EPA PROJECT REPORT NO. 74-KPM-9
CD
AIR POLLUTIO
EMISSION TEST
O
• ecr
CROWN ZELtERBACH CORPORATION
Camas, Washington
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Air Quality Planning and Standards
Emission Measurement Branch
Research Triangle Park, North Carolina
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PARTICULATE EMISSION MEASUREMENTS FROM KRAFT PULP MILLS
EMB Project Report No.
74-KPM-9
Plant Tested
Crown Zellerbach Corporation
Camas, Washington
October 15-20, 1973
Prepared for
Environmental Protection Agency
Office of- Air Quality Planning and Standards
Emission Measurement Branch
Research Triangle Park,
North Carolina 27711
by
W. R. Feairheller
D. L. Harris
M. T. Thalman
Monsanto Research Corporation
Dayton Laboratory
1515 Nicholas Road
Dayton, Ohio 45^07
Report Reviewed by Robert M. Martin
Contract No. 68-02-0226, Task No. 11
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TABLE OP CONTENTS
Page
I. INTRODUCTION . 1
II. SUMMARY AND DISCUSSION OP RESULTS 3
III. PROCESS DESCRIPTION AND OPERATION 10
IV. LOCATION OF,SAMPLING POINTS •' 14
V. SAMPLING AND ANALYTICAL PROCEDURES 19
ill
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LIST OP ILLUSTRATIONS
Page
1 Setup of Method 5 probe and heated flexible 4
line at the inlet
2 Kraft pulping process 11
3 Inlet and outlet of scrubber sampled at Crown 15
Zellerbach Corporation
4 Traverse point locations (inlet) 17
5 Traverse point locations (outlet) 18
LIST OP TABLES
1 Summary of Particulate Results 7
2 Summary of Calculations of Equivalent Pulp 9
Production Rate
IV
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I. INTRODUCTION
Under the Clean Air Act of 1970, the Environmental Protection
Agency Is given the responsibility of establishing perform-
ance standards for hew installations or modifications to
existing installations in stationary source categories. As
a contractor, Monsanto Research Corporation (MRC), under the
Environmental Protection Agency's "Field Sampling of Atmo-
spheric Emissions" program, was asked to provide emission
data from the Crown Zellerbach Corporation of Camas,
Washington.
The field test work was directed by John Synder, Field Test-
ing Section, Emission Measurement Branch. The sampling was
performed by Monsanto Research Corporation with Darrell L.
Harris as Team Leader.
This report tabulates the data collected at the inlet and
outlet of the wet scrubber system controlling the exhaust
of the smelt tank. The smelt tank is part of the overall
recovery system of the kraft pulp mill. Spent digestion
chemicals (black liquor) are burned in a recovery furnace and
smelt is formed in the bottom. This smelt is continuously
removed from the furnace and fed into the smelt dissolving
tank where it is dissolved in scrubbing liquor or makeup
water to make the uncausticized green liquor. Gaseous emis-
sions from the smelt dissolving tank are scrubbed in a..
packed tower scrubber and emitted to the atmosphere.
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Sampling was performed on the inlet and outlet of the packed
tower scrubber. Particulate loadings were determined by
Method 5, "Determination of Particulate Emissions from
Stationary Sources." . Other procedures that were required for
the Method 5 tests were: Method 1, "Sample and Velocity
Traverses for Stationary Sources;" Method 2, "Determination
of Stack Gas Velocity and Volumetric Flow Rate (Type S Pitot
Tube);" Method 3, "Gas Analysis for Carbon Dioxide, Excess
Air and Dry Molecular Weight;" and Method 4, "Determination
of Moisture in Stack Gases." All of'the above methods are
given in the Federal Register., Vol. 36, No. 247, December 23,
1971.
The only modifications required at each sampling location
consisted of correcting the port location and providing a
support surface for the sampling equipment.
This report presents a summary and discussion of sampling
results, a description of the process, the location of sam-
pling points, and a description of the sampling and analyt-
ical procedures. Appendices include all field and analyt-
ical data generated from this project.
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II. SUMMARY AND DISCUSSION OP RESULTS
The inlet and outlet gases from the scrubber system at the
Crown Zellerbach plant were sampled for particulate.loading.
The four runs on the outlet are identified by numbers 1
through 4 prefixed by "A". The one run completed on the
inlet is identified by a "B" prefix. The five particulate
runs were performed over a six-day period.
The inlet was sampled with a flexible heated probe because
the horizontal duct required a vertical traverse. Figure 1
shows the setup of the Method 5 train and the modifications
used to sample the inlet. The six-foot probe was supported
in the vertical port by a bracket attached to the port and a
clamp assembly to hold the probe in the proper location for
each sampling point. On the horizontal traverse, the probe
was supported in the correct position in the port by a board.
The heated flexible line connected the probe to the sample
train. The rest of the sampling train was exactly as spec-
ified in Method 5.
Two 20-point traverses were used on the inlet duct, but the
last two points on the vertical traverse (those on the bot-
tom side of the duct) were not sampled because of a backflow
of water in the bottom of the duct. Run B-l was ruined when
water from the bottom of the duct was sucked into the cy- ...
clone, cyclone catch flask, and filter. Subsequent runs
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HEATED FLEXIBLE LINE
INLET DUCT
SCRUBBER LIQUOR
TO SAMPLING TRAIN
Figure 1. Setup of Method 5 probe and heated flexible line at the inlet
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(B-2 and B-4) were made avoiding these last two points. Run
B-3, to be run simultaneous with run A-3, was deleted from
the program due to a cracked glass probe liner. The 38 points
were sampled for 5 minutes each for a total run time of 190
minutes. At the outlet duct, all runs used two 18-point
traverses, for a total of 36 points. Each point was sampled
for 5 minutes for a total run time of 180 minutes.
Several problems were encountered during the sampling program
involving both sampling equipment failure and plant process
upsets. One entire day was lost (October 17, 1973) due to a
"black out" or "black area" condition developing in the re-
covery furnace. This is caused when a portion of the buildup
(dried black liquor) on the furnace's walls collapses and falls
onto the smelt bed and blocks the primary air ports located
near the bottom of the furnace. These ports produce a zone
where reduction and smelting take place. If the air ports
are blocked, a black zone occurs, and the fuel flow must be
reduced until the condition is corrected.
As mentioned before, the first run on the inlet of the scrubber
was lost due to dipping the probe tip into a scrubbing liquor
backflow at the bottom of the duct. The third run at the
inlet was not performed due to breakage of the probe used at
this location. A spare probe was air shipped to Portland,
but during the fourth run the new probe's heater shorted out
and heat could not be applied to the probe gases. It was
also discovered after the run that the cyclone in the oven
had been broken; however, it was not known when the breakage
occurred. It was noted that the collected volume of water
was much lower than in the previous run for approximately
equal volumes of gas sampled. This was due either to the
lack of heat in the probe permitting condensation and run-back
of stack moisture, or to the broken cyclone allowing ambient
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air to enter the train. In any event, the run is not con-
sidered to be representative and has been deleted from the
results.
No equipment failure occurred during the runs performed at
the outlet of the scrubber. All four of these runs are con-
sidered to be representative.
A summary of the results of particulate sampling is given in
Table 1. Particulate loadings from the probe, cyclone and
filter are indicated as "front halfj" and the total catch
includes'the front half and the impinger residues.
Emission factors are calculated based on the rate of pulp
produced. This rate can be calculated by knowing the amount
of black liquor burned and the percent solids contained in
the liquor. Normal production 'is calculated on a value of
0.0004 M tons of pulp produced per liter of black liquor at
61.4$ solids content base average. The production for the
individual runs is then found by the following equation:
Tstl
[EPP] = [BLF] [PLR] \^\
LbbJ
Where:
EPP = Equivalent pulp production rate, M ton/hr
BLF = Black liquor feed charged, liter/hr
PLR = Pulp to liquor ratio at average % solids, M tons/
liter
S
t =' % solids, test average
Q
b = % solids, base average
and the emission factor is calculated by
T? _ E
EPP
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Table 1. SUMMARY OF PARTICULATE RESULTS
Run Number:
Date:
Method Type
Volume of gas sampled - (Mm3)1* - (DSCF)1.
Percent Moisture by Volume
Average Stack Temperature - °C - (°F)
Stack Volumetric Flow Rate - NmVsec - (DSCFM)2
Stack Volumetric Flow Rate - mVsec - (ACFM)3
Percent Isokinetic
Feed Rate - M tons/hr of Equivalent
Pulp Production - (tons/hr)
Duration of Run - Minutes
Partlculates
Probe, Cyclone, and Filter Catch, mg
mg/Nra3 - (grains/DSCF)6
Kg/hr - (Ib/hr)
Kg/M ton of Equivalent Pulp Production - (Ib/ton)
Total Catch - mg
mg/Nm3 - (grains/DSCF)6
Kg/hr - (Ib/hr)
Kg/M ton of Equivalent Pulp Production - (Ib/ton)
Percent Impinger Catch
A 1
10-16-73
EPA - 5
2.79 (98.6)
35.1
71.1 (160)
8780 (5170)
15500 (9140)
100.0
11.2 (12.3)
180
276.5
98.9 (0.0432)
0.866 (1.91)
0.077 (0.155)
311.1
112 (0.0191)
0.989 (2.18)
0.088 (0.177)
12.1
A 2
10-18-73
EPA - 5
2.92 (103)
35.1
'75.6 (168)
8970 (5280)
16200 (9510)
103.1
9.5 (10.5)
180
143.2
152 (0.0663)
1-36 (3-00)
0.113 CO- 286)
177-6
163 (0.0711)
1.17 (3-23)
0.155 (0.308)
7.2
A. 3
10-19-73
EPA - 5
3.11 (110)
37.7
75-0 (167)
9290 (5170)
17500 (10300)
'105.3
9.1 (10.1)
180
669.3
.214 (0.0937)
1.99 (1.39)
0.212 (0.422)
685.0
219 (0.0959)
2.01 (4.50)
0.217 (0.133)'
2.3.
A 1
10-20-73
EPA - 5
2.62 (92.6)
31.2
73-9 (165)
8220 (4840)
14700 (8680)
100 .'3
.. 11.2 (12.4)
180
368.0
. 110 (0.0612)
1.15 (2.51)
0.103 (0.205)
101.5
153 (0.0668)
1.26 (2.77)
0.113 (0.223)
,8.3
B 2
10-18-73
EPA - 5
2.83 (100)
13-5
77.8 (172)
7590 (1170)
15900 (9340)
108.9
9-5 (10.5)
190
3034.8
1070 (0.467)
8.12 (17-9)
0.855 (1.70)
3196.4
1130 (0.4920)
8.53 (18.80)
0.898 (1.79)
5..1-
iDry Standard Cubic Feet g 70°F, 29.92 in Hg
2 Dry Standard Cubic Peet per Minute @ 70°F, 29.92 in Hg
SActual Cubic Feet per Minute - Stack Conditions
^Normal Cubic Meters at 21.1°C, 760 mm Hg
5Metric Tons per Hour (1 metric ton - 1000 Kg)
"Grains per Dry Standard Cubic Feet
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where:
F = Emission factor, kg/M ton
E = Emission rate kg/hr
EPP = Equivalent pulp production rate, M ton/hr
A summary of calculations of equivalent pulp production rates
for all runs is given in Table 2.
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VD
Table 2. SUMMARY OP CALCULATIONS OF EQUIVALENT PULP PRODUCTION RATE,
Average black
liquor flow Test Black liquor Equivalent pulp Equivalent pulp
Run rate during test time, Avg % charged production production rate
Date
10/16
10/18
10/19
10/20
10/18
No.
A-l
A- 2
A- 3
A- 4
B-2
1pm
485
413
413
485
413
gpm
. 128
109
109
128
109
mln
180
180
180
180
190
solids
58.9
59.2
58.4
59-2
59.2
liters
87210
74270
74270:
87210
78390
gallons
23040
19620
19620
23040
20710
M tons
33.5
28.6
28.3
33.6
30.2
tons
36.9
31.6
31.1
37.1
33.3
M tons/hr
11.2
9.5
9.4
11.2
9.5
tons/hr
12.3
10.5 -
10.4
12.4
10.5
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III. PROCESS DESCRIPTION AND OPERATION
Kraft pulp is produced from wood as shown in Figure 2. The
wood,used at Camas is mostly fir and hemlock. In the pulp-
ing process at elevated temperature, the cooking chemicals
(a water solution of sodium hydroxide and sodium sulfide
called "white liquor") chemically dissolve the wood lignin.
The freed wood cellulose, or pulp, is filtered from the spent
liquor and washed. After being bleached the pulp is made
into paper.
The balance of the process is designed to recover cooking
chemicals. Spent cooking liquor and the pulp wash water are
combined for treatment. The combined stream, called weak
black liquor, is concentrated in multiple-effect evaporators.
The black liquor receives its final concentration in direct
contact evaporators. Liquor leaving the evaporators, con-
taining about 37% water, is fed to the recovery furnace.
The organic constituents (principally dissolved lignin) burn,
and the heat is used to generate process steam. Inorganic
chemicals in the black liquor collect at the bottom of the fur-
nace as a molten smelt. The smelt is a mixture of sodium
carbonate and sodium sulfide. After being tapped from the fur-
nace it is dissolved in water and transferred to a causticiz-
ing tank. Lime added to this tank converts sodium carbonate to
sodium hydroxide, completing the regeneration of white liquor
10
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T
en.
8
CD
Nonconden sables
Vent gas
— Wood
White liquor-*-
-Water-
— *-
1
1
I
\
1
1
J
Digester system
Recovery
furnace
system
Sm
pit
— Pi
— Pulp—*- Pulp washers
-*W
Heavy
^j^lack
liquor
•*
1
Air
1
f 4
Nonconden sables
I 1
Direct Contact
Evaporators M
-
, Multiple
• evaporator
Jlp-*-
ater —
\ '
effect
system
Smel
dissolving
t
tank
Green liquor
"—White liquor—
(recycle to digester)
Causticizing tank
-Lime
Calcium carbonate mud
Figure 2. Kraft pulping process
11
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for recycle to the digesters. A calcium carbonate mud precipi-
tates from the causticizing tank, and is recycled to a kiln
to regenerate lime.
Only one of the above process facilities was tested by EPA.
This facility was the smelt dissolving tank. However, both the
smelt dissolving tank and the recovery furnace system are
described below.
The smelt dissolving tank receives a stream of molten smelt
which is continuously tapped from the recovery furnace. The
molten smelt is subsequently dissolved in the smelt dissolv-
ing tank to form "green liquor." The green liquor is then
sent to the causticizing department for further processing.
Weak wash is used as the dissolving liquid in the smelt tank.
This is the liquid stream that results from washing the lime
mud.
The recovery furnace in which the smelt is formed was manu-
factured by the Babcock and Wilcox Company. This furnace is
designed to operate at an equivalent pulp production of 360
air-dried tons per day, but Crown Zellerbach operates this
furnace slightly above design capacity. Hot black liquor
is sprayed into the furnace through a nozzle near the fur-
nace bottom. Occasionally, when extra heat is needed or
when the black liquor supply is temporarily interrupted,
natural gas or oil is burned.
The smelt dissolving tank system consists of a smelt spout,
a dissolving tank, agitators, circulating pumps, and a sys-
tem of pumps and piping for transferring the dissolving tank
green liquor to the causticizing department. The smelt dis-
solving tank is normally supplied with a closed top, a vent
pipe, and steel housings which enclose the smelt spouts
12
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projecting from the front of the furnace hearth.
A smelt spout is basically a water cooled trough which is
used to disperse or otherwise break up the stream of smelt
before it hits the surface of the liquor in the tank. This
is accomplished by discharging a heavy stream of recirculated
green liquor into the stream of molten smelt through nozzles
located behind and slightly below the smelt spout.
Breaking up of the smelt stream before it hits the liquor
surface in the tank prevents serious explosions which might
be caused by the reaction between the hot smelt and the green
liquor in which it is to be dissolved. In effect, there is
a continual series of small explosions taking place at the
contact point of the molten smelt and the recirculated green
liquor. This contact with the hot smelt thoroughly agitates
the receiving water, and causes the formation of large a-
mounts of steam. The steam is vented to the atmosphere
through a packed tower scrubber which removes particulates.
The scrubber 'is packed with 7.6 cm (3 inch) polypropylene
intalox saddles. The gases move up through the packing where
they are scrubbed countercurrently with fresh water. Two
.streams of water leave the scrubber. One is the overflow
which is ducted to the smelt dissolving tank. The other
is recycled and blended with the incoming makeup water
(fresh water). The scrubbed exhaust gases pass through an
entrainment separator prior to leaving the packed tower.
This entrainment separator is a 0.45 meter (1.5 foot)
section packed with 5 cm (2 inch) polypropylene intalox
saddles.
"13
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IV. LOCATION OP SAMPLING POINTS
Sampling was conducted at the inlet and outlet of the wet
scrubber. The system, shown in Figure 3, has 1.22 m (48 in.)
diameter stack extending from the top of the smelt dissolving
tank through the roof of the building. A 0.91 m (36 in.)
diameter line transfers gas to the inlet of the scrubber. It
extends from the top of the smelt tank at approximately an
80° angle (10° from horizontal) to the bottom of the scrubber,
Inlet samples were taken from ports located in this line
2.18 m (86 in.) downstream from a normally open damper and
0.91 m (36 in.) upstream of an inspection manhole. This con-
stituted a 2.39 diameter distance from the nearest upstream
disturbance and a 1.0 diameter distance from the nearest
downstream disturbance. There were two 10.2 cm (4 in.) ports
at this location, positioned 90° from each other.
The outlet line of the scrubber rejoined the original stack
at a distance of approximately 9 m (29 ft) from the top of
the stack. A normally closed damper was located in the stack
between the scrubber inlet and outlet lines that could be
opened if necessary to bypass the scrubber.
The scrubber outlet was sampled at two 10.2 cm (4 in.) di-
ameter ports positioned 90° from each other on the original
stack. They were located 4.27 m (14 ft) from the junction
of the stack and scrubber outlet and 4.57 m (15 ft) from the
14
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SIDE
3-4" PORTS 0-45-90'
DAMPER (N.C.)
Figure 3. Inlet and-outlet of scrubber sampled
at Crown Zellerbach Corporation
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atmosphere outlet of the stack. This constituted a sampling
location 3.5 diameters from the nearest upstream disturbance
and 3.75 diameters.from the nearest downstream disturbance.
Figures 4 and 5 show the traverse point locations for the
inlet and outlet sampling positions.
16
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0.0
21.875
24.875
26.625
28.125
29.5 \
30.750
31.875
32.875
33.875
34.750
36.0
36 inch I.D.
Figure 4. Traverse point locations.(inlet)
17
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0.0
21.875
24.875
26.625
28.125
29.5 \
30.750
31.875
32.875
33.875
34.750
36.0
36 inch I.D.
Figure 4. Traverse point locations.(inlet)
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1
1
1
1
1
^-\ T.1PR
\ 6.0
\
\ Q.6PR
\
7.
11
5
75
.75
14.5
18.375
z_
28.875
32.75
35-375
37.b25
39-5
..125
42.625
47.25 inch I.D.
Figure 5. Traverse point locations (outlet)
18
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V. SAMPLING AND ANALYTICAL PROCEDURES
SAMPLING PROCEDURES
The wet scrubber inlet and outlet were sampled generally in
accordance with the Federal Register methods. The exceptions
to these methods are listed below.
1. On the inlet, a special flexible line was used so that
the vertical port could be sampled. As can be seen in
Figure 1, a conventional 1.82 m (6 ft)/ stainless steel
glass lined probe was used to traverse. It was held in
the duct by a bracket. A heated flexible sample line was
run from the probe to the sample box connecting it to the
cyclone in the heated oven in the same manner in which the
conventional probe is connected to the sample box. The
heat in the flexible line was controlled by a variac and
kept above 100°C (212°P).
The horizontal port was traversed in the same manner as
the vertical port except that a board was used to support
the stainless steel glass-lined probe, as can be seen in
Figure 1.
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Method 4 tests were run to determine the moisture in
the stacks. On the inlet the moisture was 33% and
unsaturated, and on the outlet, 37% and saturated.
There were droplets of water in the gas stream of
the inlet, so this stack was treated as a saturated
or super-saturated gas stream at 77°C (170°F).
Halfway through each run on both the inlet and out-
let the water in the impingers was measured and the
moisture calculated. If the moisture for the first
half of the run was different from that used in the
nomograph calculation, the nomograph was readjusted
to compensate for this difference in moisture.
ANALYTICAL PROCEDURES
Analytical procedures used on the collected samples generally
followed the methods outlined in the Federal Register .
Samples from the Method 5 sampling trains were recovered as
outlined in the August 17, 1973, Federal Register. After re-
moval of the filters, all sample exposed surfaces were washed
with distilled water or reagent grade acetone as specified.
All sample bottles for liquid samples were obtained from
Wheaton Scientific, Catalogue No. 219630. Each of these
bottles was acid soaked with 1:1 HN03 for one day, rinsed
with distilled water, and soaked with distilled water for
one day prior to use.
20
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Analytical procedure for the Method 5 samples followed the
Federal Register guidelines with one exception. Container
No. 3 as indicated in the method contains water from the im-
pingers and washing of the glassware of the train. The so-
lution was extracted with chloroform and ether, and then the
extracted portion was dried to constant weight, as specified,
In addition, the water remaining after extraction was evap-
orated to dryness at 100°C (212°F) to constant weight.* Both
weights were included in the total mass of particulate.
Sample weights from the Method 5 samplers were reported as
"front half" (probe washings and filter collection weights)
and "total" (front half plus water, chloroform-ether extract
and impinger acetone washing weights).
JSee "Specifications for Incinerator Testing At Federal
Facilities," U. S. Department of Health, Education, and
Welfare publication, October 1967, page 31.
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