United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Research Triangle Park NC 2771 1
EPA-600 2-80-106
May 1980
Research and Development
Environmental
Assessment of Dry
Coke Quenching Vs
Continuous Wet
Quenching
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RESEARCH REPORTING SERIES
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EPA-600/2-80-106
May 1980
Environmental Assessment of
Dry Coke Quenching Vs.
Continuous Wet Quenching
by
C.W. Westbrook and D.W. Coy
Research Triangle Institute
P.O. Box 12194
Research Triangle Park, North Carolina 27709
Contract No. 68-02-3152
Task No. 1
Program Element No. 1AB604C
EPA Project Officer: Robert C. McCrillis
Industrial Environmental Research Laboratory
Office of Environmental Engineering and Technology
Research Triangle Park, NC 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, DC 20460
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CONTENTS
Figures "Mi
Tables iv
Acknowledgement v
1.0 INTRODUCTION 1
2.0 SUMMARY AND CONCLUSIONS 3
3.0 PROCESS DESCRIPTIONS 7
3.1 CONTINUOUS WET QUENCHING 7
3.2 CONTINUOUS DRY QUENCHING 11
3.3 COKE TRANSPORT FACILITIES 14
3.4 STEAM GENERATING BOILERS 14
4.0 EMISSIONS 15
4.1 WET CONTINUOUS QUENCHING 15
4.2 DRY COKE QUENCHING _. 16
4.3 EMISSION FROM COKE TRANSPORT 18
5.0 EMISSION COMPARISON - WET VERSUS DRY QUENCHING 21
5.1 COKE PUSHING 21
5.2 QUENCHING EMISSIONS 21
5.3 EFFECT ON EMISSIONS FROM STEAM GENERATING 24
5.4 SUMMARY OF EMISSION COMPARISON 25
6.0 DATA NEEDS FOR COMPLETE LEVEL 1 ASSESSMENT 28
6.1 COKE PUSHING 28
6.2 CONTINUOUS WET QUENCHING 28
6.3 DRY COKE QUENCHING 29
6.4 STEAM GENERATING BOILERS 29
6.5 COKE TRANSPORT 29
7.0 REFERENCES 31
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FIGURES
Number Page
1 Coke guide and gas cleaning car 8
2 Continuous wet coke quenching schematic 9
3 PEC/AWB dry coke quenching system schematic flow sheet 12
iii
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TABLES
Number Page
1 Emissions Comparisons 4
2 Liquid Emissions from Dry Quenching 17
3 Gaseous Emissions from Dry Quenching 18
4 Pushing Emission Comparison 22
5 Overall Emission Summary 26
IV
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ACKNOWLEDGEMENT
This report has been submitted by Research Triangle Institute in
partial fulfillment of the requirements of EPA Contract No. 68-02-3152.
The authors are grateful to Mr. R. C. McCrillis, EPA Project Officer, for
his advice and technical direction.
RTI also expresses its appreciation to National Steel Corporation, the
Weirton Steel Division, Mr. Gene Current, and Mr. Gary Doak for their
cooperation and assistance with this project.
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1.0 INTRODUCTION
In the early 1970's the Weirton Steel Division of National Steel Corpora-
tion built a new coke plant consisting of a single battery of 87 ovens and
complete coal chemical plant and support facilities. The Brown's Island plant
featured the most advanced production techniques and air and water pollution
control devices. A significant feature of this plant was the development of a
new concept in abating air pollution normally associated with the pushing and
quenching operations. The system, designed and constructed by Weirton Steel,
and the Koppers Company with the support and cooperation of EPA, provided for
a totally enclosed coke pushing and a continuous wet quenching system. There
have been a number of mechanical and design problems that have prevented the
continuous operation of this system.
As a response to energy conservation needs and as a possible solution to
environmental problems from coke quenching and pushing, DOE (formerly ERDA)
and EPA awarded a contract on August 1, 1977 to National Steel Corporation to
perform a feasibility study for the installation of a dry coke quenching fa-
cility at their Weirton Steel Division's Brown's Island coke battery. A sub-
contract was awarded to Pennsylvania Engineering Corporation, the exclusive
licensee of the Waagner-Biro dry coke quenching process in the United States,
to provide the design engineering and solicitation of the necessary equipment
pricing. The project was completed in September 1978.
In addition to the basic engineering and cost data provided by this
study, estimates were made for emissions from the dry quenching process.
Unfortunately, data were not provided for the potential emissions that might
result from transport of the dry quenched coke from the quenching area to the
end users of the coke nor for the emission reductions resulting from decreased
steam production requirements at the steam generating plant.
Information from project reports, various draft reports, and observations
made during a site visit to the National Steel Corporation's Weirton, West
Virginia, plant are analyzed in this report to provide a first level assessment
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of the environmental impact of installing a dry coke quenching process at the
Brown's Island coke plant. Information needed to complete an environmental
assessment of this process change is identified.
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2.0 SUMMARY AND CONCLUSIONS
This report compares the multi-media environmental impact of continuous
wet quenching and dry quenching of coke as applicable to National Steel
Corporation's Weirton, West Virginia plant. In both cases, only coke produced
by the Brown's Island battery is considered. Very limited test data directly
applicable to either case are available. The data presented, therefore, are
based on design information, test data from related processes, and engineering
estimates. Particular notice should be taken that modifications to the con-
tinuous wet quenching process have been made, and which are not reflected in
the data tabulated, that could measurably affect the comparison, especially
for solid and liquid discharges. Table 1 summarizes the various emissions
from the processes. It does not include the emissions that might result as
the coke is transported from the quenching area to areas of final use (blast
furnace, sinter plant, etc.). The comparison includes pushing emission con-
trols, emissions from the coke cooling processes, and emissions from the steam
generating boilers. In calculating emissions from the boilers, it was assumed
that all particulate and fly ash emissions occurred as a result of coal burning
and that coal consumption would decrease in proportion to the amount of steam
produced by dry quenching.
It can be seen that dry coke quenching results in substantially lower
emissions of particulate matter, less solid waste (calculated on a dry solids
basis), and less gas that has been in direct contact with hot coke. There is
also a strong probability that less organic material would be emitted by the
dry coke quenching process. The dry quenching process, however, has a sub-
stantially higher aqueous effluent. A substantial fraction of this effluent
is untreated river water used for noncontact cooling of the bunker shell.
Effluent from the coke pushing gas cleaning car accounts for 146 Ji/Mg (this is
not counted in the wet quench since the effluent is recycled to the cooled
coke). Thus, only 36 £/Mg (from the bunker seal) is a direct dry coke quench
process effluent.
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TABLE 1. EMISSIONS COMPARISON0
Type Emission
Parti culates
Solid Waste
Liquids
Process Related
Vessel Cooling
Gaseous
Process Contact
Noncontact
Continuous
154 Mg/hr Desi
0.484 Kg
4.28 Kg
197 liters
1675 M3
_
Wet Quenching
gn 125 Mg/hr Rate
0.53 Kg
4.28 Kg
197 liters
2090 M3
Dry Quenching
125 Mg/hr Design
0.038 Kg
1.033 Kg
379 liters
269 liters
291 M3
203 M3
Difference
at 125 Mg/hr
0.492 Kg
3.25 Kg
(182 liters)
(269 liters)
1799 M3
(203 M3)
b
Rate
Organic, Air Emissions
Polynuclear Aromatic
Hydrocarbons
Polar compounds
Benzo(a)pyrene
0.42 x 10"° Kg
0.61 x 10"3 Kg
0.024 x 10~3 Kg
0.42 x 10"3 Kg
0.61 x 10"3 Kg
0.024 x 10"3 Kg
Unknown but
estimated to
be much lower
than wet
quenching.
*A11 data are calculated per megagram (1000 Kg) of coke produced.
DNumbers in parentheses indicate areas where emissions from dry quenching
exceed those from continuous wet quenching.
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Coke transport emissions are not included in Table 1 because there is
insufficient data to estimate the magnitude of the emissions. Visual in-
spection of the transport system when conventionally wet quenched coke was
being processed indicated little fugitive emissions from all sources.
Emission factor calculations indicate that dust emissions from dry coke
transport could be as much as 144 times higher than for wet coke. One
Japanese company reports that emissions at the coke screening station are
three times as great as experienced when wet coke is processed. However,
since the Japanese use enclosed conveyors in addition to the control equip-
ment at the screening station and blast furnace coke storage area, and
since there are no emission controls on the Weirton system, one can only
say that emissions from dry coke transport should be substantially greater
than from wet coke. No accurate statement of the relative magnitude can be
made.
The conclusions that can be drawn from the available data are:
1. Substantially less particulate matter should be emitted to the
atmosphere from dry coke quenching.
2. Substantially less direct process contact gas should be emitted
from dry coke quenching.
3. Substantially less solid waste will be generated by dry coke
quenching only if steam produced by the process is accompanied by
decreased coal use at the plant steam generating boilers.
4. Substantially more aqueous effluent is generated by the dry
quenching process. About 40 percent of this additional water has
been in direct contact with process solids.
5. A substantial increase in emissions from coke transport and
screening will occur from the dry coke quenching process unless
some type of dust control is instituted.
6. Obvious options available for control of transport emissions are:
wetting the coke, adding a chemical dust suppressant, or installing
dust capture and control equipment.
With regards to the last conclusion, wetting the coke may eliminate
some of the potential advantages of using dry coke in the blast
-------
furnace. Chemical dust suppressants are unproven in this appli-
cation. Installing control equipment is the most expensive but
surest way of controlling emissions and retaining the potential
advantages of blast furnace usage of dry coke.
7. Engineering assessment indicates less organics, particularly poly-
nuclear aromatic hydrocarbons, will be emitted from the dry coke
quenching process.
8. With proper operation of wastewater treatment facilities and con-
trol of coke transport emissions, dry coke quenching should have
less negative environmental impact than continuous wet quenching.
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3.0 PROCESS DESCRIPTIONS
3.1 CONTINUOUS WET QUENCHING1
The process schematic is shown in Figures 1 and 2. The coke oven door
%
machine is of standard design. The coke guide car consists of two connected
sections. The first section is the coke guide rack which is similar to stan-
dard designs except that it is totally enclosed and fits tightly against the
buckstays and against the top of the jamb casting. No smoke should escape
from the oven door opening or from the guide during a push.
The second section of the coke guide is the hood. It is a double seg-
mented, quadrant type shroud with a rectangular cross section. The shroud is
mounted on the front steelwork of the coke guide frame to totally enclose the
push. The movable section pivots to contact the raised section of the hot
coke transfer car. The hot coke transfer car is capable of handling (without
moving) the coke pushed from one oven. The hopper is totally enclosed even
during periods of travel.
A gas cleaning car, composed of two sections, is used to move the coke
car. The locomotive and operators cab forms one section and a scrubbing
system forms the other. Gases withdrawn from the hot coke car pass through a
water quench duct, a high energy variable throat Venturi scrubber, a flooded
elbow, cyclonic separator, exhaust fan (400 hp), and out the exhaust stack.
Contaminated water is returned to the main recirculation system and periodi-
cally replenished. During start up and coke transport the fan louvers are
restricted and the Venturi operated at about 18.7 mm of Hg (10 in. w.c.)
pressure drop. While receiving or discharging coke, the louvers are open and
the pressure drop across the Venturi is about 65.4 mm of Hg (35 in. w.c.).
In Figure 2 the hot coke is shown being unloaded into one of three track
receiving hoppers. Each hopper is sized to accept one oven of coke and is
equipped with top closure plates to prevent escape of fumes between discharges
of coke from the car. This opening is closed as soon as the coke dump is
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CO
STACK -
FAN HIGH SUCTION -
CLEAN GAS
37,500 CFM
170° F
02,N2,C02
CLEAN GAS
SATURATED
170° F
"SEPARATOR
_H20SPRAY
300 GPM
«x
II /
Is
/^>
\. y^-""
j^^^Sr
I 1
1 1
—~-T^-~
^VENTURI
. r
AP 50 IN WC
i
-DIRTY H20
RES
COKE GUIDE HOOD
r HOT DIRTY GAS
30,000 SCFM
2.0 GR/SCF
700° F
COKE GUIDE
PUSHER MACHINE
HOT COKE
TRANSFER CAR
COKE
24 TONS
2,000° F
.DIRTY H2O TO RESERVOIR
1.7 POUNDS/TON OF COKE
Figure 1. Coke guide and gas cleaning car.1
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I— FRESH H,O MAKE-UP
HOT COKE TRANSFER CAR
HOT DIRTY FUMES
18.500 CFM MAX.
2.0GR/SCF
CO. CO2. H2. CH4
700° F
RECEIVING HOPPER
GAS CLEANING CAR
(OPERATING IN LOW MODE)
DIRTY H2O RESERVOIR
STEAM FROM
VIBR.CONV.
H20 SPRAY —v
360 GPM WITH 4 SPRAYS \
4SO GPM WITH Slh SPRAY
SLUDGE FROM
SUMP
/—HEAT SENSING
/ H
H2O SPRAY
350 GPM
HOOD
CANOPY-' A
STEAM TO STACK
32.000 CFM/CONVEYOH
WITH 2 CONVEYOR
OPERATING
lAPBoL.^' ]~\
k™r*^2\\.
FAN > , r-
DIRTY H2O TO SUMP-
DIRTYM2OTOSUMP
70/100 GPM
RANGE 4/5 SPRAYS
CLEAN HjO TO SPRAYS
1.350 GPM
-^
H2O SPRAY
MIST SUPPRESSOR
— STACK
-70.000 CFM MAX.
0.05 GR/SCF 170° F
V— SLUDGE TO SUMP PUMP
1
JETr"
SUMP PUMP
SUMP
SLUDGE TO VIBR. CONV
100 GPM
V
Figure 2. Continuous wet coke quenching schematic.
1
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completed and the fumes in the hopper are exhausted through a duct near the
top of the hopper.
This system as originally designed is shown in Figure 2. The hopper
fume cleaning system was extensively redesigned after several explosions,
caused by combustible gas mixtures in the ducting, occurred. In the current
configuration, the hopper fumes are evacuated through a steam ejector
powered high energy scrubber during the brief (about 1 minute) coke dump
period. For the remainder of the cycle (about 15 minutes) fumes are vented
directly to atmosphere. All dirty water flows to a settling basin.
The hot coke from the track receiving hopper originally discharged
onto a vibrating conveyor where it was cooled with water sprays. This
system has been redesigned because continuing problems with the conveyor
could not be solved. The hot coke now discharges into a rotating horizon-
2
tally mounted drum. Water is sprayed onto the coke through axially mounted
spray nozzles in the center of the drum. Coke is moved through the drum by
steel plates welded to the drum interior wall (screw conveyor). Excess
water is separated from the coke by screens near the discharge end of the
drum and flows to the settling basin. Make-up water, to replace steam
losses, to the spray system is supplied from the general service source.
As designed, all solids captured by the gas cleaning car and coke quenching
were to be added to the cool coke conveyor. A second clarifier has since
been added and the solids are removed for disposal or use in other plant
processes. No water is discharged from the system.
Each drum has a steam exhaust duct at the drum inlet end. At the top
of each exhaust duct is an axial type fan for positive steam removal. The
steam goes to an exhaust main and is carried to the stack. A mist sup-
pressor is provided in the stack to remove entrained water and particulate
matter.
Coke is discharged from the quench drum onto a short, 5 meters (^15
feet), covered conveyor that has additional water sprays. Coke is trans-
ferred onto a second conveyor belt (uncovered) which is equipped with a
temperature sensor and a bank of water sprays. The coke is transported via
this belt to a junction point just below yard level where it discharges
onto a conveyor belt that conveys the coke to the top of the load-out bin.
10
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Coke from the emergency coke wharf also enters the system at the junction
point. Coke is loaded into trucks from the bottom drop load-out bin.
The discussion above basically describes the system as it currently
exists. There have been a number of changes that could affect emissions
from the process relative to the original design. For example, the track
receiving hoppers for hot coke are evacuated and cleaned only during
periods of coke dumping rather than continuously as originally designed.
Also there has been a change in handling procedures for the coke dust
captured. Since inadequate data are available to estimate the effect
these changes have on emission levels, only original design data are used
in this report.
3.2 CONTINUOUS DRY QUENCHING
This description is condensed from Pennsylvania Engineering Company's
3
Phase I Engineering report for installation of a Waagner-Biro dry coke
quenching facility (Figure 3) at National Steel's Weirton, West Virginia
Brown's Island coke plant. It is possible, therefore, that some changes
could occur if a decision to build were made.
The same basic coke pushing system as used in the continuous wet
quench will be used. Two options were identified for transferring the hot
coke to the dry quench bunkers. If the existing hot coke car is retained,
there will be an intermediate transfer, by bottom drop, into a bucket on a
shuttle car located beneath the hot coke car rail tracks. The alternative
is to replace the hot coke car with a new car and two dismountable buckets
that can be hoisted directly to the dry quench bunkers. In either case,
the gas cleaning system on the hot coke car will be used to capture emis-
sions during the push and transfer. The bucket is then positioned at the
hoist station where the spreader beam and hooks are attached to the bucket.
The bucket is raised to the top of the CDQ plant and positioned over the
appropriate bunker. The bunker extract damper and cover are opened and
the bucket lowered to supports on the bunker opening. Final lowering of
the hooks opens the bottom doors and discharges the hot coke into the
bunker. The process is repeated in reverse as the bucket is raised.
The coke is cooled by gas circulating through the bunker. Cool gas,
130°C (^270°F), is blown into the bottom of the bunker. As the gas rises
11
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1. HOT COKE BUCKET
2. HOT COKE GUIDE
3. COKE OVENS
4. BUNKER DISCHARGE
MECHANISM
5. COKE BUNKER
6. BUCKET HOIST
7. BUNKER CHARGING
MECHANISM
8. COARSE PARTICLE SEPARATOR
9. GAS DISTRIBUTOR
10. MULTI-CYCLONE SEPARATOR
11. GAS CIRCULATING BLOWER
12. WASTE HEAT BOILER
13. STEAM DRUM
14. BAG HOUSE
PRODUCT STEAM
1 ±
COOLED COKE
BOILER COKE
FEEDWATER FINES
Figure 3. PEC/AWB dry coke quenching system schematic flow sheet. 3
12
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through the hot coke, it is heated to about 675 - 790°C (1250-1450°F). The
hot gas passes through an impingement type coarse separator to remove heavy
particles released during the charge, then through a gas mixer, where cool
gas bypassing the bunker lowers the temperature to a uniform 675°C (1250°F).
The gas then passes through a steam generating waste heat boiler where the
temperature is reduced to about 130°C (265°F). After removal of additional
fine coke dust by a multiclone separator, the gases are recycled to the
bunker. Coke, cooled to 205°C (400°F) or less is removed from the bunker
almost continuously through an automatic cutoff gate and double flap valve.
Coke charging and discharging are accomplished without escape of circu-
lating gas or inlet of air. The coke is discharged onto a belt conveyor
which will convey coke to the belt junction station and to the load-out bin
described in the wet quenching section.
Coke fines are removed from the plant at: the bunker charging mecha-
nism, coarse and fine particle separators, and purge gas and coke discharge
bag filters. All these points are closed and the fines discharged through
slide and double flap valves. All fines collected are conveyed to a bin
which discharges to a closed road tank car for removal. The purge gas is
burned in a coke oven, gas fired incinerator after passing through its bag
filter. A gas purge is required by the gas volume increase resulting from
the injection of air into the hot gas leaving the bunker. Air is injected
to maintain a low level of combustibles.
River water is treated to provide boiler make-up. The water is clari-
fied and filtered to remove suspended solids. The water is then treated in
a reverse osmosis unit and softened in a base exchanger. A small stream of
this purified water is fully deionized for use in the steam atemperators.
Oxygen is removed from the boiler feed water by vacuum deareation and
injection of sodium sulfite.
Clarifier underflow, filter backwash, reverse osmosis reject, sodium
and calcium chlorides from base exchange regenerator, and spent regenerate
(HC1, NaOH, and ions removed) from the deionizer are discharged to the
wastewater treatment system (contaminated water from the hot coke car
scrubbing system will also discharge to this system). Wastewater treatment
consists of solids settling (clarifier) and pH adjustment.
13
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3.3 COKE TRANSPORT FACILITIES2
In both the previous descriptions, transport of the cooled coke was
carried through to the load-out bin. The load-out bin is an elevated struc-
ture under which large trucks can pass. Coke is loaded into the trucks via a
bottom drop chute in the bin. Drop distance varies from 3 to 6 meters (10 to
20 feet). The coke is transported to the mainland where it is dumped into an
underground bunker. The coke is transported via a loosely covered conveyor to
the screening station. The coke passes over and through several vibrating
steel screens to separate it into different size fractions. The screened coke
is conveyed to several discharge points where it is loaded into rail cars, a 7
to 9 meter drop (20 to 30 feet). The coke is transported via the rail cars to
the blast furnace stock house and loaded into bins from the bottom drop rail-
cars. The coke is conveyed to a final screening point and dumped into weigh
bins before being dropped into the blast furnace skip car. There are no
emission suppression or collection devices in use at any point described in
this section.
3.4 STEAM GENERATING BOILERS4
Steam produced by dry quenching will replace part of that produced by the
boiler house. This should result in reduced emissions at the boiler house.
There are 5 high pressure and 7 low pressure boilers. Three are normally
coal fired but can switch to coke oven (COG) or blast furnace (BFG) gas.
Fuels used in the boilers are: natural gas, COG, BFG, fuel oil, coal and
waste heat. The boilers use the excess gas produced in the plant before
switching to alternate fuels (except for two which are always coal fired).
Some of the steam is used to produce electricity.
Total steam capacity of the boiler house is 1,509,000 Kg/hr (3,327,000
Ibs/hr) or 13,218,000 Mg/yr (14,570,000 tons/yr). The design heat input is
12 fi
4.8 x 10 joules/hr (4,552 x 10 BTU/hr). The maximum permissible particu-
late emission from the boilers is 186 Kg/hr (410 Ibs/hr) (based on West
Virginia regulation of 0.09 Ib (0.041 Kg)/MBTU input with which the plant is
in compliance) or about 0.13 Kg/Mg (0.25 Ib/ton) steam produced. The plant
estimates that normally about 29 Mg/hr (32 tons/hr) of coal are burned and 118
Mg/day (130 tons/day) of fly ash is generated (wet basis, ^50 percent solids).
14
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4.0 EMISSIONS
This section provides an estimate of the emissions to the environment
from the various processes. The comparisons are based on the original
designs with the systems operating at design conditions even though the
current configuration of the continuous wet quenching system differs from
the original design. Design emissions data are given for the wet con-
tinuous process as originally designed since actual test data are not
available. Where appropriate, test data from conventional wet quenching
3 5
processes are included. Design data ' are also used for the dry quenching
process. These data, however, should be fairly reliable as they are based
on experience gained from other installations.
Since the two systems were designed with different coke throughput
rates (154 Mg/hr for continuous wet quench and 125 Mg/hr for the dry quench
system), where appropriate, the emissions from wet quenching are also
calculated at 125 Mg/hr (by assuming all design values remain the same but
less coke is processed) to provide a consistent basis for comparison.
4.1 WET CONTINUOUS QUENCHING
As originally designed, emissions from the process should occur at
only two points: the gas cleaning car stack and the process stack (which
receives gas from the continuous quenching and from the coke receiving
hopper).
The gas cleaning car is designed to operate in two modes. A low gas
o
flow, 56.6 NM /min (2000 CFM) is used during start up and coke transport.
3
A gas flow of 1062 NM /min (37,500 CFM) is used during coke pushing and
discharge. If the assumption is made that the system operates 50 percent of
the time in each mode and that the particulate emission concentration
3
equals the design rate in both cases (0.05 grain/SCF-O.llg/NM design, this
source contributes 3.69 Kg/hr (8.14 Ibs/hr) or 0.024 Kg/Mg (0.048 Ib/ton)
of coke (154 Mg/hr, 170 tons/hr design coke rate) which is equivalent to
0.030 Kg/Mg (0.06 Ib/ton) if 125 Mg/hr of coke is processed. Design
15
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3
data for the process stack shows a gas exhaust of 3,740 M /min (132,000
CFM) with a grain loading of 0.11 g/M3 (0.05 grain/SCF). At the design
rate of 154 Mg/hr (170 short tons/hr), the participate emissions would be
24.68 Kg/hr (54.5 Ibs/hr) or 0.16 Kg/MG of coke (0.32 Ib/ton) which is
equivalent to 0.20 Kg/Mg if 125 Mg/hr of coke is processed.
Solids removed from the recycle water clarifier (which contains
solids from the gas cleaning car, from the excess quench water returned to
the sump, and from the main system scrubber) are returned (design condition)
to the coke conveyor system for separation at the screening station.
(Present practice is to route the water to a second clarifier and remove
some solids for use at the sinter plant.) An estimate of these solids can
be made as follows. The process design is for 0.85 Kg of particulate/Mg
of coke (1.7 Ibs/ton) to be captured by the gas cleaning car. Conventional
wet quenching is estimated to produce 36 Kg of coke breeze per Mg of coke
produced. This added to the 0.85 Kg/Mg from the gas cleaning car yields
36.85 Kg/Mg coke (73.7 Ibs/ton) of particulate in the clarifier sludge
(37.0 Kg/Mg at 125 Mg/hr coke rate).
Organic emissions from the continuous wet quench may be similar to
that from a conventional quench tower. The tests at U.S. Steel-Lorain
can be used as an indication of possible emissions. The emissions found
for clean quench water and non-green coke are: polycyclic aromatic hydro-
carbons 0.419 x 10 Kg/Mg coke, total polar compounds 0.606 x 10 Kg/Mg
coke, benzo(a)pyrene 0.024 x 10 Kg/Mg coke. These, however, pertain
only to emissions from the main stack. No data are available to indicate
the magnitude of organic emissions from the gas cleaning car system.
4.2 DRY COKE QUENCHING
The dry coke quenching plant design capacity is 125 Mg coke/hr (138
tons/hr). On this basis the design particulate emissions from the in-
cinerated purge gas is 0.00047 Kg/Mg coke CO.0009 Ib/ton). Emissions from
the bag filter which collects dust from charging, discharging, fine solids
conveying and the fine solids storage bin are estimated to be less than
0.0047 Kg/Mg coke (0.009 Ib/ton). Estimated emissions from pressure
relief valves, 17 M3/hr at 22.8g/M3 (600 CF/hr at 10 grains/CF), gives an
additional 0.0031 Kg/Mg (0.006 Ib/ton) for a total particulate emission of
0.0083 Kg/Mg coke (0.0166 Ib/ton coke).
16
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Design solid emissions from the process are silt from treatment of
water for use in the boiler, and coke dust collected in the bunker seal
water. Silt amounts to 0.065 Kg/Mg coke (0.13 Ib/ton of coke) and coke
dust to 0.023 Kg/Mg (0.046 Ib/ton) of coke for a design solid emission of
0.088 Kg/Mg (0.18 Ib/ton) of coke.
Liquid emissions from the plant are designed for 503 &/Mg (121 gallons/
ton) of coke. The design flow rates into the wastewater treatment clarifier
are given in Table 2. The last four columns indicate the contribution these
streams make to the total dissolved solids (TDS) and suspended solids in
the wastewater plant discharge.
TABLE 2. LIQUID EMISSIONS FROM DRY QUENCHING
Effluent
Filter Backwash
Clarifier Underflow
Bunker Seal Water
Boiler Slowdown
Water Treatment Reject
Cooling Water ^ '
Water Softener Regenerant
TOTAL(2)
Volume
Coke
2.17
0.79
35.8
14.6
179
270
0.5
530
mg/£
350
350
350
1500
1330
350
8000
740
TDS
gms/Mg
Coke
0.76
0.28
12.5
21.9
238
94
4.0
371
Suspended
50
50
50
50
5
90
-
55
Solids^
gms/Mg
Coke
0.11
0.04
1.8
0.7
0.9
24
-
27.6
Note: (1) Cooling water enters the system after wastewater treatment.
TDS & TSS same as river water.
(2) Total represents mean after mixing and eoualizing all effluents,
after solids removed from clarifier and bunker seal water.
(3) With the exception of water softener regenerant, all solids
(dissolved and suspended) were present in original river water.
Water softener regenerant TDS are sodium, magnesium and calcium
carbonates, chlorides and sulfates.
17
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Gaseous emissions occur from the process at two sources—the incinerated
purge gas and bunker circulating gas from pressure relief valves. Design
data for these emissions (particulates were discussed above) are given in
Table 3.
Gaseous emission from the dust collecting bag filter is 204 M /Mg.
This is air drawn in collecting the dust, not process gas.
TABLE 3. GASEOUS EMISSIONS FROM DRY QUENCHING
Component
CO
co2
°2
H
H20
N2
Incinerated
Volume %
-
16
0.6
-
10
73.4
Purge Gas
M3/Mg Coke
3.3
0.12
2.0
15.0
Pressure
Volume %
3.0
15.6
-
0.9
6.3
74.2
Relief Valve Gases
M3/Mg Coke
0.004
0.02
0.001
0.009
0.10
The data above are design values for the dry coke quenching facility
proper. In practice, the emissions from coke pushing must also be considered.
As previously discussed, emissions from the gas cleaning car are (design):
cleaning car stack - 0.030 Kg/Mg (0.06 Ib/ton)
scrubber solids - 0.85 Kg/Mg (1.7 Ibs/ton)
Estimated scrubber blowdown is 146 &/Mg (35 gallons/ton) of coke
(5,800 mg solids/liter blowdown). Blowdown water quality is unknown. The
scrubber blowdown water will be treated in dry quench wastewater treatment
system.
4.3 EMISSION FROM COKE TRANSPORT
There are no quantitative measurements of the emissions that occur
during transport of either wet or dry quenched coke. For rough estimation
18
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purposes, however, an equation developed for particulate emission from
o
storage pile formation by means of conveyor stacker can be used.
EF = 0.0009 (S/5)(U/2.2)(H/3)/(M/2)2 Kg/Mg
where:
EF = dust emission
S = silt content of aggregate
M = moisture content
U = mean windspeed
H = drop height
If we assume S, U, and H are identical for both types of coke:
EF = 0.00011 SUH/M2
Using typical moisture contents of 6 percent for wet quenched coke and
0.5 percent for dry quenched
EF = 0.00011 SUH/36 for wet quench
EF = 0.00011 SUH/0.25 for dry quench
That is, dust emissions from dry quenching would be expected to be 144
times the dust emission from wet quenched coke. For a silt content of 2-
percent, wind speed of 1 M/sec and drop distance of 8 meters, the calculated
emissions from one drop are 0.000049 Kg/Mg and 0.0070 Kg/Mg for wet and dry
quenched coke, respectively. It should be noted that the two cokes differ
in ways that could substantially change this comparison. The dry coke is
maintained at higher temperatures for several hours longer than wet quenched
coke which promotes more complete coking; it is subjected to substantial
abrasion in the cooling chamber which removes much of the more easily
generated dust; test data indicate that dry quenched coke is substantially
q
stronger (more abrasion resistant) than wet quenched coke. These factors
may reduce the estimated difference in emissions. It is known, however,
that dust emissions from dry coke handling are significantly higher than
for wet quenched. The Kawasaki Steel Company (Chiba Works) in Japan reports
that dust emissions triple at the screening station when dry quenched coke is
processed. This plant has hoods and dust pickup points on the screening
operation, transfer points and in the stock house. Nippon Kokan (NKK)
19
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(Ohgishima Works) has two CDQ plants (a total of 8 chambers each rated at
70 Mg/hr, one chamber maintained as a standby). Dust control at the screen-
ing station is by fabric filter (3500 NM3/min). A 4,000 NM3/min fabric
filter is also used at the blast furnace coke bin. All Japanese plants
operating CDQ's transport the cooled coke with covered conveyors and col-
lect emissions at transfer points and the screening station.
Since, as previously described, there are no emission controls on the
coke transport system at Weirton, dust emissions from these areas would be
substantially greater than are observed with the use of wet quenched coke.
It would seem obvious, therefore, that some method of dust control will be
required on the coke transport system at Weirton.
20
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5.0 EMISSION COMPARISON - WET VERSUS DRY QUENCHING
5.1 COKE PUSHING
Essentially the same coke pushing system would be used for either quench-
ing method. Thus emissions from the gas cleaning car are unchanged. However,
with wet quenching the scrubber blowdown (both solids and liquids) would have
been added to the coke. The solids would have been separated at the coke
screening station and used as breeze and the aqueous phase (absorbed into the
coke), and any contaminants therein, would pass into the blast furnace or other
combustion device. With dry coke quenching, the scrubber blowdown would be
added to the CDQ wastewater treatment system and be discharged as sludge and
aqueous effluent. The emissions are summarized in Table 4.
5.2 QUENCHING EMISSIONS
Direct emissions to the atmosphere should occur only from the main quench
stack for the wet quenching process. Design data for production of 154 Mg/hr
show gas emissions of 1457 M /Mg of coke with particulate emissions of 0.16
Kg/Mg of coke. If organic emissions from the continuous wet quenching are the
same as conventional wet quenching, data obtained at U.S. Steel - Lorain would
indicate organic emission from continuous wet quenching as: polycyclic aro-
-3 -3
matic hydrocarbons 0.419 x 10 Kg/Mg coke, total polar compounds 0.606 x 10
o
Kg/Mg coke, and benzo(a)pyrene 0.024 x 10 Kg/Mg coke.
Design data for the dry quenching process show total gas emissions of 224
3
M /Mg, 90 percent of which is air drawn through the baghouse used to collect
fine coke emissions at the various cool coke transfer points. Total estimated
particulate emissions are 0.0083 Kg/Mg. No data are available to estimate the
potential organic emissions. However, since the purge gas is incinerated and
air used for dust collection contacts only cool coke, it is likely that only
the gas from pressure relief valve opening could contain organics. This gas
is estimated to be only 0.14 M /Mg. Thus the overall organic emission to the
air should be substantially less than for wet quenching.
21
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TABLE 4. PUSHING EMISSION COMPARISON
(125 Mg/hr Design) 054 Mg/hr Design)
Component Dry Quench Wet Quench
Participate from 0.030 Kg/Mg 0.024 Kg/Mg
gas cleaning
Gas emissions3 269 M3/Mg 218 M3/Mg
Scrubber blowdown
Solids 0.85 Kg/Mg All
Liquid 146 £/Mg Recycled
(125 Mg/hr Coke)c
Wet Quench
0.030 Kg/Mg
269 M3/Mg
All
Recycled
Gas composition unknown, organic content unknown.
Discharge water quality unknown.
Calculated assuming only 125 Mg/hr coke processed and all emission rates equal
to design values at 154 Mg/hr coke rate.
22
-------
There are no process solid wastes from the continuous wet quenching
system. All solids captured by the system (as designed) are added to the
quenched coke, separated at the screening station and used in other processes
(as breeze}. Present practice is to send the slurry to a second clarifier.
Solids are removed from the clarifier and used in the sinter plant. Silt
removed from river water must, however, be considered a solid waste since the
water is consumed (not returned to the river with the silt). Estimated water
consumption of the quench process is 600 £/Mg (144 gallons/ton). Silt removed
from this volume of water is estimated to be 0.024 Kg/Mg coke.
Solid emissions from the dry quenching process are coke dust collected in
the bunker seal water and silt from water treatment. Coke dust from the
bunker seal is estimated at 0.023 Kg/Mg. Silt is not removed from the cooling
water. Silt removed by feed water treatment (boiler feed water) is estimated
at 0.065 Kg/Mg coke. These solids will be disposed of by on-site landfill as
a sludge (20 percent solids).
Coke fines collected in the dry quench process can be used as pulverized
fuel, possibly returned to the coke breeze system on the coal blending station
feeding the ovens, or used at the sinter plant.
There are no liquid emissions from the continuous wet quenching system.
The blowdown slurry from the clarifier is added to the coke on the conveyor
belt or sent to the sinter plant. Water retained by the coke either passes
into the blast furnace or other combustion equipment. Effluent from the dry
coke quenching wastewater treatment plant is estimated to be 503 £/Mg coke
containing 0.37 Kg/Mg coke of dissolved solids and 0.028 Kg/Mg coke of sus-
pended solids. All of this water except the bunker seal water and once
through cooling water is associated with steam production which is discussed
below. Since the cooling water is not treated prior to or after use, it does
not constitute a process effluent (assuming credit is allowed for solids
contained in the raw water). Thus only the bunker seal water is a real pro-
cess effluent. Design data for this stream (36 £/Mg) indicate it should have
the same TDS as raw river water (350 mg/&) and only 50 mg/a suspended solids
(river water 90 mg/fc) after clarification. The assumption apparently was made
that the bunker seal water picks up no contaminants by contact with the coke
dust.
23
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5.3 EFFECT ON EMISSIONS FROM STEAM GENERATING
The design rate of steam production from the dry quenching process is
1222 Mg/day (1344 tons/day). Wastewater produced from the steam generation
system is 197 Ji/Mg coke or 484 a/Mg steam. This wastewater would contain
(obtained from design estimate of the individual stream compositions) 0.26
Kg/Mg coke of TDS (0.64 Kg/Mg steam) and 0.0018 Kg/Mg coke of suspended
solids (0.0044 Kg/Mg steam). Silt removed in treatment of water for boiler
feed is estimated as 0.065 Kg/Mg coke (0.16 Kg/Mg steam).
Design steam production from the plant steam generating boilers is
36,218 Mg/day (39,924 tons/day). Particulate emissions (maximum permiss-
ible by state regulation) are 0.12 Kg/Mg steam [0.25 Ib/ton). Data were not
available on the water quality.
To estimate the emission change potentially resulting from replacement
of steam generated by the boilers with steam from dry quenching, several
assumptions will be necessary.
The first assumption is that the same quantity of water for boiler
feed is treated and discharged (per Mg steam produced) in both systems.
The assumption is equivalent to saying there is no impact on silt removed,
TDS and suspended solids discharged, or water intake or discharged per
Mg/steam produced for those activities directly related to steam produc-
tion.
Other assumptions made are that steam reduction at the boilers will be
accomplished by reduction in coal burning and that all particulate and fly
ash from steam generation come from coal burning.
g
Coal burned in the boilers releases about 26.7 x 10 joules/Mg (11,500
BTU/lb). Design data supplied by National Steel indicate that 3.18 x 10
joules are required to produce one kilogram of steam (1368 BTU/lb). There-
fore, the amount of coal that must be burned to produce the equivalent
amount of steam generated by dry quenching (1222 Mg/day) is:
(1222 Mg steam/day)(1000 Kg/Mg)(3.18 x IP6 joules/Kg steam)
26.7 x 109 joules/Mg coal
= 145.4 Mg coal/day
= 160.3 tons coal/day
= 6.06 Mg coal/hr [6.68 tons coal/hr).
24
-------
National Steel estimates they burn about 29 Mg C32 tons) of coal/hr. Dry
coke quenching can reduce this consumption by 20.9 percent ((6.06/29) x 100).
From our assumption that all boiler produced particulate emissions and fly ash
are produced by coal burning, a reduction (maximum) of 38.9 Kg/hr (85.69 Ibs/
hr) of particulate (.from 186 Kg/hr (410 Ibs/hr) maximum), and a reduction of
12.32 Mg/day 03.59 tons/day) of fly ash (dry basis) from the current estimate
of 59 Mg/day (_65 tons/day) - dry basis - would be obtained by dry coke quench-
ing steam generation.
These potential emission reductions translate into a net credit for
emission from dry coke quenching of 0.3 Kg/Mg coke for particulate emissions
a
and 4.1 Kg/Mg for solid emissions. Energy consumption at the boiler house is
also reduced by 3.68 x 109 BTU's/day.
5.4 SUMMARY OF EMISSION COMPARISON
Table 5 gives the emissions estimates from the two quenching processes.
25
-------
TABLE 5. OVERALL EMISSION SUMMARY0
ro
cr>
Process Area
Coke Pushing, Gas Cleaning Car
Particulates, air
Gas emissions
Scrubber blowdown
Solids
Liquids
Quenching
Particulates, air
Gas, process contact
Continuous
154 Mg/hr Design
0.024 Kg
218 M3
All recycled
All recycled
0.16 Kg
1457 M3
Wet Quench
125 Mg/hr Rate
0.030 Kg
269 M3
All recycled
All recycled
0.20 Kg
1821 M3
Dry Quench
125 Mg/hr Design
0.030 Kg
269 M3
0.85 Kg
146 liters
0.0083 Kg
22 M3
Gas, noncontact
Organics
PAH
Polar compounds
BAP
Solids
Liquids
Cooling water
Bunker seal water
0.419 x I0"3 Kg
0.606 x I0"3 Kg
0.024 x 10-
0.024 Kg
None
203 MJ
Unknown but
0.419 x 10"3 Kg estimated much
0.606 x 10-3 Kg lower than wet
0.024 x I0"3 Kg quench.
0.024 Kg 0.023 Kg
None
269 liters
36 liters
(Continued)
-------
TABLE 5. (Continued)
Process Area
Continuous Wet Quench
154 Mg/hr Design 125 Mg/hr Rate
Dry Quench
125 Mg/hr Design
ro
Steam Generation
Particulate, air
Solids
Liquids
Gaseous pollutants
Cool Coke Transport
Particulate
0.3 Kg
4.26 Kg
197 liters
Not determined
0.3 Kg
4.26 Kg
197 liters
Not determined
No data. Visual observations indicate
little emission at all points.
All data are per Mg coke produced.
""Calculated basic production of 1222 Mg/day of steam.
0
0.16 Kg
197 liters
Not determined
No data. Visual ob-
servations and other
information indicate a
significant problem
unless dust suppres-
sion or collection
used all points.
-------
6.0 DATA NEEDS FOR COMPLETE LEVEL 1 ASSESSMENT
The preceding sections of this report have presented the data available
on the environmental effects of continuous wet and dry coke quenching. In
most cases this information is based on design criteria rather than actual
test data. This section defines the data needed to allow a complete com-
parative environmental assessment of the processes to be made.
6.1 COKE PUSHING
Coke pushing emission control in the two processes is virtually identi-
cal. Design data have been used to estimate the particulate and gaseous emis-
sions from the gas cleaning car. The data do not provide the following infor-
mation usually obtained in an environmental assessment (EA).
1. Size classification of the particulate emission.
2. Elemental analysis of the emitted particulate.
3. Analysis of the gas for such components as: H0S, SOV, HCN, NOV, CO,
L. A A
and metals in gaseous form such as Hg, Sb, As.
4. An estimate of organic material in the emission such as phenols,
benzene, benzo(a)pyrene and other condensed ring aromatics.
An estimate was made for the total volume and suspended solids in the
scrubber blowdown. A good EA would confirm these by actual measurement.
Also, since the blowdown will be sent to wastewater treatment in the dry
quench process but is recycled in the wet quench process, the blowdown should
be tested for organics and metals (by Level 1 procedures) and for pollutants
listed on the waste discharge permit, i.e. cyanide, etc.
6.2 CONTINUOUS WET QUENCHING
Emission estimates for particulate and hazardous organics were made for
the wet quench process stack emissions. The estimate for organics was based
on data from conventional wet quench operations. To produce adequate data for
an EA, the stack emissions should be tested for the four items listed for the
coke pushing-gas cleaning car.
28
-------
6.3 DRY COKE QUENCHING
Particulate emissions and some gas composition estimates were made for
the dry quench process. These data are probably of fairly good quality. A
level 1 EA would, however, normally provide data on the size classification
of these particles. These data could be obtained with a cascade impactor.
Emissions from the pressure relief valves, purge gas incinerator, and charging
emissions should be tested for all four items listed under coke pushing-gas
cleaning car. The wastewater treatment plant final effluent (before addition
of cooling water) should be tested for dissolved and suspended solids, metals
(by Spark Source Mass Spectrometry and Atomic Absorption Spectrometry) and
organics, by Level 1 procedures, in addition to criteria pollutants.
6.4 STEAM GENERATING BOILERS
Potential emission reductions achievable at the steam generating plant
due to steam production from the dry quench process are variable, depending
on which fuel usage is reduced. In this report, it was assumed that the use
of coal would decrease. If the plant selects this option, the data provided
yield rough emission estimates. The quality of this data could be substan-
tially improved by inspection of the boiler house operating records (tons/hr
coal burned, BTU/lb of coal, Ibs steam/ton coal burned, tons dry fly ash
generated/day, Ibs particulate emitted from coal fired boilers/ton coal
burned, amount of SOV and NOY emitted per ton of coal burned). If the plant
A A
should, however, choose to reduce its use of natural gas, oil, or some other
relatively clean fuel, the estimated emissions reduction could be substantially
reduced or eliminated. Thus, a decision by National Steel personnel is
required before the actual emission reduction from the steam generation can
be determined.
6.5 COKE TRANSPORT
Emissions from the coke transport system are an area of serious concern
and one where little data is available. Visual inspection of the Weirton
system indicated only minor fugitive emissions from this source when wet
quenched coke is processed. However, all sources contacted indicate that
emissions from handling dry coke are substantially greater. To compare the
29
-------
emissions from dry and wet quenched coke transport at Weirton would require
extensive sampling for fugitive dust at all the conveyor belts and transfer
stations as well as screening operations processing the wet quenched coke.
Comparable data from an operating dry quench plant are also needed. Since all
transport of dry quenched coke is in covered conveyors and screening emissions
are controlled, a measurement of dust captured should provide adequate infor-
mation. Such an extensive effort would be of limited value since dust control
is a virtual necessity in handling dry quenched coke.
The available control options would be wetting the coke so that it is
similar to wet quenched coke, adding a chemical dust suppressant, or installing
emission control equipment. Adding water would be the cheapest approach for
emission control but would eliminate the possibility of obtaining one of the
reported benefits of using dry coke in the blast furnace. The effectiveness of
chemical dust suppressants is questionable since fresh dust, uncoated by the
suppressant, can be generated continuously. Installing control equipment
(covered conveyors, and collectors with fabric filters at the screening station)
is probably the most capital intensive, but is the surest way of controlling
emissions and obtaining the reported benefits of using dry coke in the blast
furnace. Of course, an environmental assessment cannot be completed until
National Steel choose the control option.
30
-------
7.0 REFERENCES
1. "Enclosed Coke Pushing and Quenching System Design Manual." Pengidore,
D. A., EPA-650/2-73-028, September 1973.
2. RTI site visit, September 6, 1979.
3. "Dry Coke Quenching - Phase 1 Engineering for National Steel Corporation,
for Brown's Island Coke Plant, Weirton, W. VA. - Final Project Report,
Volume 1." Pennsylvania Engineering Corporation, DOE Contract No. EC-
77-C-02-4553, August 1978.
4. Information supplied to RTI by National Steel Corporation, Weirton
Steel Division, October 1979.
5. Reference 3, Volume 2.
6. "Environmental and Resource Conservation Considerations of Steel Industry
Solid Waste," Baldwin, V. H., M. R. Branscome, C. C. Allen, D. B. Marsland,
B. H. Carpenter, and R. Jablin, EPA-600/2-79-074, SW-740, April 1979.
7. "Coke Quench Tower Emission Testing Program." Laube, A. H. and B. A.
Drummond. EPA-600/2-79-082, April 1979.
8. "Iron and Steel Plant Open Source Fugitive Emission Evaluation." Cowherd,
Chatten, Jr., Russel Bohn, and Thomas Cuscino, Jr. EPA-600/2-79-103,
May 1979.
9. Nippon Kokan (NKK) brochure. Cat. No. 165-090.
10. "Trip Report - Visit to Iron and Steel Companies in Japan." Paul Gorman
(MRI), October 26, 1979.
31
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TECHNICAL REPORT DATA
(Please read Ituaructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-80-106
2.
3. RECIPIENT'S ACCESS]Of* NO.
4. TITLE AND SUBTITLE
Environmental Assessment of Dry Coke Quenching
Vs. Continuous Wet Quenching
5. REPORT DATE
May 1980
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
C.W. Westbrook and D.W. Coy
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Research Triangle Institute
P.O. Box 12194
Research Triangle Park, North Carolina 27709
10. PROGRAM ELEMENT NO.
1AB604C
11. CONTRACT/GRANT NO.
68-02-3152, Taskl
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND/ER
Task Final; 9-10/79
ERIOO COVERED
14. SPONSORING AGENCY CODE
EPA/600/13
15. SUPPLEMENTARY NOTES iERL_RTp project officer is Robert C. McCrillis, Mail Drop 62,
919/541-2733.
16. ABSTRACT
The report gives results of an assessment of the multimedia environmental
impacts of continuous wet and dry quenching at National Steel's Weirton, West Vir-
ginia, Brown's Island coke plant. The report, based primarily on design data, test
data from related processes, and engineering judgement, suffers from the lack of
definitive test data. The assessment indicates that dry coke quenching results in less
particulate matter emitted, less solid waste generated, less process-related gas
emitted, and potentially less emission of polynuclear aromatic hydrocarbons and
organics in general, than wet quenching. Dry coke quenching also results in increa-
sed aqueous effluents and fugitive emissions from coke transport and screening. The
assessment concludes that, with proper wastewater treatment and control of coke
transport emissions, the dry quench process should have less negative environmen-
tal impact than continuous wet quenching. The report identifies areas where data are
insufficient for Level 1 assessment and indicates the testing required for a complete
Level 1 assessment.
17.
KEY WORDS AND DOCUMENT ANALYSIS
a.
DESCRIPTORS
b.lOENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Pollution
Assessments
Coking
Quenching (Cooling)
Iron and Steel Industry
Dust
Aerosols
Waste Water
Water Treatment
Pollution Control
Stationary Sources
Environmental Assess-
ment
Coke Quenching
Particulate
13B
14B
13H
11F
11G
07D
13. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
38
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
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