SEPA
United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EMB Report 78-NHF-7
October 1979
Air
Urea Manufacture
Test Report
Union Oil Company of
California
Brea, California
-------
AIR POLLUTION EMISSIONS
TEST OF AN UREA
MANUFACTURING PLANT
Contract No. 68-02-2815
Task No. 26
EMB Report No. 78-NHF-7
Submitted to
U.S. ENVIRONMENTAL PROTECTION AGENCY
EMISSIONS MEASUREMENT BRANCH
Research Triangle Park, North Carolina 27711
Submitted by
ENGINEERING-SCIENCE
125 West Huntington Drive
Arcadia, California 91006
-i-
-------
PREFACE
The work reported herein was conducted by personnel from Engineering-
Science, Inc. (ES), Arcadia, California and McLean, Virginia; the GCA/
Technology Division (GCA); the Union Oil Company, Brea, California; the
Analytical Research Laboratory, Inc. (ARLI); and the U.S. Environmental
Protection Agency (EPA).
The scope of work issued under EPA Contract No. 68-02-2815, Work
Assignment No. 26, was under the supervision of the ES Technical Director,
Mr. John T. Chehaske. Mr. Dennis Becvar served as Project Manager and was
responsible for summarizing the test and analytical data in this report.
Analysis of samples performed at the ES field laboratory was under the
direction of Ms. Stefanie Fullmer. Analysis of samples conducted at the
ES laboratories located in McLean, Virginia was under the direction of
Mr. Scott Lambert. Kjeldahl analysis was performed at the ARLI labora-
tories under the direction of Mr. Ray R. Jay. Process samples were analyzed
at the Union Oil, Brea, California labs under the direction of Mr. Robert W.
Waddell.
Mr. Mark I. Bernstein and Mr. Stephen K. Harvey of GCA were responsi-
ble for monitoring the process operations during the testing program. GCA
personnel were also responsible for writing the Process Description and
Operations Section, along with Appendix N of this report.
Members of the Union Oil Company, Brea, California, whose assistance
and guidance contributed greatly to the accomplishments of the test program
include Mr. J. D. Swanburg, Plant Superintendent and Mr. Robert W. Waddell,
Process and Control Superintendent.
Mr. Eric A. Noble, Office of Air Quality Planning and Standards, Indus-
trial Studies Branch, EPA, served as Test Process Project Engineer and was
responsible for coordinating the process operations monitoring.
Mr. Clyde E. Riley, Office of Air Quality Planning and Standards,
Emissions Measurement Branch, EPA, served as Technical Manager and was
responsible for coordinating the emission test program.
-ii-
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TABLE OF CONTENTS
SECTION I
SECTION II
SECTION III
SECTION IV
SECTION V
PREFACE
LIST OF FIGURES
LIST OF TABLES
INTRODUCTION
SUMMARY AND DISCUSSION OF RESULTS
PROCESS DESCRIPTION AND OPERATION
LOCATION OF SAMPLING POINTS
SAMPLING AND ANALYTICAL PROCEDURES
ii
iv
1-1
II-l
III-l
IV-1
V-l
"Appendices Not Included'
-iii-
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LIST OF FIGURES
1-1 Urea Flow Diagram 1-2
II-l Particle Size Summary - Urea Cooler 11-20
II-2 Particle Size Summary - Fertilizer Grade Urea
Prill Tower Scrubber Inlet 11-22
II-3 Particle Size Summary - Feed Grade Urea
Prill tower Scrubber Inlet 11-24
II-4 Six Minute Averages of April 2, 1979 Opacity Readings
on the Rotary Cooler H-29
II-5 Six Minute Averages of April 4 and 5, 1979 Opacity
Readings for the Urea Prill Tower Feed Grade 11-30
II-6 Six Minute Averages of April 4 and 5, 1979 Opacity
Readings for the Urea Prill Tower Fertilizer Grade 11-31
III-l Urea Flow Diagram III-2
IV-1 Sampling Point Locations - Urea Prill Tower Scrubber IV-2
IV-2 Schematic of Sampling Location - Urea Prill Tower
Scrubber Inlet IV-3
IV-3 Schematic of Sampling Location - Urea Prill Tower
Scrubber Outlet IV-4
IV-4 Overhead Schematic of Prill Tower Scrubber Outlets IV-5
IV-5 Urea Prill Tower Scrubber Solution or Liquor Sampling
Point IV-7
IV-6 Observer Positions IV-8
IV-7 Fertilizer Grade Urea Rotary Cooler Sampling Site IV-11
IV-8 Schematic of Sampling Location - Rotary Cooler Outlet
Duct IV-12
-iv-
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LIST OF TABLES
1-1 Summary Log for Fertilizer Grade Urea Cooler Sampling
on April 2, 1979 1-6
1-2 Summary Log for Various Testing of Urea Prill Tower
on April 3, 1979 1-7
1-3 Summary Log for Fertilizer Grade Urea Prill Tower
Sampling on April 4, 1979 1-8
1-4 Summary Log for Fertilizer Grade Urea Prill Tower
Sampling on April 5,'1979 1-10
1-5 Summary Log for Feed Grade Urea Prill Tower Sampling
on April 5, 1979 1-11
1-6 Summary Log for Feed Grade Urea Prill Tower Sampling
on April 6, 1979 1-12
II-l Percent Urea Collected in Sulfuric Acid Impingers II-2
II-2 Percent Urea Collected in Sulfuric Acid Impingers II-3
II-3 Percent Urea Collected in Sulfuric Acid IMpingers II-4
II-4 Summary of All Engineering-Science Colorimetric Urea
Analysis Calibration Graphs II-8
II-5 Summary of All TRC Colorimetric Urea Analysis
Calibration Graphs (Oct. 1978 and Aug. 1979) 11-13
II-6 Summary of Formaldehyde Results for the Urea Cooler
Fertilizer Grade Emissions Test 11-16
II-7 Summary of Formaldehyde Results for the Urea Prill Tower
Fertilizer Grade Emissions Test 11-17
II-8 Summary of Formaldehyde Results for the Urea Prill Tower
Feed Grade Emissions Test 11-18
II-9 Summary of Urea Cooler Particle Sizing Test Results 11-19
11-10 Summary of Prill Tower Scrubber Inlet Fertilizer Grade
Urea Particle Sizing Test Results 11-21
11-11 Summary of Prill Tower Scrubber Inlet Feed Grade Urea
Particle Sizing Test Results II-23
11-12 Opacity Averages During Sampling Runs II-25
11-13 Summary of Prill Tower Scrubber Gas Velocity and Gas
Volume Data 11-32
11-14 Summary of Pressure Drop Readings at Prill Tower
Scrubber During Feed Grade Urea Testing 11-33
11-15 Summary of Pressure Drop Readings at Prill Tower
Scrubber During Feed Grade Urea Testing 11-34
11-16 Summary of Ambient Temperature and Relative Humidity
During Rotary Cooler Testing 11-36
11-17 Summary of Ambient Temperature and Relative Humidity
During Prill Tower Fertilizer Grade Urea Testing 11-37
11-18 Summary of Ambient Temperature and Relative Humidity
During Prill Tower Feed Grade Urea Testing 11-38
-v-
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LIST OF TABLES (CONT'D.)
11-19 Summary of Sieve Analysis and Bulk Density
Measurements on the Rotary Cooler and Prill Tower 11-39
III-l Average Values and Ranges for Process Equipment
Operating Parameters During Mass Emissions Test of
Cooler, 4/2/79 , " III-5
III-2 Average Values and Ranges for Process and Control
Equipment Operating Parameters During Mass
Emissions Tests of Prill Tower - Fertilizer Grade III-7
III-3 Production Rates During Mass Emissions Tests 1II-8
III-4 Average Values and Ranges for Process and Control
Equipment Operating Parameters During Mass Emissions
Tests of Prill Tower - Feed Grade 111-10
-vi-
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SECTION I
INTRODUCTION
-------
SECTION I
INTRODUCTION
Section III of the Clean Air Act of 1970 charges the Administrator of
the U.S. Environmental Protection Agency (EPA) with the responsibility of
establishing Federal standards of performance for new stationary sources
which may significantly contribute to air pollution. When promulgated,
these standards of performance for new stationary sources (SPNSS) are to
reflect the degree of emission limitation achievable through application of
the best demonstrated emission control technology. To assemble this back-
ground information, EPA utilizes emission data obtained from uncontrolled and
controlled sources involved in the particular industry under consideration.
Based on the above criteria, EPA's Office of Air Quality Planning and
Standards (OAQPS) selected the Union Oil Company's urea manufacturing plant
at Brea, California as a site for an emission test program. The test pro-
gram was designed to provide a portion of the emission data base required
for SPNSS for the processes associated with the production of urea.
The EPA Emissions Measurement Branch (EMB), contracted Engineering-
Science (ES) to collect data for urea manufacturing plants. The data
reported herein will be evaluated to determine the degree of emission
reduction achievable through application of one type of demonstrated control
technology. This report presents the results of a test program conducted
during the week of April 2, 1979.
The manufacture of urea includes the use of a prill tower to produce
the "prills" of urea. Liquid urea is pumped to a rotating chamber at the
top of the prill tower. This chamber contains several small openings,
through which urea droplets are sprayed. As the droplets fall through the
ambient air inside the prill tower, they dry to form the urea product (see
Figure 1-1). The Union Oil prill tower operates twenty-four hours per day,
365 days per year and can be used to produce either a feed grade or ferti-
lizer grade of urea. The chemical processes are identical, however, the
prill tower operation is changed for feed grade in order to produce a smaller
sized urea granule.
1-1
-------
_*.TO SEWER
UREA - UNION OIL COMPANY OF CALIFORNIA
BREA, CALIFORNIA
M
ro
CESS " ^
NSATE MAKEUP
SCRUBBI
99.8 % UREA^
FOR
:RS
.• b
V
PRILL
TOWER
J*
BUCKET
ELEVATOR
)FFSIZE,TO DISSOLVIM9 TANK
TO ATMOSPHERE
SCREEN
1
ROTOCLONE
SCRUBBER
SCRUBBER LIQUOR
TO DISSOLVING TANK
COOLER
AGRICULTURE (FERTILIZER)
GRADE PRODUCT
PEED GRADE
PRODUCT
SAMPLING P01KTS
I. ROTARY DRUM COOLER
Z, INLET TO K£ SCRUBBER
3. OUTLET FROM NE SCRUBBER
-------
The emissions control device used on the 250-foot high prill tower
is a group of four scrubbers located at the top. The four scrubbers are
operated simultaneously and have a common sump and pump system for collecting
and recycling the scrubber solution. ES sampled the inlet and outlet simul-
taneously on one of the four scrubbers during fertilizer and feed grade
operations. Prill tower sampling occurred on April 3, 4 and 5 for fertilizer
grade and April 5 and 6 for feed grade urea.
In addition to the prill tower testing, ES sampled the uncontrolled
emissions of the urea cooler. The cooler is connected by a conveyor to the
prill tower product outlet during fertilizer grade urea manufacturing.
Testing of the urea cooler occurred on April 2, 1979.
The sampling data collected from the prill tower scrubbers and urea
cooler were used to determine the mass emissions of urea, ammonia, and
formaldehyde.
All emission tests conducted at this facility were performed only
during times of normal operation as described in Section III "Process
Description and Operations". The emission testing program conducted at
this plant consisted of the following:
1. Particulate: The three repetitions of concurrent inlet and outlet
test runs were performed on the northeast prill tower scrubber. The
tests were conducted using a modified EPA Method 5 sampling train which
provided velocity, moisture and particulate data. The modification
included six impingers in series. The first two were filled with
v
deionized water and the second two were filled with IN sulfuric acid.
The fifth impinger was dry and the sixth contained silica gel. No
in-line filters were used.
2. Particle Size: Data were collected at the inlet to the northeast
scrubber and on the uncontrolled emissions of the cooler. An Anderson
six-stage cascade impactor with pre-separator was used.
1-3
-------
3. Visible Emissions: Data were collected by one observer during the entire
course of the test. Readings were taken at several locations including some
readings approximately fifty feet from the outlet. Observations were performed
in accordance with EPA Method 9 guidelines.
4. Process Samples: Grab samples of urea product were collected once during
each test run. They were collected at the conveyor before urea is carried to
the cooler and storage bins. Bulk density and sieve analyses were performed
by ES, while analyses for ammonia, urea and formaldehyde concentration of the
product samples were conducted by Union Oil laboratory personnel. The analysis
was performed on an aliquot of the samples used for the bulk density and sieve
analysis.
5. Scrubber Solution: Samples of the outlet scrubber solution were collected.
The scrubbers have a common sump which serves all four scrubbers. The solution
from the sump is then pumped through a low pressure manifold system. It is at
this location that scrubber solution grab samples were taken, measuring pH,
temperature, urea, ammonia, ect.
6. Scrubber Velocity and Differential Pressure: Method 5 sampling occurred
on only one of the four scrubbers. On the remaining three scrubbers, velocity
traverses were performed before and after each Method 5 sampling run. During
sampling runs, velocities through the scrubber were monitored every fifteen
minutes at a single average point. These data will be used to determine total
air flow through the prill tower and to estimate total emissions. Also, the
differential pressure across all four scrubbers was monitored during each run
using water-filled U-tube manometers.
7. Relative Humidity and Ambient Temperature: The prill tower is operated
using ambient air. In order to establish operating conditions for the prill
tower, relative humidity and ambient temperature data were collected during
the sampling runs.
8. Urea Cooler Particulate: Three runs of modified Method 5 sampling were
conducted on the outlet air duct of the rotary cooler.- The test location was
just before the rotoclone scrubber. Urea process samples were collected at
the inlet and outlet of the cooler.
1-4
-------
ES personnel were responsible for collecting and measuring the above
emission parameters. Simultaneously, GCA was responsible for monitoring and
recording necessary process and control equipment operating parameters.
Most of the test runs were discontinuous due to excessive loading at
the inlet sampling locations. These interruptions which also delayed the
concurrent outlet sampling were encountered throughout the test program as
indicated in Tables 1 through 6 (Daily Summary Logs).
The following sections of this report cover the summary of results,
process description and operation, location of sampling points, and sampling
and analytical procedures. In addition, Appendix L contains the summary re-
sults for the Quality Assurance Audit samples supplied by the EPA. Detailed
descriptions of methods and procedures, field and laboratory data, and
calculations are presented in various appendices, as noted.
1-5
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TABLE 1-1
SUMMARY LOG FOR FERTILIZER GRADE UREA COOLER SAMPLING
ON APRIL 2, 1979
Union Oil, Brea, California
Urea Participate Testing Meteorolocy
Clock Production
Time Race Inlet
(tons/hr)
1020
1030
1045
1048
1100 Data not
1110 recorded Started Run 1
1115 during
1130 these
1133 times
1145
1146 Changed Ports
1157 Continued
1200 1
1215 . ' 1
1221 Run 1 Completed
1230
1300 Started Run 2
1302 Stopped
1306 Continued
1308 Stopped
1315
1330 Continued
1345 ]
1358 Changed Ports
1400
1415
1430
1433
1445
1500
1506 Continued
1515 j
1524 Run 2 Completed
1530
1541
1545
1550
1556
1600
1613 Started Run 3
1615
1630
1640 . ,
1645 . Changed Ports
1655 Continued
1657 Stopped
1700
1701 Continued
1703 Stopped
1707 Continued
1709. Stopped
1713 Continued
1715 Stopped
1721 Continued
1730 |
1731 Run 3 Completed
1806
1813
Visible Particle Product Relative
Emissions Sizing Sample Humidity
(%)
57
51
47
. Crab ill
Inlet 43
43
43
Crab-#l
Outlet 42
36
39
35
43
39
(Prill 36
Tower) 31
Started Grab #2 40
Inlet 42
45
Crab //2
{ Outlet 43
Stopped 46
43
Continued 45
1 Started
I Run 1 Grab 03 45
Stopped ]f . Inlet
Completed
Run 1 44
43
43
Grab «
Outlet 38
36
31
32
Started
Completed
Run 2
Temperature
(°F)
66.5
69.0
70.5
73.0
71.0
72.5
71.0
73.0
72.0
74.0
74.'0
77.0
77.5
79.0
75.0
74.5
79.0
73.0
72.0
/l.O
70.0
68.5
68.5
63.5
68.5
70.0
70.5
70.5
70.0
Urea
1-6
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TABLE 1-2
SUMMARY
LOG FOR VARIOUS
TESTING OF
UREA PRILL TOWER
ON APRIL 3, 1979
Union Oil,
Brea, California
Meteorology . Velocity
Clock Production.
Time Rate
(tons/hr)
0820
0920
0945
0952 Data not
0959 recorded
1045 during
1110 these
1140 times
1146
1149
1250
1330
1345
1350
1400
1415
1425
1430
1445
1448
1500
1515
1530
1545
16CO
1604
1605
1615
1630
1635
1637
1645
1652
1700
Visible
Emissions
Started
Stopped
Continued
1
1
Stopped
Continued
Stopped
Continued
I
Stopped
Continued
\r
Stopped
Continued
I
Stopped
Continued
1
1
Stopped
Particle
Sizing
Started
Completed
Run 3
Started
Completed
Run 4
(Cooler)
Started
I
Completed
Run 1
Relative
Humidity
(Z)
26
26
24
23
22
21
25
29
29
27
26
25
26
28
26"
Temperature
NW Unit
<°F)
79.5
79.5
80.5 Complete
85.0 Traverse
84.5
85.0
84.0
81.0
80.0
79.5
80.5
80.0
76.0
75.5
74.5
Traverse Monitoring
S!i Unit SW Unit
Complete
Traverse
Complete
Traverse
1-7
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TABLE 1-3
SUMMARY LOG FOR FERTILIZER GRADE UREA PRILL TOUER SAMPLING
ON APRIL 4, 1979
Union Oil, Brea, California
Urea Particulate Testing2 Meteorology
Clock Production Visible Particle Product Relative
Time Rate Inlet Outlet Emissions Sizing Sample Humidity
(tons/hr) (%)
0819
0328
0345 Started
0900
0915
0930
0945
0947 Started
0950 Run 1
0954
0955 14.8
0957
0958
1000 Started
1009 Run 1
1010
1011
1015
1016
1017
1020
1028
1029
1030
1045
1046 |
1048 Changed Ports v
1059 Changed Ports
1100
1104 14.8 Cont'd
50
41
33
33
27
27
Crab 91
Outlet
27
25
1115 Run 1 Stopped 23
1116
1120 Cont'd Run 1 Cont'd
1129
1130
1131
1135
1145
1146 Y
1156 Stopped
1159
1200 Continued
1201 1
1202 i
1210 14.8 I
1212 Completed
1213 Run 1
1214
1215
1216 Y
1217 Completed
22
24
20
1220 Run 1 Stopped (Cooler)
1230 Started 23
1237 Completed
1247 Run 2
1400 24
1415 24
1424 Started
Run 2
Temperature
(°F)
65.0
70.0
74.0
75.5
78.5
78.5
79.5
80.0
82.5
82.5
81.5
81.0
80.0
86.5
87.0
1-8
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TABLE 1-3 (Continued)
SUMMARY LOG FOR FERTILIZER GRADE UREA PRILL TOWER SAMPLING
ON APRIL 4, 1979
Union Oil, Urea, California
Urea Participate Testing3 Meteorology
Clock Production Visible Particle Product Relative Temperature
Time Rate Inlet Outlet Emissions Sizing Sample Humidity
(tons/hr) (%) ("[••)
1430 14.8
1431
1435
1436
1437
1440
1444
1445
1447
1448
1450
1459
1500
1501
1510
1514
1515
1516
1528
1529
1530
1531
1536
1539
1545
1546
1547
1550
1559
1600
Started
Run 2
1
Changed Ports
Continued 24 87.0
\
23 87.5
21 87.0
Grab it2
Outlet
22 87.5
Stopped 23 85.0
r
Changed Ports
Continued
Continued
1601 14.8
1614
1615
1616
1628
1629
1630
1631
1644
1645
1646
1651
1655
1656
1657
1658
1700
1701
1718
1731
1740
1745
1755
•
Completed
Run 2 \
23 85. C
Cor
Completed
Run 2
Stop;
tinued 26 83.0
24 82.0
28 80.0
27 80. 5
'ed 30 79.0
(Cooler)
Started
Completed
Run 3
Urea partlculates also analyzed for ammonia content
1-9
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TABLE I-t
SUMMARY LOG FOR FERTILIZER CRAOE UREA PRILL TOWSR SAMPLING
ON A?1UL 5, 1979
Union Oil, Brea, California
Urea Particulate Testing3 Meteorology
Clock Production Visible Particle Product Relative
Time Rate Inlet Outlet Emissions Sizing Sample Humidity
(tons/hr) (Z)
0926
0930 Started '34
0935
0940
1000
1015 14.5
1016
1017
1020
1025
1026
1030
1031
1040
1041
1045
1043
1C49
105(1
1051
1055
1059
1100
1102
1110
1111
1114
1115
1120
1125
Started
Run. 3
.
1130 14.5
1131
,
30
29
30
Crab #3
Outlet
34
30
Stopped 26
Continued
1132 Changed
1133 Plant down Ports ,, >
7.7
1135 Stopped
1140
1145 29
1155
1200 29
1215 27
1220 14.5 Started Cont'd.
1224
1225
1226
1230
1235
1244
1245
1250
1259
1300
1305
1305 ^
Run 3
Continued
1308 14.5 Changed
1315 Ports
1317
1313 Continued
1320
1329
1330
1335
1344 14.5
1345
1347
1350
1357
1358
1359
1400
1402
1409
1415
1416
1419
1425
••
Completed
Run 3
r
Stopped
30
26
23
26
26
26
Stopped
29
Continued
Completed
,' Run 3
1430 14^5 Change to Feed Grade Urea 30
Temperature
(°F)
74.5
78.5
81.5
80.0
79.0
79.0
85.0
81.5
81.0
81.0
82.0
81.0
83.0
88.0
87.5
88.0
83.5
89.0
87.5
a) Urea particulars also analyzed for an-onia content.
1-10
-------
TABLE 1-5
SUMMARY LOG FOR FEED GRADE UREA PRILL TOWKR SAMPLING
ON APRIL 5, 1979
UNION OIL, UREA, CALIFORNIA
Urea Particulate Testing-1
Clock Production
Time Race Inlet Outlet
(tons/hr)
1545 8.92
1600
1615
1630
1641
1642
1644
1645
1646
1647
1649
1650
1658
1659
1700
1702
1705
1715
1716
1720
1723
1727
1723
1730
1735
1741
1744
1745
1750 '
Started Started
Run 1 Run 1
V >
1753 8.92 Changed Equipment
1757
1758
1800
1815
1830
1852
1859
1915
1930
1945
2000
2004
2015
2030
2040
2043
2044
2045
2055
2059
2100
2110
2114
2115
2117
2125
2128
2129
Ports Problems
Test
Voided
Started
Run 1A
,
t
Changed
Ports
Continued
Continued
2130 ¥
2140 8. 92
2144
2145
2146
2152
2155
2159
i >
Comp
eted
Completed Run 1A
Run 1
2200 8.92
2209
2210
2215
2216
Meteorology
Visible Particle Product Relative
Emissions Sizing Sample Humidity
U)
25
26
26
26
Sta ted
26
26
31
Crab Si
Outlet
31
Stopped
33
37
39
40
46
51
52
53
58
57
63
63
57
63
65
64
Temperature
(°F)
85.5
82.5
81.5
79.5
79.0
78.0
76.5
76.5
72.5
71.5
70.0
69.5
67.0
66.0
64.5
63.0
62.5
61.5
60.0
59.5
61.0
59.5
59.0
60.5
a) Urea parttculates also analyzed for ammonia content
1-11
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TABLE 1-6
SUMMARY LOG FOR FEED GRADE UREA PRILL TOWER SAMPLING
ON APRIL 6, 1979
Union Oil, Urea, California
Urea Particulate Testing3 Meteorology
Clock Production Visible Particle Product Relative Temperature
Time Rate Inlet Outlet Emissions Sizing Sample Humidity
(tons/hr) (%) (°F)
0911
0920
0931
0932
0946
1009 Started
1015 Completed 53 67.0'
1022 Run 1
1030 54 68.5
1045 8.92 . 51 69.0
1055
1057
1100
1102
1103
1104
1109
1110
1115
1116
1125
1130
1131
1.140
1145
1146
1151
1159
1200
1205 8.
1207
1209
1211
1212
.1213
1214
1215
1220
1223
1230
1231
1243
1245
.1246
1247
1259
1300
1310
1315
1316
1323
1325
1329
1330
1331
1333
1335
Started
Started Run 2
Run 2
•
92
. , Cha
Sta ted 49 71.0
47 71.0
48 70.0
48 70. 0
Grab 92
Outlet
StooDed 48 70.0
ContM
ged
Changed Ports I
Ports Continued \y
Continued
Stopped
47 72.0
54 70. 5
Cont'd
51 72.0
V
Stopped 51 72.5
Cont'd
49 74.5
'
Completed
Test 2
48 75.0
v
, Stopped
Completed
1340 8 92 Run 2
a) Urea participates also analyzed for ammonia content
1-12
-------
TABLE 1-6 (Continued)
SUMMARY LOG FOR FEED GRADE UREA PRILL TOWER SAMPLING
ON APRIL 6, 1979
Union OH, Urea, California
Urea Particulate Testing3 Meteorology
Clock Production Visible Particle Product Relative
Tine Rate Inlet Outlet Emissions Sizing Sample Humidity
(tons/hr) (%)
1345 48
1400
1422
1530 8.92 Started
1534
1605
1612
1615
1616
1620
1622
162.9
1630
1635
1644 .
1645
1650
1632
1659
1700
1705
1710
1714
1715
1717
1720
1722
1724
1725 1
Completed
Started Run 2
Run 3 Started
Run 3 52
Changed
Ports
,
Cont'd
60
Grab #3
Outlet
59
63
V
i Stopped
Changed
' Ports Cont'd
1730 Stopped 66
1745 65
1752 8.92 Continued Continued
1755
1759
1800
1810
1814
1815
1825
1823
1829
1830
1831
1840
1844
1345
1855
1859
1900
1904
1915
1931
1934
65
63
66
69
f 73
Completed Completed
Run 3 Run 3 71
Started
i . Completed
1935 8.92 Run 3
1959
2002
2004
2025
2031
2045
Temperature
(°F)
73.5
71.0
67.5
66.0
65.0
62.5
64.0
64.0
64.5
62.5
63.0
61.0
61.5
a) Urea partlculates also analyzed for ammonia content
1-13
-------
SECTION II
SUMMARY AND DISCUSSION OF RESULTS
-------
SECTION II
SUMMARY AND DISCUSSION OF RESULTS
Emissions testing was performed at the Union Oil Company of California
plant in Brea, California, during the week of April 2, 1979. During the
testing program, specific pollutants were sampled simultaneously at the
inlet and outlet of one of the four scrubbers that control the emissions
from the urea prill tower. The outlet of the fertilizer grade urea
rotary cooler was also monitored for specific pollutants. In all instances,
sampling was conducted during process conditions which were considered to
be similar to those used during normal plant operation. Process parameters
were carefully observed by representatives from GCA and emission tests
were performed only when the processes appeared to be operating normally.
The manufacture of both fertilizer grade and feed grade urea generates
ammonia, urea and formaldehyde emissions to the atmosphere. The use of a
routine method of testing, such as EPA Method 5, would not yield an accurate
measure of each of the pollutants. Sampling and analytical methods which
represented extensive modification to EPA Method 5 were developed by EPA.
These modifications were used to determine the concentrations of urea,
ammonia, and formaldehyde in the various air streams tested.
However, the results for urea and ammonia appear to be atypical from
those of other plants tested by EPA. As a result of this, an extensive
review of the ES laboratory procedures and analysis was conducted by two
independent contractors. A review of their results is summarized in the
following narrative.
In the review, it was attempted to trace the urea values presented
in the summary tables of the report to the raw data contained in the lab-
oratory notebook pages (see Tables II-l and II-3). These tables present
the percent of urea collected in the acid impingers. The data shows that
the Union Oil values are very high as compared to the values obtained at
other urea plants. Comments are as follows:
II-l
-------
TABLE II-l
PERCENT UREA COLLECTED IN SULFURIC ACID IMPINGERS
(values in mg of urea)
Union Oil. 9rea. California
Prill Tow.vr Test Fertilizer Grade Mo. 1
Northeast Stack „ _ ,
Inlet Percent Urea Collected
Impq Water Impo Acid Total jn Acid
484 1380 1864 74
755 1071 1826 59
303 685 983 69
Outlet
Run 1 653 1082 T735 62
Run 2 610 552 1162 43
Run 3 374 650 1024 63
Prill Tower Test Feed Grade No. 1
Northeast Stack
Inlet
Run 1 321 1132 1453 78
Run 2 2330 1173 3503 34
Run 3 1939 1031 3070 35
Outlet
Run 1 313 1164 1982 59
Run 2 656 1065 1721 62
Run 3 734 1300 2034 64
Cooler Test Ho. 1
Inlet
2133 75 2203 3
1803 0 7803 0
2146 43 2189 2
Union 011, Brea. California
Prill Tower Test Fertilizer Grade No. 2
Northeast Stack Percent Urea Collected
Outlet Imog Water impo Acid Total in Ursa
Run 1 77.9 1.6 79.5 2.0
Run 2 50.1 1.6 51.7 . 3.0
Run 3 62.0 1.5 63.5 2.4
Union Oil, 3rea, California
Cooler Test No. 2
Inlet
5357 1.7 5359 <1
3780 1.5 3782 <1
4517 1.9 4519 <1
II-2
-------
TABLE II-2
PERCENT UREA COLLECTED IN SULFURIC ACID IMPINGERS
(values in mg of urea)
Prill Tower Test Fertilizer Grade .'lo. 1
Stack A
Inlet
Run 1
Run 2
Run 3
Impq Water
449
622
502
Impq Acid
7.7
9.8
9.5
Percent Urea Collected
Total in Acid
457 2
632 2
512 2
Outlet
Run 1
Run 2
Run 3
33.0
85.4
59.7
6.1
7.5
12.3
39.1
92.9
72.0
16
8
17
Stack C
Inlet
Run 1
Run 2
Run 3
304
217
275
6.6
3.8
11.0
.311
226
286
Outlet
Run 1
Run 2
Run 3
37.4
66.6
61.7
5.2
8.2
7.8
42.6
74.8
69.5
12
11
11
Prill Tower Test Feed Grade No. 1
Stack A
Inlet
Run 1
Run 2
Run 3
380
590
534
10.0
9.3
10.9
390
599
545
Outlet
Run 1
Run 2
Run 3
30.4
94.0
111.0
6.0
6.9
8.2
36.4
101
119
16
7
7
Stack C
Inlet
Run 1
Run 2
Run 3
411
425
463
9.8
9.0
10.5
421
434
474
Outlet
Run 1
Run 2
Run 3
36.6
86.6
99.7
7.0
8.6
7.4
43.6
95.2
107.
16
9
7
II-3
-------
TABLE II-3
PERCENT UREA COLLECTED IN SULFURIC ACID IMPINGERS
(values in mg of urea)
Prill Tower Test Fertilizer Grade no. 2
Inlet
Percent Urea Collected
Impg Water Iiroq Acid Total in Acid
730 10 740 1.0
232 12 244 4.9
481 7.6 433.6 2.0
Outlet
Run 1
Run 2
Run 3
'6.0
17.1
20.3
6.0
17.1
20.3
Outlet
Run 1
Run 2
Run 3
11.9
13
14.6
11.9
13
14.6
0
0
0
Granulator Test No. 1
Inlet
Run 1
Run 2
Run 3
Probe
Water
Wash
37,104
31.423
23.880
Impg
Water
27,176
28.665
16,320
Water
Total
64,280
60.083
40,200
Iinpg
Acid
0
1.5
0
Total
b4.230
60,090
40,200
Percent Urea Collected
0
<1
0
in Acid
Outlet
Run 1
Run 2
Run 3
15.3
31.0
24.6
22.6
35.8
28.1
37.9
66.8
52.7
1.62
7.08
9.33
39.5
73.9
62.0
4
10
15
Granulator Test No. 2
Inlet Ifiipqr Water
Kun 1
Run 2
Run 3
23,905
25.063
26.218
Impq Acid Total Percent Ursa Collected In Acid
15.0 23.920 <1
27.0 26,090 <1
40.0 26,253 <1
Outlet
Run 1
Run 2
Run 3
65.9
65.8
57.1
7.3
5.2.
70.6
73.1
62.3
7
10
' 8
II-4
-------
1. Appendix G, Section I, Discussion of Analytical Methods.
The analytical methods for urea, ammonia and formaldehyde
appear to be correct as explained in this section. However,
there are errors in the presentation of the calculations:
a. The urea colorimetric analysis graph is correct. The slope
is similar to graphs done by other participating labs
(see EMB report 80-NHF-15).
b. The ammonia graph is similar to those done at other labs
(see EMB report 78-NHF-3). The ammonia equation should
read:
gNH3/ml = Abs. of aliquot (not mgNH3/ml).
0.166
c. The formaldehyde equation and graph should have the units
mg formaldehyde /ml. Then the graph would be similar to
those presented by other labs.
2. Appendix G, Section II, Laboratory Data Summaries; Section III,
Copy of ES Laboratory Notebook.
The numbers presented in Tables G-l and G-2 were traced back
to the raw data in Section III. The scrubber water data were
not reviewed.
a. Table G-l presents the urea colorimetric results in total
mg. It was possible to verify the sample number, volumes,
dilution factors and absorbance readings and calculations.
The first dilution factor comes from the dilution of either
50 or 100 mis to 250 ml. The second factor accounts for a
10 ml aliquot in 25 ml. The third factor comes from the
dilution of the total sample to 1000 ml if the original
volume was less than 1000 ml. Although it was possible to
follow the calculations, there was one very serious omis-
sion from the data for the prill tower fertilizer and
feed results. These samples wre analyzed on 4-14-79.
The calibration curve that corresponds to this data could
not be located. It appears that these results were cal-
culated using calibration data from 4-2-79 and 4-3-79.
II-5
-------
Without a calibration check on the day of the analysis, it
is not possible to judge the validity of this data. These
samples contained extremely large proportions of urea in
the acid impingers. In addition, there are no comments on
the appearance of these samples after the color was developed.
The fertilizer grade cooler outlet samples were analyzed on
4-3 and 4-5-79. Calibration data similar to that obtained
by TRC of New England on a similar test was run on 4-2 and
4-3-79. The sample analyses were repeated on 4-5-79 because
the analyst noted that the line current fluctuated when the
readings were being taken on 4-3. On 4-5 the Spec 20 was
connected to a stable power source. The majority of samples
were calculated from the data of 4-3. The absorbances for
the acid impinger samples were low as should be expected,
and since the calibration curve appears correct, this data
is believed to be correct. However, the water impinger
absorbances (approximately 1.0 Abs.) were well above the
highest point on the calibration curve (0.58 Abs.) These
samples should have been repeated using smaller aliquots.
These calculations of urea in the water portion are invalid
unless it was determined elsewhere that the calibration
graph was linear up to 1.0 Abs. Normally for high concen-
trations, the line tends to flatten out so that the true
results should actually be much higher than those presented
in Table G-l.
b. Table G-2 presents the ammonia colorimetric results as total
mg NH3. The method of analysis was direct nesslerization.
It was possible to verify the sample number, volume, four
factors, absorbance and calculation of mg ammonia in the
samples. The dilution factors for the prill tower fertilizer
and feed samples followed the EPA ammonia dilution procedure
exactly with an additional dilution of 100 —> 1000 recorded
in the notebook. The fertilizer cooler sample dilutions
were different and were found in the notebook next to the
absorbance readings.
The units for column five should be y g/ml (not mg/ml) but
the end calculation was correct. The calculation was based
II-6
-------
on the equation presented in Section I of Appendix G under
ammonia analysis. This graph is very similar to direct
nessler ammonia graphs run countless times by lab personnel
with consistent results. Copies of the ammonia standards
preparation done on 3-23-79 were found in the ES lab notebook.
The lab notes stated that the absorbances were read @ 405 nm,
but the absorbance readings were not found in the notebook
copies. The cooler samples were run on 4-6-79 and the prill
samples were run on 4-14-79. There was no calibration data
presented in the notebook on these dates or at any other
time. Since the graph used for the calculations agreed with
reproducible graphs presented by other labs, it would seem
reasonable to accept the calculations as valid except for
those with absorbance readings above 0.65 (the highest point
of the calibration line). The two samples above this value
should have been repeated using a smaller aliquot. These
were for the fertilizer grade, cooler outlet R2-1 and R3-1.
3. Appendix G, Section III, Copy of ES Laboratory Notebook
The colorimetric urea analysis calibration graphs have been com-
piled in an effort to determine the consistency of the method as
performed by ES (.see Table II-4). Although the concentration of
the standard was not always recorded with each run, it was assumed
that they were consistent and corresponded to the EPA Calibration
Procedure.
Graphs #2B and 3 appeared to be used for the sample urea calcu-
lations. The correlation coefficients were very good, the slopes
were similar to graphs done at TRC and the y-intercepts were very
close to 0.000 Absorbance. Samples analyzed with these standards
would be valid (cooler samples). Graphs 2B and 3 may be readings
of the same standards. The lack of good linear regression data
makes using the graph for calculating results of samples done on
4-14-79 questionable.
In order to follow proper colorimetric analytical procedures, the
y-intercept should pass through 0.00 Absorbance. The remaining
graph intercepts were much higher than this. The other seven
II-7
-------
TABLE II-4
Graph I
1
2A
I
00
l-ab Page
13
13
LW
3I.W
16
SUMMARY OF ALL ENGINEERING-SCIENCE COLORIMETRIC UREA
ANALYSIS
CALIBRATION GRAPHS
Linear Repression
Date
03-28-79
03-28-79
04-02-79
04-03-79
08-27-79
08-28-79
08-29-79
Calibration Points
Absorbancc at (mp/ml)
0.00 0.05 ~0.10 0.1S 0
.72 .92 1.20 2
0 .55 .65 .76 .
0 0.14 0.31 0.445 0
0 0.16 0.30 0.43 0
U18\ / 18 \
••'••
.17 / I .19J
\ *
.08 .12 .17 .18
0.0 .699 .866 .999 1.
0.0 .605 .805 .900 1.
.20 0.25
.15
.85
.58
.58
21
21
029
10
Corr.
Cocf.
r
.966
.904
.9991
.9994
.9214
.9792
.8828
.9374
Slope
in
9.56
3.82
2.93
2.86
0.98
0.64
4.72
4.99
Y-Incpt.
y_
.042
0.18
.002
.008
.04
0.088
0.247
0.183
Continents
Spec 505.
Diluted with 11,0?
Diluted with clhnnol.
Oilier readings written
be si ilu this Mis. appear
to be absorbance vendini; -
much lower. These appear
in parentheses.
Rend on Spec 20. "needle
waivcrcd, recalibrated
machine." Some readings
were crossed out. Diluted
with elhanol.
Readings drifted.
"Run in Orange City Lab" -
Thcnc anpear to be the saino
standards from Graplt 5.
08-30-79
0.0 0.400 0.625 0.850 1.08 1.2S ? .9908 4.866 .093
Run in Orange City.
-------
slopes varied greatly from that used to calculate the sample
concentrations and the correlation coefficients were not as
good.
During some urea analysis at ES, comments were made in the
notebook that ethanol was used to dilute the standards and/or
samples to volume after the color reagent was added in order to
"ensure clarity". The only difference between graphs 2A and 2B
was that water was used to dilute standards A and ethanol was
used to dilute standards B. The high value for the y-intercept
for Graph 2A (0.18 Abs.) indicates that there was some inter-
ference (turbidity or improper color) in these samples. From
this observation, one might presume that the lab water at ES
introduced an interference in the standards. In accordance
with the EPA procedure, all samples were diluted to 1000 mis
with water before the analyses were done. For most of the
water samples, this was a relatively small addition of water.
The acid samples, however, had much smaller volumes, so that
between 500-800 ml of lab water were added. The acid samples
were also diluted more for the urea analysis. If the lab water
was the source of interference, then the acid samples would
have had more of the interfering agent in them. This hypothesis
would be invalid if the water used in the field sampling trains
and cleanup came from the same source as the laboratory water.
4. Appendix H, Discussion of Kjeldahl Method
The raw data from the ARLI notebook was reviewed and a brief
study of the discussion and data summary was done.
a. The Kjeldahl analytical procedure as specified in the EPA
urea determination method was not followed. The specified
EPA Kjeldahl urea analytical procedure is referred to as a
"Direct Method with Preliminary Distillation to Remove
Ammonia". The Kjeldahl area analytical procedure employed
by the Analytical Research Laboratories is referred to as an
Indirect Method of Analysis.
II-9
-------
Direct Method with Preliminary Distillation to Remove Ammonia
A buffering compound is added to the sample and the solution
is then distilled (boiled) to remove ammonia. Digestion
reagents are then added to convert all organic nitrogen (urea)
to ammonia. The solution is distilled, and the distillate
is analy.zed for ammonia either by direct nesslerization or
by titration. The urea concentration is then calculated,
stoichiometrieally from the measured ammonia concentration.
Indirect Method
Two equal aliquots of sample are drawn. A buffering compound
is added to the first aliquot and this solution is then dis-
tilled. The distillate is analyzed for ammonia. The digestion
reagents are added to the second aliquot, converting organic
nitrogen (urea) to ammonia. The solution is then distilled
and this distillate is analyzed for ammonia. Urea concentra-
tion is calculated by subtracting ammonia nitrogen (first
aliquot) from total nitrogen (second aliquot) and applying
a stoichiometrie conversion factor.
The indirect method of analysis used by ARLI is susceptible
to inaccuracy, since errors in the component analyses (for
total nitrogen and ammonia nitrogen) may be compounded when
urea nitrogen is calculated by subtraction. Relatively small
titrant volumes were used in the ARLI titration analyses: the
total nitrogen and ammonia nitrogen titrant volumes ranged
from 5.0 ml to 10.0 ml. In order to minimize titration
errors, it has been found that titrant volumes of at least
20 ml should be used. A disadvantage of the indirect ti-
tration method is that the entire sample is used for one
titration; consequently, if an error is made or if a result
is suspect, there is no recourse for re-analysis.
Both of the Kjeldahl urea analysis methods require that
correction factors be applied to the urea and ammonia con-
centrations in order to account for the conversion of some
11-10
-------
urea to ammonia during distillation. The standard correc-
tion factor is: 7 percent of the urea content of the sample
is converted to ammonia during distillation1). Thus, the
urea concentrations should be increased by 7 percent, and
the ammonia concentrations should be decreased by a stoich-
iome trie ally equivalent amount.
In the Laboratory Data Summary, the correction for the 7
percent conversion of urea to ammonia during the distilla-
tion step was not done properly. Seven percent of the
ammonia value was subtracted from itself to give the cor-
rected ammonia value. The correct method is to subtract 7
percent of the ammonia equivalent to the corrected urea
value. Doing this would make many of the ammonia results
negative. However, this would be consistent with results
obtained at other sites.
5. Appendix L, EPA Audit Sample Analysis Results
Two sets of audit samples were analyzed by the Kjeldahl urea
method by Analytical Research Laboratories. The second set
was also analyzed by the colorimetric urea method by ES in
August 1979. Graphs 4 to 7 in Table I were generated during
the analysis of the audit samples. It was attempted to calcu-
late the audit results based on the sample absorbance readings
obtained when these graphs were run. Calculations based on the
three graphs did not yield results that matched the reported
values. Calculations using the equation presented in Appendix
G-l for the urea sample analysis did not yield corresponding
results. The audit calculations were not done out in the note-
book and it was not possible to follow the dilution and/or
colorimetric absorbance data. Due to incomplete data within
the report it was not possible to verify the reported values.
1) Standard Methods of Water and Wastewater Analysis, APHA, AWWA,
WPCF, 14th edition, 1975, p. 408.
11-11
-------
6. Co lor line trie Analysis by TRC at a Urea Facility
In October 1978, TRC performed its first urea sampling and analy-
tical program for the Emission Measurement Branch. The colori-
metric urea procedure was the same as used by ES. Analytical
calibrations and problems realized by TRC have been summarized
in an effort to point out some of the possible sources of problems
with the ES analytical data.
a. Table 11-5 lists the calibration data for six series of urea
standards done over a period of ten days. The seventh series
of standards were done almost one year later. The linear
regression data were consistently good for these analyses.
The correlation coefficient approached 1.000 (perfect corre-
lation) and the y-intercept approached 0.000 absorbance.
b. A problem occurred with the color development of samples
extremely high in ammonia (11 to 40 grams). After the color
reagent was added, the sample color was similar to the
blanks, but the absorbance readings were high. The sample
pH's were high due to the amount of ammonia. These samples
were repeated; first diluting them and then adjusting the pH
to less than seven with hydrochloric acid before adding the
color reagent. The absorbance of the samples then were
close to 0.000 which corresponded to the visual appearance
of the samples. The regular samples had ammonia values in
the range of 0.1 - 1.0 grams and proper color development
was observed. The ES samples were also in this same range,
so the high urea values in the acid impinger samples were
probably not due to ammonia interference.
To summarize, the notebook raw analytical data presented in
Appendix G, Section III does not provide proof of consistent
and reliable calibration data for the urea colorimetric
analysis. It does show that an effort was made to rerun
standards on different instruments, in other laboratories,
and with different solvents (water or ethanol) in an attempt
to achieve reliable calibrations. The laboratory water may
11-12
-------
1 JJ-M-89
2 JfM-90
5 MF5-61
4 MP5-68
M
H
£ 5 MP5-78
6 Mf5-78
7
10-18-78 .00
10-19-78 .00
10-20-78 .00
10-24-78 .OC
10-25-78 .0(
10-27-78 .01
08-28-79 .01
TABLE II-5
SUMMARY OF ALL TRC COLORIMETRIC UREA ANALYSIS
CALIBRATION'GRAPHS (OCT. 1978 AND AUG. 1979)
Linear Regression
Calibration Points Corr.
AbsorEnnce at TmBTmH ^^ Slopc ^'lnc^-
Date 0.00 0.01 0.02 OT05 0.10 0.15 0.70 0.75 r m £
.08 0.216 .425 .644 .854 1.0000 4.285 -.002
.000 .042 .213 .416 .630 .838 1.024 0.9998 4.127 .004
.000 .033 .191 .418 .598 .828 1.032 0.9997 4.146 -.007
.210 .424 .635 .839 1.0000 4.206 .001
.178 .385 .574 .775 0.9998 3.89 -.007
.199 .403 .605 .812 1.0000 4.06 -.002
.186 .362 .526 .68 0.9993 3.40 0.011
-------
have been a source of interference, but the ammonia concen-
centration of the samples should not have caused a problem
with the color development.
Based on the review of the Engineering-Science report, it can be
concluded that the problems with the Union Oil data resulted from the
analytical techniques used during the analyses. The values presented for
the prill tower acid impingers were extremely large as compared with
results obtained from other similar tests (Union Oil, Brea, California,
EMB Report No. 80-NHF-15). Examination of the ES lab data reveals that
the acid impinger samples were analyzed approximately two weeks after the
standards calibration curve was prepared. A summary of the various
standard curves prepared by ES show a tremendous variation from day to
day in the slope and intercept for the calibration line. As there was no
standard calibration curve prepared during the actual sample analysis the
unusual high values are believed to be the result of poor analytical
techniques.
During some of the urea analyses, ethanol was used to dilute the
standards and/or samples to volume after the color reagent was added.
High intercept values indicate there was some interference (turbidity
or improper color) associated with the samples. This interference would
have produced a positive effect on the sample values.
The cooler sample values were produced from a calibration curve that
was well below the actual sample range. The absorbances for the acid
samples were low as would be expected, however the absorbances for the
water samples were well above the highest point on the calibration curve.
These sample analyses should have been repeated using smaller aliquots.
This procedure would have a negative effect on the data thus producing
lower values than were actually present.
The Kjeldahl urea results are considered to be totally invalid due
to prescribed analytical procedures and techniques not being followed as
specified in the EPA analytical procedure.
In conclusion, it is believed that the urea and ammonia emissions
data produced in the ES report are invalid and should not be used to
support the industry Background Information Document.
11-14
-------
Formaldehyde Results for Fertilizer Grade Urea
Determinations for formaldehyde concentrations were performed by ES.
A chromotropic acid colorimetric method was used for these determinations.
The inlet side of the scrubber yielded 3.42 Ibs. per hour and the outlet
side yielded 1.22 Ibs. per hour,.for a scrubber efficiency of 63 percent.
The formaldehyde data are summarized in Tables II-6 and II-7. The lower
scrubber efficiency for the formaldehyde can be attributed to reduced
solubility of formaldehyde in water.
Formaldehyde Results for Feed Grade Urea
The formaldehyde results are summarized in Table II-8. The inlet
yielded 0.77 Ibs. per hour and 1.62 Ibs. per hour for the outlet with a
zero scrubber efficiency.
Particle Size Test Data
Particle size testing data was collected at the prill tower scrubber
inlet and the rotary cooler. An Anderson six-stage cascade impactor was
used for these determinations.
The results of the urea cooler particle sizing are summarized in
Table II-9. The majority of the particles were in the 17.00ym range.
With this large sized particle, the efficiency of the Anderson unit is
extremely limited. Grain loading averaged 4.52 grains per dry normalized
standard cubic feet (DNCF). The particle size data is also presented as
a graph in Figure II-l.
The results of the fertilizer grade urea particle size testing is
summarized in Table 11-10. The majority of the particles were in the
1.5 ym range. Grain loading averaged 0.05 grains/DNCF. The particle
size data is also presented as a graph in Figure II-2.
The results of the feed grade urea particle size testing is summarized
in Table 11-11. The majority of the particles were in the 3.0um range.
Grain loading averaged 0.02 grain/DNCF. The particle size data for feed
grade urea is also presentd as a graph in Figure II-3. Appendix B con-
tains an extensive discussion and graphical presentation of the particle
size results.
11-15
-------
TABLE I1-6
SUMMARY OF FORMALDEHYDE RESULTS FOR THE UREA COOLER
FERTILIZER GRADE EMISSIONS TEST
UNION OIL COMPANY, BREA, CALIFORNIA
H
H
I
M
CT>
Date
Volume of Gas Sampled (DSCF)
Percent Moisture by Volume
Average Stack Temperature (°F)
Stack Volumetric Flow Rate (DSCFM)a
Percent Isokinetic
Production Rate (tons/hr)
Formaldehyde Concentration and
Mass Flow Rate
Analysis Procedure -
mg
gr/DSCF
lb/hrb
Ib/ton
Run 1
4/2/79
33.12
2.7
168
4519
102
120.0
0.06
2.16
— —
Run 2
4/2/79
37.95
2..2
167
7471
85
Data Not Recorded
212.6
0.09
5.52
— —
Run 3
4/2/79
25.58
2.1
160
4236
101
During Test Period
311.7 -
0.19
6.81
— —
Average
32.22
2.3
165
5409
96
214.8
0.11
4.83
__
a) Volumetric flows determined from flow data (see Table 11-10).
b) Emission factors calculated using outlet volumetric flow rates.
-------
TABLE II-7
SUMMARY OF FORMALDEHYDE RESULTS FOR THE
UREA PRILL TOWER FERTILIZER GRADE EMISSIONS TEST
UNION OIL COMPANY, BREA, CALIFORNIA
M
Inlet Location
Run Number :
Date
Volume of Gas Sampled (DSCF)
Percent Moisture by Volume
Average Stack Temperature (°F)
Stack Volumetric Flow Rate (DSCFM)a
Percent Isokinetic
Production Rate (tons/hr)
Formaldehyde Concentration and
Mass Flow Rate
Analysis Procedure -
mg
gr/DSCF
lb/hrb
Ib/ton
1
4/4/79
26.59
1.3
146
13,599
102
14.8
53.4
0.03
3.61
0.24
2
4/4/79
28.29
1.5
149
12,928
103
14.8
43.8
0.02
2.64
0.18
3
4/5/79
25.32
2.9
149
12,931
102
14.5
59.5
0.04
4.01
0.28
Average
26.74
1.9
148
13,153
102
14.7
52.3
0.03
3.42
0.23
1
4/4/79
120.16
3.1
72
13,599
98
14.8
109.9
0.01
1.64
0.11
Outlet Location
2
4/4/79
121.02
3.4
76
12,928
104
14.8
92.3
0.01
1.30
0.09
3
4/5/79
124.20
3.5
74
12,931
107
14.5
53.9
0.01
0.74
0.05
Average
121.79
3.4
74
13,153
103
14.7
85.4
0.01
1.22
0.88
a) Volumetric flows determined from flow data (see Table 11-10).
b) Emission factors calculated using outlet volumetric flow rates.
-------
TABLE II-8
SUMMARY OF FORMALDEHYDE RESULTS FOR THE
UREA PRILL TOWER FEED GRADE EMISSION TEST
UNION OIL COMPANY, BREA, CALIFORNIA
M
M
I
M
oo
Inlet Location
Run Number :
Date
Volume of Gas Sampled (DSCF)
Percent Moisture by Volume
Average Stack Temperature (°F)
Stack Volumetric Flow Rate (DSCFM)a
Percent Isokinetic
Production Rate (tons/hr)
Formaldehyde Concentration and
Mass Flow Rate
Analysis Procedure -
mg
gr/DSCF
lb/hrb
Ib/ton
1
4/5/79
86.57
1.0
222
3109
100
8.92
57.2
0.01
0.27
0.03
2
4/6/79
99.01
1.5
230
2933
101
8.92
184.3
0.03
0.72
0.08
3
4/6/79
78.88
1.8
230
3035
104
8.92
266.4
0.05
1.35
0.15
Average
88.13
1.4
227
3026
102
8.92
169.3
0.03
0.77
0.09
1
4/5/79
52.98
96
3109
109
8.92
106.2
0.03
0.82
0.09
Outlet Location
2
4/6/79
47.67
4.0
100
2933
103
8.92
175.9
0.06
1.43
0.16
3
4/6/79
48.33
5.2
100
3035
102
8.92
322.3
0.11
2.67
0.30
Average
49.66
5.1
98
3026
105
8.92
201.0
0.07
1.62
0.18
a) Volumetric flows determined from flow data (see Table 11-10).
b) Emission factors calculated using outlet volumetric flow rates.
-------
TABLE II-9
i
M
VO
SUMMARY OF UREA COOLER
PARTICLE SIZING TEST RESULTS
Union Oil Company, Brea, California
Particulate Aerodynamic"
ES Test Sampling Test Test Concentration Size Range
No. Location Date Time grains/dscfa ym
1 Cooler 4/3/79 1637-1652 4.20 >17.49
(Pert.) 10.92-17.49
5.05-10.92
3.24-5.05
1.63.3.24
0.75-1.63
2 Cooler 4/4/79 1237-1247 4.74 XL6.57
(Pert.) 10.35.16.57
4.78-10.35
3.07-4.78
1.54-3.07
0.7-1.54
3 Cooler 4/4/79 1745-1755 4.61 XL6.87
(Pert.) 10.53-16.53
4.87-10.53
3.13-4.87
1.57-3.13
0.72-1.57
Mass in
Size Range
%
98.8
0.5
0.5
0.1
—
—
99.2
0.4
0.3
—
—
—
99.2
0.4
0.4
—
—
— —
a) Standard conditions are 20°C and 760 mm Hg.
b) As unit density spheres.
-------
FIGURE II-l
PARTICLE SIZE SUMMARY
UREA COOLER
EQUIVALENT AERODYNAMIC DIAMETER
VERSUS
.-PERCENTAGE OF MASS
UNION OIL COMPANY, BREA, CALIFORNIA
10.
9
8
7
6
5
99.99 99.9 99.8
99 98 95 90 80 70 60 5O 40 30 20 10 5 2 1 0.5 0.2 0.1 0.05 001
eS
H
H
a
Q 2.
0
M
3
53
S
§ '.
EQUIVALENT
iiiiLi
±ji'i
in;
-f!-Hfi
4 ttp
•-i-l=£
Tii
UL
-H
?I
fff
Uff
Htt
-•(-(-{-
mi
l
M*ffiM
WP
IT
itttipr
.1414.;.
I
ifflf
It lu
rirll^
till
ffi
-J-U
--fM
ii|ii
rtTri
l i n
1
•I -iftt
1+tf
I rrl'l
m-
TaTt&-r
»
•^iii
m
H!
l
ILLT
iTl-i
^:iJ
fflT-
!.tju
il
F
1
1
i-H
iflr
IT''"'
111-lfF
1C
9
8
7
6
S
0.01 O.OS 0.1 0.2 0.5 1 2 S 10 20 30 40 50 60 70 80 90 95 98 99 99.8 99.9 99.99
PERCENTAGE OF MASS < CORRESPONDING SIZE
0 ---- -
Test #1 4/3/79
Test n 4/4/79
Test #3 4/4/79
11-20
-------
TABLE 11-10
ES Test Sampling
No. Location
1 Scrubber In
(Fert.)
2 Scrubber In
(Fert.)
3 „ Scrubber In
(Fert.)
4 Scrubber
In
(Fert.)
SUMMARY OF PRILL TOWER SCRUBBER INLET
FERTILIZER GRADE UREA - PARTICLE SIZING TEST RESULTS
Union Oil Company, Brea, California
Particulate Aerodynamicb
Test Test Concentration Size Range
Date Time grains/dscfa p m
4/2/79 1541-1556 0.06 >16.16
10.09-16.16
4.66-10.09
3.00-4.66
1.50-3.00
0.09-1.50
<0.09
4/2/79 1806-1813 0.05 >17.79
11.11-17.79
5.14-11.11
3.31-5.14
1.66-3.31
0.77-1.66
<0. 77
4/3/79 0952-0959 0.06 XL9.88
12.42-19.88
5.75-12.42
3.70-5.75
1.87-3.70
0.87-1.87
<0. 87
4/3/79 1146-1149 0.09 XL5.01
9.37-15.01
4.33-9.37
2.78-4.33
1.39-2.78
0.63-1.39
<0.63
Mass in
Size Range
%
16.7
2.7
4.5
4.7
16.5
21.5
37.8
5.2
0
3.3
4.2
18.7
50.5
18.2
11.5
1.9
2.9
3.6
4.9
44.5
30.7
4.9
3.8
3.0
3.1
30.0
26.5
28.7
a) Standard conditons are 20°C and 760 mm Hg.
b) As unit density spheres.
-------
FIGURE II-2
PARTICLE SIZE SUMMARY
FERTILIZER GRADE UREA
PRILL TOWER SCRUBBER INLET
EQUIVALENT AERODYNAMIC DIAMETER
VERSUS
PERCENTAGE OF MASS
UNION OIL COMPANY, BREA, CALIFORNIA
• ' . ' .••••• — ' ..... - "•'•'" • • - '-'
32 J:
Ed
3
M
O
a
§
w
H
Z
2.
(M 1< M V 4,1 W .11 10 * ?
i o> o.' o i it n »oi
;i~^
^u
~P4:
-to
:rr
::tr^-:rrr:l:
^iH
lijliiiii
PERCENTAGE OF MASS < .CORRESPONDING SIZE
O O Test #1, 4/2/79
Q—o Test #2, 4/2/79
2
O—O Test #3, 4/3/79
A—A Test #4, 4/3/79
-------
TABLE 11-11
SUMMARY OF PRILL TOWER SCRUBBER INLET FEED GRADE UREA
i
to
U)
PARTICLE SIZING TEST RESULTS
Union Oil Company, Brea, California
Particulate Aerodynamic*)
ES Test Sampling Test Test Concentration Size Range
No. Location Date Time grains/dscf a p m
1 Scrubber In 4/6/79 1009-1015 0.02 >16. 61
(Feed) 10.37-16.61
4.79-10.37
3.07-4.79
1.53-3.07
0.69-1.57
<0. 69
2 Scrubber In 4/6/79 1530-1534 0.02 XL7.20
(Feed) 10.74-17.20
4.96-10.74
3.18-4.96
1.59-3.18
0.72-1.59
<0. 72
3 Scrubber In 4/6/79 1931-1934 0.02 >15.99
(Feed) 9.98-15.99
4.60-9.98
2.95-4.60
1.47-2.95
0.66-1.47
<0.66
Mass in
Size Range
%
7.4
2.4
7.0
24.8
45.6
8.3
4.5
11.5
6.7
9.2
22.6
34.2
13.2
2.6
12.7
7.6
10.6
20.0
28.6
11.2
9.3
a) Standard conditons are 20°C and 760 mm Hg.
b) As unit density spheres.
-------
FIGURE I1-3
PARTICLE SIZE SUMMARY
FEED GRADE UREA
PRILL TOWER SCRUBBER INLET
EQUIVALENT AERODYNAMIC DIAMETER
VERSUS
PERCENTAGE OF MASS
UNION OIL COMPANY, BREA, CALIFORNIA
9999 99099.8
J 1 0.5 02 01 0.05 001
5 KJ .'I j& «0 10 to /O Wl V)
9? '/• Vl 8
0-1
PERCENTAGE OF MASS < CORRESPONDING SIZE
0 - 0 Test #1 4/6/79
0 — O Test #2 4/6/79
11-24 Q — Q Test #3 4/6/79
-------
TABLE 11-12
M
M
I
to
OPACITY AVERAGES DURING SAMPLING RUNS
Union 01
Rotary Cooler
Run Run Observation
No. Date Time Time
1 4/2/79 1110-1221 No Readings
2 4/2/79 1300-1524 1400-1406
1407-1413
1414-1420
1421-1427
1428-1434
1435-1441
1442-1448
1449-1454
1454-1500
-
3 4/2/79 1613-1731 1530-1536
1537-1543
1544-1550
1551-1552
1 Company, Brea, California
Urea Prill Tower
Average Run Run
Opacity No. Date Time
Taken 1 4/4/79 0947-1216
20
26
16
14
16
20
23
18
29
24
19
24
26
Fertilizer Grade
Observation
Time
0945-0951
0952-0954
1005-1006
1007-1012
1213-1019
1020-1026
1027-1033
1034-1040
1041-1047
1048-1054
1055-1101
1102-1108
1109-1115
1120-1126
1123-1129
1130-1136
1137-1143
1144-1150
1151-1157
1158-1204
1205-1211
1212-1218
1219-1220
Average
Opacity
5
4
5
5
3
5
5
6
5
5
3
3
4
8
14
31
11
8
4
11
12
7
11
-------
TABLE 11-12 (Cont'd.)
I
NJ
OPACITY AVERAGES DURING SAMPLING RUNS
Union Oi
1 Company, Brea, California
Urea Prill Tower Fertilizer Grade
Run
No.
2
Run Observation
Date Time Time
4/4/79 1424-1651 1430-1436
1437-1443
1444-1450
1451-1457
1458-1504
1505-1511
1512-1518
1519-1525
1526-1530
1600-1606
1607-1613
1614-1620
1621-1627
1628-1634
1635-1641
1642-1648
1649-1654
1655-1701
Average Run Run
Opacity No. Date Time
15 3 4/5/79 1020-1132
10
12
12
10
10
13
12
0
0
0 (cont'd) 1235-1447
2
2
2
3
2
0
1
Observation
Time
1020-1026
1027-1033
1034-1040
1041-1047
1048-1054
1055-1101
1102-1108
1109-1115
1120-1126
1127-1133
1305-1311
1312-1318
1319-1325
1326-1332
1333-1335
1340-1346
1347-1353
1357-1402
Average
Opacity
7
8
5
8
5
7
9
5
13
10
7
4
4
10
11
22
31
29
-------
TABLE 11-12 (Cont'd)
M
I
K3
OPACITY AVERAGES DURING SAMPLING RUNS
Run
No.
1
2
Union Oil
Urea
Run Observation
Date Time Time
4/5/79 1852-2152 1642-1648
1649-1654
1655-1701
1702-1708
1709-1715
1716-1722
1723-1729
1730-1736
1737-1743
4/6/79 1055-1333 1100-1106
1107-1108
1112-1116
1122-1128
1129-1135
1136-1142
1143-1141
1150-1156
1157-1203
1204-1210
1211-1213
1243-1249
1250-1256
1257-1303
1304-1310
1311-1317
1318-1324
1325-1331
1332-1333
Company, Brea, California
Prill Tower Feed Grade
Average Run Run
Opacity No. Date Time
5 3 4/6/79 1612-1944
5
5
5
5
5
5
5
5
13
10
23
43
36
29
32
29
33
30
25
31
25
23
38
31
27
27
23
Observation
Time
1622-1628
1629-1635
1636-1642
1643-1649
1650-1656
1651-1703
1704-1710
1711-1717
1718-1724
1725-1730
Average
Opacity
11
15
13
14
13
14
16
15
16
14
-------
Visible Emission Data
Visible emission data were collected during all periods of testing.
The observer changed his position as the time of day changed. The
observer's readings are summarized in Table 11-12. The average readings
were calculated at six minute intervals. A graphical presentation of
this data is presented in Appendix C, Section III. In comparing the
visible emissions data to production, no conclusions could be made
correlating production variables and visible emissions. Great variation
in opacity readings was shown. Also, graphical summaries are shown in
Figures II-4, II-5, and II-6.
Velocity Traverse Test Data
During the prill tower fertilizer grade urea and feed grade urea
testing, velocity determinations were made for the untested scrubbers.
These data are summarized in Table 11-13. The average flow for fertilizer
grade urea for the scrubber tested was 13,153 cubic feet per minute, dry,
normalized conditions (DSCFM). The average flow through each scrubber
was 12,357 DSCFM. Therefore, the flow conditions through the tested
scrubber are representative of all four prill tower scrubbers.
Scrubber Solution Test Data
Samples of scrubber solution were collected during each of the
sampling runs. Five samples per run were collected and then composited.
The composite samples were analyzed for urea, ammonia, formaldehyde, pH
and temperature at collection. These data are summarized in Table 11-24.
The average pH was 8.5 for fertilizer grade and 9.0 for feed grade urea.
The average values for ammonia and urea are reported as concentration in
milligrams per milliliter (mg/ml) and averaged 3.9 mg/ml and 0.05 mg/ml
ammonia and urea, respectively, for fertilizer grade. During feed grade
urea production, the correlation of ammonia and urea was 2.3 mg/ml and
0.85 mg/ml, ammonia and urea, respectively.
Pressure Drop Measurements Test Data
U-tube manometers were connected across the inlet and outlet of each
scrubber. Data was recorded every 15 minutes during each run. These data
are summarized in Tables 11-14 and 11-15. These data are reported as an
indicator of overall scrubber function during the testing period.
11-28
-------
FIGURE I1-4
SIX MINUTE AVERAGES OF
APRIL 2, 1979 OPACITY READINGS ON THE
ROTARY COOLER
UNION OIL COMPANY, BREA, CA
4-1
c
-------
50
SIX MINUTE AVERAGES OF APRIL 4 & 5, 1979 OPACITY READINGS FOR THE
UREA PRILL TOWER FEED GRADE
UNION OIL COMPANY, BREA, CA
(I)
O
4J
•H
O
CO
P.
O
(U
00
I
U)
o
45
40
30
25
20
10
1
1642
1743 1100
4/5/79
1213 1243 1333 1622
4/6/80
1730
M
I
-------
c
o
-------
TABLE 11-13
SUMMARY OF PRILL TOWER SCRUBBER
GAS VELOCITY AND GAS VOLUME DATA
Union Oil, Brea, California
Scrubber
Location
Northeast
Northwest
Southeast
Southwest
. Average
Northeast
Northwest
Southeast
Southwest
"Average
Northeast
Northwest
Southeast
Southwest
Average
Northeast
Northwest
Southeast
Southwest
Average
Northeast
Northwest
Southeast
Southwest
Average
Northeast
Northwest
Southeast
Southwest
Average
Run
No.
1
1
1
1
2
2
2
2
3
3
3
3
1
1
1
1
2
2
2
2
3
3
3
3
Gas Velocity3
Fertilizer Grade Urea
19.35
15.99
18.89
12.73
16.74
18.53
16.06
19.77
12.73
16.77
18.71
16.09
17.99
15.03
16.96
Feed Grade Urea
4.80
4.04
5.11
3.16
4.28
4.45
4.52
6.10
4.87
4.99
4.67
4.52
5.82
4.11
4.78
Gas Volumeb
13,599
11,515
13,603
9,166
11,971
12,928
13,400
14,218
11,566
13,028
12,931
11,588
12,955
10,819
12,073
3,109
2,908
3,682
2,273
2,993
2,933
3,252
4,395
3,509
3,522
3,035
3,252
4,191
2,958
3,359
a) Feet per second, stack conditions.
b) Standard cubic feet per minute, dry, 70°F, 29.92 in Hg.
11-32
-------
TABLE 11-14
SUMMARY OF PRESSURE DROP READINGS AT PRILL TOWER
SCRUBBER DURING FEED GRADE
Union Oil
Run
No. Date Time
1 4/4/79 0958
1011
1017
1030
1046
1100
1116
1131
1146
1202
1215
Average
2 4/4/79 1437
1448
1501
1516
1531
1547
1600
1615
1629
1646
1657
Average
3 4/5/79 1017
1031
1051
1100
1115
1131
1226
1231
1245
1300
1317
1330
1345
1359
1416
Average
Company, Brea,
NE
1.85
1.85
1.85
1.90
1.90
1.90
1.90
1.85
1.85
1.90
1.85
1T87
1.80
1.80
1.80
1.80
1.80
1.80
1.80
1.80
1.80
1.80
1.80
1.80
1.85
1.90
1.85
1.85
1.85
1.85
1.85
1.85
1.85
1.85
1.85
1.85
1.85
1.85
1.85
1.85
UREA TESTING
California
AP,
NW
1.35
1.35
1.35
1.40
1.40
1.40
1.40
1.35
1.35
1.35
1.35
1.37
1.30
1.35
1.40
1.35
1.30
1.30
1.35
1.35
1.30
1.35
1.35
1.34
1.35
1.40
1.40
1.35
1.35
1.30
1.35
1.35
1.35
1.35
1.35
1.35
1.35
1.35
1.35
1.36
"H?0
SE
2.30
2.30
2.30
2.30
2.25
2.25
2.25
2.25
2.25
2.30
—
2728
2.25
2.25
2.25
2.25
2.20
2.25
2.20
2.20
2.20
2.25
2.20
2.23
2.20
2.20
2.25
2.25
2.25
2.20
2.15
2.15
2.15
2.15
2.10
2.15
2.15
2.15
2.15
2.18
SW
1.35
1.35
1.35
1.30
1.35
1.30
1.30
1.30
1.30
0.75
0.75
1.21
0.90
0.85
0.80
0.80
0.80
0.85
0.85
0.80
0.80
0.80
0.80
0.82
0.95
0.95
1.00
0.95
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
0.99
11-33
-------
TABLE H-15
SUMMARY OF PRESSURE DROP READINGS AT PRILL TOWER
SCRUBBER DURING FEED GRADE
Union Oil
Run
No. Date Time
1 4/5/79 1647
1700
1716
1728
1745
1758
2045
2100
2115
2130
2146
Average
2 4/6/79 1110
1116
1131
1146
1200
1214
1231
1247
1300
1316
1330
Average
3 4/6/79 1616
1630
1645
1700
1715
1800
1815
1830
1845
1900
Average
Company, Brea,
NE
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.20
0.15
0.15
0.15
0.15
0.20
'0.20
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.16
0.15
0.20
0.15
0.15
0.15
0.15
0.20
0.20
0.20
0.20
0.17
UREA TESTING
California
AP,
NW
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.15
0.15
0.10
0.14
0.15
0.15
0.15
0.10
0.10
0.10
0.15
0.10
0.15
0.10
0.10
OTTT
0.10
0.10
0.10
0.05
0.05
0.05
0.07
0.10
0.10
0.10
0.08
"H20
SE
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.25
0.20
0.20
0.25
0.21
0.20
0.20
0.20
0.20
0.20
0.20
0.15
0.15
0.10
0.15
0.20
0.18
0.20
0.20
0.20
0.20
0.20
0.20
0.22
0.22
0.25
0.25
0.21
SW
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.05
0.05
0.05
0.085
0.10
0.10
0.10
0.10
0.10
0.05
0.10
0.10
0.10
0.10
0.10
0.09
0.15
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
11-34
-------
Relative Humidity and Ambient Temperature Data
Relative humidity and ambient temperature data are summarized in
Tables 11-16, 17 and 18. This data was recorded during the emission
testing on the rotary cooler and prill temperatures. This data summarizes
the ambient conditions present during the testing program.
Process Sample Test Data
During the prill tower testing for each ,sample run, one process
sample was collected. Inlet and outlet samples were collected for the
rotary cooler. The collection point for the cooler inlet sample was the
same as the prill tower outlet point. These samples were measured for
bulk density and sieve analysis to determine particle size distribution.
These data are summarized in Table 11-19.
11-35
-------
TABLE 11-16
SUMMARY OF AMBIENT TEMPERATURE AND RELATIVE HUMIDITY
DURING ROTARY COOLER
Union Oil Company, Brea,
Run Sampling
No. Date Time
1 4/2/79 1020
1030
1045
1100
1115
1130
1145
1200
1215
1230
Average
2 4/2/79 1300
1315
1330
1345
1400
1415
1430
1445
1500
1515
1530
Average
3 4/2/79 1545
1600
1615
1630
1645
1700
1715
1730
Average
TESTING
California
Ambient
Temperature
67
69
71
73
71
73
71
73
72
74
71.4
74
77
78
79
75
75
73
73
72
71
70
74.3
69
69
69
69
70
71
71
70
697S
Relative
Humidity
57
51
47
43
43
43
42
36
39
35
43.6
43
39
36
31
40
42
45
43
46
43
45
41.2
45
44
43
43
30
36
31
32
3F7o
11-36
-------
TABLE 11-17
SUMMARY OF AMBIENT TEMPERATURE AND RELATIVE HUMIDITY
DURING PRILL TOWER FERTILIZER GRADE UREA TESTING
Union Oil Company, Brea, California
Run
So.
1
2
3
3
Sampling
Dace Time
4/4/79 0900
0915
0930
0945
1000
1015
1030
1045
1100
1115
1130
1145
1200
1315
1230
Average
4/4/79 1400
1415
1430
1445
1500
1515
1530
1545
1600
1615
1630
1645
1700
Average
4/5/79 0930
1000
1015
1030
1045
1100
1115
1130
1145
1200
1215
Average
4/5/79 1230
1245
1300
1315
1330
1345
1400
1415
1430
Average
Ambient
Temperature
65
70
74
76
79
79
80
80
84
83
83
82
83
81
80
78.6
87
87
87
88
87
88
85
85
83
82
80
81
29
84.5
75
79
82
80
79
79
85
82
81
81
82
80.5
81
83
88
88
88
87
89
89
88
"86TB"
Relative
Humidity
50
41
33
33
27
27
27
25
24
23
22
24
23
20
23
28.1
24
24
24
23
21
22
23
23
26
24
28
27
12—
24.5
34
30
29
30
34
30
26
27
29
29
27
29.5
30
26
23
26
26
26
26
29
30
I6T9"
11-37
-------
TABLE 11-18
SUMMARY OF AMBIENT TEMPERATURE AND RELATIVE HUMIDITY
DURING PRILL TOWER FEED GRADE UREA TESTING
Union Oil Company,
Run Sampling .
No. Date Time
1 4/5/79 1915
1930
1945
2000
2015
2030
2045
2100
2115
2130
2145
2200
Average
2 4/6/79 1045
1100
1115
1130
1145
1200
1215
1230
1245
1300
1315
1330
1345
Average
3 4/6/79 1615
1630
1645
1700
1715
1730
1745
1800
1815
1830
1845
1900
1915
Average
Brea, California
Ambient
Temperature
67
66
65 .
63
63
62
60
60
61
60
59
61
62.3
69
71
71
70
70
70
72
71
72
73
75
75
74
71.8
71
68
68
66
65
66
64
64
65
63
63
61
62
65.1
Relative
Humidity
46
51
52
53
58
57
63
63
57
63
65
64
57.7
51
49
47
48
48
48
47
54
51
51
49
48
48
49.2
52
60
56
59
63
61
65
65
63
66
69
73
71
63.3
11-38
-------
TABLE 11-19
M
H
VD
SUMMARY OF SIEVE ANALYSIS AND BULK DENSITY
MEASUREMENTS ON THE ROTARY COOLER AND PRILL TOWER
Sieve No. 8
10
12
14
16
20
Pan
Sum of Mass
on Sieves
Bulk Density
grams/25 ml
Sieve No. 8
10
12
14
16
20
Pan
Mass
gm
8.2
40.9
134.9
62.4
12.4
6.9
2.9
268.6
180.4
4.1
22.5
117.2
58.9
18.4
9.3
9.6
Run 1
% of Total
Mass
3.1
15.2
50.2
23.3
4.5
2.6
1.1
1.7
9.4
48.8
24.5
7.6
3.8
4.2
Union Oil
Cumul. %
of Total
Mass
Rotary
100 0
96.9
81.7
31.5
8.2
3.7
1.1
Rotary
100.0
98.3
88.9
40.1
15.6
8.0
4.2
Company, Brea, California
Mass
gm
Cooler
6.9
33.3
116.1
50.9
18.1
8.1
6.1
239.5
182.6
Cooler
4.7
27.5
111.5
55.3
15.8
6.7
5.9
Run 2
% of Total
Mass
Cumul. %
of Total
Mass
Inlet Fertilizer Grade
2.9
13.9
48.5
21.2
21.2
7.6
2.5
Outlet Ferti
2.1
12.1
49.0
24.3
6.9
3.0
2.6
100.0
97.1
83.2
34.7
34.7
13.5
2.5
lizer Grade
100.0
97.8
85.8
36.8
12.15
5.6
2.6
Mass
gm
Urea
6.2
31.6
103.1
52.4
52.4
15.1
7.6
22.34
183.5
Urea
5.5
32.5
110.1
53.5
15.7
6.7
7.0
Run 3
% of Total
Mass
2.8
14.1
46.2
23.4
23.4
6.8
3.4
2.4
14.1
47.6
23.2
6.8
2.9
3.0
Cumul. %
of Total
Mass
100.0
97.2
83.1
36.9
36.9
13.5
3.4
100.0
97.6
83.5
35.9
12.7
5.9
3.0
Sum of Mass
on Sieves 240.6
Bulk Density
grams/250 ml
227.4
231.0
194.1
194.5
192.0
-------
TABLE 11-19 (Cont'd)
SUMMARY OF SIEVE ANALYSIS AND BULK DENSITY
MEASUREMENTS
Run 1
Union
ON THE ROTARY COOLER AND PRILL TOWER
Oil Company, Brea, California
Run 2
Cumul. %
Sieve No. 8
10
12
14
16
20
Pan
i— i
i i
i Sum of Mass
o on Sieves
Mass
gm
8.9
45.0
107.4
42.8
17.0
5.6
17.4
244.1
% of Total
Mass
3.6
18.4
44.0
17.5
6.9
2.4
7.2
of Total
Mass
100.0
96.4
78.0
34.0
16.5
96.
7.2
Mass
gm
Urea Prill
2.5
24.9
119.3
65.1
15.0
5.2
12.7
244.7
% of Total
Mass
Cumul. %
of Total
Mass
Tower Fertilizer Grade
1.0
10.2
48.8
26.5
6.2
2.1
5.2
100.0
99.0
88.8
40.0
13.5
7.3
5.2
Mass
gm
Urea
6.0
36.9
101.6
45.7
17.0
10.9
11.0
229.1
Run 3
% of Total
Mass
2.6
16.1
44.3
20.0
7.4
4.8
4.8
Cumul. %
of Total
Mass
100.0
97.4
81.3
37.0
17.0
9.6
4.8
Bulk of Density
grams/250 ml
188.3
182.9
Urea Prill Tower Feed Grade Urea
191.9
Sieve No.
Pan
8
10
12
14
16
20
Sum of Mass
on Sieves
Bulk Density
grams/250 ml
6.7
0.8
0.8
0.5
0.5
6.4
182.9
198.6
199.7
3.4
0.4
0.4
0.2
0.2
3.3
92.1
100.0
,6
,2
96.
96.
95.8
95.6
95.4
92.1
0.6
0.2
0.1
0.1
0.2
7.4
286.9
295.5
196.7
0.20
0.06
0.03
0.03
0.06
2.50
100.0
9.8
99.7
99.7
99.7
99.6
97.10
97.1
0.5
0.2
0.1
0.1
0.1
5.2
263.9
270.1
198.5
0.20
0.07
0.04
0.04
0.04
1.90
97.70
100.0
99.8
99.7
99.7
99.7
99.6
97.7
-------
SECTION III
PROCESS DESCRIPTION AND OPERATION
-------
SECTION III
PROCESS DESCRIPTION AND OPERATION
PROCESS DESCRIPTION
Process Equipment
The urea solution leaving the synthesis section is at a concentration
of 75 percent. This solution passes through two falling film vacuum evapora-
tors in series and is concentrated to 99.7 percent. From the evaporators,
the urea melt is pumped to a head tank at the top of the prill tower. Melt
is sprayed from the top of the prill tower by a spinning bucket. Tower
capacity is estimated to be 370 tons/day for fertilizer grade product and
220 ton/day for feed grade product.
At the top of the prill tower are four exhaust ducts, each controlled
by a packed bed scrubber. Each duct is equipped with a fan. While ferti-
lizer grade prills are being produced, these four fans are in operation
pulling air upward through the tower. Air enters the tower through louvers
at the base of the prill tower. When feed grade prills are being produced,
the fans are not operated but the louvers at the bottom of the tower are
left open. Air flow in the column results from natural convection; the
air in the tower being heated by the falling prills and rising to be
replaced by the cooler ambient air entering through the louvers.
Prills are removed from the bottom of the tower by a conveyor and
screened. Agriculture grade product passes through a rotary drum cooler
and is then transported to bulk storage. Feed grade is conveyed from the
prill tower, screened, and transported directly to bulk storage. Offsize
material is dissolved and reconcentrated. Figure III-l is a flow diagram
of the process.
Control Equipment
The scrubbers at the top of the prill tower were designed by personnel
from Union Oil Company. The scrubbers are packed beds with two sections, a
low pressure spray section and a high pressure spray section. The design
of these devices is considered proprietary by Union Oil Company.
III-l
-------
PROCESS
CONDENSATE
_>.TO SEWER
TO ATMOSPHERE
i i i i
MAKEUP FOR
SCRUBBERS
i
to
99.8 % UREA
PRILL
TOWER
BUCKET
ELEVATOR
>FFSIZ£,TO DISSOLVING TAMK
UREA - UNION OIL COMPANY OF CALIFORNIA
BREA, CALIFORNIA
TO ATMOSPHERE
SCREEN
t
ROTOCLONE
SCRUBBER
SCRUBBER LIQUOR
TO DISSOLVING TANK
COOLER
AGRICULTURE CFERTiUZEA)
GRADE PRODUCT
FEED GRADE
PRODUCT
n
n
-o
SAMPLING POIMTS
I. ROTARY DRUM COOLER
2. INLET TO ME SCRUBBER
3- OUTLET FROM NE SCRUBBER
Tl
O
M
Tl
-X
-------
PROCESS OPERATION
During process operation, urea builds up in the second evaporator's
vacuum vent and gradually decreases the vacuum applied to the system. To
alleviate this problem, the steam rate to the second evaporator is increased
to melt the urea which has built up. This procedure also has the effect of
raising the temperature of the melt leaving the evaporator and going to the
holding tank at the top of the prill tower. This tank is small and while
the process is operating at capacity, there is very little holding time.
The result is that shortly after the second evaporator is heated to clear
the vacuum, the overheated melt is being sprayed from the top of the prill
tower. Theoretically, this will result in higher emissions, resulting pre-
dominantly from increased fume formation. It was therefore necessary to
schedule emissions tests around heating of the second evaporator.
Figure III-l presents a flow diagram of the solids formation section of
the Union Oil plant. Uncontrolled emissions from the cooler were measured
at the location marked 1. The exhaust ducts and scrubbers are referred
to by their compass location, i.e., NE, NW, SE, SW. Uncontrolled emissions
were measured at the inlet to the NE scrubber, marked 2 in Figure III-l.
Controlled prill tower emissions were tested at the outlet of the NE scrub-
ber, shown as location 3. Prill tower emissions measurements were run for
both agriculture grade and feed grade product; cooler emissions tests were
performed only while fertilizer grade product was being produced since
feed grade product does not require additional cooling after leaving the
prill tower.
While testing on the prill towers was being performed, ES recorded
visible emissions readings. A review of these recorded values indicates
that the opacity varied considerably during testing. Air flow rate through
the scrubbers also appeared from observation to vary, though stack test
results should indicate whether this did in fact occur and if so, to what
extent. It was noted that the air flow rate through the four scrubbers was
different, the highest flow being almost 45 percent higher than the lowest
value.
It was hoped that a comparison of visible emissions readings with pro-
cess parameter values would result in some sort of correlation to explain
the inconsistencies encountered in the former. A quick review reveals no
clear correlation between process or control equipment operating parameters
and the variations experienced in visible emissions readings.
III-3
-------
Possible explanations for some of the variations which occurred include
the buildup of material on the rake at the bottom of the prill tower.
Material can reach a height of 3 feet before collapsing. The collapse
reportedly causes a great deal of fines to be drawn up the tower resulting
in increased emissions. A similar occurrence is buildup of material on
the inside of the tower wall around the sprayhead. Since the sprayhead is
a spinning bucket, material is thrown radially and some of the urea may
hit and buildup on the tower wall. After significant buildup of material,
large chunks may fall off, resulting in considerable dust and contributing
to an increase in emissions. This may be particularly true with the produc-
tion of feed grade urea as the bucket operates at a higher rpm for this
grade product. Operators admitted that caking on the walls had been
experienced. It was also suggested that wind speed and wind direction
(the louvers are protected from the wind on the western site by the syn-
thesis equipment, but exposed to the wind on the eastern side), may have
an effect on emissions, although this is at present speculation.
While testing was being performed, a number of parameters were recorded
to monitor process stability. During testing of the cooler, nine parameters
were recorded, as shown in Table III-l. The Rotameter 75 percent Solution to
Evaporator reading reflects the flowrate of 75 percent urea solution from
the synthesis section to the concentration section (two falling film vacuum
evaporators in series). The Temperature Urea to Head Tank indicates the
temperature of the 99.7 percent melt flowing to the head tank at the top of
the prill tower. From the head tank, the melt is sprayed from a spinning
bucket. This parameter is a reasonably accurate estimate of the melt spray
temperature shortly after the parameter is recorded. The Ammonia to Reactor
value is the amount of fresh ammonia entering the reactor and not only in-
dicates process stability in the synthesis section, but can be used to
calculate production in the synthesis section. The level of 75 percent
storage tank readings gives the level in the holding tank of 75 percent
urea solution. This value is recorded to follow process stability. A
sharp change in level could mean a process upset affecting production rate
in the solids formation section. The CC>2 to reactor parameter is the
flow of fresh carbon dioxide to the reactor and reflects process stability
in the synthesis section. It can also be used to calculate production
rate of 75 percent urea solution. Air temperature into cooler, air
III-4
-------
TABLE III-l
AVERAGE VALUES AND RANGES FOR PROCESS EQUIPMENT OPERATING PARAMETERS
DURING MASS EMISSIONS TEST OF COOLER, 4/2/79*
Parameter
1110 to 1220
Mean Range
1400 to 1530
Mean Range
1600 to 1730
Mean
Range
Rotameter 75% Solution to Evaporator
Temperature Urea to Head Tank
Ammonia to Reactor
Level of 75% Storage Tank
C02 to Reactor
Air Temperature into Cooler
Air Temperature from Cooler
Product Temperature to Cooler
Product Temperature from Cooler
100 99-100
100 100-100
101 92-109
87 87-87
100 100-100
99 96-100
98b 98-98
973
96a
100 100-100
100 100-101
100 91-104
100 91-106
100 99-100
I03b 102-104
lOlb 98-104
I03a
I04a
100 100-100
100 99-100
99 97-101
111 Ill-Ill
100 100-100
100b 99-100
104a
100a
* Ranges and averages are expressed as percentages of the overall time-weighed average values of the
three test periods.
Number of readings taken during test period (2 or less):
a One
b Two
-------
temperature out of cooler, product temperature to cooler, and product
temperature from cooler are self-explanatory and used to assure the process
is in normal operation.
During the tests run on the prill tower, eight parameters were recorded
as listed in Table III-2. These values include Rotameter 75 percent solution
to evaporation, temperature urea to head tank, ammonia to reactor, level 75
percent storage tank, and C02 to reactor as were recorded during tests on
the cooler. Three other parameters were recorded, all of which were consi-
dered confidential by Union Oil. These values are scrubber liquor make-up,
low pressure scrubber liquor flowrate, and high pressure scrubber liquor
flowrate. Scrubber liquor make-up records the flowrate of fresh scrubber
liquor makeup solution to the scrubber liquor holding tank at the top of
the column. The low pressure scrubber liquor flowrate measures the flowrate
of scrubber liquor from the holding tank to the low pressure spray section
of the scrubber. The high pressure scrubber liquor flowrate measures the
flowrate of the scrubber solution from the holding tank to the high pres-
sure spray section of the scrubber. No normalized values are shown in
Table III-2 for these parameters as this information, combined with other
information in this report, would compromise the confidentiality of these
parameters.
During testing, the process operated smoothly and at production capa-
city. Table III-l shows the variation encountered in seven process
variables recorded during mass emissions testing of the rotary drum
cooler. As indicated, most parameters were steady over the entire day.
The level of 75 percent storage tank reading varied somewhat from run to
run, but was relatively stable over the course of each run. A rapid change
in level could be indicative of a process upset. Gradual changes over
the course of the day is not considered abnormal. A summary of the data
appears in Table N-l of Appendix N. (This table also shows mean values
for parameters during the particle size runs.) Production rate during
testing of the cooler was steady and close to capacity level, approximately
350 ton/day.
Table 1II-2 illustrates the variations of five process parameters taken
during the mass emissions testing of the prill tower while fertilizer grade
III-6
-------
TABLE II1-2
AVERAGE VALUES AND RANGES FOR
PARAMETERS DURING MASS EMISSIONS
Parameter
Rotameter 75% Solution to Evaporator
Temperature Urea to Head Tank
Ammonia to Reactor
Level 75% Storage Tank
CO 2 to Reactor
Scrubber Liquor Make-up
Low Pressure Scrubber Liquor Flowrate
High Pressure Scrubber Liquor Flowrate
PROCESS AND CONTROL EQUIPMENT OPERATING
TESTS OF PRILL TOWER - FERTILIZER GRADE *
4/4/79
0955 to 1210
Mean
101
100
102
88
102
Range
101-101
100-100
99-104
87-90
102-103
4/4/79
1430 to 1700
Mean Range
101 101-101
100 100-101
100 96-103
88 87-90
99 98-100
Confidential
Confidential
Confidential
4/5/79
1015 to 1130
1220 to 1430
Mean Range
99 98-101
100 99-100
99 96-103
115 104-118
99 98-101
* Ranges and averages are expressed as percentages of the overall time-weighed average values
of the three test periods.
-------
TABLE III-3
PRODUCTION RATES DURING MASS EMISSIONS TESTS
Test No.
Date
Time
Production Rate
(tons/day)
Product Grade
1
2
3
4
5
6
A/4/79
4/4/79
4/5/79
4/5/79
4/6/79
4/6/79
0955-1210
1430-1700
1015-1130
1220-1430
1545-2200
1045-1340
1530-1935
356
356
347
214
214
214
Fertilizer
Fertilizer
Fertilizer
Feed
Feed '
Feed
III-8
-------
prills were being produced. The three other recorded variables were con-
sidered confidential by Union Oil. All variables except Level of 75 Percent
Storage Tank were steady over the entire test period. Minor variation of
this parameter occurred, but this fluctuation should not have affected the
reliability of the emission test results. A summary of these data appears
in Table N-2 of Appendix N. mean values for these parameters are given for
the periods when particle size runs were performed. The process was in
operation during these tests. Production rate data were supplied by the
plant. A letter confirming these data appears in Section III of Appendix N.
Production rate for 4 April was 365 ton/day and for 5 April was 347 ton/day
according to plant calculations. Production data is summarized in Table
III-3. These quantities indicate that the plant was operating close to
capacity during the test period.
Table III-4 shows the variation of the five recorded variables taken
during the mass emissions tests on the prill tower during the production
of feed grade urea. All variables except Level 75 Percent Storage Tank
were extremely stable during the test period. This one variable fluctuated
considerably during the test period, but does not indicate that the process
was not operating properly or in a stable manner. The level of this tank
should have no effect on emissions. The summary of these data appears in
Table N-3 of Appendix N. The exact time periods when the particle size
runs were made were not available at the time of this report. The process
was operating normally over the time periods in which the particle size
runs were known to have been performed. Production rate as calculated by
the plant was near capacity at 214 ton/day (see Table III-3).
During testing of the prill tower at this plant, the process operation
appeared to be somewhat enigmatic. Process parameters indicated steady,
normal operation. Visible emissions observations recorded a great deal of
variation in opacity from the prill tower scrubbers. Recorded air flow rates
from the scrubbers during testing, if available, should be checked for
variation. Based on the process parameters, the tests run on the urea prill
tower and the urea cooler should provide reliable emissions data.
III-9
-------
TABLE II1-4
H
M
O
AVERAGE VALUES AND RANGES FOR PROCESS AND CONTROL EQUIPMENT OPERATING
PARAMETERS DURING MASS EMISSIONS TESTS OF PRILL TOWER - FEED GRADE3
Parameter
Rotameter 75% Solution to Evaporator
Temperature Urea to Head Tank
Ammonia to Reactor
Level 75% Storage Tank
CO 2 to Reactor
Scrubber Liquor Make-up
Low Pressure Scrubber Liquor Flowrate
High Pressure Scrubber Liquor Flowrate
4/5/79
1645 to 2200
Mean
98
100
97
101
97
Range
96-101
100-100
95-100
58-153
96-99
4/5/79
1045 to 1340
Mean Range
103 103-103
100 99-100
102 100-104
97 95-102
102 100-103
Confidential
Confidential
Confidential
4/6/79
1530 to 1935
Mean
101
100
102
101
102
Range
101-101
100-100
100-104
85-108
101-103
a) Ranges and averages are expressed as percentages of the overall time-weighed average values
of the three test periods.
-------
SECTION IV
LOCATION OF SAMPLING POINTS
-------
SECTION IV
LOCATION OF SAMPLING POINTS
PRILL TOWER
The urea prill tower at Union Oil is constructed with four fiberglass
scrubbers located at the top of the tower. The scrubbers were constructed
with four inch diameter ports located on the inlet and outlet. A sketch
showing the location of the inlet and outlet ports is presented in
Figure IV-1.
Inlet Sampling Locations for Urea Particulate
The inlet port was a four-inch pipe nipple sampling port located 36
inches below the scrubber packing. The diameter of the inlet side of the
scrubber was 48 inches. The sampling ports were two pipe diameters down-
stream from the scrubber fan. Since the location of the ports was not under
ideal flow conditions, it was necessary to sample on a 24-point traverse per
sample port. This is in accordance with EPA Reference Method 1. The sample
ports were oriented 90° to one another on a horizontal axis (see Figure
IV-2).
Particle size sampling was conducted on the inlet side of the scrubber.
Traverse point No. 6 of port A was chosen as the location to sample for
particle sizing. The point was arbitrarily chosen as a central point yielding
the most representative particle size data.
Outlet Sampling Locations for Urea Particulate
The outlet ports were four inches in diameter and located 24-inches
from the outlet opening and 24 inches from the nearest upstream disturbance.
The outlet duct was 47 inches in diameter. As a result of the location of
the outlet port, a 24-point sampling traverse per sample port was necessary.
The outlet ports were oriented 90° to one another (see Figure IV-3).
During each sampling run, all unused ports were either capped or
temporarily plugged to prevent leakage.
Figure IV-4 diagrams the location of the four scrubber outlets. All
four scrubbers are of similar design and construction. The scrubber located
on the northeast corner of the prill tower was the one selected for testing.
IV-1
-------
FIGURE IV-1
SCRUBBER WATER IN
74'
16'
36*
15'
58'
48'
PRILL TOWER
OUTLET SAMPLING PORTS
SCRUBBER WATER IN
I
8" FIBERGLASS
SCRUBBER WATER
OUT
INLET SAMPLING PORTS
U-TUBE MANOMETER TAP
FOR SCRUBBER DIFFERENTIAL
PRESSURE
FAN MOTOR
CONCRETE BASE
SAMPLING POINT LOCATIONS
UREA PRILL TOWER SCRUBBER
UNION OIL, BREA, CALIFORNIA
IV-2
ENGINEERING-SCIENCE
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FIGURE IV-2
SCHEMATIC OF SAMPLING LOCATION
UREA PRILL TOWER SCRUBBER INLET
UNION OIL, BREA, CALIFORNIA
Traverse Point Tra-
No.
1 20
2 21
3 22
4 23
5 24
6
7
8
9
10
11
12
13
14
15
16
17
18
19
/
1 B
Afl"
1
^
in
verse Point Location Trav
^••M
A
erse Traverse Point Location
From Outside Nipple (IN.) Point No.
4-1/2 47 25
5-1/2 48-1/4 26
6-5/8 49-3/8 27
7-7/8 50-1/2 20
9 51-1/2 29
10-3/8
11-3/4
13-3/8
15
17-1/8
19-1/2
23-1/8
32-7/8
36-1/2
39
41
42-5/8
44-1/4
45-5/8
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
From Outside Nipple (IN]
4-1/2 47
5-1/2 48-1/4
6-5/8 43-3/8
7-7/8 50-1/2
9 51-1/2
10-3/8
11-3/4
13-3/8
15
17-1/8
19-1/2
23-1/8
32-7/8
36-1/2
39
41
42-5/8
44-1/4
45-5/8
IV-3
ENGINEERING-SCIENCE
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FIGURE IV-3
SCHEMATIC OF SAMPLING LOCATION
UREA PRILL TOWER SCRUBBER OUTLET
UNION OIL, BREA, CALIFORNIA
48
Traverse Point
No.
1 20
2 21
3 22
4 23
5 24
6
7
8
9
10
11
12
13
14
15
16
17
18
19
/
o/V
V
\
\ X
y
B
L.
A
N
H/ J.LI />
Traverse Point Location Traverse
From Outside Nipple (IN.) Point No.
3-1/2
3-1/2
4-1/2
5-3/4
7
8-1/2
9-1/2
11
12-3/4
14-3/4
17
20-3/4
30-1/4
34
36-1/4
38
40
41-1/2
42-3/4
44 25
45-1/4 26
46-1/2 27
47-1/2 28
47-1/2 29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
Traverse Point Location
From Outside Nipple (IN.]
3-1/2 44
3-1/2 45-1/4
4-1/2 46-1/2
5-3/4 47-1/2
7 47-1/2
8-1/2
9-1/2
11
12-3/4
14-3/4
17
20-3/4
30-1/4
34
36-1/4
38
40
41-1/2
42-3/4
IV-4
ENGINEERING-SCIENCE
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FIGURE IV-A
LADDER
OVERHEAD SCHEMATIC OF PRILL TOWER SCRUBBER OUTLETS
AT UNION OIL COMPANY, B3EA, CALIFORNIA
IV-5
ENGINEERING-SCIENCE
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Scrubber Solution Sampling Location
The scrubber solution samples were collected at an existing valve
located in the low pressure scrubber solution recirculating system. All
scrubber solutions are collected in a common sump and then circulated through
two pump systems; a high pressure and a low pressure system. Therefore,
the scrubber solution samples were collected downstream of the sump and are
composite samples of the scrubber solution. Figure IV-5 shows the location
of this sampling site.
Visible Emissions Observations Location
During all sampling runs visible emissions data were collected by a
single observer. Figure IV-6 shows the approximate locations of the observer
during different times of the day. The observer started the morning readings
usually 200 to 400 feet southeast of the prill tower. As the day continued,
the observer would change positions in order to keep his back to the sun.
While the prill tower was operating on feed grade urea, it was neces-
sary for the observer to relocate nearer the scrubber outlets. This was
accomplished by the observer positioning himself on a staircase near the
top of the prill tower elevator. In this position the observer was about
50 feet from the scrubber outlets.
Pressure Drop Measurement Tap Locations
A U-tube manometer was connected across the inlet and outlet side of
all four scrubbers. On the inlet side, a 1-inch port was located 58 inches
from the base of the scrubber on the downstream side of the fan. One side
of the manometer was connected to this port. On the outlet side, the
sampling ports located 24 inches upstream of the outlet were adapted using
a rubber stopper, the remaining side of the manometer was then connected to
the stopper. This arrangement was the same on all four scrubbers. Each
manometer was filled with a water solution containing flourescent dye to
facilitate reading.
IV-6
-------
FIGURE IV-5
UREA PRILL TOWER SCRUBBER SOLUTION OR LIQUOR SAMPLING POINT
UNION OIL, BREA, CALIFORNIA
TO SCRUBBERS
HE
SE
FROM
SUMP
SW
NW
2 STAINLESS
STEEL LINES
ROTAMETERS
t I t
LINE
PRESSURE
GUAGE
-tx—
PUMP
SCRUBBER
WATER SAMPLE
COLLECTION
POINT
IV-7
ENGINEERING-SCIENCE
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FIGURE IV-6
ELEVATOR'
2 STEAM PIPES
4 WET SCRUBBERS
PRILL TOWER
FIGURE 1 - UREA PRILL TOWER
<
O
SUN
OBSERVER
RELATIVE HUMIDITY &
TEMPERATURE LOCATION
N
\
FIGURE 2 - OBSERVER POSITIONS
IV-8
ENGINEERING-SCIENCE
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Velocity Traverse Measurement Location
Velocity traverses were performed at the oultets of all four scrubbers.
Ports were located 24 inches upstream and downstream from the nearest flow
disturbance. Traverse points were located in accordance with EPA Reference
Method 1. Twenty-four traverses were conducted on each port, for a total
of 48 points per scrubber outlet. Each outlet was traversed twice during
each velocity test with velocity head and stack gas temperature measured
at each point.
ROTARY COOLER
A rotary cooler is connected on the product outlet side of the prill
tower. Sampling for urea particulate and particle sizing were conducted on
the inlet side. The inlet side was selected because of the counter-flow
air movement through the cooler. The outlet duct is 24 inches in diameter
and is connected to a rotoclone scrubber.
Sampling for urea particulate was accomplished by specially installed
sampling ports. Two ports, 4 inches in diameter are oriented 90° to one
another. The nearest upstream disturbance was an in-line damper located
55" from the ports. The nearest downstream disturbance was 47 inches from
the ports. In the first sampling run a 20 point traverse was sampled,
15 points per port. On sampling run two and three, a 24-point traverse,
12 points per port, was sampled. Port A was located on an horizontal axis,
and Port B was located on a vertical axis (see Figure IV-7 and IV-8).
Particle Size
Particle size data were collected at the same sampling location used
for the urea particulate. Traverse point No. 9 on Port A was chosen as
the location of the most representative flow. Three particle size runs
were conducted at this location.
AMBIENT TEMPERATURE AND RELATIVE HUMIDITY LOCATIONS
Throughout the entire period of testing ambient temperature and relative
humidity data were collected. The location of this data collection was
approximately 30 feet on the northeast side of the prill tower. The tester
positioned himself at groundlevel and directly across from one of the air
inlets to the prill tower.
IV-9
-------
Process Sample Collection Location
During each sampling run, one urea product sample was collected for
bulk density and sieve analysis. The point of collection was at the conveyor
inlet which is located at the bottom center of the prill tower. An access
hatch 12" x 24" was momentarily opened and a sample was collected.
IV-10
-------
FERTILIZER GRADE UREA ROTARY
COOLER SAMPLING SITE
<1
FERTILIZER
UREA COOLER
SAMPLING PORTS
TO ROTOCLONE
SCRUBBER
m
m
CO
I
e/3
O
f
-------
FIGURE IV-8
SCHEMATIC OF SAMPLING LOCATION
ROTARY COOLER OUTLET DUCT
UNION OIL, BREA, CALIFORNIA
Traverse Point
No.
1
2
3
4
5
6
7
8
9
10
11
12
1 B L^^^^
IA A
24 ID 7
Traverse Point Location Traverse
From Outside Nipple (IN.) Point No.
4-1/2 13
5-5/8 14
6-7/8 15
8-1/4 ig
8-7/8 17
12-3/8 18
19-1/2 19
22 20
23-3/4 . 21
25-1/8 22
26-3/8 23
27-1/2 24
Traverse Point Location
From Outside Nipple (IN.'
4-1/2
5-5/8
6-7/8
8-1/4
8-7/8
12-3/8
19-1/2
22
23-3/4
25-1/8
26-3/8
27-1/2
IV-12
ENGINEERING-SCIENCE
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SECTION V
SAMPLING AND ANALYTICAL PROCEDURES
-------
SECTION V
SAMPLING AND ANALYTICAL PROCEDURES
INTRODUCTION
This section contains the procedures followed in collecting samples
at the urea prill tower and the rotary cooler. All emission samples
were collected following specific protocols prepared by EPA.
The analytical procedures were also prepared by EPA. The analysis
of the samples was conducted at the ES, Arcadia, California air laboratory,
and at Analytical Research Laboratories (ARLI), Monrovia, California.
The particle size analysis was conducted at the ES, McLean, Virginia,.air
laboratory. Union Oil Company analyzed product samples at their quality
control laboratory, Brea, California.
EPA Reference Methods for Sampling
The location of the sampling sites was selected following the recom-
mendations in EPA Reference Method 1, Sample and Velocity Traverses for
Stationary Sources, CFR 40, Part 60.
The velocity and volumetric flow rates through the prill tower and
rotary cooler were determined by following the guidelines in EPA Reference
Method 2, Determination of Stack Gas Velocity and Volumetric Flow Rate,
CFR 40, Part 60.
Moisture content of the gas streams tested was determined by fol-
lowing EPA Reference Method 4, Determination of Moisture Content in
Stack Gases, CFR 40, Part 60.
Particulate sampling was conducted employing modifications to EPA
Reference Method 5, Determination of Particulate Emissions, CFR 40, Part
60. The modifications to EPA Method 5 are addressed in more detail in
the following sections.
During the entire period of field testing, visual observations for
opacity of emissions were performed. EPA Reference Method 9 was followed
for these determinations, as referenced in CFR 40, Part 60.
V-l
-------
Urea Particulates
Modified Method 5 sampling was conducted simultaneously at the inlet
and outlet of the northeast scrubber located at the top of the prill
tower. A total of 48 traverse points were sampled at three minutes per
point for the outlet and two minutes per point for the inlet.
Borosilicate heated glass probes were used for all sampling. Be-
tween the probe and sample box, an unheated 5/8" O.D. teflon tube was
used. The sample box contained six impingers. The first and third were
Greenburg-Smith impingers, the remainder were 1/2" straight tube impingers
with the open end within 1/2" of the bottom of the impinger jar. The
first two impingers contained deionized-distilled water. The third and
fourth contained one normal sulfuric acid (IN 112804). The fifth was
operated dry and the sixth contained 200 grams of silica gel. All impin-
gers were contained in an insulated container and kept under ice during
sampling.
All sampling was performed isokine tic ally. Sampling and meter box
conditions were recorded every two minutes for the inlet and three minutes
for the outlet. During port changes both sampling teams completed one port
and would then begin sampling the second port concurrently.
When the prill tower was switched to fertilizer grade urea, special
manometers were necessary to monitor flow. Inclined oil manometers with
a range of 0 to 0.02 inches of water were used for flow determinations.
Testing of the rotary cooler was similar in method to the prill
tower. However, no concurrent testing was conducted since the outlet
duct was tested prior to the rotoclone scrubber. No emission data for the
scrubber outlet were collected. Also, the rotary cooler is used only for
fertilizer grade urea; therefore, only data for fertilizer grade urea is
reported.
Sample Recovery
At the conclusion of each sample run, the Method 5 sample box, teflon
tube, and probe for each team were delivered to a mobile field laboratory
set-up at the Union Oil plant. During transport from the prill tower to
the laboratory, rubber plugs were inserted into all open probes, teflon
tubes and sample box openings to prevent loss of sample and contamination.
V-2
-------
Before clean-up began, two borosilicate glass bottles with teflon-
lined caps were labeled to identify the sample run, location, prill tower
product, date, and time. One container was identified as "Container #1"
and contained the contents of the first two impingers (deionized-distilled
water), and all deionized water washings, which included the first two
impingers, connecting glassware, teflon tube, and probe. The second
glass container was identified as "Container #2" and contained the con-
tents and rinses of the third, fourth (the impingers which contained the
IN H2SC-4) and fifth impingers. When these impingers were emptied and
rinsed, all rinses were performed using IN 112804. After emptying each
impinger into the appropriate container, the impinger and associated
glassware were rinsed three times with the corresponding liquid wash.
During the clean-up procedures the impingers remained assembled, i.e.,
the impinger tube assembly was not removed from the impinger jar.
The teflon tube was washed with three separate deionized-distilled
water rinses. Prior to each washing, a glass flask with 28/12 ground
glass joint was attached to the tube. The flask was filled with
approximately 75 ml of deionized-distilled water and then washed three
times by rinsing the rinse water from one end of the tube to the other.
The rinse was then emptied into Container #1 and the procedures repeated
two additional times.
The probe was washed with the nozzle attached. Seventy-five ml of
rinse water were placed into the same flask used for the teflon tube
washings. The rinsing for the probe was performed in the same manner
as the teflon tube washings above. In addition to the rinsings, the
probe was brushed and rinsed an additional three times to remove all
particulates.
After the clean-up procedure was completed, the liquid levels in
container #1 and Container #2 were marked and the caps sealed. The
containers were then transported to the ES laboratory in Arcadia for
analyses. All clean-up procedures were identical for all sample runs and
were the responsibility of the same two field technicians.
Sample Handling
Once the field samples were brought into the laboratory, they were
immediately logged into a lab notebook and then measured volumetrically
to determine their initial sample volumes. The volume of each sample was
V-3
-------
recorded in a hard-bound chemistry lab book as were all of the subsequent
dilutions and concentration results. Two hundred milliliters were removed
from each sample and delivered to Analytical Research Laboratories, Inc.
for Kjeldahl analysis to determine the concentrations of ammonia and
urea.
When a sample was transported from one location to another, the lid
of the sample jar was taped and the solution level was marked on the side
of the container. There were two types of sample solutions, labeled
Container #1 and Container #2 (identified in the report as Cl and C2,
respectively). Number 1 Containers were samples in water solutions and
Number 2 Containers were samples in IN H2S04.
Analysis
Colorimetric Analysis - One of the methods of analysis employed to
determine the mass of urea in a sample was by a colorimetric determination
following an EPA draft method "Determination of Particulates, Urea, and
Ammonia Emissions from Urea Plants". An aliquot of field sample was
prepared for analysis by adding P-dimethylaminobenzaldehyde as a color
reagent. The color intensity was determined using a visible light
spectrophotometer set at a wavelength of 420 nanometers (nm). The
concentration of urea is determined by comparing the data from the
spectrophotometer for the samples to a calibration curve constructed
from samples of known urea concentrations.
The urea concentration of the samples was determined by the following
equation:
mg/ml of urea sample *» absorbance
slope of calibration curve
Kjeldahl Analysis - The Kjeldahl analysis was performed by ARLI.
A sample aliquot was prepared and digested for approximately two hours.
The distillate was collected in a solution of boric acid and then titrated
to a bromo-creosol green-methyl red end point using a IN solution of
hydrochloric acid. This distillation and titration yielded the total
Kjeldahl nitrogen as follows :
Total Kjeldahl Nitrogen (mg/ml) = (ml of HC1) (Normality of HC1
V-4
-------
The amount of ammonia nitrogen was calculated from the amount of ammonia
determined by Nesslerization:
Ammonia Nitrogen = (Ammonia mg/ml) (0.82)
In the above formula for Kjeldahl nitrogen, 14 represents the molecular
weight of nitrogen. In the second formula, 0.82 is the percentage of
nitrogen in one mole of ammonia. Total organic nitrogen is then determined
by subtracting:
Total Organic Nitrogen = Kjeldahl Nitrogen - Ammonia Nitrogen
From the Total Organic Nitrogen, the concentrations of urea in the aliquot
can be calculated as follows:
Urea (mg/ml) = Total Organic Nitrogen x 2.14
The factor of 2.14 represents the ratio of nitrogen in one mole of urea,
calculated as follows:
2.14 = MW of Urea = MW of (NH?)9 CO => 6£
MW of Nitrogen MW of N2 28
Ammonia Analysis
The samples collected for urea analysis were also used for the
determination of ammonia. The sample recovery and preparation was
identical to that of the urea samples.
Two methods of analysis were used. At the ES laboratory the amount
of ammonia was determined by direct Nesslerization. The final concentra-
tion was determined by comparing the absorbance units of the samples
from a visible light spectrophotometer, and then calculating the amount
of ammonia from a calibration curve as follows:
mg of ammonia/ml = absorbance of sample aliquot
0.166*
*0.166 is the calculated slope of the calibration curve.
V-5
-------
Formaldehyde Particulates
The analysis of formaldehyde was performed on a sample aliquot from
the same sample used for the determination of urea and ammonia. The
formaldehyde method is a colorimetric determination using chromatropic
acid as the color indicator. A calibration curve was constructed from
solutions with a known formaldehyde content. The concentration of
formaldehyde was determined as follows:
Formaldehyde mg/ml = absorbance
0.333*
Particle Sizing Test
A total of ten particle size determinations were conducted on the
urea production area. These tests were run on the inlet of the urea
cooler, and seven tests were run on the inlet of the urea prill tower
scrubber. Three of the prill tower tests were conducted while the plant
was producing feed grade urea. The remaining four tests were conducted
during fertilizer grade urea production.
An Anderson Six-Stage Cascade Impactor was used for these deter-
minations. The sampling time per run was approximately 15 minutes.
This shorter sampling time was required because the grain loading was
so heavy. Also, most of. the particles were in the 15 to 20 micron
range, with the majority of particles in this range; the ability of the
impactor to fractionate the particulate was limited.
After the samples were collected they were shipped to the ES, McLean,
Virginia laboratory for gravimetric determination. A Cahn, Model 21,
Electro Balance was used for these weighings. All substrates were weighed
in triplicate, or until a stable weight was achieved.
Visible Emission Observations
During the entire period of testing at the urea plant, visible
observations for opacity were conducted. All observations were conducted
by the same individual. EPA Reference Method 9 was followed for all
visible emission observations.
*0.333 is the calculated slope of the calibration curve.
V-6
-------
The observer changed his observation position as each day developed.
During the feed grade urea production, when opacity was difficult to
observe, the observer moved to within 25 feet of the scrubber outlets.
The majority of the other readings were made from about 200 feet from
the prill tower scrubber outlets.
Velocity Measurements on the Untested Scrubbers
Union Oil has four scrubbers located at the top of the prill tower.
Only one scrubber was tested for emissions. The remaining three scrubbers
were measured for volumetric flow. These determinations were made during
modified Method 5 tests. Before and after each test a 48-point traverse
was conducted on each scrubber using Type-S pitot tubes. An average
point of flow was determined, and it was this point that was monitored
during each test.
The purpose of monitoring the air flow through the untested scrubbers
was to determine the flow through the entire prill tower. After the flow
has been determined, estimates of total emissions could be calculated.
Scrubber Solution Test
During the modified Method 5 testing, a protocol for sampling the
scrubber solution was developed. This protocol included the collection of
scrubber solution every 15 minutes for a total of five samples per test
run. The temperature of each sample was measured at collection. When the
samples were at room temperature, pH measurements were made on each
sample. A composite sample was then made from the five individual samples
collected and the pH was measured again.
The composite samples were delivered to ES, Arcadia laboratory for
analysis. Each sample was analyzed for ammonia, urea, formaldehyde,
percent solids, Kjeldahl ammonia and urea. The Kjeldahl analysis was
conducted at ARLI laboratories.
V-7
-------
Pressure Drop Measurements
A U-tube manometer was installed on each scrubber. During testing
each manometer was read to determine the pressure drop across each scrub-
ber. Average pressure drop determinations were calculated for each
scrubber and for each test run.
During some of the tests, the inlet side of the scrubber connected
to the U-tube would become plugged with the urea product. When this oc-
curred the manometer was disconnected, the opening cleaned and manometer
readings resumed.
Relative Humidity and Ambient Temperature Test
Data for relative humidity and ambient temperature was collected
during all phases of testing. The tester positioned himself approxi-
mately 30 feet to the northeast of the prill tower. A Bendix Model 556
Aspirated Wet-Dry Bulb Psychrometer was used for these determinations.
Readings were taken every 15 minutes. Averages for relative humidity
and temperature were then calculated.
BULK DENSITY AND SIEVE ANALYSIS METHODS
Bulk Density
Bulk density of the urea product was performed on samples taken at
the prill tower and rotary cooler according to the method listed in
Appendix I of this report. Briefly, a sample of 500 ml in volume was
taken at each of the previously mentioned sites. Each of these samples
was divided into two parts containing 250 ml of product. One-half was
set aside for sieve analysis (discussed later). The other half was poured
through a funnel into a specially prepared, tared 250 ml graduated
cylinder. When completely filled, the cylinder was leveled with a
straight edge and weighed again. The results were then calculated and
recorded (see Section II and Appendix E).
V-8
-------
Sieve Analysis
Sieve analysis of the urea product was performed according to methods
listed in Appendix I on the first half of the samples collected and
described above. A 200 gm sample was poured into a nest of sieves,
containing No. 8, 10, 12, 14, 20, 30, 40, and 50 mesh screens and shaken
for one minute. The nest was then placed on a mechanical shaker and run
for five minutes. The material on each screen and bottom pan was then
weighed. The results were then calculated and recorded (see Section II
and Appendix E).
Chemical Analysis by Union Oil
Union Oil, Brea, California, performed analysis on the urea product.
Their analysis included determination of ammonia, urea and formaldehyde.
This data is considered proprietary information and is not included in
this report.
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