RDF
Modular
9
PROJECTED TOTAL
9
COMBINED TOTAL
Organ tcs
Ann. Inc1d.d Max. Indlv.*
.08-2 10-5 . lfl-4
.01 - .3 10"5 - 10"4
.01 - .2 10"* - 10"5
<. 00001 10"7 - 10"6
.1-3 10"5 - 10"4
.02-.4 10"7 - 10"*
.05 - .9 10~* - 10"5
.001-. 04 10"7 - 10"*
.07-1 10"7 - 10"*
.2-4 «f5 - 10"4
Met«lsb
Ann. lucid. Max. Indlv.
.05 10"*
.01 10"*
.03 10"*
.001 10"*
.1
.2 10"*
.04 10"*
.001 10~*
.2 10"*
.3 10"*
Combined
Ann. Incld. Max. Indlv.
.1-2 10"5 - 10"4
.02 - .3 10"5 - 10~4
.04 - .2 10"* • 10"5
.001 10"*
.2-3 10~5 - 10"4
.2 - .6 10~*
.09 - .9 10"* - 10*5
.01 - .03 10"*
.3-1 10"*
.5-4 10"5 - 10"4
*COOs. chloropnenols> chlorooenzenes. formaldehyde* PCS. PAH. Risk ranges for organic* result fro* assumptions about
the carcinogenicIty of pollutant classes and the recovery efficiency for COO/CDF In stack tests.
"Arsenic, beryllium. cad»1ue>. chromium +€
CVM control organic* «1th ESP, 95S with OS/FF
"Annual Incidence Is the modeled number of cancer cases per year In population HltMn 50 km of all municipal
vaste combustors In the U.S.
*Max1mum Individual risk Is the modeled probability that a person exposed to the highest modeled concentration of
.pollutants from a municipal uaste combustor will develop cancer over his or her 70-year llfespan.
Rounded to one significant figure. See text for assumptions Involved In producing these estimates.
^Totals do not add due to rounding.
-------
TABLE 5-6. CONTRIBUTION OF INDIVIDUAL POLLUTANTS TO THE ESTIMATED CANCER RISK
Pollutant
rr Chlorinated dioxins and
dlbenzofurans
Chlorophenols
Chlorobenzenes
Formaldehyde
_, Polycyllc aromatic
— 7 hydrocarbons
f- Polychlorlnated blphenyls
Arsenic
Beryllium
Cadmium
Chromium46
Rounded Total ic
Existing MMC
Annual Cancer 1
Incidence
2 to 40
0.0001 to 0.0003
0.009 to 0.02
0.009
0.01 to 0.6
0.02
0.2
0.02
0.2
0.2
2 to 40
Existing MMC
Haxlmum Individual
Risk Range0
10"6 to 10"3
IO"9 to 10"8
10"7 to 10"6
io-8
10"7 to 10~5
IO"8 to 10"5
10"7 to 10"4
10"9 to 10"6
10"* to 10"4
10"7 to 10"4
IO"6 to 10"3
Projected MMC
Annual Cancer
Incidence
0.8 to 20
0.0001 to 0.0003
0.004 to 0.01
0.02
0.05 to 3.0
0.2
0.1
0.001
0.2
0.1
2 to 20
Projected MNC
Maximum
Individual.
Risk Range"
10"* to 10"4
10"l° to ID'9
10"9 to 10"7
10"8 to 10'7
lo"7 to lo"5
ID'9 to ID"6
10"8 to 10"7
10"U to 10"8
10'7 to 10"6
10"7 to 10"6
10*6 to 10"4
*The ranges In annual cancer Incidence reflect the assumptions made regarding the potential carcinogenictty
the evaluation of
.of classes of organic compounds.
The ranges In maximum Individual lifetime cancer risk reflect differences In emissions and
emissions from MMC technologies within the existing and proposed categories.
Rounded to one significant figure. Totals do not add due to rounding.
-------
Second, a basic inconsistency exists between emission factors data and
toxicity data, both of which are needed to estimate risk. Emission data are
available for mixtures or classes of organic compounds. However, Uxicity
data have been developed with respect to human exposure for individual organic
compounds. Furthermore, toxicity data are not available for all compounds
within a class. Nevertheless, scientists generally agree that structurally
related compounds may exhibit similar toxic effects. Therefore, some
assumptions are necessary to relate the emissions data to the risk measures
and to account for the potential toxicity of various compounds in a mixture.
In the case of COD/CDF, a method involving toxic equivalency factors (TEF) was
used to convert emissions of a mixture of CDD and CDF congeners to equivalent
quantities of a single compound, 2,3,7,8-TCDD. The method for conversion,
using weighting factors based on relative toxicities, was adopted by EPA as an
interim procedure (52 FR 11749). It is described more fully in "Interim
Procedures for Estimating Risks Associated with Exposure to Mixtures of
Chlorinated Dibenzo-p-dioxins and Dibenzofurans (CDD and CDF)."
To apply the TEF to CDD/CDF emissions, another discrepancy between
emissions data and toxicity data remained to be overcome. TEF are isomer
specific, but most emissions data are in terms of homologs. Emission tests on
a few facilities have reported data on the emission levels of specific
isomers. When TEF calculations based on isomer-specific data are compared to
calculations based on homologs for those facilities, the calculations based on
homologs are higher by a factor of 3 to 7. These limited data suggest that
risk estimates based only on homolog-specific data may overstate the actual
risk by a factor of 3 to 7. Although it is unclear whether this same pattern
would hold for those facilities for which only homolog-specific data are
available, the ranges shown for CDD/CDF have incorporated these factors of
3 to 7.
Additional inconsistencies between emissions data and toxicity data exist
for other organics. For the classes of polycyclic aromatic hydrocarbons
(PAH), chlorobenzenes, and chlorophenols unit risk factors have been
established only for specific compounds within each classes: benzo(a)pyrene
(a specific PAH), hexachlorobenzene, and trichlorophenol. However, emission
data are available only for the class as a whole. Therefore, ranges were
89
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formed based on assumptions of the relative carcinogenicity of each class
compared to the carcinogenicity of the individual compounds. Using
chlorobenzenes as an example, the high risk estimate represents the assumption
that all chlorobenzenes have cancer potencies equal to that of
hexachlorobenzene, which is 43 percent of the mixture. The low estimate is
based on the assumption that only hexachlorobenzene (of the chlorobenzenes) is
associated with any risk of cancer.
The range of risk estimates from direct inhalation of formaldehyde is
shown to reflect the uncertainty surrounding which tumors caused in laboratory
animals by exposure to formaldehyde are indicative of formaldehyde's potential
cor causing cancer in humans. The low estimate is based on the assumption
that only some of the tumors in animals are indicative of formaldehyde's
potential for causing cancer in humans, and the high estimate is based on the
assumption that all of the tumors are indicative of formaldehyde's potential
for causing cancer in humans.
Still another area of uncertainty has not been incorporated in the risk
ranges shown. A significant portion (80 percent or more) of the organic stack
gases emitted from MWC have not been identified and quantified. Although some
portion of the mixture may be carcinogenic, the carcinogenic fraction, its
composition, and its potency remain unknown. If the unspeciated organics had
a carcinogenic potency equivalent to the average potency of those compounds
evaluated, even excluding CDO/COF, the contribution to the annual incidence
estimates could be appreciable. However, there is no information to quantify
this potential source of risk.
5.1.2.2 Cancer Risk. Looking at the direct inhalation cancer risk summary
shown in Tables 5-4 and 5-5, it is apparent that most of the cancer risk is
attributable to organics. Table 5-6 shows further that virtually all of the
total risk from existing facilities, and most of the risk from projected
facilities is attributable to CDD/CDF emissions. Thus, COD/CDF dominate the
estimated total cancer risk due to direct inhalation of pollutants from
municipal waste combustors.
Several potentially carcinogenic metals (arsenic, beryllium, cadmium,
chromium) are emitted from municipal waste combustors in trace quantities.
90
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Under reasonable worst case assumptions, the nationwide inhalation cancer risk
associated with these emissions is estimated to be 0.5 cases per year (annual
incidence) for existing sources and 0.4 annual incidence from the projected
population of municipal waste combustors. Maximum individual lifetime cancer
-4 -7
risk for the trace metals ranges from 10 to 10 for existing facilities.and
10 to 10 for the projected population of combustors.
With the exception of CDD and COP the organic carcinogens studied
(chlorobenzenes, chlorophenols, formaldehyde, PAH, PCB) are estimated to pose
cancer risks similar to the trace metals: 0.05-0.7 annual incidence and 10
Q
to 10 maximum individual risk from existing sources and 0.2 to 3.0 annual
-5 -9
incidence and 10 to 10 maximum individual risk from the projected
facilities.
As is evident from Table 4, most of the estimated cancer risk is
<^_ , ^ -- —
attributable to the class of CDD/CDF, measured as the equivalent to
2,3,7,8-TCDD . There remain basic questions concerning the mechanism of
carcinogenesis for dioxins and related compounds. The models used to estimate
the plausible, upper bound carcinogenic potency of compounds such as dioxin,
implicitly assume that the substance acts directly to initiate cancer. If,
however, dioxin acts as a promoting agent, as some scientists believe, to
amplify the carcinogenic response of other direct acting carcinogens, the
present model may not be appropriate. A change of this nature in the
assumption on which the cancer potency estimate is based could lead to a
reduction in this estimate.
The inhalation risk estimates indicate that mass burn municipal waste
combustors, and especially mass burn combustors that do not incorporateheat
r^j^/jexy^_joj]linate^ the cancer risk from existing facilities, but RDF units
contribute more than half of the higher predicted cancer incidence from
projected sources.
As noted above, however, CDD/CDF risks dominate those attributable to
other pollutants. The conclusions about the categories of sources
contributing the most to risk, therefore, reflect assumptions about CDD/CDF
emission factors for these categories of sources. CDD/CDF emission estimates
from mass-burn facilities without heat recovery were based on tests from only
one facility, the Philadelphia-NW facility. It is impossible to determine
91
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whether emissions fr- this facility are representative of those from other
such facilities. Facilities without heat recovery, are generally older than
facilities with heat recovery, so there may be a real basis for the difference
in the estimated emissions.
Similarly, the incidence estimates for existing mass-burn facilities is
influenced by the emission levels found at the Hampton, VA facility, which are
much higher than those found at other mass-burn facilities with heat recovery.
Without further tests, one cannot ...tersrine the extent to which other
facilities may have emissions as high as Hampton's. As noted above, the
emissions from Hampton were excluded in calculating the average emission
factor for planned facilities because the known operational problems at
Hampton make it non-representative of planned facilities.
Finally, the risk attributable to planned RDF facilities is influenced by
the inclusion of emission data from the SWARU facility (Hamilton, Ontario).
SWARU's emissions are significantly higher than those of other RDF facilitiesr
and SWARU had known operational problems at the time the tests were performed
(which modifications have recently attempted to correct). There are
insufficient emission data for RDF facilities, however, to determine whether
these known problems with SWARU make its emission data unsuitable for use in
estimating emissions from new RDF facilities. To reflect the knowledge of the
problems encountered at SWARU, the emission factor for SWARU used in
estimating emissions from new facilities was adjusted based on engineering
judgment, to reflect the expected improvements through recent modifications.
5.1.2.3 Non-carcinogenic Effects. The EPA also evaluated the potential
adverse, but non-carcinogenic, health effects associated with inhalation of
lead and mercury emissions from municipal waste combustors. Comparisons were
made between the predicted maximum modeled ambient air concentrations and the
existing ambient air quality standard for lead. Comparisons were also made
with a guideline for long-term ambient levels of mercury developed in setting
the national emission standards for mercury (Review of National Emission
Standards for Mercury, OAQPS, EPA-450/3-84-014b). The modeling results
predicted no long-term concentrations above the ambient lead standard of
1.5 ug/m . Similarly, modeling predicted no long-term concentrations of
mercury in excess of the guideline of 1 ug/m under baseline conditions.
92
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5.1.3 Indirect Exposure
The indirect exposure analysis was designed to test the hypothesis of
whether indirect exposure routes could contribute significantly to the total
exposure to municipal waste combustion emissions. The analysis evaluated both
cancer and non-cancer risk. Cancer risks are estimated from the combination
of exposure and carcinogenic potency factors. For non-carcinogens, exposured
are compared to the threshold levels corresponding to "Risk Reference Doses"
(RfDs). RfDs are based on thresholds for effects and have uncertainty factors
included. The indirect exposure analysis complements the traditional direct
exposure analysis by adding consideration of ingestion and dermal contact of
deposited air emissions.
Several important notes should be made about the indirect exposure
analysis. First, the methodology for modeling Indirect exposure to pollutants
emitted to the atmosphere has been reviewed by the Science Advisory Board. At
this time, however, the Board's comments on the methodology have not been
fully incorporated. Furthermore, chemical fate parameter data selected for
use in the model were found in the published literature, but they have not
been peer reviewed for this use. Because of the preliminary nature of the
methodology and assumptions, the EPA feels that the resits cannot be
interpretated quantitatively at this time.
Perhaps most critically, because the objective of the analysis was to
determine whether indirect exposures could contribute significantly to the
total exposure due to municipal waste combustors, the analysis used
conservative, potentially worst-case, assumptions about the individuals to be
studied. It was Impossible to model every possible combination of variables
in estimating exposure due to Indirect routes, so the analysis sought that set
of parameters that defined the worst, but still plausible exposure case. The
analysis looked at a hypothetical farm family that obtained most of their food
supply from the area of maximum deposition of pollutants emitted from the
stacks of municipal waste combustors, and whose children ingested 0.5 grams of
dirt per day. This family was assumed to live just outside the estimated
boundary (200 meters, or about one-tenth of a mile) of the modeled combustion
facility. The preliminary conclusions must be interpreted in light of this
worst-case scenario. The general population exposure would be expected to be
less, probably significantly less.
93
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Subject to the above assumptions and jncertainties, the preliminary
analysis indicates that indirect exposure may'be comparable to direct
inhalation for some environmentally persistent organic carcinogens. Indirect
exposures to lead and mercury also appear to warrant further analysis. As
noted above, these conclusions may si«ply be reflective of the conservatism of
the exposure scenario.
The preliminary analysis also served to indicate that indirect exposures
to some pollutants were not of significant concern. The analysis found that
indirect exposure to nickel, chromium (+6), beryllium, and formaldehyde would
not approach reference levels under the scenarios and time frames modeled.
Analysis of the indirect exposure routes and further development of the
data and methodology are continuing. This additional work will be necessary
before the methodology can be used with confidence to evaluate risks from
indirect exposure.
5.2 ENVIRONMENTAL EFFECTS
Among the pollutants found in stack gases from municipal waste combustors
are acid gases, the major acid specie of concern being hydrochloric acid, HC1.
Short-term and long-term modeled concentrations of HC1 surrounding existing
and projected sources are shown in Table 5-7. Emissions factors used to
estimate HC1 emissions from municipal waste combustors were calculated from
the data contained in "Municipal Waste Combustion Study: Emission Data Base
for Municipal Waste Combustors." The average of emissions values reported
were used for annual average predictions. To estimate long term ambient HC1
concentrations around municipal waste combustors, the Human Exposure Model was
run for all existing units and for the model units used to represent the
planned population. Maximum emission values were used for the short-term
modeling. Since the emissions data reported are averages over several hours
and several test runs, the maximum value is a conservative choice for a
short-term emission factor. The resulting ranges of maximum ambient
concentrations are shown in Table 5-7.
The estimated ambient concentrations were then compared to a level
3 34
associated with corrosion of metals, 3.0 ug/m , and to an 8-hour threshold
94
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TABLE 5-7. PROJECTED AMBIENT HC1 C'(NCENTRATIONS
CONTRIBUTED BY MUNICIPAL WASTE COMBUSTORS
SOURCES
CONTROL
LEVEL
TOTAL ANNUAL
EMISSIONS
(Mg)
RANGE OF
PREDICTED
ANNUAL AVERAGE
MAXIMUM
CONC,
(ug/ra3)
RANGE OF
PREDICTED
1-HOUR
MAXIMUM
CONC.
(ug/nT)
Baseline
44,900
.1-68
64 - 2,500
EXISTING
SOURCES
Controlled
4,490
.01 - 7
6 - 250
PROJECTED
SOURCES
Baseline
Controlled
194,400
19,400
.7 -
.07 - 9
110 - 170
11 - 17
95
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limit val-ie (TLV) for workers, 7000 ug/m . The comparisons s.iowed that
short-term (1-r T) maximum concentrations do' not exceed the TLV, but the
majority of the existing municipal waste combustors, under the baseline
scenario, would be expected to exceed the materials damage level. The
modeling results for the projected facilities under the baseline scenario •
showed that short-term concentrations may exceed the 3.0 ug/m level for the
larger mass burn and RDF units and for all sizes of modular units, depending
on location and meteorological data.
5.3 POSSIBLE REDUCTIONS IN IMPACTS
Reductions in predicted carcinogenic health risks and in concentrations
of hydrochloric acid achievable through uniform application of dry scrubbers
combined with particulate control devices is summarized in Table 5-8. As the
table shows, maximum individual lifetime risk is predicted to be reduced by an
order of magnitude, and annual incidence is predicted to be reduced
substantially. Reductions of approximately 90 percent can also be seen in
predicted hydrochloric acid concentrations.
Finally, health risk through indirect exposure routes would also be
expected to be reduced; although, the extent of the potential reduction cannot
be reliably estimated at this time.
As noted in Chapter 4, additional reductions in organic emissions may be
achievable through combustion optimization. At this time there is
insufficient information to determine the expected reduction in emissions and
health risk achievable through this approach.
5.4 COSTS
The capital and annualized operating costs associated with controlling
municipal waste combustor emissions have been estimated as described in the
volume titled "Municipal Waste Combustion Study: Costs of Flue Gas Cleaning
Technologies." Tabular summaries of capital costs and annualized operating
costs for new and existing units are included in this volume in Appendix E.
96
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TABLE 5-8. POSSIBLE REDUCTIONS OF HEALTH RISK AND HC1 CONCENTRATIONS
FROM DIRECT EMISSION PATHWAYS
st Ing Sourc
Projected So..rr««
Mass Burn ROf Modular Mass Burn RDF Modular
Baseline Estleated Cancer 1-34 0.3 - 2.7 0.01 - 0.02 0.6-7 1-14 0.05 - 0.*
Incidence*
Reduction Achievable Under 0.6 - 32 0.3 - 2.5 0.01 - 0.02 0.4 - 6 0.9 - 13 0.04 - 0.8
Controlled Scenario*
Baseline Estimated 10-< - 10~3 10'5 - 10~3 10"* - 10~* W6 - 10~5 10~5 - lo~* 10~* - 10~5
-*< MaxlHM Individual
Ltfettew Risk
Reduction Achievable Under 1 1 1 11 1
Controlled Scenario (orders
of Magnitude)
Baseline Estimated 0.1 - 68 0.7 - M
MaxlMW Long-Tera HC1
Concentration (ug/*3)
Reductions Achievable Under
Controlled Scenario 0.09 - 61 0.6 - 79
*Rounded to precision necessary to Illustrate potential reduction In annual Incidence.
-------
A model plant approach was -tsed in the sizing and costing of the emission
control systems. Due to differences . the waste feed characteristics,
combustion parameters, and emissions, separate cost estimates were required
for mass burning, modular, and refuse-derived fuel (RDF) combustors. Control
equipment systems for which costs were evaluated included ESPs, spray
dryer/ESPs, and spray dryer/fabric filters.
Capital and annualized operating costs were developed in August 1986
dollars using the cost information received from a number of air pollution
control equipment manufacturers for various flue gas flow rates and design
capacities. Capital cost estimates were developed for 25 percent excess
combustor capacity and were increased by an additional 20 percent to account
for contingencies. They include the cost of the control system and auxiliary
equipment.(i.e., ductwork and I.D. fan). In addition, a credit was included
in the calculations of the capital costs for those control systems which
include spray dryers to account for the reduction in capital cost for a stack.
that does not require acid-resistant lining.
The increase in capital cost for control equipment at new facilities with
the addition of spray drying ranges from 50 to 500 percent. The lower end of
the range is for the mass burn and RDF model facilities while the higher value
is for modular facilities. Spray dryer/fabric filter systems require 0.5 to
5.5 percent less capital than spray dryer/ESP systems for 1,000 ton per day
and larger mass burn and RDF model facility sizes at the 0.03 gr/dscf
particulate matter emission level; the savings become 5 to 8 percent at the
0.01 gr/dscf level. For the modular model facilities, spray dryer/fabric
filter systems require an additional 30 percent of capital as compared to a
similarly designed spray dryer/ESP system.
Annualized operating cost estimates for control equipment at new
facilities incorporate assumptions of 8,000 operating hours per year, 20 years
of equipment life for ESPs, and 15 years of equipment life for spray dryers
combined with fabric filters and for spray dryers combined with ESPs.
Maintenance costs were assumed to be 2 percent of the total capital cost, the
waste disposal cost was assumed to be $15/ton, and taxes and insurance were
estimated to be 4 percent of the total capital cost.
98
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Indirect operating costs (i.e., primarily repayment of capital) are more
significant than direct operating costs in eath c the annualized operating
cost estimates for new facilities. Indirect coi-s represent from 60 to 80
percent of the total annualized cost of operating the emission control systems
for new mass burn and modular facilities. The Indirect operating costs are
slightly lower (55 to 70 percent of the total annualized operating cost) for
the RDF facilities.
The waste disposal cost is the major component of the direct operating
costs. Waste disposal costs represent from 25 ta 40 percent of the total
direct cost of particulate matter emission control systems (ESPs) for mass
burn facilities. Waste disposal cost for particulate matter control only for
RDF facilities is 50 to 60 percent of the direct operating costs. The waste
disposal cost associated with spray dryer/ESP and spray dryer/fabric filter
systems are 15 to 30 percent for mass burn facilities and approximately 40
percent for RDF facilities. The waste disposal cost is insignificant for
modular facilities due to the small quantities of particulate matter
generated. Obviously, these control costs depend to a large extent on
landfill costs.
Figures 5-1 through 5-3 present the annualized operating cost estimates
for the emission control systems for new model plants in terms of dollars per
ton of refuse burned. All figures indicate that the relative costs of
operating the emission control systems decrease as the facility sizes
increase. Also, as the particulate matter emission control levels become more
stringent, the annualized operating costs increase. The additional cost of
spray drying compared to PM control alone is $4 to $9 per ton of waste burned
for mass burn facilities. For the RDF model plants, the addition of spray
dryers accounts for an additional $4 to $5 per ton. The corresponding cost
for the model modular facilities is $5 to $12 per ton of waste burned.
The spray dryer/ESP system is generally slightly more costly to operate
than the spray dryer/fabric filter system, based on the information presented
in Figures 5-1, 5-2, and 5-3. The exceptions are mass burn model plants at
the 0.03 gr/dscf outlet particulate matter loading and the modular model
plants.
99
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15-
1 12-
"Z
I 9-
— 6-
= 3-
1
s
fe
s
s
s
I
Is
I
c
^
$
^ c
s
s
V
s
i
>
1
•> 1 $
1
i
1
n
s
s fTP
Ij
: • :
r
| ESP
Q SD/ESP
^3 '•'•
Hi
lil
^ '" v^ "^
•
^\ 8000 hrs/yr operation
August 1986 dollars
Des gn Capacity (tpd)/Outlet Loading (gr/dscf)
Figure 5-1. Annualized Operating Cost Estimates for
Model Mass Burning Facilities
16-
u-
•o
2 12-
c
J 10-
I
N
S
S
5
^
-i
S
p
J
I
r*
f
• r
i
a
i
Ncf>v <$ ' fi'
| ESP
Q SD/ESP
S SD/FF
J
3
O^ 8000 hrs/yr operation
August 1986 dollars
Des gn Capacity (tpd)/Outlet Loading (gr/dscf)
Figure 5-2. Annualized Operating Cost Estimates for
Model Modular Combustor Facilities
10-
•o a-
0
u?
! 4.
o
O
5 2-
0-
A
I
^
^
I
1,
«_
1
N^ -^
| ESP
-i Q SD/ESP
?
1
: ^ SD/FF
^N 8000 hrs/yr operation
August 1986 dollars
Design Capacity (tpd)/Outlet Loading (gr/dscf)
Figure 5-3. Annualized Operating Cost Estimates for
Model Refuse-Derived Fuel Burning Facilities
o
oo
100
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Capital cost estimates for control equipment at existing n> ncipal waste
combustion facilities must take into account the additional expense
retrofitting additional control equipment into an existing control system.
For example, the capital cost for a spray dryer/ESP system at an existing
massburn or RDF facility with a highly efficient ESP currently in place would
be estimated on the basis of the spray dryer cost times a retrofit factor
of 1.4. Similarly, the retrofit factor for estimating the cost of a spray
drver/fabric filter at an existing massburn or RDF facility with a wet
scrubber or a less efficient ESP in place would be 1.8. Finally, the capital
cost of retrofit combustion improvements at an existing facility is estimated
to be $6.5 million per 1000 tons per day capacity. Operating costs or savings
can not be determined on a general basis. These retrofit factors are based on
extremely limited data and are highly uncertain, especially in view of the
site-specific nature of retrofits.
The emission control systems costed for existing municipal waste
combustion facilities were designed to provide particulate matter control only
or both acid gas and particulate matter control. For existing mass burn and
RDF facilities the control systems evaluated included a spray dryer system
retrofit to facilities with a highly efficient ESP in place and a spray
dryer/fabric filter system retrofit to facilities with a wet scrubber or less
efficient ESP currently in place. The majority of existing modular facilities
are uncontrolled. Therefore, ESPs and spray dryer combined with ESPs were
evaluated for modular facilities.
The cost for modification of one existing combustor and retrofit of a new
particulate matter control device at Quebec City was slightly less than
$1.5 million. This cost included a computerized process control system
designed to operate four combustors at the facility.
5.5 COST/RISK ANALYSIS
The previous discussion has presented the health risk estimates expected
from municipal waste combustors under two different control scenarios and
reductions in risk that might be achieved through uniform application of
alkaline scrubbers combined with particulate matter emissions control. This
101
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was followed by an analysis of monetary costs of the two levels of control: 1)
ESPs and 2) spray dryers combined with ESP or fabric filter particulate
controls.
This section seeks to weigh costs and risk reductions and other benefits
achievable. Table 5-9 is a direct comparison of the incremental cost of the
stringent control case with cancer risk due to direct inhalation that could be
reduced through application of stringent control measures, both calculated for
the entire U.S.
^-*-
Direct inhalation cancer risk reduction is one of several benefits that
would accrue through the uniform addition of alkaline scrubbers to the
baseline particulate matter control technology. Emissions to the air of HC1,
particulate matter, and volatile organic compounds (VOC) would also be
reduced. Furthermore, exposure through indirect routes would also be reduced,
including exposure to non-carcinogens. Although these additional benefits are
not accounted for quantitatively in the cost/risk comparison quotients
presented in Table 5-9, they are, nonetheless, real benefits which must be
considered.
102
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TABLE 5-9. INCREMENTAL COST/RISK COMPARISON
Mass Burn
EXISTING SOURCES
RDF
Modular
PROJECTED SOURCES
Mass Burn
RDF
Modular
TOTAL
DIRECT INHALATION EXPOSURE:
Baseline Cancer Incidence (annual)
Incidence Reduction Obtainable
Through Controlled Scenario
Maximum Individual Lifetime Risk
(baseline scenario)
1-34
0.3 - 2.7 0.01 - .02
0.8 - 32 0.3 - 2.5 0.01 - .02
0 .6 - 7
0.4 - 6
1 - 14
0.9 - 13
0.05 - 0.9
0.04 - 0.9
1.7 - 31
1.3 - 29
10"4 - 10"3 10"5 - 10"3 10"6 - 10"4 10"6 - 10"5 10~5 - 10"4 10"6 - 10"5 10"6 - 10"4
INCREMENTAL COST OF CONTROL:
(•II lion S)
65 - 127
29-45
4.6 - 23
201
62
17
260
COST EFFECTIVENESS
(nillion $/cancer case avoided)
2.7 - 160
11 - 150 230-2300
34 - 503
4.8 - 69
19 - 425
9.7 -215
'Rounded to precision necessary to facilitate cost/risk comparison.
Does not consider benefits resulting from reduced emissions of mercury, HC1, partlculate matter, or volatile organic compounds; nor
reduction In potential Indirect exposure.
""Difference between annual Ized cost of 2 control scenarios.
-------
6. SAMPLING, ANALYSIS AND MONITORING*
One of the most rapidly developing areas within the overall subject of
municipal waste combustion is sampling, analysis, and monitoring of municipal
waste combustor emissions and waste streams. In the analytical chemistry
field alone, the state of the art has moved rapidly from semi-quantitative for
selected isomers of CDD and CDF in the late 1970s to quantitative
determination of all CDD and CDF isomers today. In this section a brief
summary of sampling, analytical and monitoring methods is offered. More
detail may be found in "Municipal Waste Combustion Study: Sampling and
32
Analysis of Municipal Waste Combustors."
6.1 SAMPLING
Stack testing at municipal waste combustors has been carried out for a
variety of air pollutants 1n several categories, including:
o Criteria pollutants (particulate matter, CO, SO , NO , lead)
o Acid gases (HC1, HF)
o Metals (Cr, Cd, As, Hg, Ni, Be, etc.)
o Organics (CDD, CDF, and others)
Characterization and leachate testing has also been carried out for ash
residues.
For both flue gas and bottom ash sampling a difficulty arises in
obtaining representative samples. For example, flue gas sampling may be
complicated by uneven flow conditions and by high particulate matter and acid
gas loadings that clog or corrode conventional sampling equipment.
Other problems may be encountered in sampling bottom ash which may include
bulky items, such as metal containers.
*Information presented in this section is summarized from Reference 32,
Municipal Waste Combustion Study: Sampling and Analysis of Municipal Waste
Combustors.
104
-------
Table 6-1 lists EPA-approved stack sampling methods for various
pollutants. Most of these methods have been subjected to extensive
development and validation procedures. Moreover, a number of these methods
have been employed in recent municipal waste combustion sampling and analysis
programs.
The EPA Method 5 type train has been the principal method for stack
sampling of criteria pollutants, acid gases, metals, and semi-volatile
organics, including COD, CDF, and PAH, chlorobenzenes and chlorophenols. The
Modified Method 5 train incorporates a condenser section and a module filled
with solid sorbent between the exit of the filter and the entrance to the
first impinger. It should be noted that testing is underway to verify
recoveries of organic compounds using this modified train. New developments
are occurring rapidly and should be monitored closely.
The number of sampling trains and sample runs required for stack sampling
of a municipal waste combustor depends on the list of pollutants specified foe
quantification and the accuracy and precision with which concentrations must
be measured. Quantitative results for an extensive list of pollutants may
require multiple determinations of the same chemical specie and, generally
speaking, no more than 2 to 3 species can be determined from one train. The
situation is further complicated by physical limitations due to restricted
space in the stack sampling area and the number of sampling ports available in
one plane. Even if ports are available, the logistics of running more than
two trains can be complicated. These physical limitations limit the number of
trains that can be run simultaneously. For example, for a recent EPA test of
a municipal waste combustor, stack gases were to be sampled by manual methods
in three separate runs for CDD/CDF, HC1, Pb, Cd, Cr, Ni, and particulate
matter. SO- and 02 were measured with continuous emissions monitors.
Sampling for this list of pollutants required four separate trains. For
statistically significant data at least triplicate measurements per species
were required, resulting in a total of 12 separate runs. The site specific
considerations of a circular duct with two sampling ports and an actual
sampling time of 4 to 6 hours for each run, based on expected concentrations
in the stack, restricted the test program to 2 runs a day for a total of six
sampling days.
105
-------
TABLE 6-1. STACK (FLUE GAS) SAMPLING METHODS
Pollutant
Principle
Comment
Reference
Criteria and Conventional Parameters
Participate
Sulfur
Oxides
Carbon
Monoxide
Nitrogen
Oxides
Isok1net1c collection of a 1 hr. sample
on glass fiber filter at 120± 14°C.
Train Includes: T-controlled probe*
optional cyclones* heated filter*
1mp1ngers» flow control and gas volume
metering system.
Visual determination of opacity
Instrumental measurement of opacity
(optical density)
Collection In Isopropanol (SO-) and
hydrogen peroxide (S0~) Implngers of
M5-type train.
Integrated gas bag or direct Interface
via air-cooled condenser.
Collection In evacuated flask
containing sulfurlc acid and hydrogen
peroxide.
Designed to meet 0.08 gr/SCF
standard. Probably valid
down to 0.01 gr/SCF.
EPA Meth. 5
Not reliable for quantifica-
tion at 0.03 gr/SCR or below.
Low ppm to percent
Water vapor* carbon dioxide
are Interferences; need
silica gel* ascarlte traps to
remove.
20-1000 ppm
Grab sample (not
time-Integrated)
ppm levels
Does not measure NO
EPA Meth. 9
EPA Meth. 6,8
EPA Meth. 10
EPA Meth. 7,7A
-------
TABLE 6-1. STACK (FLUE GAS) SAMPLING METHODS (Continued)
Pollutant
Principle
Comment
Reference
Hydrochloric
Add
Hydrogen
Fluoride
Collection In aqueous NaOH Implngers In
M5-type train.
Collection on paper or membrane (not;
glass fiber) filter and aqueous
Implngers In M5-type train.
ppm to percent range.
Low ppm range.
(18)
EPA Meth. 13B
Trace Metals
General
i—i
2 Lead
MS or SASS train* glass fiber filter
and nitric acid or ammonium persulfate
Implngers
Collection on glass fiber filter and
nitric acid Implngers In M5-type train.
ppb to ppm levels
j _ /\ "»f~ »*J
rr~ *•— rr—
Is _ 0.75
of stack gas
(18)
EPA Meth. 12
Mercury
Arsenic
Beryllium
Collection In Iodine monochlorlde or
acidic permanganate Implngers In
M5-type train.
Collection on glass fiber filter and
aqueous Implngers In MS-type train.
Collection on mllllpore AA filter and
aqueous Implngers 1n MS-type train.
Probe must be glass- or
quartz-lined.
ppm levels. Other reagents
also possible.
Probe must be glass or
quartz-11ned.
EPA Meth. 101
EPA Meth. 108
EPA Meth. 104
-------
TABLE 6-1. STACK (FLUE GAS) SAMPLING METHODS (Continued)
Pollutant
Principle
Comment
Reference
Trace Organics
Specific Volatile
organIcs
Collection on Tenax-GC
1 LPM for 20 minutes.
and charcoal at
Semi-volatile MS train modified to Include XAD-2 trap
organ1cs, Including for organic collection between filter
dloxlns* furans and Implngers.
5-fold scale up of MM5 system.
ppb-ppm 1evels;mult1ple
species
ppb-ppm levels; multiple
species
sub-ppb levels for
dloxlns/furans If dedicated
sample
VOST
MM5
SASS
£ Vinyl chloride
00
Formaldehyde
Integrated gas bag
0.1-50 ppm
Collection on DNPH-coated so r bent or In ppm levels
aqueous DNPH Implngers.
EPA Meth. 106
Gaseous Hydro-
carbons* total
Gaseous Hydro-
carbons* total
Integrated bag sample or direct
Interface
Evacuated stainless steel or aluminum
tank behind chilled condensate trap.
ppm levels
EPA Meth. 18
EPA Meth. 25
-------
6.2 SAMPLE PREPARATION
Stack samples taken from municipal waste combustors must be converted
into a matrix which is compatible with the analytical methods needed.
Table 6-2 summarizes sample preparation procedures commonly used for municipal
waste combustor stack samples.
In some cases (e.g., analysis of chloride in caustic impinger solutions)
the required sample preparation may be minimal. In other case (e.g. analysis
of CDDs/CDFs in a Modified Method 5 stack gas sample) preparation procedures
may be complex, requiring multiple extraction, concentration, and clean-up
steps. (See Table 6-2.)
The use of surrogate or standard addition methods is recommended as a
check on losses in sample preparation procedures. Additions should be made
prior to sample preparation.
6.3 ANALYSIS
Analytical methods are available for most chemical species likely to be
selected for quantification in emissions and effluents from municipal waste
combustors. Table 6-3 shows analytical methods for organics and metals that
may be specified in testing requirements.
6.4 MONITORING
Continuous monitoring at municipal waste combustors may be carried out
for:
temperature
opacity
CO, CO-, NO , SOg concentration
HC1 concentration
total hydrocarbon concentration
109
-------
TABLE 6-2. SUMMARY OF SAMPLE PREPARATION METHODS
MSW
Combustor
Stream
Sample
Type
For
Analysis
of
Preparation
Procedure
Stack Gas
Flue Gas
Bottom Ash and Fly Ash
MS, MMS or SASS
- probe wash
- filter
-probe wash
- filter
- Implnger
solutions
- probe wash
- filter
- sorbent nodule
- condensate
VOST
- sorbent cartridges
- condensate
MS, MMS. SASS '
VOST
Composite Grab
Partlculate
Metals
Semivolatile organIcs
Semivolatile
Volatile organIcs
Volatile organIcs
(same as for stack gas)
Metals
Olsslcate to constant weight
Standard addition to split
samples. Digest In acidic
oxidizing medium.
Add surrogate. Soxhlet
extract with CH-Cl,.
Concentrate. CTean-up
as necessary.
Add surrogate Liquid-liquid
extract at pH 2 and pH 11
with CHJC1-. Concentrate.
Clean-up as necessary.
Spike with Internal standard.
Thermally desorb onto
analytical trap. Desorb this
trap Into QC/MS.
Spike with Internal standard.
Purge onto analytical trap.
Desorb Into QC/MS.
Standard addition to split
samples. Digest In acidic
medium In Parr bomb.
-------
-------
TABLE 6-2. SUMMARY OF SAMPLE PREPARATION METHODS (Continued)
HSM
Combustor
Stream
Sample
Type
For
Analysis
of
Preparation
Procedure
Semi-volatile organlcs Add surrogate. Soxhlet
extract with CH-C1-.
Concentrate. Ciean-up as
necessary.
Liquid Effluents Composite Grab Metals Standard addition to split
samples. Digest In acidic,
oxidizing medium.
Volatile Organlcs Spike with Internal standard.
Purge Into analytical trap.
Desorb Into GC/MS.
Semi volatile Organlcs Add surrogate. Liquid
extract at pH 2 and pH 11
with CH-CK. Concentrate.
Clean-up as necessary.
Waste Feed Composite Grab Grind or mill to reduce
particle size. Take
subsamples.
Metals
Semlvolatlle Organlcs Same as for ash samples.
Volatile9 Organlcs Spike with Internal standard.
Dilute In reagent water or
polyethylene glycol In purge
cell. Purge, trap and desorb
Into GC/MS.
Reference: Miller, N.C., R.W. James and W.R. Dlckson, "Evaluated Methodology for the Analysis of Residual
Waste, "Report prepared under EPA Contract No. 68-02-1685 (December 1980).
-------
TABLE 6-3. ANALYSIS METHODS FOR TRACE ORGANICS AND TRACE METALS,
APPLICABLE TO MUNICIPAL WASTE COMBUSTOR SAMPLES
Species
Method
Volatile Organics
Semivolatile Organics
Dioxins/Furans
Metals
Pack column GC/MS; full mass range
scanning 20-260 amu.
Capillary column GC/MS; full mass
range scanning 40-500 amu.
Capillary column GC/MS; selected ion
monitoring.
Flame (high levels) or furnace (low
levels) AAS.
Inductively coupled plasma
spectroscopy (not for mercury, lead,
arsenic)
112
-------
Possible continuous monitoring devices for measuring these variables and gas
concentrations in municipal waste combustol" stack gases are summarized in
Table 6-4. Most pollutants are measured using an extractive method where the
flue gas is withdrawn from the stack, transferred in a heat traced line to
ground-level to an instrument trailer where the flue gas is conditioned'to
remove moisture and then split for analysis by individual instruments.
Particulates and temperature are two parameters which are usually measured
in-situ.
Continuous temperature measurements in combustor flue or stack gases are
generally accomplished by using thermocouples. The thermocouples must be
shielded from radiation and protected against mechanical damage and corrosion
by shielding inside a ceramic or metal protection tube or in a thermowell.
Continuous monitoring of particulate material is generally accomplished
using an in situ opacity meter. Typically, these devices measure changes in
optical density, 00 (percent transmittance), due to scattering and/or
adsorption of light by particulates that are present, but their performance is
affected by particle size distribution, the particulate shape, particle
composition, the system's temperature, the presence or absence of water
droplets and the configuration of the stack. Also, commercially available
opacity meters for stack monitoring may be uncertain by a factor of two or
more at particulate loadings below 0.03 gr/scf. The lack of measurement
specificity of the instrument may render opacity monitors less reliable at
municipal waste combustors than at other stationary sources, since waste feed
is highly variable, emission levels and compositions may vary significantly
over time.
SCL, NO and HC1 concentrations can be measured using instruments based
on several different principles. Perhaps the most common detection principle
used by continuous analyzers for stack gases is nondispersive infrared (NOIR).
The principal advantages of NOIR based instrumentation is the fact that it is
comparatively low in cost and that the technology is applicable to a wide
variety of pollutant species. Also, instruments are relatively rugged and
commercially available systems have been in use in field monitoring situations
for many years. Problems that are associated with this detection principal
are that other chemical species will absorb similar signature wavelengths of
113
-------
TABLE 6-4. CONTINUOUS MONITORING DEVICES FOR MUNICIPAL WASTE COMBUSTORS
Temperature
Opacity
CO concentration
Oxygen Concentration3
S0« Concentration
NOX Concentration*
HC1 Concentration*
Total Hydrocarbon Concentration*
Thermocouple
Opacity meter
Nondispersive Infrared
Polarographic
Polarographic
Electrocatalytic
Paramagnetic
Nondispersive Infrared
Nondispersive Ultraviolet
Polarographic
Nondispersive Infrared (NO)
Nondispersive Ultraviolet (NO-)
Polarographic (NO)
Chemiluminscent
Nondispersive Infrared
Polarographic
Flame ionization detector
Infrared detection
Catalytic combustion detector
Thermal conductivity detector
aUsing an extractive method.
114
-------
infrared light, and the fact that optical systems needed to produce, transmit,
and receive the generated infrared light may degrade due to contact with the
sample gas.
Non-dispersive ultraviolet analyzers have an important advantage over
NDIR analyzers in that in the NDUV analyzers water vapor is not an
interference, as water does not absorb light in the ultraviolet region of the
spectrum. As is the case with most extractive monitoring techniques, however,
particulates which will absorb or scatter generated light must be removed from
the sample gas stream.
Numerous pollutant species of potential interest at municipal waste
combustors may be measured continuously using polarographic analyzers. The
polarographic analyzers offer several advantages over other analyzers,
including multi-pollutant capability, fast response and simplicity of
operation. Principle disadvantages of this technique are that parts of the
system must be replaced or rejuvenated periodically, and the instrument must
be frequently calibrated because the response deteriorates with use.
Oxygen may be measured continuously using electrocatalytic analyzers and
paramagnetic oxygen analyzers. Chemiluminescence may be used for Inorganic
pollutants, most notably nitrous oxide and ozone.
Hydrocarbons may be monitored continuously with a flame ionization
detector (FID) or an infrared detection (IRD). These detectors are relatively
rugged and are quite sensitive to hydrocarbons. Response factors are
generally lower for organics that incorporate functional groups such as
halides, hydroxyl, carbonyl, carboxylate. The photoionization detector (PID)
is applicable to many organic categories, but experience with this detector as
a continuous monitor is more limited. There is some evidence that maintenance
is more of an issue with PID than with FID or IR Instruments.
The electron capture detector (ECD), which has high sensitivity and
selectivity for halogenated organics under laboratory conditions, is not
rugged enough for routine continuous monitoring in the field. Also, because
these detectors contain radioactive materials, NRC permitting regulations
govern their installation and use. The Hall detector, also specific for
halogenated species, has been used at hazardous waste incineration sites, but
with difficulty.
115
-------
Catalytic combustion (hot wire) and thermal conductivity detectors are
also used for continuous monitoring of organics. However, most commercially
available instruments based on these principles are generally designed for
gases and vapors. A few low-level instruments suitable for municipal waste
combustor monitoring are available, however.
Monitoring of specific organic compounds, rather than total organics,
require that chromatographic separation be accomplished prior to detection.
Instrumental monitors that interface a gas chrpmatograph to an FID or PID are
commercially available. These operate in a semi-continuous basis, since the
chromatographic separation imposes a cycle time of (typically) 5-30 minutes
between measurements. GC/FIO or GC/PID analyzers are vulnerable to false
positive interferences because the retention time is an imperfect means of
compound identification.
Instruments based on more selective detection principles (e.g., GC/MS or
GC/FTIR) are beyond the present state-of-the-art for stack monitoring, except
in research installations. Instruments using these detectors may be
sufficiently expensive to install and demanding to operate that they are not
suitable for routine continuous monitoring. Most require more stringent
control of temperature, humidity and power supply than is likely to be
practiced at an operating municipal waste combustion plant.
Continuous monitoring requires close attention to calibration and other
quality assurance measures. These topics and additional information on
monitoring of stack gases at municipal waste combustors are covered in
"Municipal Waste Combustion Study: Sampling and Analysis of Municipal Waste
32
Combustion."
116
-------
7. REFERENCES
1. Ballschmiter, et. al. Automobile Exhauses Versus Municipal-Waste
Incineration as Sources of the Polychloro-Dibenzodioxins (PCDD) and
Furans (PCDF) found in the environment. Chemosphere Vol. 15, No. 7. pp.
901-915. 1986.
2. Ballschmiter, K. and H. Buchert. Polychloratibenzofurans (PCDF) and
-Dioxins (PCDD) as Part of the General Pollution in Environmental Samples
of Urban Areas. Chemosphere. Vol 15., Nos. 9-12. pp. 1923-1926." 1986.
3. Ballschmiter, K. et. al. C. jrrence and Absence of
Polychlorodibenzofurans ana olychlorodibenzodioxins in Fly Ash from
Municipal Incinerators. Chemosphere. Vol 12, No. 4/5. pp. 584-594.
1983.
4. Barnes, Donald F. "Dioxins" Production from Combustion of Biomass and
Waste. Presented at Symposium on Energy from Biomass and Wastes VII.
Lake Buena Vista, Florida. January 24-18, 1983.
5. The Trace Chemistries of Fire-A Source of and Routes for the Entry of
Chlorinated Dioxins into the Environment. The Chlorinated Dioxin Task ^
Force, The Michigan Division, Dow Chemical U.S.A., 1978.
6. U.S. Environmental Protection Agency. Municipal Waste Combustion Study:
Characterization of the Municipal Waste Combustion Industry.
EPA/530-SW-87-021h. Prepared by Radian Corporation, June 1987.
7. Franklin Associates, LTD. Characterization of Municipal Solid Waste in
the United States, 1960 to 2000. Final Report. EPA Contract No.
68-01-7037, WA 349. July 11, 1986.
8. New Jersey Department of Environmental Protection - Division of Waste
Management. Progress in Waste Management • A Solution to New Jersey's
Garbage Dilemma. March 1986.
9. Garbage: A 413,000 Ton-A-Day-Dilemma, Inform Reports. 5(3):1-4.
May-June 1985.
10. U.S. Environmental Protection Agency. Survey of selected firms in the
Commercial Hazardous Waste Management Industry: 1984 Update. Final
Report. Prepared by ICF Incorporated. September 30, 1985.
11. Johnson, Charles A. and C.L. Pettit. The 1986 Tip Fee Survey Documenting
Rising Prices. Waste Age. March 1987. pp. 61-64.
12. Hertzberg, Richard. New Directions in Solid Waste and Recycling.
Biocycle. Volume 27, January 1986. pp. 22-26.
13. Update: Resource Recovery Activities Report. Waste Age. 16
(11):99-183. November 1985.
117
-------
14. Introduction to the ORFA Process and ORFA Corporation of America.
September 1986. Cherry Hill, NJ.
15. Concord Scientific Corporation. National Incinerator Testing &
Evaluation Program. P.E.I. Testing Program. Prepared for Environmental
Canada. July 1985.
16. U.S. Environmental Protection Agency. Municipal Waste Combustion Study:
Emissions Data Base for Municipal Waste Combustors. EPA/530-SW-87-021b.
Prepared by Midwest Research Institute. June 1987.
Seeker, W.R., W.S. Lanier, and M.P. Heep. Municipal Waste Combustion
Study: Combustion Control of Organic Emissions. EPA/530-SW-87-021c.
June 1987.
18. Acurex Corporation. Assessment of Flue Gas Cleaning Technology for
Municipal Waste Combustion. Final Report. EPA Contract No. 68-02-3993,
Work Assignment 11031. Prepared for Environmental Protection Agency,
Research Triangle Park, NC. September 1986.
19. Brna, Theodore G., and Charles B. Sedman. Municipal Waste Combustion
Study: Flue Gas Cleaning Technology. EPA/530-SW-87-021d. U.S.
Environmental Protection Agency, Research Triangle Park, NC.
June 22, 1987.
20. Kramlich, J.C., M.P. Heap, W.R. Seeker, and G.S. Samuel son. Flame Mode
Destruction of Hazardous Waste Compounds in 20th Symposium
(International) on Combustion.
21. Finkelstein, A. e_£ il. Presentation by Environmental Canada at Municipal
Solid Waste Incineration Research and Planning Meeting. Durham, NC.
December 9-11, 1986.
22. Federal Register 48:48932 (October 21, 1983). Standards of Performance
for New Stationary Sources: VOC Emissions from the SOCMI Air Oxidation
Unit Processes.
23. Trenholm, A., P. Gorman, and F. Jungclaus. Performance Evaluation of
Full-Scale Hazardous Waste Incinerators. 3 Volumes. PB 85 1296528, PB
85 129518, PB 85 129531. U.S. Environmental Protection Agency,
Cincinnati, OH. November 1984.
24. Nielsen, K.K., J.T. Moellers and S. Rasmussen. Reduction of Dioxins and
Furans by Spray Dryer Absorption from Incinerator Flue Gas. Presented at
Dioxin 85, Bayreuth, W. Germany. September 19, 1985.
25. Environment Canada. The National Incinerator Testing and Evaluation
Program. Air Pollution Control Technology. Summary Report. Report EPS
3/UP/2. September 1986.
26. Moller, J. Thousig, K. Kragh Nielsen, and E. Jons. New Developments in
Spray Dryer Absorption of Household Incinerator Flue Gas. Presented at
International Recycling Congress. Berlin. October 29-31, 1986.
118
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27. U.S. Environmental Protection Agency. Municipal Waste Combustion Study:
Assessment of Health Risks Associated with Municipal Waste Combustion
Emissions. EPA/530-SW-87-021g. U.S. Environmental Protection Agency,
Research Triangle Park, NC. June 1987.
28. U.S. Environmental Protection Agency. User's Manual for the Human
Exposure Model (HEM). EPA-450/5-86-001. Research Triangle Park, NC.
June 1986.
29. U.S. Environmental Protection Agency. Industrial Source Complex (ISC)
Dispersion Model User's Guide - Second Edition. EPA-450/4-86-005a.
Research Triangle Park, NC. June 1986.
30. U.S. Environmental Protection Agency. Interim Procedures for Estimating
Risks Associated with Exposures to Mixtures of Chlorinated Dibenzodioxins
and -Dibenzofurans (CDD and CDF). EPA-625/3-87-012, March 1987.
31. Johnston, Michael. Municipal Waste Combustion Study: Costs of Flue Gas
Cleaning Technologies. EPA/530-SW-87-021e. U.S. Environmental
Protection Agency, Research Triangle Park, NC. June 1987.
32. U.S. Environmental Protection Agency. Municipal Waste Combustion Study,:
Sampling and Analysis of Municipal Waste Combustors. EPA/530-SW-87-021f.
Prepared by Arthur D. Little, Inc. June 1987.
33. Jamgochian, Carol L., Winton E. Kelly, and Donna J. Holder. Revised
Sampling and Analytical Plan for the Marion County Solid Waste-To-Energy
Facility Boiler Outlet. Salem, Oregon. EPA Contract No. 68-02-4338.
Prepared for Environmental Protection, Research Triangle Park, NC.
September 1986.
34. Telecon. Kellam, Bob, Section Chief. U.S. Environmental Protection
Agency, with Joanne Wiersma, Section Chief, Texas Air Control Board.
June 1987.
35. American Conference of Government Industrial Hygienists. Threshold Limit
Values and Biological Exposure Indices for 1986-1987.
ISBN:0-936712-69-4. Cincinnati, Ohio.
36. Telecon. Johnston, Mike, EPA:OAQPS with Abe Finklestein, Environment
Canada. February 24, 1987. Conversation about modifications at Quebec
City.
37. U.S. Environmental Protection Agency. Municipal Waste Combustion Study:
Emissions Data Base for Municipal Waste Combustors. Review Draft. EPA
Contract No. 68-02-3817. Prepared by Midwest Research Institute.
January 1987.
119
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APPENDIX A
DOCUMENTS PREPARED BY THE EPA'S ENVIRONMENTAL
CRITERIA ASSESSMENT OFFICE
-------
INTRODUCTION
The following documents were prepared hy the Office of Health and
Environmental Assessment for the Office of Air Quality Planning and Standards
.These documents are of three types: Air Quality Criteria Documents, Health
Assessment Documents, and Health Issue Assessments. Brief descriptions of
these document types follow:
Air Quality Criteria Documents (AQCD) are the primary
source of information used by EPA decision makers in
setting or revising the National Ambient Air Quality
Criteria Standards. These documents are evaluations of
the available scientific literature on the health and
welfare effects of criteria pollutants. Criteria documents
are mandated by the Clean Air Act and are revised at
5-year intervals, as directed by the Act.
Health Assessment Documents (HAD) are comprehensive
evaluations of health data, including carcinogenicity,
mutagenicity, and other effects due to exposure to particular
chemicals or compounds. These documents serve as the
scientific data base for establishing relationships
between ambient air concentrations and potential health
risks and are used to determine the possible listing of
hazardous air pollutants under Sections 111 and 112 of
the Clean Air Act.
Health Issue Assessments (HIA) are an initial review of
the scientific literature concerning the most important
health effects associated with a given chemical substance.
These assessments may be published as is, or developed
into a comprehensive health assessment document if evidence
suggests that significant health effects may be associated
with environmental exposures to a specific substance.
A-l
-------
ECAO DOCUMENTS
Document Ti tie
Acrolein
Acrylonitrile
Arsenic
Asbestos
Be ryl 1 i urn
Butadiene, 1,3-
CFC-113
Cadmium
Cadmium-Updated Mutagenicity
and Carcinogenicity
Assessment
Carbon Monoxide
Carbon Monoxide-Revised
Evaluation of Health
Effects
Carbon Tetrachloride
Chlorinated Benzenes
Chloroform
Chloroprene
Chromium
Copper
Coke Oven Emissions
Oibenzofurans
Hi ox ins
Epichlorohydrin
Ethyl ene Di chloride
Document
Type
HAD
HAD
HAD
H •*
HAD
HAD
HAD
HAD
HAD Addendum
AQCD
AQCD Addendum
HAD
HAD
HAD
HIA
HAD
HIA
HAD
HAD
HAD
HAD
HAD
EPA Number
(600/)*
8-86-014A
8-82-007F
8-83-021F
-. 8-84-003F
8-84-025B
8-85-004F
8-82-002F
8-81-023
8-83-025F
8-79-022
8-83-033F
8-82-001F
8-84-01 5F
8-84-004F
8-85-011F
8-83-014F
8-87-001F
8-82-003F
8-86 -01 8A
8-84-014F
8-83-032F
8-84-006F
NT IS Number
(PB-)
87-139960/AS
84-149152
84-190891
86-242864
86-183944
86-125507/AS
84-118843
82-115163
85-243533
81-244840
85-103471
85-124196
85-150332
86-105004
86-197662
85-115905
87-137733
84-170182
86-221256
86-122546
85-132363
86-122702
A-2
-------
ECAO DOCUMENTS
Document Title
Ethyl ene Oxide
Hexachl orocycl opentadi ene
Hydrocarbons
Hydrogen Sul fide
Lead (4 volumes)
Manganese
Mercury
Methyl Chloroform
Methyl ene Chloride
Methyl ene Chloride-
Updated Carcinogenicity
Assessment
Nickel
Nitrogen Oxides
Ozone (5 volumes)
Polycyclic Organic Matter
Particulate Matter/
Sul fur Oxides
Particulate Matter/
Sulfur Oxides - Assessment
of Newly Available Health
Effects Information
Phenol
Phosgene
Propylene Oxide
TetrochI oroethyl ene
Document
Type
HAD
HAD
AQCD
HAD
AQCD
HAD
HIA
HAD
HAD
HAD Addendum
HAD
AQCD
AQCD
HAD
AQCD
AXD Addendum
HIA
HAD
HIA
HAD
EPA Number
(600/)*
8-84-009F
8-84-001F
8-81-022
8-86-026A
8-83-028F
8-83-013F
8-84-019F
8-82-003F
8-82-004F
8-82-004FF
8-83-012FF
8-82-026F
8-84-020F
9-79-008
8-82-029F
8-86-020A
8-86-003F
8-86-022A
8-86-00 7F
8-82-005F
NTIS Number
(PB-)
86-102597
85-124915
82-136516
87-117420
87-142378
84-229954
85-123925
84-183565
85-191559/AS
86-123742
86-23212
83-163337
87-142949
82-186792
84-156777
86-221249
86-178076
87-147039/AS
Not yet avail a
85-249704
A-3
-------
AVAILABILITY OF ECAO DOCUMENTS (Continued)
Document Ti tie
Document
Type
EPA Number
(600/)*
NT IS Number
(PB-)
TetrocM oroethyl ene-
Updated Carcinogenicity
Assessment
Toluene
Tn'chl oroethyl ene
Vinylidene Chloride
HAD Addendum
HAD
HAD
HAD
8-82-005FA
8-82-008F
8-82-006F
8-83-031F
86-174489
84-100056
85-249696
86-100641
* Key:
A * First External Review Draft
B * Second External Review Draft
F * Final
FA « Addendum Review Draft
FF * Addendum Final
FOR INFORMATION ON DOCUMENT AVAILABILITY CONTACT:
NATIONAL TECHNICAL INFORMATION SERVICE
U.S. DEPARTMENT OF COMMERCE
5285 PORT ROYAL ROAD
SPRINGFIELD, VIRGINIA 22161
703/487-4650
CENTER FOR ENVIRONMENTAL RESEARCH INFORMATION
U.S. ENVIRONMENTAL PROTECTION AGENCY
26 WEST ST. CLAIR STREET
CINCINNATI, OHIO 45268
513/569-7562 (FTS: 684-7562)
A-4
-------
APPENDIX B
LISTS OF EXISTING AND PLANNED MUNICIPAL
WASTE COMBUSTION FACILITIES
-------
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B-2
-------
03
TABLE B-l.
LOCATION
CITY
C*nt«r
Palvstln*
Haxahachla
Ogo»n
Portsmouth
Norfolk (Navy Station)
Haapton
Harrlsonburg
Galax
Sale*
Nnport Ne»s (Ft. Eustls)
BclUngham
Balllnghaai
Sh«boygan
Haukcsna
Barron County
Madison
EXISTING FACILITIES ORDERED BY STATE AND
TOTAL
STATE TYPE RECOVERY
TX
TX
TX
UT
VA
VA
VA
VA
VA
VA
VA
HA
HA
HI
HI
HI
HI
MI/SA
MI/SA
MI/SA
MB/OF
MB/OF
MB/OF
MB/OF
MB/OF
MB/RC
MI/SA
MI/SA
MI/EA
MI/SA
MB/OF
MB/OF
MI/SA
RDf/C
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
NO
YES
NO
YES
t flf f
9 Ur i
COMBUST ORS
1
1
2
3
2
2
2
2
1
4
1
1
2
2
2
2
2
PLANT
*A0Af* I TV
,HrK 1 1 Y
(TPOI
36
28
50
450
160
360
200
100
56
100
35
100
100
240
175
80
400
TYPE OF
CONTROL (S)
NONE
HS
HS
ESP
ESP
ESP
ESP
ESP
BAG
NONE
NONE
NONE
NONE
HS
ESP
ESP
ESP/C
DESIGN TYPE (Continued)
STARTUP
DATE
1985
NA
1982
NA
1971
1967
1980
1982
NA
1970
1980
1986
1986
NA
1971
1986
1979
REFERENCES
STATE OF TEXAS
CITY CURRENTS 10/86
CITY CURRENTS 10/86
STATE OF WISCONSIN
STATE Of WISCONSIN
CITY CURRENTS 10/86
KEY
COMBUSTOR TYPES:
MI/SA - MODULAR COMBUSTOR HITH STARVED AIR
MI/EA • MODULAR COMBUSTOR HITH EXCESS AIR (VICON)
ROf • REFUSE DERIVED FUEL FIRED IN DEDICATED BOILER
ROF/C • REFUSE DERIVED FUEL/COAL COFIRING
MB/OF - MASS BURN HI TH OVERFEED STOKER
MB/RC - MASS BURN IN ROTARY COMBUSTOR
TYPES OF CONTROLS:
C • CYCLONE
ESP - ELECTROSTATIC PRECIPITATOR
HS • HET SCRUBBER
OS - DRY SCRUBBER
VHS - VENTURI HET SCRUBBER
BAG * BAGHOUSE
EGB - ELECTROSTATIC GRAVEL BED
NA • DATA NOT AVAILABLE OR TECHNOLOGY UNDECIDED
-------
TABLE B-2. PLANNED FACILITIES ORDERED BY STATE AND DESIGN TYPE
TOTAL
LOCATION
CITY
JUNEAU
HUNTSVIllE
FAYETTEVILLE
SAN DIEGO (SANDER)
DOWNEY
LOS ANGELES CO. (PUENTE HILLS E)
LOS ANGELES CO. (PUENTE HILLS H)
SAN MARCOS (SAN DIEGO CO.)
LOS ANGELES CO. ISPADRA)
CITY OF COMMERCE (LOS ANGELES CO.)
UK1AH
IRH1NDALE
V1SALIA
BRISBANE
SOUTH GATE (LOS ANGELES)
FRESNO COUNTY
SANTA CLARA
STANISLAUS COUNTY
GARDE NA
LONG BEACH. STAGE 1
LONG BEACH. STAGE II
LANCER (LOS ANGELES)
NILMINCTON
VENTURA COUNTY
SANGER
FREMONT '
PLEASANT ON
SANTA CRUZ
ALAMEDA
RIVERSIDE
LOS GATOS
SACRAMENTO COUNTY
CONCORD
REDWOOD (SAN FRANCISCO)
SAN BERNARDINO
M1LIIKEN LANDFILL
A2USA
CONTRA COSTA COUNTY (RICHMOND)
COMFTON
NEW MIL FORD
MIDDLE TOWN
BRIDGEPORT
WATERBURY
BRISTOL
PRESTON
HAUINGFORD
NEW HAVEN
DANPURY
STRATFORD
STATE
AK
AL
AR
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CT
CT
CT
CT
CT
CT
CT
PT
I* I
CT
TYPE
MI/SA
MB/OF
MB/OF
MB/OF
MB/OF
MB/OF
MB/OF
MB/OF
MB/OF
MB/OF
MB/OF
MB/OF
MB/OF
MB/OF
MB/OF
MB/OF
MB/OF
MB/OF
MB/OF
MB/OF
MB/OF
MB/OF
MB/RC
MB/RC
MB/RC
MI/EA
MI/SA
NA
NA
NA
RDF
RDF
RDF
ROF
RDF
RDF
RDF
ROF
RDF
MB/OF
MB/OF
MB/OF
MB/OF
MB/OF
MB/OF
MI/EA
MI/SA
NA
NA
1^ AT
nt ft 1
RECOVERY
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
PI ANT
CAPACITY
(TPO)
70
690
ISO
2250
200
2000
2000
1672
1000
300
100
3000
350
1500
375
600
400
800
1200
920
1350
1600
2000
1000
500
480
100
175
1600
1500
200
700
900
3850
1600
1600
2000
900
1800
750
230
2250
360
650
600
420
450
450
360
STARTUP
DATE
NA
1989
NA
1989
NA
NA
NA
1989
NA
1987
1987
1989
1990
NA
1990
NA
NA
1989
1991
1988
NA
1989
1988
NA
1987
1989
NA
NA
1989
1990
HA
NA
1989
NA
1989
NA
1989
1989
NA
HA
1989
1988
1989
1988
1990
1988
1989
1990
1989
STATUS
CODE
3
4
3
2
3
2
2
4
1
4
2
3
1
1
1
3
3
4
3
4
3
3
4
0
2
4
2
1
2
1
5
1
1
3
3
2
0
4
CONTROL
STATUS
NA
NA
NA
HA
NA
NA
NA
NA
NA
NA
NA
HA
NA
HA
NA
NA
NA
HA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
HA
NA
HA
NA
NA
NA
NA
DS/BG
DS/BG
NA
DS/BG
NA
DS/BG
DS/BG
NA
NA
REFERENCES
McILVANE 5/86. HASTE AGE 11/86
CITY CURRENTS. 10/86
McILVANE 5/86, HASTE AGE 11/86
CI1Y CURRENTS 10/86
McILVANE 5/86
HASTE AGE
CHMB
CITY CURRENTS 10/86
CHMB
CITY CURRENTS 10/86
CITY CURRENTS 10/86
McILVANE 5/86
SCAMD SUBMITTAL
McILVANE 5/86
U.S. EPA
McILVANE 5/86
CITY CURRENTS 10/86
U.S. EPA
HASTE AGE
SCAMD SUBMITTAL
U.S. EPA
McILVANE 5/86
U.S. EPA
McILVANE 5/86
CITY CURRENTS 10/86
McILVANE 5/86
FRANKLIN
McILVANE 5/86
SCAMD SUBMITTAL
EPA REGION IV
SCAMD SUBMITTAL
CHMB
McILVANE 5/86, HASTE AGE 11/86
CHMB
McllVANE 5/86
HASTE AGE
HASTE AGE
HASTE TO ENERGY
McILVANE 5/86
CITY CURRENTS 10/86
EPA REGION VII SUBM1TTAL
CITY CURRENTS 10/86
SCAMO SUHMimi
CITY CURRENTS 10/86
McllVANE 5/86
FRANKLIN
CITY CURRENTS 10/86
-------
5-8
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B-7
-------
TABLE B-2. PLANNED FACILITIES ORDERED BY STATE AND DESIGN TYPE (Continued)
CD
i
CD
LOCATION
CITY
CORPUS CHRIST I
GAL VEST ON
GRAND PRAIRIE (IRVING)
ALEXANDRIA/ ARLINGTON
FAIRFAX COUNTY
PETERSBURG
PORTSMOUTH
RUTLAND
LYNOONVILLE
SPOKANE COUNTY
SNOHOMISH COUNTY
SKAGET COUNTY
KING COUNTY
TACONA
STATE
n
TX
TX
VA
VA
VA
VA
VT
VT
MA
•A
HA
HA
HA
COMBUSTOR
TYPE
NA
MA
NA
MB/OF
NA
RDF
ROf/C
NI/EA
NA
MB/OF
MB/OF
MB/RC
NA
RDF
HEAT
RECOVERY
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
TOTAL
PLANT
CAPACITY STARTUP STATUS CONTROL
(TPO> DATE CODE STATUS
SSO NA
I NA NcILVANE 5/86,
200 1992 3 NA Nell VANE S/86,
700-800 NA
975 1967
3000 1990
2400 1986
2000 1967
240 1987
NA NcILVANE 5/86.
NA CITY CURRENTS
NA NcILVANE 5/86
NA CITY CURRENTS
NA CITY CURRENTS
ESP CITY CURRENTS
200 NA 3 NA NcILVANE 5/86,
REFERENCES
HASTE AGE
HASTE AGE
HASTE AGE
10/86
10/86
10/86
10/86
HASTE AGE
11/86
11/86
11/86
11/86
1000 1990 2 NA NcILVANE S/86
1500 1992
NA HASTE TO ENERGY 9/25/85
ISO 1988 2 NA HASTE AGE
2000 1993
1 NA EPA REGION X
500 1988 4 NA FRANKLIN
KEY
COMBUSTOR TYPES)
Ml/SA MODULAR CONBUSTOR HITH STARVED AIR
MI/EA MODULAR COMBUSTOR HITH EXCESS AIR (VICON)
RDF REFUSE DERIVED FUEL FIRED IN DEDICATED BOILER
RDF/C REFUSE DERIVED FUEL/COAL COFIR1NG
MB/OF MASS BURN HITH OVERFEED STOKER
MB/RC MASS BURN IN ROTARY CONBUSTOR
NA DATA NOT AVAILABLE OR TECHNOLOGY UNDECIDED
STATUS CODE:
0 STATUS UNKNOHN
1 EARLY PLANNING STAGES
2 PERMITTING STAGES
3 CONTRACT AHARDED
4 CONSTRUCTION UNDERHAY OR EXPECTED SOON
S TESTING STAGES
CONTROL STATUS!
BH - BAGHOUSE
S - HATER SCRUBBER
ESP • ELECTROSTATIC PRECIPITATOR
AG - ACID GAS CONROL
OS • DRY SCRUBBER
-------
APPENDIX C*
SUMMARY MATRICES OF EMISSIONS TEST DATA
*The information presented in this appendix is from Reference 16, Municipal
Waste Combustion Study: Emissions Data Base for Municipal Waste Combustors,
-------
TABLE C-l. OVERVIEW OF EMISSION DATA BASE
Faci 1 i ty name
Mass burn3
Waterwal ID
ESPC
Bal t (more
Braintree
Ch i cago
Hampton (1981)
Hampton (1982)
Hampton (1983)
Hampton (1984)
Peek ski II (4/85)
Tulsa (Unit 1)
Tulsa (Unit 2)
CYC/FF
Gal latin
ESP/WS
Kure
SD/ESP
Munich
CYC/DI/ESP/FF
Mai mo
WSH/DI/FF
Quebec
Quebec
Quebec
Quebec
Wurzburg
SO/FF
Marion County
Quebec
Quebec
Refractory
ESP
Philadelphia (NW1)
Philadelphia (NW2)
CYC/ESP
Washington, O.C.
CYC
Mayport
MS
Alexandria
N ! cos i a
SO/FF
Tsushima
EG8
Pittsfield
Starved air
No controls
Cattaraugus County
Dyersburg
N. Little Rock
Prince Edward Island
Prince Edward Island
Prince Edward Island
Prince Edward Island
ESP
Tuscaloosa
Test Cr i ter i a
condition pollutants
Norma 1 d
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
MSW only*
Normal
no*
125'
MOf
200f
Normal
Normal
1409
140 4 Rn
Normal
Normal
Normal
I
MSM/waste oil*
Normal
Normal
Normal
Experimental-!
Normal
Normal
Normal
Normal
Long1*
High1
Low1"
Normal
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Acid
gases
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Metals
X
X
X
X
X
X
X
X
X
X
X
X
X .
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Organ ics
X
X
X
X
X
X
X
X
X
X
X
X -
X
X
X
X
X
X
X
X
X
X
X
X
X
X
(continued)
-------
TABLE C-l. OVERVIEW OF EMISSION DATA BASE (Continued)
Fac i 1 i ty name
RDF f i red
ESP
Akron
Albany
Hami 1 ton-Wentworth
Hami 1 ton-Wentworth
Hami 1 ton-Wentworth
Hami 1 ton -Went worth
Hami I ton-Wentworth
Hami 1 ton-Wentworth
CYC/ESP
Wright Pat. AFB
Wright Pat. AFB
CYC/DI/ESP/FF
Mai mo
Test
condition
Normal
Normal
F/Nonen
F/Low back0
F/Backp
F/Back, low
front**
H/Noner
H/Low '-icks
Norma
Dense RDFr
ROFU
Cr i ter i a
pollutants
X
X
X
X
X
X
X
X
X
Acid
gases
X
X
X
X
Metals Organ ics
X x
X X
X
X
X
X
X
- <
X
X
?Type of incinerator design.
^"ype of furnace.
°Emission control device(s) as follows: CYC * Cyclone; Dl - dry sortaent injection; SO =
spray dryer; EG8 * electrostatic granular bed; ESP * electrostatic precipitator; FF * fabric
.filter; WS » wet scrubber; and WSH » water spray humidifier.
Unit operated under normal conditions during tests.
*Unit burned MSM only during tests.
Gases entering the fabric filter were at the temperature specified in *C. .
^Normal operations: gases entering the fabric filter were at 140'C and normal lime feed ra*e
was used.
"Sorbent recycle was used. Gases entering the fabric filter were at 140*C.
'.Unit burned HSW and waste oil during tests.
rjUnit under normal conditions during experimental test program.
Unit operated under longer feed cycle to decrease demand on the tractor operator during
tests.
Unit operated with high secondary chamber temperature during tests.
mUnit operated with low secondary chamber temperatures during tests.
nUnit operated under full load with no overfire air.
°Unit operated under full load with only lower back overfire air ports open.
pUnit operated under full load with both back overfire air ports open.
qUnit operated under full load with both back and lower front overfire air ports open.
rUnit operated under half load with no overfire air.
'Unit operated under half load with only lower back overfire air ports open.
Unit burned densified RDF during tests.
uUnit burned RDF during tests.
-------
•TABLE C-2. OVERVIEW OF SUPPLEMENTARY EMISSION DATA BASE
Fac iIi ty name
Test condftion
Metals
Organics
Mass burn
WaterwaI I/ESP
Avesto
Iserlohn
MVA Lausanne
MVA Munich
Montreal (1982)
Montreal (1983)
Quebec (1981)
Umea (1984)
Umea (1985)
Zur i ch/Josephstrasse
Waterwa11/ESP/DS
Hamburg/StapeIfeId
MVA-I Borsigstrasse
MVA-II StelIinger M.
Waterwa11/OS/ESP/FF
Ma I mo
Waterwall/DS/FF
Avg Borsigstrasse
Waterwa11
Issy-les-Moulineaux
Saint-ouen
Ref ractory/SPRAY/ESP
Toronto I
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
X
X
X
X
X
Refractory/ESP
Brasschaat
Hare I beke
L i nkop i ng
Stuttgart
Zaanstad
Refractory
Beveren
Milan 1
Milan II
Starved air
None
Lake COM! Chan
CS/ESP
Schio
Schio
Fluid bed
FF
Eskjo
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal9
Unprocessed
Normal
X
X
X
X
X
X
X
X
X
X
X
X
aWaste separated to produce compost is termed processed. This is the normal operating
condition for this facility.
-------
APPENDIX D
MUNICIPAL WASTE COMPOSITION
-------
TABLE D-l. ASSUMED MSW COMPOSITION
Species
Carbon
Hydrogen
Sulfur
Nitrogen
Chlorine
Ash
Oxygen
Moisture
Weight Percent
26.73
3.60
0.12
0.17
0.12
22.38
19.74
27.14
Higher Heating Value
4500 Btu/lb.
-------
APPENDIX E
EMISSION CONTROL COST TABLES
-------
TABLE E-l.
SUMMARY OF
SYSTEMS FOR
($l,OOOs 1n
ESTIMATED CAPITAL COSTS OF EMISSION CONTROL
NEW MODEL MUNICIPAL WASTE COMBUSTOR FACILITIES6
August 1986 based on 8,000 hrs/yr operation)
Mass burnlna Model facilities
Modular Model facilities
PM emission
level *ft«r
control.
nr/dscf at
121 CO,
Refusa-dar1ved fuel
LLLlfti -
250 tod
caoacttv
(Modal No.
1)
1.000 tpd
caoacttv
(Model No. 2)
3,000 tpd
caoacltv
(Model No. 3)
100 tpd
caoacttv
(Model No. 4)
250 tpd
caoacttv
(Model No.
5)
400 tpd
capacity
(Model No. 6)
l.SOO tpd
capacity
(Model No. 7)
3.000 tpd
capac 11 v
(Model No.8)
0.03
0.02
0.01
Soray Dryer/
£ SE-SjiiBiT
0.03
0.02
0.01
Spray Dryer/
1,549
1.951
2,252
4,108
4,589
4.668
3,900
4.693
5,$21
9.352
10.246
10.916
10.230
11,830
14.105
23.197
24.468
26.641
341
447
487
1.426
1.516
1.564
695
645
929
2.420
2.526
2,646
1.020
1.194
I 114
3.149
3.469
3,609
6,919
8.293
9.193
14,413
15,972
16.539
12.006
14.24S
15.881
25.91 7
27,423
28.069
0.03
0.02
0.01
4.242
4.242
4.421
8, 90S
6.905
9.463
21,691
21,691
23. 197
1,960
1,960
2,020
3.176
3.176
3.296
4,179
4.179
4.779
13.170
13,170
13.989
22.042
22,402
23. 119
*The caoltal cost estimates wara develooed for control systens at 125 percent of actual size and Include a 20 percent
contlnoencv factor.
'Sprav drver desloned for 90 and 70 percent control of HC1 and SO^. respectively.
-------
TABLE E-2.
SUMMARY OF ESTIMATED ANNUALI2ED OPERATING COSTS OF EMISSION
CONTROL SYSTEMS FOR NEW MODEL MUNICIPAL WASTE COMBUSTOR FACILITIES
(SlfOOOs In August 1986 based on 8.000 hrs/yr operation)
f'M emission
level After
control.
nr/d&cf «t
US CO,
N»»* Bur«l«a *odel
:ll ltle»
Modular e>bdel
I Itle*
Refuse-derived «u»l
UtJUtlBi
250 tpd
c«p«c Itv
(Model No.
11
1.000 tpd
c«««cltv
(Model No. 21
3.000 tpd
ceo«cItv
(Model No. 31
100 tpd
ceo«Cltv
(Model No. 41
250 tpd
c«eecltv
(Model NO.
51
400 tpd
c«o«cItv
(Model No. 61
1000 tpd
c«p«c I ty
(Model No. 7)
3.000 tpd
ctftc I Iy
(Model No.81
0.0)
0.02
0.01
Snrty Orver/
0.0)
0.02
0.01
Sprty Oryer/
370
443
499
1.061
1.156
1.212
921
1.067
1.220
2.529
2.706
2.839
2.449
2,744
3.163
6.SIS
6.771
7.198
90
110
117
360
396
408
162
190
206
645
666
691
229
261
26)
858
925
949
1.86S
2,1 18
2.284
4.278
4,6)2
4,700
3.348
3,761
4.063
_>.876
8,1/6
8,SOS
0.0)
0.02
0.01
l.HS
I.MS
1.150
2.S49
2.549
2.661
6.5)6
6.540
6.638
496
496
510
825
825
•49
1.110
1.110
1.229
4.198
4,199
4,362
7,442
7.444
7.637
*Spr»v drver detloned (or 90 «nd 70 percent control of MCI «nd SO^. respectively.
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TABLE E-3. SUMMARY OF ESTIMATED CAPITAL COSTS OF EMISSION COMTROL SYSTEMS FOR
EXISTING MODEL REFRACTORY MUNICIPAL WASTE COMBUSTOR FACILITIES
(SlOOOs In August 1986 based on 6,500 hrs/yr operation)
Control Dovtc*
Mass Burn 1 I—Modular--1
200 tpd 4SO tpd 600 tpd 7SO tpd 1200 tpd 100 tpd
capacity capacity capacity capacity capacity capacity
(Mod*! No. 1) (Mod*! No. 2) (Mod*! No. 3) (Mod*! No. 4) (Mode! Mo. 5) Modal No. 6)
ESP SystM*
Dry Scrubber Systwa
Dry Scrubb*r/ESP SystM *'b
Dry Scrubber /Fabric FllUr
SystM a'b
6.335
11,346
6. DOS
11.062
6.879
12,726
10.32S
18.745
526
2.619
*0.02 gr/dscf corr*ct*d to 12 p«rc*nt CO^.
°90 and 70 p*rc*nt reduction of HC1 and S02, r«sf«ctlw*ly.
-------
TABLE E-4. SUMMARY OF ESTIMATED ANNUALIZED OPERATING COSTS OF EMISSION CONTROL SYSTEMS FOR
EXISTING MODEL REFRACTORY MUNICIPAL WASTE COMBUSTOR FACILITIES
(SlOOOs In August 1986 based on 6,500 hrs/yr operation)
Control Device
I Mass Burn
200 tons/day 450 tons/day 600 tons/day 750 tons/day
capacity capacity capacity capacity
(Model No. 1) (Mod*I No. 2) (Model No. 3) (Model No. 4)
1
1200 tons/day 100 tons/day
capacity capacity
(Mode) No. 5) (Model No. 6)
Esp Syste»*
Dry Scrubber Syste* b
Dry Scrubber/ESP Syste» *'b
Dry Scrubber/Fabric Filter
System X75
1.478
2.686
1,669
2.692
1,941
3,124
2,884
4.597
123
645
*0.02 gr/dscf corrected to 12 percent O>2.
b90 and 70 percent reduction of HC1 and SO-, respectively.
-------
TABLE E-5. SUMMARY OF ESTIMATED CAPITAL COSTS OF EMISSION CONTROt SYSTEMS
FOR MODEL EXISTING WATERWALL MJNICIPAL WASTE COMBUSTOR FACILITIES
(SlOOOs In August 1986 based on 6,500 hrs/yr operation)
I Ha*» Burn II ModuUi II RDF I
200 tpd 400 tpd 1000 tpd 2200 tpd 100 tpd 200 tpd 300 tpd 1000 tpd 2200 tpd 3000 tpd
capacity capacity capacity capacity capacity capacity capacity capacity capacity capacity
Control Device (Hod*! No.l) (Model Mo.2) (Model Mo.3) (Mod*I Mo.4> (Modal Mo.5) (Mod*! Mo.6) (Model Mo.7) (Model Mo.6) (Model No.9) (Model No.10)
ESP Syste»*
Dry Scrubber
Syste»b
Dry Scrubber
ISP Syst*»*'b
Dry Scrubber/
Fabric Filter
3.063
4.544
S.997
8.S39
9,901
18.690
487
763
999
14.353
10.202
12.926
19.492
2.S51
3,853
4.865
25,307
19.189
22.090
34.058
*0.02 gr/dscf corrected to 12 percent (X>2.
b90 and 70 percent reduction of HC1 and S02, respectively.
-------
TABLE E-6. SUMMARY OF ESTIMATED ANNUALIZED OPERATING COSTS OF EMISSION CONTkUl
FOR MODEL EXISTING WATERWALL MUNICIPAL WASTE COMBUSTOR FACILITIES
($1000s in August 1986 based on 6,500 hrs/yr operation)
I MMS Burn I I Modular 1 I ROf 1
200 tpd 400 tpd 1000 tpd 2200 tpd 100 tpd 200 tpd 300 tpd 1000 tpd 2200 tpd 3000 tpd
capacity capacity capacity capacity capacity capacity capacity capacity capacity capacity
Control D«vlc« (Model Ho.l) (Nodal No.2> (Model Mo.3) (Model No.4) (Model No.S) (Model No.6) (Model Mo.7) (Mod*) Mo.8) (Model No.9) (Modal No.10)
ESP Systeei* ll5
Dry Scrubber
Systa»b 810 1.222 2.724 4.27B
Dry Scrubber/
ESP Syste.4'5 "8
Dry Scrubber/
fabric Filter
Syiteei*'" 1.399 2.030 4.506 6.543
177 224
3., " 4.S74 6.3SO
884 1.124
4.676 6.458 9.SS8
*0.02 gr/dscf corrected to 12 percent O>2.
b90 and 70 percent reduction of HCl and S02. respectively.
-------
APPENDIX F
SUMMARY OF SYMBOLS, ACRONYMS, AND
ABBREVIATIONS
-------
TABLE F-l. SUMMARY OF SYMBOLS, ACRONYMS, AND ABBREVIATIONS
Symbol Meaning
As Arsenic
BaP Benzo(a)pyrene
Be Beryl 1i urn
Cd Cadmium
CDD Chlorinated dibenzo-para-
dioxins
CDF Chlorinated dibenzo furans
CO Carbon monoxide
C02 Carbon dioxide
Cr Chromium
ESP Electrostatic precipitator
HC1 Hydrogen chloride
HF Hydrogen fluoride
Hg Mercury
Ni Nickel
NO Nitrogen oxides
A
NSPS New source performance
standards
02 Oxygen
Pb Lead
PCB Polychlorinated biphenyl
PCDD Polychlorinated dibenzo-p-
dioxins
-------
TABLE F-l. SUMMARY OF SYMBOLS, ACRONYMS, AND ABBREVIATIONS (Continued)
PCDF Polychlorinated dibenro-
furans
ppb Parts per billion
RfO Risk Reference Dose
RDF Refuse-derived fuel
SASS Source assessment sampling
system
SCR Selective catalytic
reduction
S02 . Sulfur dioxide
TCDD Tetrachlorodibenzo-p-dioxins
TEF Toxic equivalency factor
TCDF Tetrachlorodibenzofurans
TPD Tons per day
-------
APPENDIX G
LIST OF CONVERSION FACTORS
-------
TABLE G-l. LIST OF CONVERSION FACTORS
Multiply
mg/Nm3 a
m
m /min
m/s
kg/h
kPa
1pm
kg/Mg
By
4.37 x 10"4
10.76*
35.31
3.281
2.205
4.0
0.264
2.0
Temperature conversion equations
°F - (9/5)*°C + 32
°C - (5/9)*(°F - 32)
To obtain
gr/dscfb
ft2
ft3/min
ft/s
Ib/h
in. of H20
gal/min
Ib/ton
aNormal conditions on a dry basis are 1 atm and 20 C.
Dry standard conditions are 1 atm and 68°C.
-------