United States
Environmental Protection
Agency
Hazardous Waste Engineering
Research Laboratory
Cincinnati OH 45268
. * A i.
/ I \
Research and Development
EPA/600/S2-85/030 May 1985
SOW Project Summary
Evaluation of Hazardous Waste
Incineration in an Aggregate
Kiln: Florida Solite Corporation
D. R. Day, L. A. Cox, J. A. Peters, and R. E. Mournighan
Aggregate kiln incineration of chlo-
rinated liquid organic waste was investi-
gated in a one-week program at Florida
Solite Company. POHCs (toluene, tetra-
chloroethylene, methyl ethyl ketone,
and methyl isobutyl ketone) were mon-
itored in waste and stack emissions. In
addition, stack emissions were mon-
itored for particulate matter, particulate
trace metals, HCI, S02, and NO,. Proc-
ess samples were collected and ana-
lyzed for trace metals and chloride. The
destruction and removal efficiency of
POHCs and the fate of trace metals and
chloride ion in the kiln process were
determined.
Consistent achievement of greater
than 99.99% ORE was demonstrated
for each POHC. Emissions of other
pollutants ranged as follows: particu-
lates4.4 to 6.5 kg/hr; HCI0.008 to
0.034 kg/hr; SO2-72.2 to 99.6 kg/hr;
NOx-1.9 to 11.7 kg/hr. Between 60
and 90% of the element chlorine is fed
to the kiln from the waste fuel and
scrubber influent water, while 95% of
the chlorine is discharged from the
process as chloride ion in the scrubber
effluent water.
This Project Summary was developed
by EPA's Hazardous Waste Engineering
Research Laboratory, Cincinnati, OH,
to announce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Introduction
Cofiring of hazardous wastes in high
temperature industrial processes is an
attractive alternative to hazardous waste
incineration. The alternative makes use
of the waste's heat content. Manycofiring
processes, which include cement and
dolomite kilns, glass furnaces, steel fur-
naces, and some industrial boilers, pro-
vide temperatures and residence times
similar to those required for incinerators
dedicated to incineration of hazardous
wastes. In addition to the savings derived
from the heat value, the use of existing
industrial equipment does not require the
capital required if a separate incinerator
to process a given amount of hazardous
waste is to be built, and it may provide an
environmentally acceptable alternative to
conventional hazardous waste disposal.
Aggregate kilns, because of their high
energy use, are an excellent example of
this concept. Such kilns typically operate
at temperatures over 1100°C (2000°F),
have gas residence times in excess of 1.5
seconds, and have a highly turbulent
combustion zone. However, the need
exists for data that shows the effect of
cofiring hazardous waste on the emis-
sions from the aggregate process.
The sampling and analysis program
included evaluation of: {!) the effects of
cofiring coal and waste fuel on the
destruction and removal efficiency (ORE)
of principal organic hazardous constit-
uents (POHCs); (2) the concentrations of
particulate matter, SOZ, NO*, HCI, and
metals in stack emission, and (3) the
concentration and fate of metals and
chlorine in the process streams.
Facility and Process Description
The Florida Solite Company operates
an aggregate kiln in Green Cove Springs,
Florida, which is located approximately
20 miles south of Jacksonville. Annual
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production of the expanded lightweight
inorganic material used as aggregate in a
cement mix is approximately 5.45 x 107
kg (60,000 tons) per year.
This industrial process involves the
heating of clay to 1100°C in a horizontal
rotary kiln to prepare an expanded light-
weight inorganic material used as aggre-
gate in cement mix.
The kiln, with refractory linings, is 2.7m
(9 ft) in diameter and 45.7m (150 ft) long.
The kiln rotates slowly (90 revolutions per
hour), has a gentle slope (6.25 cm/m) to
allow material to pass through by gravity.
The kiln operates in a counter current
flow pattern; i.e., solid materials travel in
one direction and hot gases and dust
travel in the opposite direction. Clay is fed
into the kiln at the upper end at a rate of
approximately 12,260 kg/hr (27,000 Ib/
hr). At the opposite end of the kiln, a
mixture of coal and waste fuel is burned
at rates of approximately 700 kg/hr
(1,540 Ib/hr) and 0.87 rnVhr (230 gal/
hr), respectively, to provide a heat i nput of
approximately 220 kw(0.74 million Btu/
hr). As the clay feed travels down the
inclined rotating kiln, it passes through
various temperature ranges which cause
transformation of the clay into the light-
weight aggregate product. The light-
weight aggregate is produced at a rate of
approximately 9,080 kg/hr (20,000 Ib/
hr). After heating and transformation in
the kiln, the aggregate is graded and large
clumps are crushed for sizing. The final
product is stored in large piles until sold.
The kiln exhaust gases pass through a
pair of mechanical dust collectors, whose
dust is recycled into the kiln, then into a
horizontal cross-flow water scrubber of
fiber-reinforced-plastic (FRP) construc-
tion. The series of water sprays cleans the
particulate matter and reduces the gas
temperature from about 370°C to 70°C
(700°F to 160°F) before the gases reach
the knockout chamber and fiberglass
stack. The scrubber discharge released
from the knockout chamber is a mixture
of raw steam and water with the en-
trapped particulate matter. This discharge
stream is released to an open ditch which
drains to a pond. There is no recycle of the
scrubber water.
The fuel used to fire the kiln is an
unblended combination of crushed coal
and waste organic liquids. The liquid
wastes, which are trucked directly from
the generators, consist primarily of sol-
vents, alcohols, ethers, still bottoms, and
a small fraction of chlorinated hydrocar-
bons. Any manifested wasteload that
contains pesticides, PCBs, acids, caustics,
cyanides, sulfides, mercaptans, electro-
plating wastes, or metal finishing wastes
is rejected and returned to the generator.
The organic waste mixture makes up
from 50% to 100% of the fuel used.
During the test period, the waste fuel
made up approximately 54% of the total
fuel input.
Experimental Program
The sampling and analytical program
was designed to identify the major pol-
lutants from burning waste fuel in an
aggregate kiln, quantify their respective
emission rates, determine the destruction
and removal efficiency (ORE) of the
POHCs, and provide information for a
mass balance around the process for
metals and chlorine. Measured stack
pollutants include POHCs (toluene, tetra-
chloroethylene, methyl ethyl ketone, and
methyl isobutyl ketone), particulate mat-
ter, particulate trace metals, carbon di-
oxide, hydrogen chloride, sulfur dioxide,
and nitrogen oxides. In addition, the
distribution of the metals andthe element
chlorine were measured in all of the
process input and output streams; i.e.,
the coal feed, waste fuel feed, clay feed,
scrubber influent water, aggregate prod-
uct, and scrubber effluent water. Waste
fuel and coal samples were submitted for
analyses of sulfur, ash, and Btu content.
Waste fuel and scrubber effluent water
also were analyzed for principal organics.
Table 1 summarizes the overall test
program and lists each sampling and
analytical method used.
Results and Discussions
Waste Fuel
A detailed summary of the waste fuel
composition for two waste fuel samples
collected is shown in Table 2. Tables 3
and 4 show the concentration of each
POHC and other properties for the five
waste fuel samples (one sample per day.
Runs 1-5).
POHC Destruction and Removal
Efficiencies
The complex combustion chemistry for
organic materials becomes perplexing
when a broad range of organic com-
pounds present in a liquid waste are
burned. On a weight basis, most of the
organic carbon in the waste is oxidized to
C02 in the combustion process, but trace
amounts of organic chemicals survive the
oxidation process.
The four POHCs were sampled in the
exhaust gas by the volatile organic sam-
pling train (VOST) and analyzed by gas
chromatography/massspectrometry(GC/
MS). Due to sampling and analysis prob-
lems, the number of acceptable VOST
runs made each day are as follows: day
1 0 runs; day 26 runs; day 36 runs;
day 48 runs; day 55 runs. The average
and range for DRE is shown in Table 5.
Methyl ethyl ketone was destroyed and
removed to at least 99.99% efficiency.
Only three runs showed DREs less than
99.999%: Runs 4A, 3A3, and 3B3. Runs
3A3 and 3B3 were side-by-side runs (with
3A and 3B) that were split with the EPA
QA contractor. Runs 3A3 and 3B3 do not
show good comparison with Runs 3A and
3B for MEK, possibly owing to high blank
contamination problems on the QA con-
tractor field blanks. Run 3B3 is an outlier
and is not considered a significant part of
the data. The overall DRE average for
MEK for all 5 days was 99.998% ±
0.006% (95% confidence limits).
DREs for methyl isobutyl ketone (MIBK)
ranged from 99.986% to > 99.999%. The
99.986% value was the only DRE less
than 99.992%. The overall average for
MIBK was 99.998% ± 0.006% (95%
confidence limits).
DREs for tetrachloroethylene (Perc)
ranged from 99.993% to > 99.999%.
Excellent consistency was found for each
day of sampling. Split samples on Day 3
(Runs 3A3, 3B3, and 3D1) all showed low
relative difference. The overall DRE av-
erage for Perc was 99.997% ± 0.004%
(95% confidence limits).
DREs toluene ranged from 99.995% to
>99.999%. The overall average for tolu-
ene was 99.999% ± 0.002% (95% confi-
dence limits), making toluene the easiest
POHC to destroy and remove.
Stack Samples
Results for particulates, hydrogen chlo-
ride, sulfur dioxide, and nitrogen oxides
are summarized in Table 6. The stack rate
averaged 652 mVmin (23,320 ftVmin)
and the dry stack rate averaged 419
dscm/min (14,780 dscf/min). Particulate
emissions of 5.3 kg/hr (11.7 Ibs/hr) were
less than air permit regulations for this
site issued by the Florida Department of
Environmental Regulations (DER) of 8.82
kg/hr (19.43 Ib/hr). The first SO2 test
result had a low value of 270 ppm and is
considered an outlier when compared to
the remaining seven SO2 test results
which ranged 1,030 to 1,470 ppm. The
low NOx value of 40 ppm was expected as
it occurred on Day 3 during startup of the
kiln.
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Table 1 . Summary of Florida So/its Aggregate Kiln Sampling and Analytical Program
Parameter Sampling Method Analytical Method
Stack Gas
POHCs (tetrachloroethylene.
toluene, MEK. MIBK)
Paniculate matter
Metals on paniculate
Hydrogen chloride
COzandOt
Nitrogen oxides
Sulfur dioxide
Waste Fuel
Principal organics
Metals
Chlorine, sulfur
Btu content
Ash content
Scrubber Discharge"
POHCs
Metals
Lead
Hexavalent chromium
Chlorine
Aggregate Product
Metals
Chlorine
Clay Feed
Metals
Chlorine
Coal
Metals
Chlorine, sulfur
Btu and ash content
Scrubber Influent
Metals
Chlorine
Volatile organic sampling
train (VOST)
EPA 5
EPA 5
Impinger absorption in 0.5 M
NaoAc (back half of EPA 5)
EPA 3
EPA 7
EPA 6
Grab composite
Grab composite
Grab composite
Grab composite
Grab composite
Grab composite
Grab composite
Grab composite
Grab -* composite
Grab composite
Grab composite
Grab composite
Grab composite
Grab composite
Grab composite
Grab composite
Grab composite
Grab composite
Grab composite
GC/MS, thermal desorption
and SIM
EPA 5
ICP
Specific ion electrode
Fyrite
EPA 7
EPA 6
GC/MS
ICP
XRF
ASTM D240-64
ASTM D482-IP4
GC/MS
ICP
AAS
APHA312B
XRF
ICP
XRF
ICP
XRF
ICP
XRF
ASTMD240-64
ICP
XRF
HCI 0.008 to 0.034 kg/hr;S02 72.2
to 99.6 kg/hr; and N0» 1.9 to 11.7
kg/hr.
Approximately 60-90% of the element
chlorine is fed to the kiln from the
waste fuel, while virtually all the
element is discharged from the process
as chloride in the scrubber effluent
water.
The major percentage of metals is fed
to the kiln from the clay feed and waste
fuel, while the major percentage of the
metals leave the process in the ag-
gregate product and scrubber effluent.
Very little is discharged to the air.
'The scrubber discharge was split into sludge and supernatant fractions and was analyzed
separately where applicable.
Conclusions
The results of the program were as
follows:
The aggregate kiln appears to be
suitable for destruction of the type of
hazardous waste tested in this pro-
gram. DRE and HCI met the RCRA
subpart 0 incinerator standards.
Emissions of conventional pollutants
were determined and ranged as fol-
lows: particulates4.4 to 6.5 kg/hr;
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Table 2.
Results of Capillary GC/MS A nalysis of Major Components of Waste Fuels Number 1
and Number 4
Waste Fuel Component
Ethanol
2-Propanol
1 -Butanol
Ethyl acetate
Methyl ethyl ketone (POHC)
Methyl isobutyl ketone (POHC)
Toluene (POHC)
Tetrachloroethylene (POHC)
Ethylbenzene
Xylene fisomer No. 1)
Styrene
Xylene (isomer No. 2)
2-Ethoxyethyl acetate
Cs-Benzene (isomer No. if
Cs-Benzene (isomer No. 2f
C ' 10- Alkane (isomer f
Cti-Alkane (isomer f
n-Propyl acetate
2-Propanol, 1 -(2-methoxy-1 -methylethoxyl-isomer No. 1
2-Propanol, 1 -(2-methoxy-1 -methylethoxyj-isomer No. 2
2-Cyclohex 4-1 -one, trimethyl (isomer)
Concentration,
wt%
Number Number
1" 4'
1.55
4.55
1.78
0.68
2.03
1.52
8.40
0.19
1.23
4.47
0.71
1.29
2.03
0.47
0.57
0.83
0.72
1.50
0.46
0.49
1.28
1.83
1.97
0.77
0.72
2.81
1.12
8.06
0.07
2.28
7.89
0.28
2.52
1.20
0.33
0.35
0.76
0.60
1.00
0.14
0.16
0.54
"Average of split sample.
"Compounds containing three carbons associated with a benzene ring.
"^Compounds containing ten carbons associated with an alkane.
^Compounds containing eleven carbons associated with an alkane.
Table 3.
POHCs in Waste Fuel
Waste fuel concentration,'
Waste fuel mass rate (W\,J, g/min
POHC
Methyl ethyl ketone
Methyl isobutyl
ketone
Tetrachloroethylene
Toluene
1
1.99
1.53
0.19
8.38
2
1.78
1.70
0.19
9.27
3
1.83
1.41
0.17
8.21
4
2.81
1.12
0.06
7.99
5
4.25
3.90
0.03
7.54
1
332
255
31
1.397
2
390
373
43
2,033
3
254
195
24
1,137
4
328
131
7
932
5
564
518
4
1,000
Table 4.
Waste Fuel Conditions
Run
number
1
2
3
4
5
Chlorine.
%
1.08
1.08
1.04
0.55
0.55
Sulfur,
%
0.41
0.41
0.39
0.26
0.42
PCB
ppm
ND'
10
ND
ND
ND
Heat value,
Btu/lb
12,550
1 1,450
12.740
9,530
12,670
Ash.
%
7.74
7.28
7.47
15.5
6.18
Specific
gravity,
g/cc
0.966
0.922
0.978
1.07
0.966
Feed
rate.
gal/min
4.56
5.84
3.74
2.88
3.63
Mass rate.
g/min
16.670
21,930
13,850
1 1.660
13.270
"NOnot detected, detection limit -0.1 ppm.
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Table 5. Destruction and Removal Efficiencies of POHCs
Run
number
Day 2
Range
Average
Day 3
Range
Average
Day 4
Range
Average
DayS
flange
Average
Overall
A verage
POHC 1
(MEK)
99.999
>99.999
99.999
99.968
99.999
99.992
99.998
99.999
99.999
99.999
>99.999
99.999
99.998
DRE.%
POHC 2
(MIBK)
99.999
>99.999
99.999
99.998
99.999
99.999
99.986
99.998
99.995
99.999
99.999
99.999
99.998
Table 6. Average Results for Stack Gas, Particulates, HCI,
Parameter and Unit
Stack rate, m3/min
Stack moisture. %
Stack velocity, m/sec
Particulates
mg/dscm
kg/hr
HCI, ppm
SOa ppm
NO* ppm
Range
623 - 673
21.5 - 28.8
16.6 -17.1
163 - 273
4.4 - 6.5
0.15 - 0.68
270 - 1.470
40 - 227
POHC 3 POHC 4
(Perc) (Toluene)
99.999 99.999
>99.999 >99.999
99.999 99.999
99.998 99.999
99.999 99.999
99.999 99.999
99.993 99.995
99.998 99.999
99.997 99.998
99.991 99.998
99.997 99.999
99.995 99.999
99.997 99.999
SOa and NO* Emissions
Standard
Average Deviation
652 19
26.2 3.3
16.8 0.2
215 48
5.3 1.0
0.46 0.22
1,130 380
162 67
*U.S.GOVERNAAENTPRINTINGOmCE:1985/5» 111/10837
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D. R. Day, L A. Cox, and J. A. Peters are with Monsanto Research Corporation,
Dayton, OH 45407.
Robert Morningham is the EPA Project Officer (see below).
The complete report, entitled "Evaluation of Hazardous Waste Incineration in an
Aggregate Kiln: Florida Solite Corporation." (Order No. PB 85-189 066/AS;
Cost: $13.00, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Hazardous Waste Engineering Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
OCOC329 PS
220 S OEAR3CRN STREET
CUCAGO IL 60604
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