-CHO-2
(REPORT NUMBER]
AIR POLLUTION EMISSION TEST
REICHHOLD CHEMICALS. INC.
(PLANT NAME)
Moncure, North Carolina
(PLANT ADDRESS)
U. S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Water Programs
Office of Air Quality Planning and Standards
Emission Standards and Engineering Division
Emission Measurement Branch
Research Triangle Park, N. C. 27711
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Emission Testing Report
EMB Test No. 73-CHO-2
REICHHOLD CHEMICALS, INC.
Moncure, North Carolina
Roger 0. Pfaff
Project Officer
Environmental Protection Agency,
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
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IHBLt Ul- LUNItlNIb
Page Number(s)
I. INTRODUCTION . 1-2
. TABLE-1 - Summary of Results ......... 2
II. DISCUSSION OF RESULTS 3-4
III. PROCESS DESCRIPTION . . 5-7
Figure 1 - Process Diagram 6
Figure 2 - Location of Sampling Point ... 7
IV. SAMPLING AND ANALYTICAL PROCEDURES 8
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J.N! RODUCTION
Under the Clean Air Act, as amended, the Environmental Protection
Agency is responsible for establishing Federal performance standards
for new stationary sources which contribute significantly to air
pollution or cause or contribute to the endangerment of public health
or welfare. Petrochemical manufacturing plan-ts have been included in
a listing of such sources.
The Office of Air Quality Planning and Standards establishes
performance standards from emission data gathered from the best emission
control systems which have been shown to be operable and economically
feasible.
The Industrial Studies Branch performs a study of all aspects of
the industry which are pertinent to the development of emission standards.
As part of the industry, study for formaldehyde, one of the petrochemicals
for which a standard may be established, emission rates from well-
controlled plants were desired. TRW, Inc., under contract to the
Emission Measurement Branch, performed source tests at Reichhold
Chemicals, Inc. in Moncure, North Carolina during the week of July 16, 1973.
Measurements were made of formaldehyde, methanol, dimethyl ether, carbon
monoxide, and total hydrocarbons emitted from the process. Three tests
were conducted during normal production conditions when most of the
stack gas is recycled to the process. Then the process was altered to
a condition of no recycle, and three more tests were conducted. Production
rate is decreased during oncethrough, or no recycle, conditions.
Production rate was maximum during the first three tests.
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TABLE 1. SUMMARY OF RESULTS
Run
1
rc
Stack Flow Rate, DSCFMa(Nm3/min)b 3510(99.39)
Stack Temperature, °F (°C) 75(24)
THC as Methanol, Ib/hr (Kg/hr) 35.4(16.1)
THC as Carbon, Ib/hr (Kg/hr) 13.3(6.04)
Formaldehyde, Ib/hr (Kg/hr) 2.56(1.16)
Methanol, Ib/hr (Kg/hr) 58.64(26.6)
Dimethyl Ether, Ib/hr (Kg/hr) 53.22(24.2)
Carbon Monoxide, .Ib/hr (Kg/hr) 55.02(25.0)
3395(96.14) 3248(91.97) 13,608(385.3)
70(21) 75(24) 75(24)
46.9(21.3) 358(163) 553(251)
17.6(7.99) 134(60.8) 207(94.0)
3.36(1.53) 2.40(1.09) 23.94(10.87)
66.91(30.38) 49.98(22.69) 143.7(65.24)
39.20(17.80) 45.25(20.54) 74.56(33.85)
61.17(27.77) 86.05(39.07) 14.63(6.64)
13,672(387.1)
75(24)
529(240)
198(89.9)
23.50(10.67)
146.5(66..51)
68.23(30.98)
77.10(35.00)
13,992(396.2)
75(24)
576(262)
216(98.1)
23.31(10.58)
170.1(77.23)
71.82(32.61)
23.06(10.47)
aDry standard cubic feet per minute at 70°F, 29.92 in Hg.
3Dry normal cubic meters per minute at 21.1 C, 760 mm Hg.
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DISCUSSION OF RESULTS
The following inconsistencies in the test results are noted,
after taking into account the change in process conditions between
runs 3 and 4. . .... . .
1. THC (total hydrocarbon) results are higher after run 2 because
the voltage of the combustor was increased, causing a better combustion
efficiency. However, the total moles to THC measured during the last
four runs are much higher than the sum of the measured constituents
(about 100% high.er). Due to the consistency of the individual constituent
tests, as well as the several problems encountered with the THC method,
the THC results are considered less reliable than results from the
individual methods.
2. Carbon monoxide results are inconsistent in the last three
runs. No reasonable explanation was found.
As expected, emissions increased sharply when the process was
changed to oncethrough conditions. Average values of organic emissions
are as follows:
Runs 1, 2, 3 Runs 4, 5, 6
Formaldehyde 2.77 Ibs/hr 23.58 Ibs/hr
Methanol 58.51 Ibs/hr 153.4 Ibs/hr
Dimethyl Ether 45.88 Ibs/hr 71.54 Ibs/hr
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Run 1 for individual hydrocarbons was slightly below
isokinetic limits (88.2%) because of an incorrect assumption of
moisture content. Runs 4, 5, and 6 had high isokinetics. In run 4
a preliminary traverse indicated an isokinetic rate could not be
maintained, so sampling was at a constant rate. Percent isokinetics
were 246% and 234% for the two tests. In runs 5 and 6 (each 120%)
apparent null velocity points were encountered, at which the sampling
rate was maintained at a constant low rate, resulting in a high
isokinetic value. The results of the last three tests are very
consistent, which suggests that the error introducted by anisokinetic
sampling may be negligible.
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PROCESS DESCRIPTION
The chemistry of the formation of formaldehyde from methanol,
via the mixed (metal) oxide catalyst process may be shown as follows:
CH3OH + 1/2 02 '• CH20 + H20 + 38 Kcal.
' This differs from the classical silver-catalyzed process in that
(apparently) no hydrogen is produced, and the methanol molecule itself,
rather than the produced hydrogen, is oxidized.
Methanol is mixed with a combination of air and recycle vent gas
and then heated to between 220 and 350°F in a steam jacketed vaporizer.
The air/recycle gas mixture will normally contain about 10% (vol.)
oxygen, but always less than 10.9%. The methanol will normally comprise
about 9.5% (vol.) of the total converter feed, although it is limited
to about 7.5% for non-recyle operations.
The super-heated vapors from the vaporizer pass into the converter,
where the oxidation reaction takes place, in tubes filled with a mixed
oxide catalyst, between 650°F and 800°F. The heat of reaction is
removed by the circulating Dowtherm fluid surrounding the catalyst
tubes and is used to produce steam. The converter effluent gases
are cooled from approximately 500°F to about 220°F in a heat exchanger
prior to being quenched to near 100°F in the absorber.
The converter effluent vapors are introduced into the bottom
section of the column and flow counter-current to the dilution/scrubbing
water, which is pumped onto the top tray and flows downward through the
tower. The formaldehyde vapors are absorbed by the water, forming a 46
to 53% solution. This exits from the bottom of the tower. The non-
condensibles are vented from the top of the absorber where part is
recycled and part goes directly to the atmosphere.
5
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Distance to nearest upstream disturbance: 60 inches
Type of disturbance: Butterfly valve
Distance to nearest downstream disturbance: 6 feet
Type of disturbance: End of stack . •
Inside diameter of duct: 3Q inches
Number of traverse points: 40 .
Figure 2
Location of Sampling Point
7
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SAMPLING AND ANALYTICAL PROCEDURES
Formaldehyde and methanol were collected in water using a
modified EPA Method 5 participate train. Details are in Appendix D.
Dimethyl ether was collected in a glass bomb at the back of the
formaldehyde train during Runs 1, 2, and 3. In 'the last three runs,
an integrated bag sample was used.
Carbon monoxide samples were collected in integrated bag samples.
The total hydrocarbon sample was collected through a sidearm
takeoff arrangement directly at the rear of the glass probe of an EPA
Method 5 particulate train. Particulate train and sampling procedures
were used here as well as in formaldehyde and methanol sampling due
to the occurrence of pollutant-containing water droplets in the gas
stream.
Analysis of formaldehyde was by colorimetry after reacting the
impinger solution with a chromotropic-sulfuric acid reagent. Details
are in Appendix D.
Methanol, dimethyl ether, and carbon monoxide were analyzed by
gas chromotography.
Total hydrocarbons were analyzed continuously by combusting all
hydrocarbons to CC^ and measuring the CCL with a non-dispersive infrared
analyzer. Background CO^ was measured with the same instrument. Details
are in Appendix D.
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