v-xEPA
United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Research Triangle Park NC 27711
Research and Development
EPA-600/S7-81-134 Aug. 1981
Project Summary
Source Test and Evaluation
Report: Cane Run Unit No. 6,
Louisville Gas and Electric Co.
L. L. Scinto, R. F. Maddalone, D. K. McNeil, and J. A. Wilson
A comprehensive multimedia emis-
sions assessment was performed on a
coal-fired boiler equipped with electro-
static precipitators (ESPs) and a dual-
alkali flue gas desulfurization systetem.
Levels 1 and 2 sampling and analysis
procedures were used to characterize
pollutant emissions in gaseous, liquid,
and solid waste streams. Flue gas pollu-
tant concentrations were measured at
the inlet and outlet of both control de-
vices.
Flue gas emissions after scrubbing
had the following criteria pollutant load-
ings: 273 ng/J So2, 419 ng/J NO, (as
N0« at 88 percent load), 39 ng/J CO,
7.46 ng/J total particulate, 3.8 to 4.3
ng/J total organics, and <0.3pg/J
lead. Scrubbing efficiency for SOt was
88 percent. Particulate removal effi-
ciencies were 99.7 percent across the
ESPs and 19 percent across the
scrubbers for a total removal efficiency
of 99.86 percent. Participates (exclusive
of sulfuric acid aerosol) less than 3 i/m
in diameter accounted for 59 percent by
weight of total particulate emissions.
Emissions of primary sulfates averaged
6.6 ng/J, or 2 percent of total sulfur
species emitted. Primary sulfate re-
moval efficiencies were 48 percent
across the ESP and 77 percent across
the scrubber. Particulate sulfate emis-
sions after scrubbing accounted for
approximately 50 percent by weight of
total particulate emissions, with about
10 percent of this particulate sulfate
ascribed to entrainment of scrubber
liquor. Elements in stack emissions
which may be of environmental concern
include As, Cr, and Fe. Specific anion
analyses for nitrate, chloride, and fluo-
ride showed that these emissions aver-
aged 0.0018, 0.175, and 0.122 ng/J,
respectively. Neither chloride nor fluo-
ride emissions appeared to pose a
health hazard. Numerous compounds of
polycyclic organic matter were identi-
fied in the air emission. Phenanthrene
was present at the highest concentra-
tion, but was not deemed to pose a sig-
nificant health hazard.
The two liquid streams discharged
from the site showed concentrations of
Al, Ca, Cd, Fe, Mn, Ni, P, and Pb at levels
of potential environmental concern.
However, in most cases, the levels dis-
charged to the river were not
significantly different from those found
in makeup water obtained from the
river. Only Ca content increased appre-
ciably from makeup to discharge. Total
organic content of the discharges
ranged from 0.002 to 0.290 mg/l.
Waste solids consisted of three col-
lected ash streams and scrubber filter
cake. The ashes contained several
elements of potential health and ecolog-
ical concern including Al, As, Ca, Fe,
and Mn, but few organics (0.04-0.48
mg/kg). Filter cake contained more
organics (19.22 mg/kg), but fewer
elements appeared to be of environ-
mental concern.
This Project Summary was develop-
ed by EPA's Industrial Environmental
Research Laboratory, Research
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Triangle Park. NC, 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
Louisville Gas and Electric Co. owns
and operates the Cane Run generating
station, in Jefferson County, KY, about
13 km southwest of Louisville on the
east bank of the Ohio River. The power
station consists of six coal-fired
generating units with a total peak
capacity of 1040 MW. Unit No. 6, a
tangentially fired dry-bottom boiler,
equipped with electrostatic precipita-
tors (ESPs) and a dual-alkali flue gas
desulfurization (FGD) system, was
tested in this program. Cane Run No. 6
is a 300 MW gross peak capacity boiler
developed by Combustion Engineering.
It was placed in service in 1969. It is
nominally rated at 280 MW and has a
continuous rating of 300 MW. Its
minimum controllable rating is 60 MW,
and its annual average load has been
about 180 MW. The unit normally fires
Western Kentucky No. 9, a high-
slagging eastern bituminous coal,
which limits the time the unit can
operate at high load. The coal is quite
variable in composition. Ash content
varies from about 16 to 25 percent and
fuel sulfur varies from 3.5 to 6.3 percent
(dry bases). Particulate emissions are
controlled by two single-stage Buell
ESPs installed in parallel in a cold-side
configuration. SOz emission control is
provided by a dual-alkali FGD system
developed by Combustion Equipment
Associates, inc., and Arthur D. Little,
Inc.
The principal waste streams from the
plant are flue gas, ash, scrubber filter
cake, ash pond overflow, and discharge
from a liquid sump in the scrubber
circuit. Bottom ash, fly ash, and
economizer ash are sluiced to an ash
pond which also accepts ash and scrub-
ber sludge from two other units at the
site. Overflow from the pond and the
liquid waste from the scrubber circuit
are discharged into the Ohio River.
Dewatered filter cake is sent to a sepa-
rate on-site disposal area. Figure 1 is a
simplified process flow diagram show-
ing emission streams and sampling
locations.
Summary and Conclusions
Level 1 flue gas sampling was con-
ducted with the boiler operating at s
constant load of 265 MW (gross), 8£
percent of maximum capacity. Subse-
quent tests were performed while the
boiler operated at lower loads, fluctua-
ting from 170 to 249 MW. Approximate-
ly 30 percent excess air was used to
combust the coal which, based on
several analyses, was quite variable
over the course of the test program. Coal
ash and sulfur contents averaged 16
and 3.8 percent, respectively, during the
test period. During Level 1 tests, one of
the oil reheaters in the scrubber system
was not in operation. Observations indi-
cated that poor combustion conditions
were common in one of the reheaters
during the entire test period. On some
Oil
Coal
Economizer
,, Boiler ^Ln
UJ -0
r^ »
1 M'r Heater \ H^l rjl
X ll>. 1 ».
V/ * tSP * Hen
Flue Gas Modules Moc
Bottom > A and B * A at
Ash
1 ' Flv [7]
Ash ^
Pond Spent
,, .. Snrnhhpr
Ash Solution
Pond (To)
Overflow \s\ ,
T . "n-1 Lime
Carbide 1 ^ Reaction
Lime Tanks
i i Sample Location
1 ' and Number
i Jt
//ue 6 as
_ , Emission
Air . Reheater Reheater ^ A/r A
A B ]
[7?? R / \
' ' ' i/l
ibber i ' L ,1
/I//05 ?A i 1-JsfacAl
7 \^
TlHtiHtihtsi [^
VVact/u/n
f/'/fers
Filter
Cake
R
1 JSump
Discharge
Figure 1. Simplified process flow diagram of Cane Run No. 6.
2
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Level 2 test days, the scrubber system
was operated in an "acid cleaning"
mode which resulted in reduced SO2
removal. This clouded interpretation of
Level 2 sulfur species analyses.
Flue gas emissions are summarized
in Table 1. Sulfur emissions data indi-
cate an S02 scrubbing efficiency of 88
percent. Primary sulfate removal effici-
encies were 48 percent across the ESP
and 77 percent across the scrubber.
Paniculate sulfate emissions after
scrubbing accounted for approximately
50 percent by weight of total particulate
emissions, with about 10percentof this
particulate sulfate ascribed to entrain-
ment of scrubber liquor.
NOX was determined at 88 percent
boiler load. These emissions averaged
over 400 ng/J, which is considered
high relative to other sources of this
type.
CO data showed high variability. A
100 percent increase in average emis-
sions (from 19 to 39 ng/J) was experi-
enced across the scrubber. The increase
pan be attributed to poor combustion
conditions in the oil reheaters.
Total particulate data indicated an
ESP removal efficiency of 99.7 percent.
A further reduction of 19 percent is
made by scrubbing. At the ESP inlet, 53
percent by weight of the particulate was
larger than 10//m, 29 percent was 3-10
fjm, 17 percent was 1 -3 /urn, and 1 per-
cent was smaller than 1 Aim. At the ESP
outlet, 9 percent of the particulate was
larger than 10/um, 15 percent was 3-10
/jm, 49 percent was 1 -3/urn, and 27 per-
cent was smaller than 1 yum. Of the
particulate emissions to the
atmosphere, 41 percent were larger
than 3 um, while 59 percent were less
than 3 /um in diameter. Size distribution
data obtained with an MRI impactor
indicate that about 7O percent of the
particulate (including HgSOi aerosol)
emissions to the atmosphere were less
than 1 /urn in diameter and capable of
deep lung penetration.
Total organic emissions at the scrub-
ber outlet ranged from 3.8 to 4.3 ng/J,
and were composed primarily of Ci-C6
organics. As with some other
pollutants, organic emissions increased
across the scrubber, most likely due to
inputs from the oil-fired reheaters. Poly-
cyclic organic matter (POM) was found
to some extent in all three flue gas
streams, but was by far most prevalent
at the scrubber outlet. Phenanthrene
had the highest concentration (37
of the 17 POM compounds
Table 1. Average Flue Gas Emissions
Pollutant
Emission Factor, ng/J
ESP Inlet
ESP Outlet
Scrubber Outlet
S02a
Primary Sulfate"
/VOx (as NOz at
88% loadf
CO"
Total Paniculate"
Total Organics'
N03~e
crs
r°
2270 ± 250h
56
408 ± 25
19 ±20
3260
0.87 - 1.4
0.0126-0.0359
2.88
4.26
2250 ± 240
29
404 ± 13
19 ±20
9.20
1.8-2.3
0.0016
2. 98 ±0.60
3.37 ± 0.81
273 ± 75
6.6
419 ±25
39 ± 15
7.46
3.8 - 4.3
0.0018
0.1 75 ±0.065
0.122 ±0.017
^Determined by pulsed fluorescence (Level 2).
toBest estimates based on combined data obtained with the CCS, SASS, and MRI
impactor.
^Determined by chemiluminescence (Level 1).
^Determined by non-dispersive infrared (NDIR) analysis (Level 1).
^Determined with the SASS (Level 1). Nitrate was determined by extraction of the
SASS particulate catch (Level 2).
'Ci-Ci6 fractions were determined by gas chromatography; >Cie fraction was deter-
mined gravimetrically (Level 1).
Determined with the CCS (Level 2).
"Dafa expressed asT± s are mean ± 1 standard deviation.
found at the scrubber outlet, and had
the highest discharge severity, 0.023.
Inorganic elemental analyses
indicated that at least 17 elements
exceeded their respective Discharge
Multimedia Environmental Goal
(DMEG)* levels at the ESP inlet, while
only 4 elements exceeded their DMEG
levels at the ESP outlet. Scrubber outlet
data showed that only As, Cr, and Fe ex-
ceeded their DMEG values, and maybe
of environmental concern.
Specific anion analyses indicated
emission levels of NOs", Cr, and F'were
0.0018, 0.175, and 0.122 ng/J, respec-
tively. DMEG values have not been
established for NOs". Concentrations of
CI" and F~ did not exceed their respec-
tive DMEG values at the scrubberoutlet.
Hence, these specific anions did not.
appear to pose a health hazard with
short-term direct exposure.
Liquid streams analyzed included two
streams which were discharged to a
river: ash pond overflow and liquid from
a sump in the scrubber circuit. In
general, the elements posing the great-
*For background and charts for DMEGs, see EPA-
600/7-77-136a/b (NTIS PB 276 919 and PB 276
920) and EPA-6OO/7-79-176a/b (NTIS PB 80-
115 108 and PB 80-115 116).
est environmental concern in these dis-
charges (Al, Ca, Cd, Fe, Mri, Ni, P, and
Pb) are all present at similar concentra-
tions in makeup water from the river. Ca
concentration increased in the pond dis-
charge relative to the makeup because
lime scrubber wastes from other units
at the generating station were also dis-
posed of in the ash pond. Organic
content of the sump discharge was
0.283-0.290 mg/l and of the ash pond
overflow, 0.002 to 0.011 mg/l. Traces
of naphthalene were also found in the
sump discharge.
Solid wastes include fly ash, econo-
mizer ash, bottom ash, and scrubber
filter cake. The ashes contained three or
four elements at concentrations ex-
ceeding health-based DMEG valuesand
numerous elements exceeding ecology-
based DMEG values. Elements of
primary concern from a health stand-
point included Al, As, Ca, Fe, and Mn.
Filter cake exceeded health-based
DMEG values for Ca and Fe, and numer-
ous ecology-based DMEG values.
Organics were present at the highest
concentration in the filter cake (19.22
mg/kg), and included naphthalene,
phenanthrene, and 11 other POM
compounds.
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L L Scinto, R. F. Maddalone, D. K. McNeil, and J. A. Wilson are with TRW's
Environmental Engineering Division, One Space Park, Redondo Beach, CA
90278.
Michael C. Osborne is the EPA Project Officer (see below).
The complete report, entitled "Source Test and Evaluation Report: Cane Run
Unit No. 6, Louisville Gas and Electric Co.." (Order No. PB 81 -238 644; Cost:
$11.00, 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:
Industrial Environmental Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
if U S GOVERNMENT PRINTING OFFICE, 1981 - 757-012/7318
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Postage and
Fees Paid
Environmental
Protection
Agency
EPA 335
Official Business
Penalty for Private Use $300
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