ATMOSPHERIC EMISSIONS
FROM HYDROCHLORIC ACID
MANUFACTURING PROCESSES
r*
•F'l
U. S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
Public Health Service
Consumer Protection and Environmental Health Service
-------
ATMOSPHERIC EMISSIONS
FROM HYDROCHLORIC ACID
MANUFACTURING PROCESSES
Cooperative Study Project
Manufacturing Chemists' Association, Inc.
and
Public Health Service
U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
Public Health Service
Consumer Protection and Environmental Health Service
National Air Pollution Control Administration
Durham, North Carolina
September 1969
For sale by the Superintendent of Documents, U.S. Government Printing Office
Washington, D.C. 20402 - Price 35 cents
-------
The AP series of reports is issued by the National Air Pollution Control Admin-
istration to report the results of scientific and engineering studies, and infor-
mation of general interest in the field of air pollution. Information reported in
this series includes coverage of NAPC A intramural activities and of cooperative
studies conducted in conjunction with state and local agencies, research insti-
tutes, and industrial organizations. Copies of AP reports may be obtained upon
request, as supplies permit, from the Office of Technical Information and Publi-
cations, National Air Pollution Control Administration, U.S. Department of Health,
Education, and Welfare, 1033 Wade Avenue, Raleigh, North Carolina 27605.
National Air Pollution Control Administration Publication No. AP-54
ii
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FIGURES
1. Yearly production of 100 percent hydrochloric acid .... 2
2. Typical by-product hydrochloric acid process (chlorobenzene) 10
3. Synthesis chlorine-hydrogen process 14
4. Synthesis process hydrogen chloride burner 15
5. Cross-sectional view of Mannheim furnace 17
6. Mannheim hydrochloric acid manufacturing
process flow diagram 18
7. Cross-sectional view of Laury furnace 21
8. Hydrogen chloride distillation system for reagent-quality acids 23
9. Falling film absorber with external piping and tails tower . . 27
10. Falling film absorber with integral gas piping and tails tower . 28
11. Typical adiabatic hydrochloric acid absorption
unit flow diagram 29
A-l Impinger gas sampling train 36
A-2 Grab sample bottle 37
A-3 Burette for adding absorbing reagent 38
A-4 Mist sampling train 42
C-l Vapor pressure of hydrochloric acid at various concentrations 53
C-2 Specific gravity and density versus percent hydrogen chloride 53
C-3 Relationship of viscosities of hydrogen chloride and water . . 54
C-4 Heats of solution of hydrogen chloride in water 54
C-5 Vapor-liquid equilibra for hydrochloric acid 55
C-6 Boiling point of hydrochloric acid solution 56
C-7 Freezing point of aqueous hydrogen chloride 57
111
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TABLES
1. Production of hydrochloric acid by process type 1
2. Hydrochloric acid production in United States 6
3. Emissions from by-product hydrochloric acid
manufacturing plants 12
4. Hydrogen chloride emissions from synthesis plants 16
5. Emissions from Mannheim plants 20
C-l Specific gravities of aqueous hydrochloric acid solutions ,,. . .52
iv
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PREFACE
To provide reliable information on the nature and quantity of
emissions to the atmosphere from chemical manufacturing, the
Public Health Service, United States Department of Health,
Education, and Welfare, and the Manufacturing Chemists'
Association, Inc., entered into an agreement October 29, 1962, to
study emissions from selected chemical manufacturing processes
and to publish information that would be helpful to air pollution
control and planning agencies and to chemical industry
management.* Direction of thes^ studies is vested in an MCA-PHS
Steering Committee, presently constituted as follows:
Representing PHS Representing MCA
Stanley T. Cuffef Willard F. Bixbyt
Robert L. Harris, Jr. Louis W. Roznoy
Dario R. Monti Clifton R. Walbridge
Raymond Smith Elmer P. Wheeler
Information included in these reports describes the range of
emissions during normal operating conditions and the performance
of established methods and devices employed to limit and control
such emissions. Interpretation of emission values in- terms of
ground-level concentrations and assessment of potential effects
produced by the emissions are both outside the scope of this
program.
*Reports in this series to date are Atmospheric Emissions from Sulfuric Acid Manufacturing
Processes, Public Health Service Publication No. 999-AP-13; Atmospheric Emissions from
Nitric Acid Manufacturing Processes, Public Health Service Publication No. 999-AP-27;
and Atmospheric Emissions from Thermal-Process Phosphoric Acid Manufacture, National
Air Pollution Control Administration Publication No. 48. These publications are available
from the Manufacturing Chemists' Association, Washington, D.C., and the Superintendent
of Documents, U.S. Government Printing Office, Washington, D.C. 20402.
f Principal representatives.
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ACKNOWLEDGMENTS
Sincere gratitude is extended by the project sponsors to the
many individuals and companies who have contributed to this
study.
Special thanks are due the following companies, which
participated in the stack sampling program.
Detrex Chemical Industries.
Diamond Shamrock Chemical Company.
Olin Mathieson Chemical Corporation.
PPG Industries, Inc.
Tennessee Corporation.
The following companies provided technical information and
other assistance in the preparation of this report.
Carbon Products Division, Union Carbide Corporation.
Falls Industries Process Equipment Division of Carborundum.
Haveg Industries, Inc.
Samuel L. Bean of Allied Chemical Corporation, Industrial
Chemicals Division, and Howard Wall, Jr., National Air Pollution
Control Administration, were the investigators in the study and are
the authors of this report. The sponsors acknowledge the
contribution of the Allied Chemical Corporation in providing the
services of Mr. Bean.
VI
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USE AND LIMITATIONS OF THIS REPORT
This report is one of a series on atmospheric emissions from
chemical manufacturing processes. It provides such information on
the manufacture of hydrochloric acid. Basic characteristics of the
industry, including growth rate, manufacturing processes, product
uses, and the number of producing plants in the United States are
discussed. Process descriptions are given for the chlorinated
by-product process and the synthesis process, which employs the
direct combustion of hydrogen in chlorine. Mannheim, Hargreaves,
and several other processes are included for their historical interest,
even though the number of plants that use them is decreasing
rapidly. Process information includes the range of emissions of
hydrogen chloride from hydrochloric acid manufacturing plants and
the methods of limiting or controlling these emissions to the
atmosphere. Although other contaminants such as chlorine,
chlorinated organics, and other hydrocarbons emitted to the
atmosphere from these plants are mentioned and in some cases
discussed, they are not the primary concern of this report. Detailed
descriptions of the sampling and analytical methods used in
measuring such emissions are also included.
The production of hydrochloric acid has been a basic industry in
the United States for many years; manufacturing procedures have
become well established. Plant design, throughput rates, and the use
of special systems to reduce emissions are factors that influence
atmospheric emissions.
Emission data contained in this report were obtained from 18
percent of the present hydrochloric acid manufacturing locations.
Most of the data are from the records of acid producers. The data
include results of stack sampling programs conducted by the
National Air Pollution Control Administration as part of the joint
study.
Although this report is a technical review prepared primarily for
public officials concerned with the control of air pollution, it is
expected that it will also be helpful to chemical plant management
and its technical staff. This report should be reviewed at intervals to
determine when revision is necessary to reflect prevailing
conditions.
Vll
-------
CONTENTS
SUMMARY 1
Manufacturing Processes 1
Hydrochloric Acid Production . 2
Typical Emissions 3
Control of Emissions 3
Emission Guidelines 3
GROWTH OF HYDROCHLORIC ACID
MANUFACTURING INDUSTRY 5
Historical Background 5
Current Uses 5
HYDROCHLORIC ACID MANUFACTURING
PROCESSES 9
By-Product Hydrogen Chloride 9
Typical Process Description—Chlorobenzene 10
Emissions 11
Control of Hydrogen Chloride Emissions 11
Synthesis Process 13
Introduction 13
Emissions 16
Control of Emissions 16
Mannheim Process . ,-, 16
Introduction 16
Emissions 19
Control of Emissions 19
Hargreaves Process , 19
Introduction 19
Emissions 19
Laury Process 21
Introduction 21
Emissions 21
ANHYDROUS HYDROGEN CHLORIDE 23
Introduction 23
Emissions 24
IX
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REAGENT-GRADE HYDROCHLORIC ACID
MANUFACTURE 25
Emissions 25
Air Blowing 25
Hydrogen Chloride Absorption Systems 26
Falling Film Absorber 26
Adiabatic Absorber 26
Emissions From Absorber Systems 26
Control of Emissions 29
DEFINITIONS 31
APPENDIX A: SAMPLING AND
ANALYTICAL TECHNIQUES 34
Determination of Hydrogen Chloride and
Chlorine in Stack Gas 34
Acid Mist Sampling 41
Determination of Sulfates and Sulfuric Acid 43
APPENDIX B: HYDROCHLORIC ACID
MANUFACTURING ESTABLISHMENTS
LOCATED IN UNITED STATES 45
APPENDIX C: PHYSICAL DATA-
HYDROCHLORIC ACID 51
REFERENCES 5§
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ATMOSPHERIC EMISSIONS
FROM HYDROCHLORIC ACID
MANUFACTURING PROCESSES
SUMMARY
MANUFACTURING PROCESSES
Approximately 80 percent of the hydrochloric acid in the United States is
manufactured as a by-product of the chlorination of organic compounds.
By-product hydrogen chloride is produced in the manufacture of chlorinated
benzene, vinyl chloride, chlorinated methane, chlorinated ethylene, toluene
diisocyanate, and other such compounds.
The second most important source of hydrochloric acid is the synthesis
process in which hydrogen is reacted with chlorine. This process produces a
relatively pure hydrogen chloride, which may be converted to hydrochloric
acid or recovered as anhydrous hydrogen chloride.
Less than 10 percent of the hydrogen chloride manufactured in the United
States is produced by a reaction of sulfuric acid on metal chlorides, the
principal one of which is sodium chloride. Table 1 illustrates the decline in
importance of the salt process and the increased importance of by-product
hydrogen chloride sources.
Table 1. PRODUCTION OF HYDROCHLORIC ACID
BY PROCESS TYPE
(percent of total)1
Year
1935
1947
1958
1961
1962
1966
1967
Salt
reaction
86
53
13
10
9
9
8.5
Synthesis
14
4
18
13
14
7
7
By-product
43
69
77
77
84
84.5
Hydrogen chloride is often processed into hydrochloric acid in package
plants that consist of a falling film absorber and a packed tower. If the unit is
-------
used to make acid from a by-product process, the organic materials are usually
removed from the hydrogen chloride by condensation or absorption before the
hydrogen chloride is absorbed in water.
If the organic content of the acid is objectionable, another kind of package
plant, which consists of an adiabatic unit in which the acid is formed at its
boiling point in a packed column, may be used. In this case, organic materials
with low boiling points are not allowed to condense. The acid is then cooled
and passed through a carbon bed to remove the final traces of organic material
Regardless of the type of hydrogen chloride absorber used to form
hydrochloric acid, the most efficient system, from an atmospheric emission
viewpoint, is characterized by a final scrubber that removes any remaining
trace of hydrogen chloride from the system.
HYDROCHLORIC ACID PRODUCTION
In 1965 a total of 1,318,122 tons of hydrochloric acid was produced in the
United States.1 Based on the increase in production between 1945 and 1965,
the growth rate is 40,000 tons per year, as shown in Figure 1.
1,300
1,200 —
1930 1935 1940 1949 19» 1955 I960 1965 1970
Figure 1. Yearly production of 100 percent hydrochloric acid.
HYDROCHLORIC ACID EMISSIONS
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TYPICAL EMISSIONS
The atmospheric contaminants emitted from the manufacture of
hydrochloric acid are hydrogen chloride, chlorine, chlorinated organic
compounds, and other organic materials. The exact type and quantity of
contaminants vary with the process and the type of tail gas control system
used.
The concentration of hydrogen chloride emitted to the atmosphere is
usually less than 0.5 percent of the tail gas volume emitted to the atmosphere.
The average tail gas volume emitted to the atmosphere from the plants
reviewed for this report is 40 cubic feet per minute, with the rates ranging from
2 to 550 cubic feet per minute.
On a combined basis, the tables herein show that 6 of the 26 plants
reporting were emitting hydrogen chloride above the 0.5 percent level. One of
the six plants was permanently shut down after testing. Another was in the
process of installing a new scrubber to reduce emissions to the 0.5 percent
level. Another dispersed its gases by diluting them with stack gases from a
boiler.
CONTROL OF EMISSIONS
Emissions from hydrochloric acid plants are adversely affected by (1) high
temperatures in the absorption system, (2) improper balance of absorption area
and contact time, (3) faulty equipment, and (4) inadequate tail gas scrubbing
systems. Emissions of hydrogen chloride or hydrochloric acid can also be
caused by operational upsets.
The most common method used to remove hydrogen chloride from tail gas
is to scrub the gas with water. This method is inexpensive and effective.
Alkaline scrubbing is sometimes used when other compounds that are not
readily absorbed in water, such as chlorine or phosgene, are present.
Emissions of organic and chlorinated organic compounds, which come from
sources other than the direct manufacture of hydrogen chloride or
hydrochloric acid, vary considerably and present a different problem in each
case. Reduction of emissions of these compounds may requke a more efficient
organic absorption system, a phosgene breaker, a benzol absorption system, or
some other system especially suited to remove a particular emission.
Efficiencies of these control systems often exceed 99 percent.
In some cases, emissions to the atmosphere are prevented by utilizing a
closed system for the entire organic and hydrogen chloride plant.
EMISSION GUIDELINES
Hydrogen chloride emissions to the atmosphere! usually total less than 0.5
percent of the tail gas volume. This is a relatively small quantity of hydrogen
chloride because gas volumes for plants reporting range from 2 to 550 cubic
feet per minute with an average of 40 cubic feet per minute.
Adequate control equipment is available to prevent emissions of more than
0.5 percent hydrogen chloride, or about 0.5 pound per ton of acid produced.
In the event of an emergency shutdown of a hydrochloric acid plant, the
hydrogen chloride gas source should be shut down first. Liquid flow to
absorption equipment should be maintained at a level sufficient to keep all
Summary
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tubes and/or packing wetted and thus prevent hydrogen chloride emissions to
the atmosphere. Some weak acid will be made during this shutdown period,
but it can usually be adjusted by producing somewhat highei-than-normal-
strength material later. This technique of maintaining at all times more liquid
flow than the amount required for surface wetting should also be used to
prevent hydrogen chloride emissions during routine shutdowns and startups.
HYDROCHLORIC ACID EMISSIONS
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GROWTH OF HYDROCHLORIC ACID
MANUFACTURING INDUSTRY
HISTORICAL BACKGROUND
Hydrochloric acid, which is also called muriatic acid, was first described by
Valentius in the Fifteenth Century and was studied by such eminent chemists
as Thenard, Cavendish, Priestly, and Gay-Lussac.2 The first large-scale
production of hydrogen chloride began as a by-product in the LeBlanc soda
ash process wherein salt and sulfuric acid are reacted to produce salt cake.
Originally this hydrogen chloride gas was vented to the atmosphere; however,
since this indiscriminate discharge killed vegetation, over a large area
surrounding the manufacturing plants, legislation was soon introduced in
England to prohibit it This restriction initiated the expedient of dissolving the
hydrogen chloride in water, which forms hydrochloric acid. Soon uses
were discovered for the acid, and subsequently plants were built for its
manufacture as the primary product with salt cake as a by-product. Demand
for salt cake was reduced as the Solvay process replaced the LeBlanc process
for making soda ash.
In the United States, the reaction of sulfuric acid and salt, an initial step in
the LeBlanc process, was used to manufacture hydrochloric acid rather than
soda ash as the prime product. The heating of salt and sulfuric acid to form
hydrogen chloride gas is also the principal operation of the Laury and the
Mannheim processes. The Hargreaves process, which involves reaction of salt
and sulfur dioxide, is used in only two plants in the United States; and like the
Mannheim process, it is costly and its use probably will be discontinued soon.
As can be seen in Table 1, originally, most hydrochloric acid was produced
from the reaction of salt and sulfuric acid. As the chemical industry grew, more
acid was produced through by-product methods and more acid was produced
by burning hydrogen in chlorine than was produced from the reaction of salt
and sulfuric acid. At the present time, the by-product process is the largest
source of acid; burning of hydrogen in chloririe (synthesis process), the second
largest source; and salt sulfuric acid and other processes, the third largest
source of acid. Table 2 and Figure 1 show the growth trends of this industry.
CURRENT USES i
Because a large portion of the total hydrochloric acid produced is derived
from by-product operations, the locations of production do not always
coincide with the areas of use. Shipping costs for acid are high because about
70 percent by weight of the usual commercial-strength acid is water. Unusual
regional supply-and-demand situations result. In some localities a Mannheim
furnace, which is usually costly to operate, can be run at a profit to produce
acid for local needs. At other locations (along the east coast of the United
States in particular) by-product acid is often in oversupply and is dumped into
the ocean. Some manufacturers ship hydrogen chloride in its anhydrous liquid
-------
form to reduce transportation costs and to enable them to compete in markets
far from the source of production.
Table 2. HYDROCHLORIC ACID PRODUCTION IN UNITED STATES1
Year
1933
1935
1937
1939
1941
1943
1945
1947
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966 (preliminary)
1967 (preliminary)
Tons HCI produced
100% basis
63,000-
87,000
122,000
140,000
228,000
342,000
408,000
442,558
484,000
618,784
693,541
683,742
771,241
740,604
838,249
911,430
917,081
848,487
955,914
970,167
910,967
1,052,116
1,079,443
1,228,068
1,368,122
1,505,000
1,597,000
Hydrochloric acid is used for pickling steel, for producing glucose from corn
and other starches, making and purifying bone char, bleaching sugar,
chlorinating chemical compounds, chlorinating rubber, activating petroleum
wells, and processing food and drugs.
Less well known uses include the manufacture of alkyl chloride used in
making tetraethyl lead; preparation of chlorides from alcohols; preparation of
pharmaceutical-grade chemicals such as adipic acid, citric acid, amine
hydrochlorides, and aconitic acid; dehairing of skins in tanning; and production
of silica gel Hydrochloric acid is also used as a catalyst in organic reactions. I
Several recently built vinyl chloride plants both make and use hydrochloric
HYDROCHLORIC ACID EMISSIONS
-------
acid.3-4 Part of such a plant manufactures vinyl chloride with chlorine, wmcn
yields the by-product hydrochloric acid. The other part of this plant
manufactures vinyl chloride utilizing the by-product hydrogen chloride. Such a
plant can be designed and operated so that no excess acid is produced.
Growth of Industry
-------
HYDROCHLORIC ACID MANUFACTURING
PROCESSES
BY-PRODUCT HYDROGEN CHLORIDE
By-product hydrogen chloride, which results from the chlorination of
organic compounds, constitutes the largest source of hydrochloric acid.
Numerous reactions will form hydrogen chloride. Most of these reactions take
place when chlorine is added to an organic compound. If a chlorinated
hydrocarbon is hydrolized with water, hydrogen chloride is produced. An
example of a process that generates hydrochloric acid as a by-product is the
direct chlorination of benzene. The equation for the chlorination of benzene
is:
eerie *• ci2. - »• c6risci + HCI
This reaction takes place in the presence of a chlorine carrier, such as ferric
chloride.2 The yield is about 70 percent. In addition to the conversion of
benzene to benzene monochloride, some benzene dichlorides are formed
according to the reaction:
C6H5C1 + C12 - > CetttClj + HCI
Benzene dichloride concentration can be increased by allowing the
monochloride to remain in the reactor for a longer period of time than
required for its production. The ratio of paradichlorobenzene formed to
orthodichlorobenzene is generally fixed, but trace additives can be used in the
chlorine to vary this ratio.
Chlorobenzenes are used as intermediates for synthesizing various organic
compounds, solvents and preservatives for paints, moth balls, fumigants,
germicides, and deodorants.2
Hydrogen chloride is formed also by regeneration in some chlorination
processes. For example, the chlorination of benzene and subsequent hydrolysis
to phenol occur according to the following reactions:
2HC1 + 03 - > 2C6HsCl + 2H20
H2O - > C6H5OH + HCI
In such reactions, the chlorination and hydrolysis take place in separate steps
and the acid is separated, purified, and sent back to the chlorination process.
Other processes that produce hydrogen chloride include the chlorination of
methane, the chlorination of paraffin, and the formation of intermediates for
urethane foams.
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TYPICAL PROCESS DESCRIPTION - CiSLOROBENZENE
The raw materials required for making chloroben/.cne are ben/.cne, chlorine,
hydrogen, air, and some (race catalysts for special reactions.
Benzene used is cither moisture free or is dried with sodium hydroxide
before being introduced into the reaction. The chlorine is also moisture free.
Before chlorine is introduced to the ben/.enc, 1 to 3 percent hydrogen is added
along with sufficient air to reduce the chlorine concentration to between 80
and 85 percent. As shown in Figure 2, the benzene and chlorine streams are fed
into tanks containing iron rods. These rods act as a chlorine carrier by forming
ferric chloride. Because the reaction is exothermic, a portion of the chlorinated
benzene mixture is cooled in a heat exchanger and returned to the reactor.
Cooling controls the rale of reaction.
FRESH WATER IN
HYDROGEN CHLORIDE GAS IN
EXHAUST
GASES
CHILLED MONOCHLOROBENZENE
HYDROGEN CHLORIDE GAS
NTOWER. [ssnrl
1——I IN i —I ' h
NZENE—•» •— •—I
IOCHLOROBENZENE
t
FALLING FILM
ABSORBER
COOLING WATER OUT
PRODUCT ACID
BENZENE
»TER-H I
IATER -t4_ \ " BEN.
iZENE TO STORAGE
MONOCHLOROBCNZENE
PARADICHLOROBENZENE
ORTHODICHLOROBENZENE
STORAGE
Figure 2. Typical by-product hydrochloric acid process (chloro-
benzene).
The liquid components of the reaction are clJorobenzenes and benzene. The
gases from the reactor consist of hydrogen chloride, ben/enc, chlorobenzenes,
and air.
Product liquid is neutrali/cd with sodium hydroxide and separated into
constituents by fractionation. Any separated benzene is returned as process
feed. Gases leaving the reactor are processed to recover ben/.cne,
chlorobenzenes, and hydrogen chloride gas. These gases arc first scrubbed in a
10
HYDROCHLORIC ACID EMISSIONS
-------
packed tower with a chilled mixture of monochlorobenzcne and
dichlorobenzene to condense and recover any benzene or chlorobenzene. The
hydrogen chloride is then absorbed in a falling film absorption plant as
described in the section on absorption systems. The chlorobenzene scrubbing
liquid is recycled to the main reaction vessel.
EMISSIONS
Hydrogen chloride emission data, in addition to data on other trace
emissions from by-product plants, are presented in Table 3. Most of the plants
contacted by questionnaire (^Plants Number 1 through 17) indicated no
emissions of hydrogen chloride. However, further investigation indicated that a
value of 0.5 percent hydrogen chloride by volume in the exit gas is considered
by most plants to be negligible and is therefore reported as zero. Two of the
four plants tested by the PHS sampling team (Plants Number 18 through 21),
however, showed results somewhat higher than the reporting plants. To ensure
more accurate results, greater effort was expended by the sampling team in
making these tests than would normally be used in making routine analyses.
Concentration of hydrogen chloride in the emissions to the atmosphere
range from 0 to 50.6 percent by volume. Because of the diverse methods of
production, no correlation exists between exit gas volumes and plant
productiori~Yates. However, smaller volumes of exit gas usually show greater
hydrogen chloride concentrations. This variation in concentration in exit gas is
partly due to the varying amounts of inert materials in this gas stream. For this
reason the amount of hydrogen chloride emitted in pounds per ton of acid
produced gives a more accurate picture of the contaminant emissions. On this
basis emissions range from 0 to 8.5 pounds of hydrogen chloride per ton of
actual acid produced.
In plant BP-19, where the 8.5 value was recorded, the hydrogen chloride
was emitted during a period of about 30 minutes of a 4-hour test period. This
particular plant was arranged so that two separate chlorination units were
connected to one acid plant. In this test one unit was turned on too rapidly
and hydrogen chloride was blown out of the absorption plant until the unit
could be stabilized. This represents an example of improper operation because
this unit could have been turned on gradually and the hydrogen chloride
emitted to the atmosphere would have remained in the range of 0.16 to 0.24
pound per ton as it was in the two 1 -hour tests that followed.
Plant BP-21 emitted about 2.6 pounds of hydrogen chloride per ton of acid
produced. This plant was not equipped with a final scrubber, a fact which
partially accounts for the higher hydrogen chloride emission rate. However,
mixing this gas with the exhaust gases from a 1,0,00,000-Btu-per-hour boiler
dilutes the emissions to the atmosphere.
A hydrogen chloride emission concentration of 0.5 percent at an exit gas
flow rate of 40 cubic feet per minute will result in an emission rate of about
1.2 pounds of hydrogen chloride per hour.
CONTROL OF HYDROGEN CHLORIDE EMISSIONS
Tail gas concentrations of contaminants emitted from a typical by-product
plant are often reduced by scrubbing in a packed tower located behind the
Acid Manufacturing Processes 11
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Table 3. EMISSIONS FROM BY-PRODUCT HYDROCHLORIC ACID MANUFACTURING PLANTS
Plant
number
BP-1
BP-2
BP-3
BP-4
BP-5
BP-e
BP-7
BP-8
BP-9
BP-10
BP-11
BP-12
BP-13
BP-14
BP-1S
BP-16
BP-17
BP-18b
BP-19b
BP-200
BP-21b
Plant
capacity,
tons per day
115
40
30
15
220
70
16
7
76
12
26
30
30
105
141.5
17.8
8.3
90
60
140
226
Add
concentration.
'Be"
20
20
20
20
20
22
20
22
22
20
20
20
20
20
22
22
22
20
20
20
20
20
Exit gai eondltloni
Volume,
cfm
200
0
0
NA
2
180
NA
0
270
NA
0.01
Leakage
only
10
315°
138°
NA
0.1-3.5
520
187
187
8.3
Temperature,
°F
180
60
NA
NA
100
50
NA
85
104
NA
60
85
100
70
70
70
108
75
57
40
50
Percent
HCI«
0
NA
NA
NA
0
0
0
0
NA
NA
0.01
NA
3
0
0
0
0
<0.001
0.024
0.160
1.95
0.0023
0.0019
0.0745
50.6
47.2
53.9
Control
equipment
Water jets on
storage tanks
Water scrubber
None
Caustic scrubber
None
None
None
Water scrubber
backup
Phosgene decom-
position towers
None
None
Fume jet
None
Closed system
Closed system
None
Na3CO3 scrubber
Caustic scrubber
Water scrubber
Water scrubber
None for HCI,
CCU scrubber
for chlorine
Substances other
than HCI entering
atmosphere
Air, hydrogen, carbon
monoxide and dioxide
Trace inerts
NA
NA
Air, carbon dioxide
Air, benzol
None
None
Nitrogen and Phosgene
NA
Water vapor
Chlorine
Air, organic*
Methane, nitrogen,
RCI
Chlorine, R Cl
Inerts
Chlorine
Nitrogen, traces of
eromatics
NA
Organics
Chlorine,
carbon dioxide
Pounds HCI emitted
per ton of 20° Be'
«cid produced11
None
Nora
None
None
None
None
None
None
None
None
None
None
1
None
None
None
None
<0.008
0.10
0.70
8.5
0.0044
0.0037
0.14
2.6
2.5
NA not available.
•Represents 0.6 percent HCI or leu.
"Temd by PHS sempKn»t»eni.
eRecycled-c1osed system.
-------
final process tower. Venturi scrubbers are also used occasionally. If hydrogen
chloride is the only component to be removed, water is universally used as the
scrubbing agent. As shown in Table 3, water scrubbers can reduce hydrogen
chloride concentration to less than 0.1 pound of HC1 emitted per ton of acid
produced. Alkaline scrubbing is sometimes employed when the gases contain
substances like chlorine or phosgene, which are not readily absorbed in water.
Removal of organic materials from exhaust gases poses a separate design
problem for each specific compound. If phosgene is present, a decomposition
system is needed. If benzene or phenol is present, scrubbing with a solvent is
necessary. In some cases use of the proper scrubbing solution will efficiently
remove all of the organic compounds present.
Some plants use a completely closed system from which there is no
continuous emission of exhaust gases to the atmosphere.
By-product hydrogen chloride plants, by their nature, are adjuncts to other
processes; therefore, they may be affected by upsets that occur in the process
in which the hydrogen chloride is evolved. Good controls and secondary
scrubbing systems can reduce the possibility of increasing emissions resulting
from such upsets.
SYNTHESIS PROCESS
Introduction
High-purity concentrated hydrogen chloride may be synthesized by burning
hydrogen in chlorine, as shown in Figures 3 and 4. High purity is desirable for
organic compound or drug synthesis and in the manufacture of reagent-grade
acid.
Hydrogen chloride is made in accordance with the equation:
H2 + C12 > 2 HC1
The source of chlorine is usually chlorine cell gas, although waste chlorine
(blow gas) can be used. Hydrogen can come from any source of relatively pure
hydrogen, but usually it is from the electrolysis of brine or steam reforming of
a relatively pure organic compound.
The.purity of the raw materials determines the purity of the product.
Chlorine usually contains some organic materials and oxygen in addition to
water that can result in water vapor within the combustion chamber. Hydrogen
may also contain water vapor and organic compounds. The net result of water
vapor in the feed gases is that it can condense in the'combustion chamber and
form hydrochloric acid. This may cause corrosion unless impervious graphite
materials are used in the combustion chamber.
A typical product will contain 0.5 percent hydrogen, 0.1 percent water
vapor, 0.1 to 1.5 percent inerts, and the balance hydrogen chloride. In
addition, some carbon dioxide may be present.
A slight excess of hydrogen is used in this process, and this assures a
chlorine-free product. Combustion takes place in a closed chamber under a
slight positive or slight negative pressure, depending on chamber type. A
burner, shown in Figure 4, injects the chlorine into a surrounding hydrogen
Acid Manufacturing Processes 13
-------
WASHER AND
MIST ELIMINATOR
a
§
o
o
93
hH
O
>
O
8
K)
I
BURNER CHAMBER
PRODUCT GASES (HCI, Hj, AND WATER VAPOR)
HYDROGEN-*-
CHLORINE
PRODUCT ACID
Figure 3. Synthesis chlorine-hydrogen process.
-------
stream. The original ignition is initiated by using a retractable air-hydrogen
torch or an electrical ignition device.
COOLING WATER IN
EXPLOSION DOOR
COMBUSTION
HYDROGEN CHLORIDE
COOLING WATER OUT -<
«*• CHAMBER '
I
BURNER-*-
P
ISIGHT GLASS
^-••HYDROGEN
4
CHLORINE
Figure 4. Synthesis process hydrogen-chloride burner.
Synthesis plants differ in detail because of differences in raw material sources
and qualities, and plant capacity. However, all plants consist of a chlorine
burner, including control and safety devices, and acid purifying and absorption
facilities. Burners may be steel with a silica or brick lining, water-jacketed steel,
or water-cooled graphite. Brick burners are commonly used, especially for large
units, but they have the disadvantage of a high product temperature, i.e., about
2,200° F. Water-jacketed steel is good if the temperature of the jacket is
maintained above the dew point of the materials within the burner. The outlet
temperature from a water-cooled burner is within a range of 700° to 1,000° F.
A burner consists of one or more nozzles, which inject the gases into the
combustion chamber, and can have a range of capacity of 8 to 16 tons of
hydrogen chloride per day. Control of the gas burner may be manual or
automatic. The trend presently is toward automatic operation.
Controls include safety devices and purge systems. Burner chambers have an
explosion rupture disc to protect the vessel and surrounding area. The inlet gas
lines are provided with automatic shutoff valves and seals to prevent back flow
of reactants due to reports. An ignition device is sometimes included in the
outlet duct to prevent the delivery of an explosive mixture of gases instead of
hydrogen chloride. Other control and safety devices include flame sensors;
temperature-regulated controls for various purposes; and a purge system, which
usually injects carbon dioxide, that operates automatically in case of an
interruption in any of the services.
The hydrogen chloride formed in the combustion chamber is cooled and
absorbed in a hydrochloric acid absorption plant as described in the section on
absorption systems.
Acid Manufacturing Processes
15
-------
Emissions
As shown in Table 4, almost no hydrogen chloride is emitted from synthesis
plants. Chlorine is eliminated by combusting it with excess hydrogen. In the
plants surveyed, no additional air pollution control equipment is used after the
tails tower. The data in Table 4 were obtained from operating plants in
response to questionnaires.
Table 4. HYDROGEN CHLORIDE EMISSIONS FROfiiSYNTHESIS PLANTS
Plant
number
S-1
S-2
S-3
Plant
capacity,8
tons per day
33
100
32.5
Acid
concentration.
"Be
20
22
20
Exitc
Volume,
ufm
85
NA
130
las conditions
Temperature,
°F
NA
70
80
Percent
HCI
<0.01
0
Trace
Pounds HCI
emitted per
ton of 20° Be
acid produced
<0.035
None
Trace
a20" 6^(31.5 percent) HCI.
NA = not available.
During startup and shutdown the possibility exists that chlorine and
hydrogen chloride may be released into the air. Normally, an inert purge system
is a part of the control system and any chlorine, hydrogen, or hydrogen
chloride present in the system is purged through the absorber-cooler and tails
tower before a shutdown.
In the event of an emergency shutdown of a hydrochloric acid plant, the
hydrogen chloride gas source should be shut down first. Liquid flow to
absorption equipment should be maintained at a level sufficient to keep all
tubes and/or packing wetted and thus prevent hydrogen chloride emissions to
the atmosphere. Some weak acid wfll be made during this shutdown period,
but this can usually be adjusted by producing material of somewhat
higher-than-normal strength later. This technique of maintaining at all times
the flow of more liquid than is required for surface wetting should also be used
to prevent hydrogen chloride emissions during routine shutdowns and startups.
Control of Emissions
The design, operation, and maintenance of synthesis plants result in no
significant emissions of hydrogen chloride, as shown in Table 4.
MANNHEIM PROCESS
Introduction
The Mannheim process is the principal process used to produce hydrochloric
acid from salt and sulfuric acid. It also produces salt cake, Na2SO4, which is
used in glass and paper manufacturing. The chemical reactions for the salt and
sulfuric acid process are:
NaCl + H2SO4
NaHSO4 + HC1
16
HYDROCHLORIC ACID EMISSIONS
-------
NaCl + NaHS04
Na2SO4 + HC1
2NaCl + H2S04
Na2S04 + 2HC1
Salt and an excess of sulfuric acid are fed into the top center of a Mannheim
furnace, as shown in Figure 5, where the mixture is heated to about 1,000° F.
This feed is constantly mixed and moved toward the outside of the furnace by
plows until it is discharged through an opening into a pan or conveyor.
SALT. /SULFURIC ACID
OIL
ROTATING ARMS
WITH PLOWS
1300° F.
COMBUSTION
GASES TO STACK
-SILICON CARBIDE ARCH
1000° F. GASES TO
ABSORPTION
SYSTEM
1000° F.
SALT CAKE
PAN WITH HEARTH
Figure 5. Cross-sectional view of Mannheim furnace.
Hot gases containing 30 to 60 percent hydrogen chloride in air go to the
falling film absorber where the hydrogen chloride is cooled and absorbed.
Gases from the furnace contain sulfuric acid vapor that condenses to a mist
when the gases are cooled. This mist is partially absorbed together with the
hydrogen chloride and becomes an impurity in.the hydrochloric acid.
Although the several types of Mannheim furnaces in use differ somewhat in
detail, they all consist essentially of stationary circular muffles made up of a
pan and a domed cover (Figure 6). Size of the pans ranges from 11 to 18 feet
in diameter, and construction is of cast iron or refractory. The dome is cast
iron or silicon carbide. Agitation of the reaction mass is accomplished by
rotating arms that have plows mounted on a centrally located under-driven
shaft. A firebrick enclosure provides insulation and directs combustion gases
over the cover. Mannheim furnaces generally have salt cake capacities ranging
from 6 to 24 tons per day. ,
A gas duct, a cyclone, and a gas cooler are usually considered a part of the
furnace installation. The gas ducting allows the gases to cool somewhat before
entering the cyclone. The cyclone removes the salt cake that is carried out with
the gases, and the cooler cools the gases before absorption. A careful choice of
construction materials is required. Heat resistance is of primary concern ahead
of the cooler, and corrosion resistance is of importance downstream of the
cooler where sulfuric and hydrochloric acids have condensed.
Acid Manufacturing Processes
17
-------
oo
a
•<
O
ffi
r
i
o
>
o
3
ts
SULFURIC ACID
CHLORIDE SALT (KCI OR NaCI)
COMBUSTION
GASES TO
STACK
CYCLONE
ROTATING ARMS pRQDUCT GAS /
COOLER.
ABSORBER
TAILS TOWER
TAIL GAS
TO ATMOSPHERE
MANNHEIM
FURNACE
SALT CAKE
TO
COOLING
STORAGE
AND GRINDING
COOLING
WATER-
COOLING
WATER*
2=0-
LEAN
PROCESS WATER
GAS
STORAGE
PRODUCT ACID
Figure 6. Mannheim hydrochloric acid manufacturing process flow
diagram.
-------
Emissions
In addition to hydrogen chloride gas, both sulfuric and hydrochloric acid
mists are emitted from Mannheim process plants. Data in Table 5 show that in
general, emissions from such plants are higher than those from by-product or
synthesis process plants. Data reported by manufacturers and collected by
actual test showed hydrogen chloride emissions of 1.3 to 3.8 pounds per ton of
acid produced. These emissions are probably higher because of poor operation
and maintenance and in some cases poor design of absorption systems.
Particulate emissions also occur from the salt cake as it is discharged,
pulverized, and handled.
During startup and shutdown, emissions will not occur when the exhaust fan
is on, and the hydrogen chloride gas and fumes are sucked through the furnace
to the absorber. Liquid flow in the absorber must be maintained.
Control of Emissions
Three basic methods of controlling atmospheric emissions exist. They are
proper operation, an efficient emissions collecting system, and effective
maintenance. Proper operation assumes good design, and results in maximum
product recovery, thus reducing the possibility of hydrogen chloride emissions.
An adiabatic wet-scrubbing tower that utilizes hydrochloric acid has been used
with good results both to scrub and to cool the furnace gas.
To reduce atmospheric emissions, a scrubber system can be installed on the
tails tower exhaust. Scrubbers presently in use for this purpose include venturi
scrubbers and packed water scrubbing towers.
The few remaining Mannheim plants in this country are gradually being
retired from service because of their high cost of operation and maintenance.
HARGREAVES PROCESS
Introduction
The Hargreaves process was developed in England, and after about 1850 it
appeared as if it might become an important source of hydrochloric acid and
salt cake. However, new processes were introduced and its use declined. Only
one plant of this type is in operation in the United States.
In this process, hydrochloric acid is formed by the reaction of sulfur
dioxide, steam (water), air (oxygen), and salt at temperatures of about 800 to
1,000° F. The formulas for the reaction are:
S + O2 > SO2
2S02 + 4NaCl + 2H20 + O2 * 2Na2S04 + 4HC1
The reaction is exothermic and will maintain itself once the reactants are
heated to the proper starting temperature.
Emissions
The potential emissions from the Hargreaves process are unreacted sulfur
dioxide, hydrogen chloride, and salt dust. Dusts are removed initially by
Acid Manufacturing Processes 19
-------
Table 5. EMISSIONS FROM MANNHEIM PLANTS
Plant
number
M-1
M-2b
Plant
capacity,8
tons per day
79
* 10
Acid
concentration,
°Be
20
20
Exit gas conditions
Volume,
cfm
440
168
Temperature,
°F
150
95
Percent
HCI
0.46
0.16; 0.18
0.06; 0.14
Control
equipment
None
Water scrubber
Substances other
Than HCI present
in exit gas
H2SO4, 30ppm
H2S04 and S02 0-160 ppm
Pounds HCI emitted
per ton of 20° Be
acid produced
3.0
Gas 3.5, 3.9
1.3,3.1
Mist 0.04-0.065
8
£
8
Q
§
H
I
CO
a20° Be" (31.5%) HCI.
bTested by MCA-PHS.
-------
cleaning the product gas with a cyclone. During periods of operational upsets
or additions of new salt, hydrogen chloride or sulfur dioxide can be emitted to
the air. Since the reaction occurs at 1,000° F, it is desirable to interrupt the
process as little as possible, thereby preventing loss of heat and excessive
emissions.
LAURY PROCESS
Introduction
In the Laury process, hydrochloric acid is produced in a rotary furnace from
the reaction of sodium chloride and sulfuric acid.
The equations are:
NaCl + H,S04
Nad + NaHSO4
NaHSO4
HC1
Na2SO4 + HC1
A Laury furnace consists of an oil-fired combustion chamber that discharges
into a horizontal revolving drum containing a roasting section and a grinding
section (See Figure 7). Materials are charged at the end opposite the heating
source. As they move counter-current to the flow of hot gases, they are mixed,
ground, and roasted. The flue gases and hydrogen chloride from the roasting
processes are exhausted at the same end of the drum in which the sodium
chloride and sulfuric acid are charged. The hydrogen chloride gas and flue gas
from the furnace are exhausted first through either a settling chamber or a
cyclone to collect the dust, and then are sent to the hydrochloric acid absorber
section of the plant.
TO STACK
t
SALT AND FH HOT SECTION
NITRE CAKE GRINDING CHAMBER [ 11 —
SALT CAKE TO COHVI
Figure 7. Cross-sectional view of Laury furnace.
This process was used before the introduction of the falling film absorber
and probably all units were installed with two packed columns to absorb the
hydrogen chloride.
No plants of this type currently operate in the United States.
Emissions
Emissions of hydrogen chloride from this process are low in concentration
but high in volume. Other emissions from this process include salt cake dust
Acid Manufacturing Processes
21
-------
and sulfuric acid mist. Salt cake dust is eliminated by a dust removal system or
is removed in the acid absorption system.
22 HYDROCHLORIC ACID EMISSIONS
-------
ANHYDROUS HYDROGEN CHLORIDE
INTRODUCTION
Anhydrous hydrogen chloride is sometimes recovered without further
processing from the synthesis process. It is also produced from aqueous acid in
three basic steps:
1. Thermal stripping of a strong hydrochloric acid feed to the 21 percent
azeotropic mixture.
2. Cooling, condensing, and recycling part of the hydrogen chloride as
reflux.
3. Cooling and removing the moisture from the gas.
Strong hydrochloric acid from storage is stripped in an impervious carbon or
graphite shell-and-tube stripper or a similarly packed stripping column (Figure
8). A reboiler is required at the base of the stripper to provide thermal energy
for the liquid-gas separation. Spent acid leaves the bottom of the stripper. This
acid is either cooled and stored or sent to the concentration unit for cooling
and concentration in a falling film absorber.
CONDENSER COOLING BRINE PURE WATER
CONDENSER TRAP
FILTER TO
REMOVE WATER
.ING BRINE I 1~
ju
I PRODUCTSOLU
1 ' nr Mri
DRY
HO
GAS
l-4-TREATED ACID FEED
31.5 PERCENT
PACKED SECTION'
= | » SPENT ACID OUT
II PERCENT
Figure 8. Hydrogen chloride distillation system for reagent-quality
acids.
23
-------
The hydrogen chloride gas and other vapors from the top of the stripper are
passed through a heat exchanger where the condensate is removed and fed back
as a reflux to the stripper. The remaining gas, which is substantially pure
hydrogen chloride, is then dried in a shell-and-tube condenser with a 0° to 5° F
cooling brine and then passed through a particulate entrainment separator for
water removal
A complete unit that will produce anhydrous acid is available from several
hydrochloric acid equipment manufacturing companies. These units operate in
a similar fashion to the process described here.
EMISSIONS
This process yields no emissions to the atmosphere because the
manufacturing system is closed and the product vapors are piped directly to
the process area.
24 HYDROCHLORIC ACID EMISSIONS
-------
REAGENT-GRADE HYDROCHLORIC ACID
MANUFACTURE
Commercial-grade 31.5 percent hydrochloric acid is distilled in a rectifying
column to form reagent-grade 37 to 38 percent hydrochloric acid. Packaged
commercial systems for making reagent acid, as illustrated in Figure 8, are
available.
A system for making the reagent-grade acid may also make dry hydrogen
chloride gas and hydrochloric acid solutions. These systems are made up of a
boiler at the base of a split column, a feed to the column (at the split section)
that serves as reflux for the acid being vaporized, a condenser that forms
product hydrogen chloride and refluxes the hydrogen chloride gas section of
the column, and a cooler-absorber for forming 31.5 percent hydrochloric acid
product if desired. The system is valved so that any one of the three desired
products can be made with only a change of valving. A flow diagram of a plant
of the type described is illustrated in Figure 8.
Other types of plants making reagent-grade acid are not of the "package"
type. These plants are constructed largely of glass and have tantalum or
titanium heat exchangers for condensing the acid.
Any acid must be treated before it is distilled. Minerals and gases, which
may carry over with the acid vapors, must be stabilized to stay in the 21
percent azeotropic acid remaining after boiling. Processes for stabilizing the
minerals and gases are proprietary and differ with the acid manufacturer. The
azeotropic mixture of acid remaining after distillation can be used to absorb
more hydrogen chloride and then be redistilled, or it can be used in other
processes.
Reagent-grade acid may also be made directly from a relatively pure gas
such as is produced in the synthesis process without the need for chemical
treatment or distillation.
EMISSIONS
This process yields no emissions to the atmosphere because the
manufacturing system is closed.
AIR BLOWING
Air blowing, used to remove organic substances from hydrochloric acid, can
cause hydrogen chloride and organic emissions that can be a potential source of
odors. Fortunately, this obsolete practice is seldom used and is of little
industrial importance.
In the process, air is blown through a sparger installed in a tank of
hydrochloric acid to remove dissolved organic gases and to evaporate organic
materials in the acid. This blowing may take place for a 30- to 60-minute
period.
Emissions from air blowing can be eliminated by water scrubbing the gases
25
-------
vented from the tank. A water ejector can be used to remove the fumes from
the tank as well as to scrub them.
No reports of air blowing practices were obtained during the preparation of
this report
HYDROGEN CHLORIDE ABSORPTION SYSTEMS
Falling Film Absorber
The most widely used absorption unit is the falling film system. It consists
of a falling film cooler-absorber and a small packed tails tower.5'6 As shown in
Figures 9 and 10, the gases and the absorbent, which is usually weak acid, enter
at the top of the absorber and the hydrogen chloride is absorbed in the liquid
wetting the inside of the tube. The absorption is limited by the number of
tubes, which determines the amount of wetted area available for absorption
and cooling.
After passing through the falling film absorber, the gases pass through a tails
tower where the remaining portion of the hydrogen chloride is reduced to less
than 0.5 percent of the exit gas. Fresh water, which is used as the absorbant, is
fed to this tower, and a weak acid results from the absorption of the hydrogen
chloride in the water.
Adiabatic Absorber
Another system that is relatively new is the adiabatic absorption unit,6 '7
shown in Figure 11. Used to make an organic-free acid, this unit consists of a
packed column into which water is fed near the top, and hydrogen chloride
near the bottom. Hydrogen chloride and water-contact one another to form
hydrochloric acid that is at its boiling point. Excess heat is removed by the
formation of steam. Inert substances, steam, and lower-boiling organic
materials that cannot condense in the acid because it is at its boiling point are
vented from the column. A water ejector-type scrubber is usually used to scrub
the gases coming from the column.
Further removal of organic materials may be accomplished by cooling the
acid and running it through a carbon bed where the organics are absorbed.
A variation of this plant is the modified adiabatic absorption unit. It is not a
true adiabatic system in the usual sense; it is designed to remove more organic
substances and chlorine. In this process, hydrogen chloride gas is injected near
the middle of the column to maintain an adiabatic section in the upper portion
of the column. Heat then can be added to the bottom of the column to strip
the acid in the bottom section of the column. These plants are usually sold
complete with instruments.
Emissions from Absorber Systems
Hydrogen chloride emissions from a falling film absorber may be influenced
by several factors.8 These include a lack of cooling and a lack of sufficient
weak acid to absorb the hydrogen chloride gas. During startups andi shutdowns
when hydrogen chloride gas flow is less than normal, it is possible that'not all
of the tubes in the absorber will be wetted if the feed water rate is reduced to
maintain product strength. In this situation gas passes through the falling film
26 HYDROCHLORIC ACID EMISSIONS
-------
FRESH WATER IN
INERTS OUT
TO ATMOSPHERE
GAS FLOW
WEAK HYDROGEN
CHLORIDE GAS
FROM FALLING
FILM ABSORBER
TO TAILS TOWER
PRODUCT OUT.
Figure 9. Falling film absorber with external piping and tails tower.
Reagent-Grade
27
-------
VENT
_L
TAILS
TOWER SECTION
COOLING WATER
•**— FEED WATER
COOLING WATER
STRONG ACID
Figure 10. Falling film absorber with integral gas piping and tails
tower.
HYDROCHLORIC ACID EMISSIONS
-------
ORGANIC CONTAMINANTS - STEAM
CONDENSED STEAM*.
ORGANICS - CHLORINE
AND ORGANIC
1. ADIABATIC ABSORPTION TOWER RECEIVES BY-PRODUCT HCI GAS STREAM CONTAMINATED
WITH ORGANICS. ABSORPTION OF HCI IN WATER GENERATES HEAT.
2. TOWER OVERHEAD CONDENSES BY DIRECT CONTACT FUME SCRUBBER.
3. HOT HCI SOLUTION COOLED BY SHELL AND TUBE COOLER.
4. COOLED HCI SOLUTION PUMPED TO EITHER OF TWO ACTIVATED CARBON ADSORBERS ACTING
ON ADSORB-REGENERATE CYCLE. ORGANIC CONTAMINANTS ADSORBED IN CARBON
RESULTING IN FINISHED ACID. 32% CONCENTRATION CONTAINING LESS THAN 1 ppm
ORGANICS AT 100-F. ACID NOW TRANSFERRED TO STORAGE AREA.
Figure 11. Typical adiabatic hydrochloric acid absorption unit flow
diagram.
unit and overloads the tails tower, which also is receiving less than a normal
amount of feed water.
The solution to this problem is to maintain a minimum flow sufficient to
wet the tubes. Weak acid produced during these periods can either be discarded
or concentrated by making higher-strength acid when normal conditions are
restored.
The adiabatic absorption unit is not nearly as sensitive to cooling problems
as the falling film unit because heat is removed by the^ormation of steam. It is,
however, just as likely to produce hydrogen chloride emissions if all of the
packing is not wetted The technique of maintaining minimum liquid flow as
described above is also effective with the adiabatic unit. The adiabatic unit,
with its. counter flow liquid and gas, is more easily flooded than the
parallel-flow falling film unit.
Control of Emissions
Hydrogen chloride emissions may be effectively controlled by installing any
of several types of scrubbers after the tails tower in the case of the falling film
unit and after the adiabatic tower in the case of the adiabatic unit. Regardless
Reagent-Grade
29
-------
of the type of absorption unit used for making hydrochloric acid, the best
design is characterized by a final scrubber to remove residual hydrogen chloride
passing through the system
An adiabatic absorption system normally has a scrubber designed to reduce
the hydrogen chloride content of the gases emitted to 0.5 percent or less by
volume.
30 HYDROCHLORIC ACID EMISSIONS
-------
DEFINITIONS
Absorber
Absorption system
Acid mist
BaimuS (Be)
Contaminant
Emission
Establishment
Muriatic acid
Rant
Reforming
Tail gas
Chemical equipment that serves to contact a gas or
vapor with a liquid so that gas or vapor is absorbed into
the liquid. In this report, it refers to equipment used to
contact hydrogen chloride with water to form
hydrochloric acid.
An absorber or several absorbers used to absorb
hydrogen chloride.
Extremely small particles of liquid acid that are
suspended in a gas or vapor.
Acid strength is determined by use of a floating
instrument (hydrometer) calibrated to read degrees
Baume and by a conversion chart. The Baume can also
be calculated if the specific gravity of the acid is
known: .*?
' Be =145- (||)
Any substance not normally found in the atmosphere.
Any gas or vapor stream emitted to the atmosphere.
A works having one or more hydrochloric acid plants
or units, each of which is a complete production
entity.
20° Be hydrochloric acid.
A chemical works at whidh hydrogen chloride is
manufactured and converted with an absorption unit
into hydrochloric acid.
Burning an organic fuel in the presence of water or
water vapor in such a manner that hydrogen-rich gas is
formed.
Gases and vapors that leave hydrochloric acid
absorption units.
31
-------
APPENDICES
A. SAMPLING AND ANALYTICAL TECHNIQUES
B. HYDROCHLORIC ACID MANUFACTURING
ESTABLISHMENTS LOCATED IN UNITED STATES
C PHYSICAL DATA-HYDROCHLORIC ACID
33
-------
APPENDIX A. SAMPLING AND ANALYTICAL
TECHNIQUES
DETERMINATION OF HYDROGEN CHLORIDE AND
CHLORINE IN STACK GAS.
The method discussed herein is used to determine the presence of hydrogen
chloride in the stack gases from hydrochloric acid manufacturing processes.
Samples are collected from the gas stream in either midget impingers or a
grab-sampling bottle containing sodium hydroxide, and hydrogen chloride is
determined by the Volhard titration.9 If chlorine is suspected to be present in
the stack emission, another sample is collected in a similar manner, except that
a known quantity of alkaline arsenite absorbing reagent is substituted for
sodium hydroxide. Chlorine is reduced to chloride by arsenite, and is measured
by titration of the unconsumed arsenite with standard iodine solution. Total
chloride content of the sample is determined by the Volhard titration.
Hydrogen chloride concentration is calculated by subtraction of the chlorine
concentration from total chloride concentration. This method is applicable in
determining hydrogen chloride and chlorine concentrations ranging from 10
ppm to percentage quantities.
Reagents
All chemicals must be ACS analytical reagent-grade.
Water
Deionized or distilled water.
Absorbing Reagents:
1. Sodium hydroxide (IN)- Dissolve 40 g of sodium hydroxide in water
and dilute to 1 liter. This reagent is used when the stack gas
concentration of hydrogen chloride is suspected to be less than 1,000
ppm.
2. Sodium hydroxide ( 2.5 N) - Dissolve 100 g of sodium hydroxide in
water and dilute to 1 liter. This reagent is used when the stack gas
concentration of hydrogen chloride is suspected to be greater than 1,000
ppm.
3. Alkaline arsenite (IN NaOH and 0.1 N NaAsO2 ) Dissolve 40 g of
NaOH and 6.5 g of sodium arsenite ( NaAs02 ) in water and dilute to 1
liter in a volumetric flask. This reagent is used when the stack gas
concentration of hydrogen chloride and C12 is suspected to be less than
1,000 ppm.
4. Alkaline arsenite ( 2.5 N NaOH and 0.5 N NaAsO2 ) Dissolve 100 g of
NaOH and 32.5 g of NaAsO2 in water and dilute to ] liter in a
volumetric flask. This reagent is used when the stack gas concentration
of hydrogen chloride and C12 is suspected to be greater than 1,000 ppm.
34 HYDROCHLORIC ACID EMISSIONS
-------
Ferric Alum Indicator
Dissolve 28.0 g of ferric ammonium sulfate FeNH4 ( SO4 )2 • 12 H2O in 70
ml of hot water. Cool, filter, add 10 ml of concentrated nitric acid( HNO3 ),
and dilute to 100 ml in a volumetric flask.
Nitric Acid (8N)
Prepare NOx-free nitric acid by adding 100 ml of HN03 to 100 ml of water
and boiling in a flask until the solution is colorless. Store in a glass reagent
bottle.
Nitrobenzene
Reagent grade.
Sodium Chloride (Primary Standards)
1. NaCl (0.1 N) - Dissolve 5.846 g of dried sodium chloride (NaCl) in
water and dilute to 1 liter in a volumetric flask.
2. NaCl ( 0.01 N ) - Dissolve 0.5846 g of dried NaCl in water and dilute to
1 liter in a volumetric flask, or dilute 100 ml of 0.1 N NaCl to 1 liter.
Ammonium Thiocyanate
1. NH4CNS ( 0.1 N ) - Dissolve 8 g of NH4CNS in water and dilute to 1
liter in a volumetric flask.
2. N^CNS ( 0.01 N ) - Dilute 100 ml of 0.1 N NH,CNS to 1 liter in a
volumetric flask, or dissolve 0.8 g NUjCNS in 1 liter of distilled water.
Silver Nitrate
1. AgNC-3 ( O.I N) - Dissolve 17.0 g of silver nitrate ( AgN03 ) in water
and dilute to 1 liter in a volumetric flask. Transfer to an amber reagent
bottle. Standardize this solution against 0.1 N NaCl solution, according
to the Volhard titration.9
2. AgN03 'C0.01 N) - Dissolve 1.7 g of AgN03 in water and dilute to 1
liter in a volumetric flask. Transfer to an amber reagent bottle.
Standardize this solution against standard 0.01 N NaCl solution,
according to the Volhard titration.
Starch Solution (Iodine Indicator), 1.0%
Make a thin paste of 1 g of soluble starch in cold water and pour into 100
ml of boiling water while stirring. Boil for a few minutes. Store in a
glass-stoppered bottle.
Standard Iodine Solution ( 0.1 N ) '
Dissolve 12.69 g of resublimed iodine (I2 ) in 25 ml of a solution
containing 15 g of iodate-free potassium iodine (KI); dilute to 1 liter in a
volumetric flask. Standardize this solution against a standard tliiosulfate
solution using starch as an indicator. This solution should be stored in an
amber reagent bottle and refrigerated when not in use.
Apparatus
(See Figures A-l and A-2)
Appendix A 35
-------
Sampling Probe
10-mm Pyrex® glass tubing of any convenient length.
Filter
A small fiberglass filter may be fitted to the probe inlet when particulate
matter is present in the gas stream being sampled.
Heating Tape
Used to heat probe.
Variable Voltage Regulator
Used to regulate probe heating.
Dry Gas Meter
Readable to the nearest 0.01 cubic foot.
Vacuum Pump
A diaphragm-type pump rated at 15 liters per minute.
Absorbers
1. Midget impinger — An all-glass midget impinger sampling train capable of
removing hydrogen chloride and chlorine from a gas sample may be used
when sampling stack gas suspected of containing less than 0.1 percent
hydrogen chloride or chlorine.
The sampling train should consist of a probe, four midget impingers, a
gas drying tube, a vacuum pump, and a flow meter, as illustrated in
Figure A-l.
PROBE
WITH HEATING
ELEMENT
ICE BATH I
METER
Figure A-l. Impinger gas sampling train.
A Pyrex® glass tube serves as the probe. It should have a ball joint on the
outlet to which other glassware can be easily connected. The probe
should be wrapped with nickel-chromium heating wire, insulated with
glass wool and installed into a protective 1-inch-diameter stainless steel
36
HYDROCHLORIC ACID EMISSIONS
-------
tube. During sampling, the heating wire is connected to a calibrated,
variable transformer to maintain a temperature of up to 250° F on the
probe wall. A heating tape may also be used to heat the probe.
Four midget glass impingcrs are connected in series to the probe outlet
with glass ball joints. The first three impingers each contain 15 ml of
absorbing reagent. The fourth impinger is left dry to catch any material
that is carried over from the other impingers. All four impingcrs are
cooled in an iccwatcr bath.
Gases leaving the impingers are dried as they pass through a tube of silica
gel. They then are pumped to the airtight vacuum pump and gas meter.
Sampling rales are regulated by using a valve to adjust the flow through
the pump.
2. Grab-sampling bottle An accurately calibrated 2-liter glass bottle
equipped with Teflon® stopcocks (Figure A-2) should be used when
sampling percentage quantities of hydrogen chloride or chlorine.
Absorbing reagent is added to the grab-sample bottle after the sample has
been collected.
ATTACH ^ ^ TO
PROBE VACUUM
Figure A-2. Grab sample bottle.
Dispenser (Absorbing Reagent)
A 100-milliliter round-bottom flask, modified with a Teflon® stopcock and
ball joint extension (see Figure A-3) is used as a dispenser for absorbing
reagent. It is used to add reagent to the grab-sampling bottle after the sample
has been collected.
Analytical Procedure
Collection of Samples
1. Midget impinger train:
Pipet 15 ml of absorbing reagent into each of the three midget impingers.
Heat probe to prevent moisture condensation. Start pump and sample at
a rate of 1 to 3 liters per minute for at least 60 minutes.
2. Grab sampling:
Flush probe and draw about 20 liters of gas through the sample bottle.
Pipct 25 ml of absorbing reagent into the dispenser and add to the
grab-sample bottle following collection of the sample. Shake bottle
thoroughly for about 2 minutes to insure complete absorption.
3. Transfer the contents of the impingers or grab-sampling bottle to a
sample container, such as a polyethylene bottle, containing deionixed or
distilled water.
Appendix A 37
-------
100-ml CAPACITY
NO. 12/5
'TEFLON STOPCOCK
Figure A-3. Burette for adding absorbing reagent.
Sample Preparation
Measure the actual volume of the liquid sample or adjust to a known volume
using a graduated cylinder or volumetric flask.
Procedure A
Analysis of Hydrogen Chloride
Pipet an aliquot of the sample into a 250-ml Erlenmeycr flask. Add 25 ml of
water, 5 ml of nitric acid and swirl to mix. Depending on chloride content, add
O.I N or 0.01 N silver nitrate from a buret until the silver chloride formed
begins to coagulate. When coagulation occurs, add an additional S ml of silver
nitrate. Add 3 ml of nitrobenzene and 2 ml of ferric indicator, then
back-titrate with 0.1 N or 0.01 N ammonium thiocyanate until the First
appearance of the reddish-brown Fe(CNS)6~3 complex. A blank determination
for chloride in the absorbing reagent should be run simultaneously and
subtracted from the sample results. From the titcr of NH4CNS solution, as
determined previously by titration against standard AgNO3 solution using
ferric alum as an indicator, calculate the net volume of AgNO3 required for
precipitation of the chloride.
Calculations
Compute the number of milligrams of hydrogen chloride present in the
sample by the following equation:
38
HYDROCHLORIC ACID EMISSIONS
-------
C = Hd, mg = net ml AgN03 X T X F
T = hy drogen chloride equivalent of standard AgNO3
( T = 3.65 mg HCl/ml for 0.1 N AgN03 )
( T = 0.365 mg HCl/ml for 0.01 N AgNO3 )
„ sample volume, ml
r —
aliquot volume, ml
Convert the volume of gas sampled to the volume at standard conditions of
70° F and 29.92 in. Hg.
530°R
29.92 ( t + 460 R)
V = volume of gas sampled, as measured on dry gas meter or equal to
volume of grab sample bottle-liters
P = barometric pressure (in. Hg) or absolute pressure at gas meter
t = average temperature of gas sampled, ° R
Determine the concentration of hydrogen chloride in the gas sample by the
following formula:
Vs
662 = jul/mg of HC1 at 70° F and 29.92 in. Hg
C = concentration of HC1, mg
V s = volume of gas sampled in liters at 70° F and 29.92 in. Hg
Procedure R
Analysis of Hydrogen Chloride in the Presence of Chlorine
Pipet an aliquot of the sample into a 250-ml Erlenmeyqr flask and proceed
with the Volhard titration for total chlorides as described under Procedure A.
A blank determination for chloride in the absorbing reagent (alkaline-arscnite
reagent) should be run simultaneously and subtracted from the sample results.
Pipet another aliquot of the sample into a 250-ml Erlenmeyer flask. Add a
few drops of phenolphthalein indicator, neutralize carefully with concentrated
hydrochloric acid, and cool. Add sufficient solid sodium bicarbonate
( NaHCO3 ) to neutralize any excess hydrochloric acid, then add 2 to 3 g more.
Add 2 ml of starch indicator and titrate with 0.1 N iodine solution to the blue
endpoint. For the reagent blank, determine the number of ml of 0.1 N 12
required to titrate 25 ml of alkaline-arsenite absorbing reagent, as described
above.
Appendix A 39
-------
Calculations
Determine the number of milliliters of 0.1 N I2 required to titrate the entire
sample by the following formula:
Sample ( ml 0.1 N I2 ) = ( ml of 0.1 N 12 for aliquot) X F
volume of sample, ml
P _
volume of aliquot, ml
Cl2,mg = Blank ( ml 0.1 NI2) Sample(ml0.1 NI2) X 3.546
3.546 = chlorine equivalent of 0.1 N I2, mg
Convert the volume of gas sampled at standard conditions of 70° F, 29.92
in. Hg, using the formula in Procedure A. Calculate the concentration of C12 in
the sample using the following formula:
(340) (C)
ppm C12 by volume = —
"s
340 = 1/mg of C12 at 70° F and 29.92 in. Hg
C = concentration of C12, mg
V s = volume of gas sampled at standard conditions, liters
Determine the number of milligrams of hydrogen chloride present in the
sample by subtracting the number of milligrams of chlorine present, as
determined by the iodine titration, from the total number of milligrams of
chloride present as determined by the Volhard titration. Calculate the
concentration of hydrogen chloride in parts per million using the formula in
Procedure A.
Total stack gas volume must also be measured in order to determine the
emissions on a weight basis. This may be done by measuring the gas velocity
with a pitot tube.
The following equations are used to determine gas velocity and gas volume:
= 172(F)(VAPavg) |\/TS.X
L
X —
MS
Vg = velocity in feet per minute at stack conditions
F = pitot tube—correction factor (0.85 for type S)
Mo = molecular weight of stack gas
To = average stack gas temperature ° R
Po = average stack gas pressure, in. Hg
AP = pitot tube manometer reading, in. water
40 HYDROCHLORIC ACID EMISSIONS
-------
The total stack gas volume-is then:
TPc"
(17.4)
A = stack area, sq ft
Qs = gas volume, ft3/minat 70° F and 29.92 in. Hg
The emissions on a weight per hour basis may then be determined by the
following equation:
W = ppm X 10-6 X Q X 60 X
s 387
W = emissions, Ib/hr
ppm = parts per million by volume of contaminant
Qs = stack gas flow rate, scfm
mol wt = molecular weight of contaminant
C12 = 70.92 HC1 = .36.46
387 = volume (ft3) occupied by 1 Ib mol at 70° F and 29.92 in. Hg
Discussion of Procedure:
The estimated error for the combined sampling and analytical procedure is
±10 percent. The precision of the analytical methods is ±2 percent on standard
samples containing NaCl and NaAsO2.
The usual volumetric errors are encountered with the Volhard titration.
Premature endpoints may occur if the NH4 CNS is not added by drops near the
equivalence point and the solution shaken before the next addition.
Nitrobenzene is used to effectively remove AgCl by forming an oily coating on
the precipitate and preventing reaction with the thiocyanate.10 Bivalent
mercury, which forms a stable complexion with the thiocyanate, and
substances that form insoluble silver salts interfere in the analysis and must be
absent from the sample. Titration should be made at temperatures below
25° C, as is customary in other titrations with thiocyanate.11
The chief source of error in the iodine titration of arsenite is the failure to
use sufficient bicarbonate to neutralize all the excess acid. If insufficient
bicarbonate is added, serious errors may be incurred because of a fading
endpoint. A reducing agent such as sulfur dioxide and oxidizing agents such as
iodine, nitrogen dioxide, and ozone interfere with the iodine titration and yield
high results when present in the stack gas sample.
ACID MIST SAMPLING.
The sampling apparatus is made up of a probe, a cyclone, a filter, four
impingers, a dry gas meter, a vacuum pump, and a flow meter, as shown in
Figure A-4.12'13
Appendix A 41
-------
Figure A-4. Mist sampling train.
A stainless steel, buttonhook-type probe tip (1) is connected to the probe
by a stainless steel coupling (2) and Viton® "0" ring bushings.
The probe (3) is a 5/8-inch-outside-diameter medium-wall Pyrex® glass tube
with an §-ball joint on one end. The glass probe is wound from the entrance
end with 25 feet of 26 guage nickel-chromium wire. During sampling the wire
is connected to a calibrated variable transformer to maintain a gas temperature
of 250° F in the probe. The wire-wound glass tube is wrapped with fiberglass
tape and encased in a 1-inch-outside-diameter stainless steel tube for
protection.
A glass cyclone (4) is connected to the outlet end of the probe to catch
larger size mists.
A very coarse-fritted glass filter holder (5), which holds a 2-H-inch tared
glass fiber filter of MSA type 1106 BH filter paper, follows the cyclone.
The cyclone and filter are contained in an electrically heated, enclosed box
(6), the temperature of which is thermostatically maintained at a minimum of
250° F to prevent condensation of water.
Four impingers in series, placed in an ice bath, are connected to the filter
holder outlet. The first impinger is a Greenburg-Smith design modified by
replacing the tip with a H-inch diameter glass tube extending to 0.5 inch from
the bottom of the flask. This impinger contains 100 ml of sodium hydroxide.
The second impinger is a Greenburg-Smith impinger with tip that also contains
100 ml of sodium hydroxide. The third impinger is modified the same as the
first and is left dry. The fourth impinger (11) is also a modified
Greenburg-Smith type. It contains about 175 g of dry silica gel.
From the fourth impinger (11) the effluent stream flows through a check
valve (13), a needle valve, a leakless vacuum pump, and a dry gas meter. A
calibrated orifice and a dual manometer complete the train and are j used to
measure instantaneous flow rates.
42
HYDROCHLORIC ACID EMISSIONS
-------
DETERMINATION OF SULFATES AND SULFURIC ACID.
This method is used to determine concentrations of sulfuric acid or sulfur
dioxide14 in stack gases from the manufacture of hydrochloric acid by the
Mannheim process.
Sulfur dioxide in the stack effluent is absorbed and oxidized to the sulfate
form in midget impingcrs containing 3 percent hydrogen peroxide.
Sulfuric acid mist is collected on a glass fiber filter paper by an acid mist
sampling train. Sulfates are determined turbidimetrically by the formation of
barium sulfate as barium chloride is added. The absorbance of the barium
sulfate suspension is measured spectrophotometrically at 500 m/* with a 1-inch
cell path. This method is applicable for the determination of sulfate ion
concentrations of from 0 to 50 Mg/ml in aqueous media.
Reagents
All chemicals must be ACS analytical reagent grade.
Water
Deionized or distilled water.
Absorbing Reagent
Hydrogen peroxide (3 percent) — Dilute 10 ml of 30 percent hydrogen
peroxide to 100 ml.
Sulfa Ver Powder
For sulfates in water manufactured by the Hack Chemical Company, Ames,
Iowa.*
Standard Sodium Sulfate
Dissolve 1.469 grams of sodium sulfate in 1 liter of water. Dilute 100.0 ml of
this solution to 1 liter with water in a volumetric flask. This solution contains
100Mg(S04')/mL
Sample Preparation
Transfer the contents of the midget impingers or the glass fiber filter to a
sample container. Dilute the impinger solution to a known volume and/or add
a known volume of water to the filter for solubalization of the sulfate.
Procedure
Pipet 20 ml or a suitable aliquot made up to 20 ml into a 1-inch cuvette or
test tube. Read the absorbance against a distilled water blank (blank
correction). This value will be subtracted from the final absorbance reading to
correct for unmatched cuvettes. Add one level spoonful (0.3 g) of Sulfa Ver
powder and shake to mix.
Between 5 minutes and 20 minutes after the Sulfa Ver powder is added, the
absorbance should be read on'a spectrophotometer at 500 rh/Lt. Use a blank of
*Mcntion of company or product name does not constitute endorsement by the U.S.
Department of Health, Education, and Welfare.
Appendix A 43
-------
water and Sulfa Ver powder to set the spectrophotometer to zero absorbance.
Determine the amount of sulfate present from a previously prepared
calibration curve.
Preparation of Calibration Curve
Prepare a series of standards ranging from 0 to 50 Mg/ml from the working
standards solution. Measure the absorbance of these standard solutions in the
manner described in the procedure. Construct a calibration curve by plotting
/ug (S04 )/ml versus absorbance.
Calculations
Compute the number of mg of SO2 present in the sample by the following
formula:
64 = molecular weight of SO2
96 = molecular weight of (S04)
Compute mg of H2 SO4 present in the sample by the following formula:
no
H2S04,mg = (SOi),mgX
96 = molecular weight of (SO4)
98 = molecular weight of sulfuric acid.
(377)(mgofS02)
SO2,ppm = - T;
V
s
377 = jd/mg of S02 at 70° F and 29.92 inches of Hg
V s = volume of gas sampled in liters at 70° F and 29.92 inches of Hg
, H2SO4,/ug
H2S04,|Ug/m3 = '
v s
V s = volume of gas sampled in cubic meters at 70° F and 29.92 inches of
Hg
44 HYDROCHLORIC ACID EMISSIONS
-------
APPENDIX 6. HYDROCHLORIC ACID
MANUFACTURING ESTABLISHMENTS LOCATED
IN UNITED STATES
January 1968
Type of Process Utilized
B = By-Product
S = Chlorine-Hydrogen Synthesis
M = Mannheim
H = Hargreaves
State
Company name
Alabama
Giegy Chemical Corp.
Monsanto Co.
Olin Matheison Chemical Corp.
Olin Matheison Chemical Corp.
Stauffer Chemical
Arkansas
Arkla Chemical Corp.
California
American Chemical Corp.
J.H. Baxter & Company
Chevron Chemical Company
Dow Chemical Co.
E.I. duPont dcNemours & Co.
Neville Chemical Co.
Stauffer Chemical Co.
Montrose Chemical Corp. of Calif.
Witficld Chemical Corp.
Connecticut
The Upjohn Co.
Uniroyal Co.
Delaware
Allied Chemical Corp.
Standard Chlorine of Delaware
Location Type
Mclntosh B
Anniston B
Mclntosh B
Huntsville B
LeMoyne B
Pine Bluff
Long Beach B
Long Beach B
Richmond B
Pittsburgh B
Antioch B
Santa Fe Springs B
Domingue/. (LA.) B
Torrance B
Watson B
North Haven B
Naugatuck B
North Claymont B
Delaware City B
Appendix B •
45
-------
Georgia
Chemical Products Corp. Cartersville
Hercules, Inc. Brunswick
Merck & Company Albany
Illinois
Allied Chemical Corp. Danville
Baird Chemical Industries, Inc. Peoria
Cabot Corp. Tuscola
Monsanto Co. Sauget
The Richardson Co. Chicago
The Richardson Co. Lemont
Indiana
E.I. duPont deNemours & Co. East Chicago
Keil Chemical Hammond
B
B
B
B
B
B
B
B
B
B
B
Kansas
Racon, Inc.
Vulcan Materials Co.
Clearwater
Wichita
B
B,S
Kentucky
E.I. duPont deNemours & Co. Louisville
Hooker Chemical Corp. South Shore
Pennsalt Chemical Corp. Calvert City
Stauffer Chemical Co. Louisville
B
B
B
B
Louisiana
Allied Chemical Corp. Geismar
Allied Chemical Corp. Baton Rouge
Conoco Lake Charles
Dow Chemical Co. Plaquemine
Ethyl Corp. Baton Rouge
Hooker Chemical Co. Taft
Kaiser Aluminum & Chemical Co. Gramercy
Morton Chemical Co. Weeks Island
Morton Chemical Co. Giesmar
Pittsburgh Hate Glass Co. Lake Charles
Rubicon Chemicals, Inc. Lake Charles
Shell Chemical Co. Norco
Vulcan Materials Co. Geismar
Wyandotte Chemical Corp. Geismar
B
B
B
B,S
B,S
B
B
H
B
B
B
B
B
B
Maryland
Chemetron Corp.
Continental Oil Co.
FMC
Elkton
Baltimore
Baltimore
B
B
B
46
HYDROCHLORIC ACID EMISSIONS
-------
Massachusetts
Monsanto Co. Everett
Solvent Chemical Co. Maiden
Michigan
Dow Chemical Co. Midland
Dow Corning Co. Midland
E.I. duPont deNemours & Co. Montague
Hooker Chemical Corp. Montague
Ott Chemical Corp. Muskegon
Pennsalt Chemical Corp. Wyandotte
Missouri
Monsanto St. Louis
Nevada
Montrose Chemical Corp. of Calif. Henderson
Stauffer Chemical Co. Henderson
B
B
B
B
B
S
B
B,S
B
B
New Jersey
Allied Chemical Corp. Elizabeth
Baldwin-Montrose Calif. Co. Newark
Benzol Products Div. Newark
W.A. Cleary Corp. New Brunswick
Diamond Alkali Co. Newark
E.I. duPont deNemours & Co. Carney's Point
E.I. duPont deNemours & Co. Deepwater
E.I. duPont deNemours & Co. Linden
Enjay Chemical Co. Bayway
General Aniline & Film Corp. Linden
Hercules, Inc. Parlin
ICI Bayonne
Merck & Co. Rahway
Mobil Oil Corp. Metuchen
Pearsall Chemical Corp. Phillipsburg
Tenneco Chemical Inc. Fords
Toms River Chemical Corp. Toms River
Vulcan Materials Co. Newark
Weston Chemicals Corp. Newark
White Chemicals Co. Bayonne
B
B
B
B
B
B
B
M
B
S
B
B
B
B
B
B
B
B
B
B
New Mexico
Climax Chemical Co.
Hobbs
M
New York
Allied Chemical Corp. Buffalo
Allied Chemical Corp. Syracuse
E.I. duPont deNemours & Co. Niagra Falls
B
B
B,S
Appendix B
47
-------
Eastman Kodak Co.
Hooker Chemical Corp.
Hooker Chemical Corp.
Stauffcr Chemical Corp.
Rochester B
Niagra Falls B,S
North Tonawanda B,S
Niagra Falls B
Ohio
Detrex Chemical Ind. Ashtabula
Diamond Alkali Co. Painesville
Dover Chemical Corp. Dover
E.I. duPont deNemours & Co. Cleveland
Olin Matheison Chemical Corp. Ashtabula
Pittsburgh Plate Glass Co. Barberton
Tennessee Corp. Evendale
B
B,S
B
M
B
B
M
Oregon
Pennsalt Chemical Corp.
Portland
Pennsylvania
Allegheny Electronic Chemical Co. Bradford
Koppers Co., Inc. Bridgeville
Lebanon Chemical Co. Lebanon
Rohm & Haas Co. Philadelphia
U.S. Steel Corp. Clairton
B
B
B
B
B
Tennessee
Stauffer Chemical Co.
Velsicol Chemical Corp.
Mt. Pleasant
Chattanooga
B
B
Texas
Atlantic Richfield Co.
Diamond Alkali Co.
Diamond Alkali Co.
Dow Chemical Co.
Dow Chemical Co.
E.I. duPont deNemours & Co.
Ethyl Corp.
Monsanto Co.
Monsanto Co.
Phillips Petroleum Co.
Phillips Petroleum Co.
Potash Co. of America
Shell Chemical Co.
Stauffer Chemical Co.
Union Carbide Corp.
The Upjohn Co.
Vulcan Materials Co.
Port Arthur
Deer Park
Greens Bayou
Freeport
Oyster Creek
La Porte
Houston
Texas City
Alvin
Pasadena
Deer Park
Dumus
Houston
Fort Worth
Texas City
La Porte
Denver City
B
B,S
B
B
B
S
B,S
B
B
B
B
B
B
M
B
;B i
S
48
HYDROCHLORIC ACID EMISSIONS
-------
Utah
National Lead Co. Lakepoint (experimental)
Virginia
Hercules, Inc. Hopewell M
Olin Matheison Chemical Corp. Saltville S
Washington
Hooker Chemical Corp. Tacoma S,B
Pennsalt Chemical Corp. Tacoma S
Reichhold Chemicals, Inc. Tacoma B
West Virginia
Allied Chemical Corp. Moundsville B
Diamond Alkali Co. Belle B
FMC Corp. South Charleston B
FMC Corp. Nitro B
Mobay Chemical Co. New Martinsville B
Monsanto Co. Nitro B
Pittsburgh Plate Glass Co. Natrium B,S
Stauffer Chemical Co. Gallipolis Ferry B
Union Carbide Corp. Institute B
Union Carbide Corp. South Charleston B
Appendix B 49
-------
APPENDIX C.
PHYSICAL DATA-HYDROCHLORIC ACID
51
-------
Table C-1. SPECIFIC GRAVITIES OF AQUEOUS HYDROCHLORIC ACID SOLUTIONS8
Standard Adopted 1903
Authority - W. C. Ferguson
Density,
°Be
1.00
2.00
3.00
4.00
5.00
5.25
5.50
5.75
6.00
6.25
6.50
6.75
7.00
7.25
7.50
7.75
8.00
8.25
8.50
8.75
9.00
9.25
9.50
9.75
10.00
10.25
10.50
10.75
11.00
11.25
11.50
11.75
12.00
12.25
12.50
12.75
13.00
13.25
13.50
13.75
14.00
14.25
14.50
14.75
15.00
15.25
15.50
15.75
Specific
gravity
1.0069
1.0140
1.0211
1.0284
1.0357
1.0375
1.0394
1.0413
1.0432
1.0450
1.0469
1.0488
1.0507
1.0526
1.0545
1.0564
1.0584
1.0603
1.0623
1.0642
1.0662
1.0681
1.0701
1.0721
1.0741
.0761
.0781
.0801
.0821
.0841
.0861
1.0881
1.0902
1.0922
1.0943
1.0964
.0985
.1006
.1027
.1048
.1069
.1090
.1111
.1132
.1154
.1176
.1197
.1219
Percent
HCI
1.40
2.82
4.25
5.69
7.15
7.52
7.89
8.26
8.64
9.02
9.40
9.78
10.17
10.55
10.94
11.32
11.71
12.09
12.48
12.87
13.26
13.65
14.04
14.43
14.83
15.22
15.62
16.01
16.41
16.81
17.21
17.61
18.01
18.41
18.82
19.22
19.63
20.04
20.45
20.86
21.27
21.68
22.09
22.50
22.92
23.33
23.75
24.16
Density,
"Be1
16.0
16.1
16.2
16.3
16.4
16.5
16.6
16.7
16.8
16.9
17.0
17.1
17.2
17.3
17.4
17.5
17.6
17.7
17.8
17.9
18.0
18.1
18.2
18.3
18.4
18.5
18.6
18.7
18.8
18.9
19.0
19.1
19.2
19.3
19.4
19.5
19.6
19.7
19.8
19.9
20.0
20.1
20.2
20.3
20.4
20.5
20.6
20.7
Specific
gravity
.1240
.1248
.1256
,1265
.1274
.1283
.1292
.1301
.1310
.1319
.1328
.1336
.1345
.1354
.1363
.1372
.1381
.1390
.1399
.1408
.1417
.1426
.1435
.1444
.1453
.1462
.1471
.1480
.1489
.1498
,1508
.1517
.1526
.1535
.1544
.1554
.1563
.1572
.1581
.1590
.1600
.1609
.1619
.1628
.1637
.1647
1:1656
1.1666
Percent
HCI
24.57
24.73
24.90
25.06
25.23
25.39
25.56
25.72
25.89
26.05
26.22
26.39
26.56
26.73
26.90
27.07
27.24
27.41
27.58
27.75
27.92
28.09
28.26
28.44
28.61
28.78
28.95
29.13
29.30
29.48
29.65
29.83
30.00
30.18
30.35
30.53
30.71
30.90
31.08
31.27
31.45
31.64
31.82
32.01
32.19
32.38
32.56
32.75
Density,
"Be1
20.8
20.9
21.0
21.1
21.2
21.3
21.4
21.5
21.6
21.7
21.8
21.9
22.0
22.1
22.2
22.3
22.4
22.5
22.6
22.7
22.8
22.9
23.0
23.1
23.2
23.3
23.4
23.5
23.6
23.7
23.8
23.9
24.0
24.1
24.2
24.3
24.4
24.5
24.6
24.7
24.8
24.9
25.0
25.1
25.2
25.3
25.4
25.5
Specific
gravity
1.1675
1.1684
.1694
.1703
.1713
.1722
.1732
.1741
.1751
.1760
.1770
.1779
.1789
.1798
.1808
.1817
.1827
.1836
.1846
.1856
.1866
.1875
.1885
.1895
.1904
.1914
.1924
.1934
.1944
.1953
.1963
.1973
.1983
1.1993
1.2003
15013
15023
1.2033
1.2043
1.2053
1.2063
1.2073
1.2083
1.2093
1.2103
15114
1.2124
1.2134
Percent
HCI
32.93
33.12
33.31
33.50
33.69
33.88
34.07
34.26
34.45
34.64
34.83
35.02
3551
35.40
35.59
35.78
35.97
36.16
36.35
36.54
36.73
36.93
37.14
37.36
37.58
37.80
38.03
38.26
38.49
38.72
38.95
39.18
39.41
39.64
39.86
40.09
40.32
40.55
40.78
41.01
41.24
41.48
41.72
41.99
42.30
42.64
43.01
43.40
Allowance for temperature:
10-15° Be.-1/40° Be or 0.0002 Sp. Gr. for 1° F.
10-22° Be.-1/30° Be or 0.0003 Sp. Gr. for 1° F.
22-25° Be.-1/28° Be1 or 0.00035 Sp. Gr. for 1° F.
Originally published as Manufacturing Chemists' Association, Inc. Manual Sheet
SD-39. Copies of a similar table giving ° Be1, Sp. Gr. and Tw ° corresponding with
percent HCI, are available through the MCA as Manual Sheet T-3.
52
HYDROCHLORIC ACID EMISSIONS
-------
VAPOH PRESSURES OF AQUEOUS
Miunom OF HYDBOCHLOSIC ACID
0.01 .05 0.1 0.5 1 5 10 SO 100
PARTIAL PRESSURE-HCI, mm Hg
500 1000
Figure C-l. Vapor pressure of hydrochloric acid at various concen-
trations.
-. 20
3 10
I
r
^SPECIFIC GRAVITY
20 30
HCI BY WEIGHT, p.rc.nt
Figure C-2. Specific gravity and density versus percent hydrogen
chloride.
Appendix C
53
-------
ACID BY WEIGHT, p.r«nt
figure C-3. Relationship of viscosities of hydrogen chloride and
water.
a 650
a
OF SOLUTION AT 50* C __
INTEGRAL HEAT OF SOLUTION AT IS* C
V
"*«% BOILING POINT-***^
PARTIAL HEAT OF SOLUTION AT !»• C
\
J I I
10 II 20
j I
ACID CONCENTRATION,
Figure C-4. Heats of solution of hydrogen chloride in water.
54
HYDROCHLORIC ACID EMISSIONS
-------
so
HCI CONCENTRATION, weight p.rc.nl
Figure C-5. Vapor-liquid equilibra for hydrochloric acid.
Appendix C
55
-------
10 IS 20 25 30 35
ACID CONCENTRATION, w.ijt.1 p»rc«nl
45
Figure C-6. Boiling point of hydrochloric acid solution.
56
HYDROCHLORIC ACID EMISSIONS
-------
•20
-30
•40
•60
-70
-80
•90
10 20 30 40 50 60
CONCENTRATION, w.ight p.rc.m
70
80
Figure C-7. Freezing point of aqueous hydrogen chloride.
Appendix C
57
-------
REFERENCES
1. Statistical Abstracts of the U.S., Bureau of the Census, U.S. Department of
Commerce, 1933-1967.
2. Furnas, G.C., Rodgers' Industrial Chemistry, 6th Edition, Volumes I and II, D. Van
Nostrant Co., Inc., 1962.
3. Buckley, Joseph A., "Vinyl Chlorides via Direct Chlorination and Osychlorination,"
Chemical Engineering, November 21, 1966, pp. 102-104.
4. Albright, Lyle F., "Vinyl Chloride Processes," Chemical Engineering, March 27, 1967,
pp. 123-130.
5. "Karbate Brand Impervious Graphite Falling Film Type Absorber, Series 31 A,"
Bulletin N 38-3, National Carbon Company, Division of Union Carbide Corporation,
November 6,1961.
6. "Process Design, Haveg Chemical Equipment," Haveg Catalog, Section 7-0, Chemical
Equipment Division, Haveg Industries Inc.
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Chlorowasserstoff and Fluorwasserstoff Absorption," Chem.-Ingr.-Tech., Volume 35,
pp. 262-266, 1963.
8. Gaylord, W.M. and M.A. Miranda, "The Falling-Film Hydrochloric Acid Absorber,"
Chemical Engineering Progress, Volume 53, No. 3, March 1967, pp. 139-M- 144-M.
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Company, Inc., 1962, pp. 329-330.
10. Caldwefl, I.E. and H.V. Mayer, fnd. Eng. Chen, Anal. Ed., 7, 38, 1935.
11. Jacobs, M.B., The Chemical Analysis of Air Pollutants, Interscience Publishers, Inc., p.
199,1960.
12. Patton, W.E. and J.A. Brink, "New Equipment and Techniques for Sampling Chemical
Process Gases,"/. Air Poll. Control Assoe^, 13:162-66, 1963.
•
13. Smith, W., et al., "Stack Gas Sampling Improved and Simplified with New
Equipment," APCA paper 67-119, Cleveland, Ohio, June 1967.
14. ASTM Standards, Part 23 Industrial Water; Atmospheric Analysis, 1965, pp. 26-28.
15. Perry, J.H., Chemical Engineering Handbook, Volume IV, McGraw-Hill Book Co.,
New York.
59
* U.S. GOVERNMENT PRINTING OFFICE: 1969 O—3S5-116
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