EPA-450/3-73-006-d
MARCH 1975
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ENGINEERING
AND COST STUDY
OF AIR POLLUTION CONTROL
FOR THE
PETROCHEMICAL INDUSTRY
VOLUME 4: FORMALDEHYDE
MANUFACTURE
WITH THE SILVER
CATALYST PROCESS
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U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
-------
PB-242 118
ENGINEERING AND COST STUDY OF AIR POLLUTION CONTROL
FOR THE PETROCHEMICAL INDUSTRY
VOLUME 4 - FORMALDEHYDE MANUFACTURE WITH THE SILVER
CATALYST PROCESS
Air Products and Chemicals, Incorporated
PREPARED FOR
Environmental Protection Agency
March 1975
DISTRIBUTED BY:
National Technical Information Service
U. S. DEPARTMENT OF COMMERCE
-------
EPA-450/3-73-006-d
ENGINEERING
AND COST STUDY
OF AIR POLLUTION CONTROL
FOR THE
PETROCHEMICAL INDUSTRY
VOLUME 4: FORMALDEHYDE
MANUFACTURE
WITH THE SILVER
CATALYST PROCESS
by
R. B . Morris , F . B . Higgins, Jr. ,
J. A. Lee, R. Newirth, and J . W. Pervier
Houdry Division
Air Products and Chemicals, Inc.
P.O. Box 427
Marcus Hook, Pennsylvania 19061
Contract No. 68-02-0255
EPA Project Officer: Leslie B. Evans
Prepared for
ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Air Quality Planning and Standards
Research Triangle Park , N. C. 27711
March 1975
-------
This report is issued by the Environmental Protection Agency to report
technical data of interest to a limited number of readers. Copies are
available free of charge to Federal employees, current contractors and
grantees, and nonprofit organizations - as supplies permit - from the Air
Pollution Technical Information Center, Environmental Protection Agency,
Research Triangle Park, North Carolina 27711; or, for a fee, from the
National Technical Information Service, 5285 Port Royal Road, Springfield,
Virginia 22161.
This report was furnished to the Environmental Protection Agency by
the lloudry Division of Air Products and Chemicals, Inc. , in fulfillment
of Contract Nu. 68-02-0255. The contents of this report are reproduced
herein as received from the Houdry Division of Air Products and Chemicals,
Inc. The opinions, findings, and conclusions expressed are those of
the author and not necessarily those of the Environmental Protection
Agency. Mention oi company or product names is not to be considered
as an endorsement by the Environmental Protection Agency.
Publication No. EPA-450/3-73-006-d
i
-------
PETROCHEMICAL AIR POLLUTION STUDi
INTRODUCTION TO SERIES
This document" is one of a series prepared for the Environmental Protection
Agency (EPA) to .assist it in determining those petrochemical processes for
vhich standards should be promulgated. A total of nine petrochemicals produced
by 12 distinctly different processes has been selected for this type of
in-depth study. These processes are considered tc be ones which might varrant
standards as a result of their impact on air quality. Ten volumes, entitled
Engineering and Cost Study of Air Pollution Control for the Petrochemical
Industry (EPA-450/3-73-G06a through j) have been prepared.
A combination of expert knowledge and an industry survey was used to
select these processes. The industry survey has been published separately
in a series of four volumes entitled Survey Reports on Atmospheric Emissions
from the Petrochemical Industry (EPA-450/3-73-005a, b, c and d).
The ten volumes of this series report on carbon black, aerylonitrile,
ethylene dichloride, phthalic anhydride (two processes in a single volume),
formaldehyde (two processes in two volumes), ethylene oxide (two processes
in a single volume) high density polyethylene, polyvinyl chloride and vinyl
chloride monomer.
-------
ACKNOWLEDGEMENTS
The study reported in this volume, by its nature, relied on the fullest
cooperation of the companies engaged in the production of formaldehyde. Had
their inputs been withheld, or valueless, the study would not have been
possible or at least not as extensive as here reported. Hence, Air Products
wishes to acknowledge this cooperation by listing the contributing companies.
Allied Chemical Corporation
Borden Chemical Company
Celanese Corporation
E. I. duPont deNemours & Company
GAF Corporation
Georgia Pacific Corporation
Gulf Oil Corporation
Hercules, Inc.
Hooker Chemical Company
Monsanto Company
Reichhold Chemical Company
Tenneco Chemical Company
Wright Chemical Company
Additionally, Air Products wishes to acknowledge the cooperation of the
member companies of the U. S. Petrochemical Industry and the Manufacturing
Chemists Association for their participation in the public review of an
early draft of this document., More specifically, the individuals who served
on the EPA's Industry Advisory Committee are to be commended for their advice
and guidance at these public meetings.
-------
TABLE OF CONTENTS
SECTION
PAGE NUMBER
Summary
i
I.
Introduction
FS-1
II.
Process Description
FS-2
III.
Manufacturing Plants and Emissions
FS-8
IV.
Emission Control Devices and Systems
FS-20
V.
National Emission Inventory
VI.
Ground Level Air Quality Determination
FS-31
VII.
Cost Effectiveness of Controls
FS-32
VIII.
Source Testing
FS-37
IX.
Industry Grovth Projection
FS-38
X.
Plant Inspection Procedures
FS-40
XI.
Financial Impact
FS-42
XII.
Cost to Industry
FS-48
XIII.
Emission Control Deficiencies
FS-50
XIV.
Research and Development Needs
FS-52
XV.
Research and Development Programs
FS-53
XVI.
Sampling, Monitoring and Analytical Methods for
Pollutants in Air Emissions
FS-56
XVII.
Emergency Action Plant aor Air Pollution Episodes
FS-59
References FS-66
Appendix I I-I
Appendix II II-I
Appendix III III-I
-------
LIST OF ILLUSTRATIONS
Figure No. Title
; FS-1
Simplified Flow Diagram
FS-4
FS-2
Formaldehyde Production - Capacity Projection
FS-39
LIST OF TABLES
No.
Title
Page Number
FS-1
Typical Material Balance - Lbs.
FS-5
FS-2
Typical Material Balance - Ton/Ton
FS-6
FS-3
Formaldehyde Converter Section Heat Balance
FS-7
FS-4
Tabulation of U.S. Formaldehyde Plants (2 pages)
FS-9
FS-5
Survey of U.S. Formaldehyde Plants and Atmospheric
Emissions from these Plants (6 pages)
FS-U
FS-6
Typical Absorber Vent Gas Composition
FS-17
FS-7
Catalog of Emission Control Devices (2 pages)
FS-21
FS-8
Thermal Incinerator Emission Control System
(Absorber Vent)
FS-23
FS-9
Catalytic Incinerator Emission Control System
(Absorber Vent)
FS-25
FS-10
Water Scrubber Emission Control System
(Absorber Vent)
FS-27
FS-11
Total Recycle System for Emission Control
(Fractionator Vent)
FS-29
FS-12
Cost Effectiveness for Alternate Emission
Control Devices (2 pages)
FS-33
FS-13
Formaldehyde Manufacturing Costs for a Typical
Existing 100 MM Lbs./Yr. Facility
FS-43
FS-14
Formaldehyde Manufacturing Costs for a New
100 MM Lbs./Yr. Facility with Boiler
House Incinerator
FS-44
FS-15
Formaldehyde Manufacturing Costs for a Typical
Plume Burner Addition to a 100 MM Lbs./Yr.
Facility
FS-45
FS-16
Proforma Balance Sheet
FS-4 6
FS-17
Estimated 1985 Air Emissions for Alternate
Control Systems
FS-49
FS-18
Detailed Costs for R&D Project
FS-54
FS-19
Summary of Sampling and Analytical Methods
Reported for Pollutants
FS-57
FS-20
Financial Impact of Air Pollution Episodes
(2 pages)
FS-63
-------
i.(p
SUMMARY
The formaldehyde industry has been studied to determine the extent of air
poLLution resulting from the operations of the various plants and processes of
the industry. The purpose of the work was to provide the Environmental
Protection Agency with a.portion of the basic date, required in order to reach
a decision on the need to promulgate air emission standards for the industry.
It was concluded that there are two basic processes for the production of
formaldehyde. They both utilize methanol as a raw material in an air oxidation
process. Neither appears to have any significant advantage which would alter
its relative growth rate. A third process, utilizing partial oxidation of
light hydrocarbons to produce formaldehyde appears to be obsolete. The
principal differences between the two methanol based processes are the catalyst
and the methanol/air ratio. The subject of this report is the process utilizing
a silver catalyst and a methanol rich feed mixture with air. A separate study
devotes itself to the other process which uses a mixed metal oxide catalyst and
a methanol lean feed mixture with air, (Report Number EPA-450/3-73-006e.)
In general terms, the air emissions from the silver catalyst process fall
into the categories of hydrocarbons (formaldehyde, methanol,, methyl formate
and methylal) and carbon monoxide. As practiced today, virtually no oxides
of nitrogen, oxides of sulfur or particulates are emitted from the process.
Additionally, although not considered a pollutant, significant quantities of
hydrogen are emitted. This fact contributes to the current trend to burn the
waste stream, which could in turn, contribute to an increase in the emissions
of nitrogen oxide in the waste gas incineration process. The emission factor
for the process is about 0.022 lbs./lb. of 37% formaldehyde. Of this total,
over 80 percent is carbon monoxide which in 1973 was equivalent to over 100
million lbs. of CO emitted into the atmosphere. The hydrocarbon emissions
were nearly 25 million lbs. during 1973 and although there is considerable
variation from plant to plant, the best generalization is that the total is
about 75 percent methanol, 25 percent formaldehyde with only traces of other
hydrocarbons. It has been estimated that emissions in 1985 will increase to
about 225 million lbs./year of carbon monoxide plus about 50 million lbs./year
of hydrocarbons, if all future silver process plants are built as is typical
today.
Formaldehyde is normally marketed as a 37-51 percent water solution.
Therefore, all plants have a water scrubber (absorber) on the main process
stream before it is vented to the atmosphera. Most plants also have a mist
eliminator on this stream to minimze the tjntrainment of water from the absorber.
In addition, four of the plants surveyed have an incineration device on the
waste stream. Two of these use the waste''gas as a supplement to their steam
boiler fuel and the other two incinerate the waste gas without energy recovery.
All four believe that combustion of carbon monoxide and hydrocarbons is nearly
complete and that nitrogen oxide generation is practically nil. This belief is
probably valid but no analytical data exist to support it. If all plants were
equipped with efficient incineration devices, the 1985 emissions of carbon monoxide
from the process would drop to nearly zero and the hydrocarbon emissions would
drop to about ten million lbs./year. The explanation of this fact is that
because of the methanol rich feed stream a considerable quantity of methanol
passes through the reactor unconverted. It is then recovered by fractionation
and recycled. Vent losses from the fractionation amount to about 25 percent
of the hydrocarbon emissions from the process. The mixed oxide process does not
-------
SUMMARY (continued)
require a comparable fractionation step because of the methanol lean feed.
Only one respondent to the questionnaire reported pollution control on the
fractionator vent in the form of a water scrubber, although it is believed
that at least one plant recycles some portion of the vent. The study proposes
a "tonal recycle" type of system which reduces fractionator vent emissions to
zero. However, due to the fact that it may result in a build up of minor
impurities, it cannot be considered as the ultimate solution to the problem
although a continuously purged modification of the concept may be workable.
In summary, the study has concluded that the most feasible air pollution
control system for new plants using the silver catalyst process consists of
utilizing the waste gas as a fuel supplement in the boiler house and effecting
a total (or partical) recycle of vent gases from the. product fractionator.
This would result in practically no increase in today's level of emissions
if all new silver process formaldehyde plants incorporated this sy6tem. In
addition, a fuel gas saving of about three billion standard cubic feet per
year of natural gas would be realized by 1985. The estimated capital cost of
installing this equipment on all new plants is less than $50,000 per plant
(1973 dollars) or about $3,000,000 for the industry by 1985. Neither aspect of
this "most feasible" pollution control system may be applicable to existing
plants but pollution reductions have been demonstrated by means of incinerators
on absorber vent gases and by a scrubber on the fractionator vent. The cost of
these devices on all existing plants has been estimated to be lsss than
$3,000,000 (1973 dollars) but because of unknown problems in individual plants,
the estimate may not be valid in all cases.
From the foregoing, it appears that the major efforts for industry researc
should be in catalyst research to improve yields and perhaps in the use of
oxygen enriched feeds to make the waste gas more readily combustible (or
recyclable) through nitrogen content reduction. A study on the recycling of
fractionator vent gases would also be a worthwhile project. All of these can
best be carried out by today's producers of formaldehyde.
-------
FS-1
I. Introduction
Formaldehyde was first produced in the U. S. in 5 901, fit that time its
chief use was as an embalming agent and disinfectant. Today, some seventy
odd years later production capacity exceeds seven and one half billion
pounds per year, ($) with approximately two thirds of the production utilized
in the formulation of various synthetic resins.
Formaldehyde is normally marketed in aqueous solutions containing from
36 to 50 weight percent formaldehyde. The standard (USP) solution is 37
percent, although large scale industrial users prefer a nominal 50 percent
solution.. Formaldehyde solutions usually contain sufficient methanol to
prevent precipitation of polymer during storage and shipping, although
precipitation may be prevented in solutions containing relatively small amounts
of methanol by keeping the solution warm.
Formaldehyde is produced principally from methanol. Two processes are
dominant in the U. ?. today, the mixed oxide catalyzed process and the silver
crystal Cor gauze) catalyzed process.
The primary licensors of the mixed oxide process are Reichhold and Lummus,
while ICI and Borden prevail in the licensing of the silver process. The
silver catalyzed process is the subject of this report.
A third process, based on the partial oxidation of light hydrocarbons,
had been utilized by Celanese at their large Bishop, Texas plant until
quite recently. That particular facility at Bishop has now been shutdovn
and replaced by a silver process unit. T-'ith rational energy source demands
escalating feedstock costs for the partial oxidation process, it is
extremely doubtful that any nev facility in the U. S. will again employ
this process.
Atmospheric emissions generated by the silver catalyst process are
associated primarily with the absorber vent gas stream. Minor quantities
of hydrocarbons may be discharged by steam ejectors on the product fractionator.
Additionally, small quantities of spent caustic or waste water may he produced.
Today an estimated 77of U.S. formaldehyde capacity is based on the
silver catalyst process. This is appreciably more than its estimated share
of 617, in 1969.A large part of this increaje is due to Celanese
switching to the silver process, but even discounting that situation, the
capacity of the silver-catalysed process appears to be increasing at a faster
rate than does the capacity of the mixed oxide process. If the silver
process can maintain its present share of the total formaldehyde capacity,
it will expand tol.2xlQl0 lbs./year in 1985.
*About 5.9 x 10' lbs./year.
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FS-2
II. Process Description
Despite the fact that formaldehyde was produced from methanol over o^.e
hundred years ago (in 1868 by A. W. Hofmann), the chemistry - of the silver
catalyzed process - is still in dispute. It is thought that the reaction
involves either the dehydrogenaticn of methanol (EQ. 1) followed by the
oxidation of hydrogen (EQ. 2A).
(1) CH3OH — CH20 + H2
(2A) H2 + -i 02 > H20
or a combination of methanol dehydrogenation (EQ. 1) and methanol
oxidation (EQ. 2B)
(1) CH3OH ^ — CHoO + H2
(2b) CH3OH + k 02 — y CH20 + H20
Regardless of this controversy, the implementation of the process is
relatively simple and quite straightforward, as evidenced by the following
brief process description (which may be more easily followed by referring
to the Figure FS-I flow sheet):
Prior to its admixture with methanol vapors, air is caustic washed
to remove C02 and trace sulfur compounds - the latter of which will poison
the silver catalyst. The air is then heated to about 150° F.
Fresh methanol and recycle methanol are combined, vaporized and then
superheated to approximately 170° F. Heat is supplied by either exchange
with the converter effluent or medium pressure stean.
The heated air and superheated methanol vapors are combined in such
proportions that the oxygen/methanol mole ratio is about 1:4. (Decreasing
the percentage of methanol in the mixture decreases conversion while
increasing yield; however, methanol must comprise more than 37 percent
by volume of the mixture to avoid the explosive area. Increasing the
amount of methanol increases conversion and decreases yield.) The air/
methanol mixture is induced into a battery - sometimes about three -
of catalytic converters. Upon passing through the silver catalyst, the
net exotherm generated heats the vapors to about 1175° F. Thifi temperature
is maintained either by varying the air/methanol ratio or by means of
combination heating and cooling coils located within the converters. The
hot effluent gases must be quenched to avoid decomposing the formaldehyde.
This is generally accomplished solely within the primary absorber, which
is close-coupled with the converters, but feed vs effluent heat exchange
is utilized - in part - by some plants.
The primary absorber is a packed tower. The primary absorption liquid -
aid quench - for the formaldehyde and unreacted methanol vapors is the
so-called "F-M Liquor". This liquor is an aqueous solution containing
about 28 to 30 percent formaldehyde and 20 to 22 percent methanol. Part
of the FM liquor is withdrawn from the bottom of the primary absorber,
pumped through a water cooled exchanger, and recirculated to the top of
the primary absorber. The remainder of the FM liquor is withdrawn from
the bottom of the absorber and pumped to intermediate storage. Uncondensed
vapors and non-condensibles are withdrawn from the top of the primary
absorber and 'blown' into the secondary absorber.
-------
FS-3
The secondary absorber recovers the major portion of the uncondensed
vapors by providing the necessary contact betveen the vapors and cool
distilled water, which is introduced onto the top tray of the secondary
absorber. The top of the tower is maintained at about 75° F to 80° F by
providing additional cooling via secondary coolers for the upper tray
section. This minimizes hydrocarbon loss via the relatively large non-
condensible overhead vent. The veak formaldehyde/methanol solution
withdrawn from the bottom of the secondary absorber is pumped to the
primary absorber and used as make-up.
The FM liquor in the intermediate storage or surge tank is pumped to
the product fractionator - a vacuum column. Here pure (99 + '%) methanol
is taken as overhead product and recycled to either methanol storage or
to the vaporizer. The bottom product is a nominal 37 vt. "L solution of
formaldehyde, containing less than 1% methanol. This solution may be
treated for removal of trace amounts of formic acid prior to storage.
Polymer formation and precipitation in storage is prevented either by the
addition of supplemental methanol, by providing heated storage, or by
both.
Table FS-1 presents a typical material balance for silver process
formaldehyde production. Absorber vent gas composition is based on a
combination of published data ^1") and questionnaire responses, whereas
che below-listed yields, etc., are representative of published data only:(8)
Mole %
Methanol in air/methanol
feed mixture 44
Methanol conversion 65
Formaldehyde yield (Fresh Feed Basis) 89
Table FS-1 material balance relates to an average size plant C100 MM
lbs. /year of 377a formaldehyde). This typical unit will be used in
economic studies discussed later in this report. Table FS-2 presents
the same material balance with "juantities expressed as tons per ton of
37°/o formaldehyde.
Table FS-3 presents an estimated heat balance around the converter section.
-------
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-------
TABLE FS-1
TYPICAL MATERIAL BALANCE FOR
SILVER CATALYST PROCESS FORMALDEHYDE PLANT
PRODUCING 100 MM LBS.'YR. OF 377 FORMALDEHYDE
Stream No.
1
2
3
4
5
6
7
8
Methanol
Absorber
Absorber
Fractionator
Fresh
Total
Converter
Vent
Make-up
Overhead
Fractionator
Component
Feed
Feed
Effluent
fas
Vater
Liq. (Recycle)*
Off-Gas **
Produc
Formaldehyde
4,546
7
4
4.535
Methanol
5,429
8,131
2,853
31
2,752
10
60
Hydrogen
123
123
Carbon Dioxide
558
558
Carbon Monoxide
64
64
Water
2,160
178
5,678
7,660
Oxygen
2,161
2,161
38
38
Nitrogen
7,147
7,147
7,147
7,147
Total - Lbs./Hr.
14,737
17,489
17,489
8,146
5, 678
2, 752
14
12,255
*AIso includes unknown (but very small) amount of formaldehyde.
"*Also includes air, water vapor and ejector steam.
-------
TABLE FS-2
TYPICAL HATHRIATTnXlANCE
FOR
SILVER CATALYST PROCEFS FORMALDEHYDE PLANT
UNITS - TON/TON OF 37% FORMALDEHYDE
Stream 1. D. No.
Formaldehyde
Methanol
Hydrogen
Carbon Dioxide
Carbon Monoxide
Water
Oxygen
Nitrogen
Total
1 (A & B)
Fresh Feed
.4430
.1763
¦ 5B32
1.2025
Total Feed
.6675
.1763
.5832
1.4270
Methanol
Converter Effluent
.3 709
.2328
.0100
.0455
.0052
.1763
.0031
.5832
Absorber
Vent Gas
.0006
.0025
.0100
.0455
.0052
.0145
0031
.5632
Absorber
Make-up Water
1.4270
. bh4 b
.4632
.4632
Product
Fractionator Vent*
.0003
.0008
Prod vie t
.3 700
.0050
.6250
Product Fractionator
Li
-------
FS-7
TABLE FS-3
FORMALDEHYDE PRODUCTION
VIA
SILVER CATALYST PROCESS
GROSS HEAT BALANCE - CONVERTER SECTION ONLY
Heat In
Air Heater
Methanol heater, vaporizer
and superheater
Exothermic heat of reaction
BTU/Lb. of 3 7% Formaldehyde
23
364
022
Total 1,409
Heat Out
Converter temperature control 100
Endothermic heat of reaction 441
Converter effluent quench plus
enthalpy residual (above base temp.) 868
Total 1,409
Note:
(1) Based on air/methanol and oxidation/dehydrogenation ratios shown in
Table FS-1.
(2) Converter temperature - 1175° F.
(3) Base temperature - 60° F.
-------
FS-8
III. Manufacturing Plants and Emissions
Table FS-4 presents a list of U. S. plants producing formaldehyde.
Production via the silver process is distributed among over thirty different
plants, ranging in size from 25 to 1300 MM lbs./year. The relatively large
number of plants results from the economy of captive production, vhereby
consumers find it more attractive to produce formaldehyde than to buy it.
Concentrations of formaldehyde plants: therefore, are to be found in the
same geographical areas as are the formaldehyde consuming industries. These
locations -nclude the Pacific Northvest, the Metropolitan Northeast, Texas
and the lumber producing areas of the pouth.
Table FS-5 shovs individual plant capacity figures and atmospheric
emission data for the various formaldehyde plants surveyed in this study.
The plants included in the tabulation range in capacity of from 40 to 855
MM lbs./year' and represent about 1/3 of the total U. S. installed silver
process capacity. Emissions from these plants are as follovs:
A. Continuous Air Emissions
1. Absorber Vent
The emissions from this vent constitute the most important
source of air pollution associated vith the production of for-
maldehyde. Indeed, many respondents report it as their sole
source of noxious emissions.
The composition of the absorber vent stream varies somev'hat
with catalyst age or activity. The normal range in composition
(excluding for the moment unccndensed hydrocarbons) is*:
Component Vo 1. °L (Dry Basis)
C02 4.8 to 5.5
CO 0.2 to 0.6
CH4 0.3 to 0.4
02 0.3
H2 20.2 to 17.5
No 74.2 to 75.7
These reaction by-products transport varying quantities of
hydrocarbons to the atmosphere vhen they are vented. Respondents
report the folloving hydrocarbon emissions are associated vith
their absorber vents.
Amount
Component Lb./Lb. of 377 HCHO
Formaldehyde 0 to .001
Methanol 0 to .004
Methyl Formate 0 to .008
Methylal 0 to .001
A more complete summary of these emissions is listed in
Table FS-6, representing a selected number of silver catalyst process
plant operators.
^''Formaldehyde" - 3rd Edition, AC? Monograph Series, pp 18
-------
FS-9
TABLE FM-4
SUMMARY OF U. S. FORMALDEHYDE PLANTS
Sheet 1 of 2
NOTE: The following tabulation of formaldehyde producers indicates published
production capacity (MM lbs./year) by company, location and process. Deter-
mination of the process utilized was by combination of published information,
questionnaire responses and private communications.
Company
A1 lied
Borden
Locat ion
Ironton, Ohio
Demopolis, Ala.
Diboll, Texas
Favettevilie, N. C.
Fremont, Calif.
Kent, Wash.
La Grande. Oregon
Louisvilie, Ky.
Missoula, Mont.
Sheboygan, Wise.
Springfield Oregon
Si 1ver
Process
308
80
70
200
80
70
40
70
80
120
260
Metal Oxide
Process
Celanese
Bishop, Texas
Newark, N. J.
Rock Hill, S. C.
1300
117
117
Commercial Solvents
Sterlington, La.
Seiple, Pa.
30
80
Du Pont
Belle, W. Va.
Grasselli, N. J.
Healing Spring, N. C.
La Porte, Texas
Toledo, Ohio
Linden, N. J.
485
150
200
200
320
150
GAF
Georgia Pacific
Calvert City, Ky.
Columbus, Ohio
Coos Bay, Oregon
Crosett, Ark.
Albany, Oregon
Taylorsville Miss.
Vienna, Ga.
100
100
100
100
80
60
100
100
Gulf
Hercules
Vicksburg, Miss.
Louisiana, Mo.
Wilmington, N. C.
170
95
40
Hooker
Monsanto
N. Tonawanda, N. Y.
Alvin, Texas
Addyston, Ohio
Eugene, Oregon
Springfield, Mass.
135
150
110
100
280
-------
FS-10
TABLE FM-4 CONTINUED
SUMMARY OF U.S. FORMALDEHYDE PLANTS
Compdny
Reichhold
Rohm 6t Haas
Skelly
Tenneco
Union Carbide
Wright
Location
Hampton, S.C.
Houston, Texas
Moncure, N.C.
jvi/dia, Wash.
Tuscaloosa, Ala.
Kansas City, Kansas
White City, Oregon
Malvern, Ark.
Philadelphia, Pa.
Springfield, Oregon
Winfield, La.
Fords, N.J.
Garfield, N.J.
Silver
Process
36
70
40
25
105
105
Bound Brook, N.J.
Acme, N.C.
Total Process Capacity - MM Lbs./Year = 5,914
Number of Plants = 35
Average Plant Size - MM Lbs./Year = 169
Capacity of Total Industry - MM Lbs./Year «
Sheet 2 of 2
Metal Oxide
Process
100
100
40
50
100
70
70
160
150
75
1,729*
19
91
7,643
Percent of Total Industry Capacity = 77.4
22.6
•^Most recent total reported
-------
TABLE FS-5
NATIONAL EMISSIONS INVENTORY
FORMALDEHYDE VIA SII.VKB CATALYST FROCKS?- pape I of h
EPA Code Number
14-1
IV 3
~
Date on-stream
Capacity - Ton# of 377. HCHO/Yr.
154,000
4 7.500
Average Production - Ton6 of 377. HCHO/Yr.
4 7,500
Range In Production - % of Ma*
17
0
Emissions to Atmosphere
Stream
Absorber Vent
Converter Emergency Vent
Converter Start-up Vent
Absorber v'ent
Flow - lbs./hr.
Not Specified
Not Specified
2b20
Not Spec i f i ed
Flov Characteristic - Continuous or Intermittent
Continuous
Interai ttent
Int ermi 11 «-nt
f or,t i iniou s
if Intermittent - hrs/yr.
0.10
5
Composition - Tons/Ton of 3 7% HCHO
Forma ldebyde
+
.001 u
Methanol
4-
.00011
,003-w
Methyl Formate
Di-methyl Ether
Methylal
Oxygen
+
Nitrogen
+
Carbon Monoxide
.00159
Carbon Dioxide
+
*
Methane
Water
4-
+
.00003
.01193
Hydrogen
.007 V.
Sample Tap Location
None
None
None
Date or Frequency of Sampling
Never
Never
Never
Type of Analysis
Odor Problem
No
Vent Stacks
Yes
Not Speci fled
Not Specified
Yes
Flow - SCFM per stack
718
Number
1
1
Height - Feet (elev. @ tip)
43.8
Diameter - Inches
42
. t)7
Exit Gas Temperature - F°
>500o
8?°
Emission Control Devices
Yes
No
No
No
Type - Vater Scrubber
Incinerator
X
Catalog I. D. No.
FS-1
Total Hydrocarbon Emissions - Ton/Ton HCHO (3770
Not Specified
.00489
Total Particulate & Aerosol Emissions - Ton/Ton HCHO (377.")
0
Total N0X - Ton/Ton HCHO (3 7%)
0
Total S0X - Ton/Ton HCHO (3 7%)
0
Total CO - Ton/Ton HCHO (377.)
.00159
__ ......
-------
EPA Code No.
Date on-stream
Capacity - Tons of 37% HCHO/Yr.
Average Production - Tons of 37% HCHO/Yr.
Range In Production - X of Max.
Emissions to Atmosphere
Stream
Flow - lbs./hr.
Flow Characteristic - Continuous or Intermittent
if Intermittent - hrs./yr.
Composition - Tons/Ton of 377, HCIK)
Forma idehyde
Methanol
Methyl Formate
Di-methyl Ether
Methylal
Oxygen
Nitrogen
Carbon Monoxide
Carbon Dioxide
Methane
Water
Hydrogen
Sample Tap Location
Date or Frequency uf Sampling
Type of Analysis
Odor Problem
Vent Stacks
Flow - SCFM per stack
Number
Height - Feet (elev. @ tip)
Diameter * Inches
Exit Gas Temperature - F°
Emission Control Devices
Type - Water Scrubber
Incinerator
I
Catalog I. D. No.
Total Hydrocarbon Emission." - Ton/lor. HCHO (377.)
Total Particulate Aerosol Emissions - Ton/Ton HCHO (3TV)
Total NOx - Ton/Ton HCHO (377.)
Total SOx - Ton/Ton HCHO (37%)
Total CO - Ton/Ton HCHO (37%)
TABLE FS-5
(iATIONAL lMSStOHS "INVENTORY
FORMALDEHYDE VIA SILVER
CATALYST PROCESS
pane 2 of 6
- -"i
521500
1
52.500
0
¦
^ i
Absorber 'M
Absorber #2
Absorber ;i3
St ri ppcr
Vent
Vent
Vent
Overhead Vent
4040
1350
4040
54
Cont inuous
Cont i nuous
Cont i nioii?
Cont i nuous
.00035
.00012
.00035
.00002
.00111
.00037
.00111
.00005
.00269
.00090
.002(^9
+
.25569
.08523
.255*9
. 00 3 7?
.00238
.0C08C
.00238
.03354
.01115
.03354
.0094 6
.00315
. 0094')
.00038
.00523
.00174
.00573
None
None
None
Never
Never
Never
Never
Calc.
Calc.
Calc.
Est imflte
No
No
No
No
Yes
yes
Yes
Yes
1090 to 1152
363 to 384
1090 to 1152
5 to 20
1
1
1
1
60
50
65
65
.9
. 6
q
4
104° to 140°
104° to 140°
104° to 140°
78" to 110°
No
No
No
+
FS-y
.00348
0
0
0
.00556
-------
EPA Code Number
Date on-streara
Capacity - Tons of 377, HCHO
Average Production - Tons of 37% HCHO
Range in Production - 7. of Max.
Emissions to Atmosphere
Stream
Flov - lbs./hr.
Flov Characteristic - Continuous or Intermittent
if Intermittent - hrs./yr.
Composition - Tons/Ton of 377* HCHO
Formaldehyde
Methanol
Methyl Formate
Di-methyl Ether
Methylal
Oxygen
Nitrogen
Carbon Monoxide
Carbon Dioxide
Methane
Water
Hydrogen
Sample Tap Location
Date or Frequency of Sampling
Type of Analysis
Odor Problem
Vent Stacks
Flow - SCFM per stack
Number
Height - Feet (elev. (3 tip)
Diameter - Inches
Exit Gas Temperature - F°
Emission Control Devices
Type - Water Scrubber
Incinerator
Demister
Other
Catalog I. D. No.
Total Hydrocarbon Emissions - Ton/Ton of 377, HCHO
Total Particulate & Aerosol Emissions - Ton/Ton of 377, MCHO
Total NO^ Emissions - Ton/Ton of 377. HCHO
Total S0X Emisalons - Ton/Ton of 377. HCHO
Total CO Emissions - Ton/Ton of 377,, HCHO
TABLE FS»5_
NATIONAL EMISSIONS INVENTORY
FORMALDEHYDE VIA SILVER CATALYST PROCESS
Pa^e ^ of 6
14-7
14-8
50,000
75,000
75,000
0
0
Absorber Vent
73f>9
Cont inuous
Absorber Vent
11,600
Cont i ntious
.let Exhaust
Cont i nmuip
14-9
30,919
30,919
0
Absorber Kmert;. Vent ?
Ma una 1 /Auto
Int ermi11 cnt
.00035
.00340
,00067
.00033
.00230
+
.53000
.56129
+
.00100
.00529
+
.03850
.05920
+
.02750
.00634
.01100
.01263
+
Vone
Stack
None
Process
Never
1972
Never
Random
Calc'd. ex Design
GLC + Titration
Ca 1 c M .
Prsat +
N'o
No
No
No
Yes
Yes
Yes
Yes
2000
3200
1
1
1
i/1
98
100
43
30/20
8
16
1.5
8/8
95
54
200
50°/50°
Yes
Yes
Yes
No
+
+
+ (condenser^
FS-3
FS-5
FS-9
.00b05
.00100
0
0
0
0
0
0
.00100
.00529
Absorber Vent
Not Speci f icd
FS-?
Not Specified
_ _ J
-------
TABLK FS-5
NATIONAL EMIS5TON~TW£NTORY
FORMALDEHYDE VIA SILVER CATALYST PROCESS
pa^c 4 ot
EPA Code Number
Capacity - Tons of 37% HCHO/Yr.
'Average Production - Tons of 377. HCHO/Yr.
Range in Production - 7. of Max.
Emissions to Atmosphere
Stream
Flov - lbs./hr.
Flov Characteristic - Continuous or Intermittent
if Intermittent - hrs./yr.
Composition - Tong/ton of 377. HCHO
Formaldehyde
Methanol
Methyl Formate
Di-methyl Ether
Methylal
i Oxygen
/ Nitrogen
| Carbon Monoxide
i Carbon Dioxide
J Methane
! Water
Hydrogen
Sample Tap Location
Date or Frequency of Sampling
Type of Analysis
Odor Probitm
Vent Stacks
Flow - SCFM per stack
Number
Height - Feet (elev. @ tip)
Diameter - Inches
Exit Gas Temperature - F°
Emission Control Devices
Type - Water Scrubber
Incinerator
Catalog I. D. Number
Total Hydrocarbon Emissions - Ton/Ton HCHO (37%>
Total Particulate & Aerosol Emissions - Ton/Ton HCHO (377;)
Total N0X - Ton/Ton HCHO (377.)
Total S0X - Ton/Ton HCHO (377.)
Total CO - Ton/Ton HCHO (377.)
14-10
240.000
Absorber Vent Incinerator
Flue gas
39,727
Conti nuous
TR
TR
200.000
!'ot Fpeci t fed
.01005
.47940
.04269
. 18491
TR
Never
CLC
No
Yes
10.050
1
85
60
900
Yes
FS-7
0
0
0
0
0
+ Hoilcr
FS-»
Carrot Re Determined
-------
TAPLE FS-5
NATIONAL EMTSSIONS~tNVENTORY
EPA Code No.
Date on-stream
Capacity - Tons of 377„ HCHO
Average Production - Tons of 3770 HCHO
Range in Production - 7« of Ma*.
Emissions to Atmosphere
Stream
Flov - lbs./hr.
Flov Characteristic - Continuous or Intermittent
if Intermittent - hrs./yr.
Composition - Tons/Ton of 377, HCHO
Forma Idehyde
Methanol
Methyl Formate
Di-methyl Ether
Methylal
Oxygen
Nitrogen
Carbon Monoxide
Carbon Dioxide
Methane
Water
Hydrogen
Sample Tap Location
Date or Frequency of Sampling
Type of Analysis
Odor Problem
Vent Stacks
Flov - SCFM per stack
Number
Height - Feet (elev. {? tip)
Oiaiaeter - Inches
Exit Gas Temperature - F°
Emission Control Devices
Type - Water Scrubber
Incinerator
Demister
Other
Catalog I. D. No.
Total Hydrocarbon Emissions - Ton/Ton of 377. HCHO
Total Particulate & Aerosol Emissions - Ton/Ton of 37% HCHO
Total N0X Emissions - Ton/Ton of 377. HCHO
Total SOx Emissions - Ton/Ton of 377, HCHO
Tottil CO Emissions - Ton/Ton of 377P HCHO
formaldehyde via
SILVr-K CATALvCT PROCESS
Pay;c 5 of
14-12
K- ta
14-70
35,000
20,000
30.000
35,000
20,000
50.000
0
0
0
Absorber Vent
Jet Exhaust
Absorber Vent
Absorber Vent
5,855
1000
33h0
738b
Cont tnuous
Cont inuous
Cont i nuotis
font inuous
.00041
.00035
.00082
.0032 h
.00224
.00250
.54826
.5101b
.0027f>
.00292
.00104
.0585b
.03^88
.00191
.001^7
. 1B519
02b5b
.01390
.00989
.01040
None
Top of Tover
Daily
Never
Fi-annua 1
Random
Calc'd.
Orsat + ?
Calc'd.
No
No
No
Yes
Yes
Yes
Yes
.460
891
1
1
i
1
73
22
44
95
18
1
f>
132
80
200
50
95
Yes
No
No
No
+
FS-4
.00123
0
.00325
0
0
0
0
0
0
0
0
0
.00276
.00292
.00104
!)i st i 1 1 at i on To'
Overhead Vent
30
Cont i nuou.-
.001?0
.00120
Never
Not SpecifiH
No
1
95
13?
95
No
-------
TABLE FS-5
NATI ONAT.TTmISS TONP TNVEN'TOHv
FOKMAl.DF.l'YDE VTA SILVER CATALYST WOCEFS Paeu 6 of b
EPA Code No.
14-11
J'-20
Dace on-straam
50,000
Capacity - Tons of 377,. HCHO/Yr.
427,500
Average Production - Tons of 37% HCHO/Yr
30,000
Range in Production - % of Max.
0
0
Emissions to Atmosphere
Pi Mat i on
Stream
Absorber Vent
Absorber Vent
1.>ver Overhead
Flov - Lbs./Hr.
54, 640
738b
30
Flov Characteristic - Continuous or
Intermittent
Cont i nuous
font i munis
font muujp
if Intermittent - Hrs./Yr.
Composition - Tons/Ton of 37?. HCHO
Formaldehyde
<.00001
.00035
00120
Methanol
.00076
.0326
00120
Methyl Formate
.00829
.00224
Di-methyl Ether
Methylal
.00120
Oxygen
Nitrogen
.396975
.5101ft
Carbon Monoxide
.021010
.00104
Carbon Dioxide
.092096
.03688
Methane
.000126
Water
.02636
Hydrogen
.016271
.01040
Sample Tap Location
Ground J.evel
Never
Date or Frequency of Sampling
Dai ly
Random
Type of Analysi s
Chromatograoh
Ca1c'd.
Not Speci f ied
Odor Problem
No
No
No
Vent Stacks
Yes
Yes
flov - SCFM per sta'.k
4200 3600 10,000
Number
1 1 1
1
1
Height - Feet (elev. (3 tip)
90 93 95
95
05
Diameter - Inches
10 12 14
132
132
Exit Gas Temperature - F°
50 50 50
95
95
Emission Control Devices
No
No
No
Type - Water Scrubber
Incinerator
b A 1 >k f M«—»
cacaiog i. u, no.
Total Hydrocarbon Emissions - Ton/Ton HCHO (377)
.C1025
.00825
Total Particulate & Aerosol Emissions -
Ton/Ton HCHO C37")
0
Total NOx - Ton/Ton HCHO (37%)
0
Total SOx - Ton/Ton HCHO (37%)
0
Total CO - Ton/Ton HCHO (377.)
.02101
.OOlOi
-------
Component
TABLE FS-6
TYPICAL ABSORBER VENT GAS COMPOSITION
FOR
100 MM LB./YR. (E) FORMALDEHYDE PLANT
SILVER CATALYST PROCESS
Normal Range in Composition
ex Source "A" ex Source "B"
Vol % (A) Vol % (B)
Average Flow Rate and Composition
Mole 7o
MPH
LB./HR.
Formaldehyde
0
to
0.5
0.07
0.24
7
Methanol
0
to
0.9
0.28
0.96
31
Hydrogen
17.5
to 20.2
13.
.0
to
27.0
17. 72
60.79
123
Carbon Dioxide
4.8
to 5.5
0
to
7.0
.3. 69
12. 67
558
Carbon Monoxide
0.2
to 0. 6
0.
, 1.
to
2.8
0. 66
2.28
64
Oxygen
0.3
0
to
1.0
0.35
1. 19
38
Nitrogen
74.2
to 75.7
6-7.
0
to
75.7
74.35
255.07
7147
Methane
0.3
to 0.4
0
to
0.4 (D)
0
0
0
Water
0
to
6. 6
2.88
9.86
178
Methyl Formate
0
to
0.80
0
0
0
Methylal
0
to
0.12 (C)
0
0
0
Methoxy Methylal
0
to
0.01 (C)
0
0
0
Dimethyl Ether
0
to
0.01 (C)
0
0
0
Totals
100.00
343.06
8146
NOTES
(A) Source "A" is 3rd edition of ACS Monograph on "Formaldehyde", page 18.
(B) Source "B" listing shows lowest and highest limits of normal range, as reported by questionnaire respondents
(C) Reported by one respondent only.
(D) Reported by two respondents.
(E) Of 3770 formaldehyde.
(F) Based on weighted average of component concentrations as reported by questionnaire respondents and applied
to flow race for "typical." 100 MM lbs./year facility (see Table FS-1).
-------
FS-18
2. Product Fractionator Ejector Exhaust
It is believed that all product fractionators are operated at
sub-atmospheric pressures. Therefore, the use of either steam
ejectors or vacuum pumps is required. Four respondents reported
emissions from this source, but only three (EPA Code No's. 14-4,
14-8 and 14-20) reported the emission of ncxious compounds. The
emissions from the ejectors are listed in Table FS-5.
B. Intermittent Air Emissions
1. Converter Start-Up Vent
The operator of plant EPA Code No. 14-3 reported emissions from
this source and stated that, "during start-ups the feed to the
converter is vented to the atmosphere until stabilized and then
switched gradually into the reactor. Total vent time is about 30
minutes. There are about 10 start-ups per year". Data provided
by the respondent indicate that this operation results in the
emission of .0001 lbs. of hydrocarbons/lb. of formaldehyde.
Start-up vents of a different nature were reported by respondents
14-6 and 14-9, both of whom burn their absorber tail gases in the
boiler house. During start-ups, until the tail gas composition and
flow have stablilized, the tail gas is vented to the atmosphere.
After this period the tail gas is cut to the boiler house and burned.
No estimate was given of the emissions resulting from this operation,
but they should be negligible.
2. Converter Emergency Vent
Again, only operator 14-3 reported emissions from this source.
Lack of data prevents the calculation of emission rates, but the
infrequency and short duration of the emission preclude its
characterization as a significant emission source.
C. Continuous Liquid Wastes
1. Waste Water
The production of various waste water streams have been reported
as follows:
Plant 14-3 - .030 gallons/lb. of 37% formaldehyde or 350
gallons/hour. The waste is treated on plant in
an extended aeration biological treatment plant.
Plant ]4-7 - 62,500 gallons/hour of cooling water. 'Treated' on
plant.
Plant 14-8 - 120 gallons/hr. from the waste heat boiler blowdown plus
4500 gallons/hour from the cooling tower blowaown.
Plant 14-20 - 7,500 gallons/hour cooling tower blowdown. Treated
in plant.
-------
FS-19
2. Spent Caustic
While no operator reported the generation of spent caustic, it
seems reasonable to surmise that most plants do produce small
quantities of this substance as a result of their air washing
operation.
D. Intermittent Liquid Wastes
1. Ion Exchange Regeneration
Presumably most operators remove formic acid from product
formaldehyde via an ion exchange resin system. Such systems are
normally regenerable by intermittent back-flushing procedures,
which would produce an intermittent waste liquid stream. Operator
14-10 reports that every six to 20 days a weak aqueous solution
containing about 0.4 percent formic acid and 1.5 percent formaldehyde
is discharged to the waste treatment plant as a result of this operation.
Flow rates are not given. Operator 14-3 shows such a waste stream on
this block flow diagram, but gives no further details in the body of
his response.
2. Methyl Formate Removal.
One operator reported privately that it was his practice to
remove methyl formate from stored formaldehyde. Presumably, this
would result in the production of a small intermittent liquid waste
stream. It is believed that this operation is atypical of the
industry.
E. Solid Wastes
All respondents to the silver process questionnaire reported that
their facility produced nc solid waste material.
F. Odors
None of the respondents reported receiving any odor complaints
during the past year. Half of the respondents, however, did report
that odors are occasionally detectable at the plant site. The
odoriferous materials were identified as formaldehyde and methanol.
All operators reporting odors mentioned the absorber vent as at
least one of the sources. In addition, operators 14-3 and 14-8
identified the product fractionator as a source.
G. Fugitive Emit=sions
Only the operator of plant 14-3 has offered a quantitative
estimate of fugitive emissions. Hi.s estimate is 30 lbs./hr. or
.00025 lbs./lb. All other operators state that fugitive emissions
are either nil or quite smaLl. As operator 14-4 summarizes the
situation, "minor losses of formaLdehyde and/or methanol occur mainly
due to leaks in pump seals and occasional piping leaks. The actual
amount is considered negligible and most likely will not show in
material balance calculations."
-------
FS-20
Emission Control Devices and Systems
A. Emission Controls on Absorber Vent
1. Devices Currently Employed
Excluding the ever-present mist eliminator in the top of the
secondary absorber, the majority of U.S. plants do not employ
emission control devices. Those that do, invariably utilize some
type of combustion device. Plant 14-6 and 14-9 both burn their tail
gases in the fire box of a steam boiler. Details of design, performance
and cost are considered by the respondents to be proprietary, however,
they intend to offer the unit to the industry on a licensing arrangement.
Plant 14-10 has installed a (thermal) 'fume abatement1 unit, which in
their opinion "represents the latest technical art". Actual performance
data for the fume abatement unit are lacking, however, the respondent
reports that data extrapolated from pilot unit runs indicate that
combustion is close to iOO percent. Plant 14-1 utilizes a 'waste
gas incinerator', again performance is estimated rather than measured.
The cost and performance details that have been reported on these
devices are listed in Table FS-7,
(a) Thermal Incinerators
Table FS-8 presents a material balance for this type of
control device. The data in the table are based on a 1750° F
combustion zone temperature and 4 mole % oxygen (dry basis) in
the stack gas, this should normally assure complete combustion
of pollutants on a self-sustaining basis (i.e., no auxiliary fuel).
However, there maybe some periods of operation when the vent gas
is at the lean end of its composition, thus requiring auxiliary
fuel.
Although there are several tail gas incinerators extant,
no actual performance data were provided by the questionnaire
respondents. Available information indicates that combustion
efficiency should be quite high - 99+7».
There are several problem areas with this type device.
They are:
(1) Vent gas is available at low pressure.
(2) Because the gas has a low heating value ( 60 BTU/SCF
on a dry basis), special incinerator designs must be
utilized to assure self-sustenance.
(3) Flame control is difficult due to low heating value and
low level of incandescence, therefore, flame-outs could
be a problem.
(4) The stream has a relatively high hydrogen content which
might cause some special hazards.
(b) Boiler House Burner
The heating value of the tail gas can be recovered, appar-
ently economically, by utilizing the tail gas as a boiler house
fuel supplement. Combustion would be expected to be essentially
-------
TABLE FS-7
CATALOG OF EH1SSTON CONTROL DEVICES
formaldehyde via the silver catalyst process
1 of 2
absorber/scrubbers 7 m st eliminators
EPA Code No. for plant using
Flov dlagr#m (Fig. I) stream I. D.
Device I. D. No.
Control Emission of
Scrubbing/Absorbing liquid
Type - Spray
Packed Column
Column w/tr«ys
Number of trays
Tray type
Other
Scrubbing/Absorbing liquid rate - GFN
Design Temp. (Operating Temp.) F°
Gas Rate, SCFM (lb./hr.)
T-T Height, Ft.
Diameter, Ft.
Hashed gases to-stack
Stack height - Ft.
Stack Diameter - Inchea
Installed Cost - Mat'l. & Labor - $
Installed Cost based on - "year" - dollars
Installed Coat - c/lb. of Zl'u HCHO - Yr.
Operating Cost - Annual - 3 - H7?
Value of Recovered product, $/Yr.
Net Operating Cost - Annual, $
Net Operating Cost - c'lb. of "i'lZ HCHO
Efficiency - % - SE*
Efficiency - 7. - SERR*
INCINERATION DEVICES
EPA Code No. for plant using
Flov Diagram (Fig. I) stream I. D.
Device I. D. No.
Type of Compound Incinerated
Type of Device - Flare
Incinerator
Other
Material Incinerated, SCfM (Lb./Hr.)
Auxllllary Fuel Req'd. (excl. pilot)
Type
Rate - BTU/hr.
Device or Stack Height - Ft.
Installed Coat - Mat1I. & Labor - $
Installed Coat baaed on - 'V^ar" - dollars
Installed Coat - r/lb. of 37X HCHO
Operating Cost - Annual - $ (107!)
Operating Cost - c/lb, of 37X HCHO
Efficiency - % - CCR*
Efficiency - 7. - SERR*
14-4
&
FS-8
Formaldehyde & Hetharol
Water
1
2
12 f. 14
Bubble Cap
8 to
1 to
Yes
15
1.3
Not Available
14-7
A
FS-3
Formaldehvde & Methanol
N/A
+ Dcralater
None
2,000
Ycr
98
a
1,440
14-1
FS-1
14-12
A
FS-4
Formaldehyde & Methanol
N/A
+ Demister
None
f 80)
1,4'>0
Yes
73
18
5,000
1972
.00714
14-*
A
FS-6
14-9
A
FS-2
li-8
A
FS-5
Forma 1 dehvde Methanol
N/A
¦+• Demi st cr
None
(
3, ?00
Yep
100
700
I n 71
,000'W
400
0
400
.00027
Formaldehyde & Methanol Formaldehyde & Methanol Formaldehyde 6 Methanol
Not Specified
43.75
100
100
+ Boiler
3028
Yes
Not Disclosed
+ Boiler
Not Di fc loped
14-10
A
KS-7
Formaldehyde Methanol
10.050
No
8S
700.000
1772
.04\ \:
60,000
.01233
100
100
"Sec Appendix for explanation of these Items
-------
TABLE KS-7
CATALOG OF EHTSSION CONTROL DEVICES
FORMALDEHYDE VIA THE SILVER CATALYST PROCESS
CONDENSERS
EPA Code No. for plant using
Flov Diagram Stream I. D.
Device I. D. No.
Controls Emission of
Primary Refrigeration Liquid
Capacity of Refrigeration Unit - Tons
Gas Rate - SCFM
Temperature to Condenser - F°
Temperature out of Condenser - F°
Liquid Recovered - GPM
Non-Condensibles - SCFM
Installed Cost - Mat'l. & Labor - $
Installed Cost based on * "year" - dollars
Installed Cost - c/lb. of 377. HCHO/Yr.
Operating Cost - Annual - $ (1972)
Value of Recovered Products - $/Yr.
Net Operating Cost - Annual - $
Net Operating Cost - c/lb. of 377, HCHO
Efficiency - 7r - SE*
Efficiency - 7» - SERR*
14-8
A
FS-9
Methanol
Unknown
131 Lb./hr
3,300
1971
.00220
2,000
Unknown
*See Appendix for explanation of these terms.
-------
FS-23
TABLE FS-8
THERMAL INCINERATOR
FOR
100 MM LB./YR. FORMALDEHYDE PLANT
ABSORBER VENT STREAM
OVERALL MATERIAL BALANCE - LB./HR.
Absorber
Combustion
Flue "
Component
Vent Gas
Air
Gas
Formaldehyde
7
Methanol
31
Hydrogen
123
Carbon Dioxic'e
558
711
Carbon Monoxide
64
Oxygen
38
1614
590
Nitrogen
7147
5316
12463
Water
178
56
1368
Total
8146
6986
15132
"ExcLudes any NOx that may form as result of incineration, probably about 50 ppm.
1 Stack Gas 1750° F
/ \
Absorber Vent Gas
(60° F)
I
Combustion Air - 1500 SCFM
(80° F)
Natural Gas
(Pi lots)
-------
FS-24
complete, and thus, the emission level should be commensurate
with that attained through the use of a thermal or catalytic
incinerator. Actual performance data from the two units
currently on-stream are considered to be proprietary.
2. Feasible Devices Not Currently Employed
It is assumed that these devices are not in use on current
silver catalyst process plants, since they were not reported on
questionnaires, at the public meeting nor in the literature.
(a) Plume Burner
This control device is distinguished from a flare stack by
the definition that it does not normally require supplemental
fuel. It would haye the following limitations:
(1) Efficiency for removal of contaminants is less than
for other combustion devices. The efficiency is
influenced by the BTU content of the vent gas. Based
upon qualitative data from similar control devices, it
is estimated that 90 percent of CO and hydrocarbon
pollutants will be burned.
(2) Small changes in vent gas composition could extinguish
the burner if supplemental fuel and adequate instru-
mentation are not provided.
(b) Catalytic Incinerator
A conventional catalytic incinerator could reduce pollutants
to levels similar to those attainable with a thermal unit.
Although no existing- formaldehyde plant is known to employ such
a device, certain generalizations about design, operation and
performance can be drawn from information available on similar
applications.
It is estimated that a 900° F inlet temperature to the
catalyst bed should be sufficient to obtain complete combustion
of all hydrocarbon and carbon monoxide over standard noble metal
catalysts. Maximum temperatures within the bed should be limited
to 1200° F in order to prevent loss of catalyst activity through
sintering and loss of surface area. This type of temperature
control can be attained by permitting part of the process vent
gas to by-pass the thermal combustion zone while co-currently
employing excess air as quench between the thermal combustion
zone and the catalyst bed. As the catalyst ages, combustion
efficiency will decrease. With aged catalyst, it is expected
that 10 to 15 percent of the feed combustibles will be vented to
the atmosphere. Catalyst poisons, such as sulfur, will not normally
be present in the process vent gas because they have previously
been excluded to protect the main process silver catalyst. Table
FS-9 presents a material balance for a catalytic incinerator with
fresh catalyst.
It is possible that NOx emissions from a catalytic incinerator
will be less than those from a thermal incinerator since the
-------
FS-25
TABLE FS-9
CATALYTIC INCINERATOR
FOR
100 MM LB./YR. FORMALDEHYDE PLANT
ABSORBER VENT STREAM
OVERALL MATERIAL BALANCE - LB./HR.
Absorber
Air to
Flue*
Component
Vent Cas
Incinerator
Gfi 8
Formaldehyde
7
Methanol
31
Hydrogen
123
Carbon Dioxide
558
711
Carbon Monoxide
64
Oxygen
38
3429
2404
Nitrogen
7147
11286
18434
Water
178
118
1430
Total 8146 14833 22979
^Excludes NOx formation -which is probably less than 50 ppm because of relatively
low temperature.
Stack Gas
(1200° F)
Absorber Vent Gas
(60° F)
WM
900° F
.Catalyst Bed
Air - 3200 SCFM
(80° F)
Natural Gas
(Pilots)
-------
FS-26
homogenous oxidation of N2 does not occur to any extent at 1200° F.
Another possible advantage of the catalytic device is the lower
requirement tor supplemental fuel during periods of operation
when the vent gas is abnormally low in heat content. On the
debit side, operational costs can be expected to be 50 percent
higher than for straight thermal devices.
(c) Water Scrubber
None of the silver process formaldehyde plants surveyed use
water scrubbing. However, data are available from a mixed oxide
catalyst formaldehyde plant, and that information was utilized to
construct the water scrubber material balance presented in Table
FS-10. A water scrubber requires less capital investment than
any of the combustion devices except the plume burner. However,
when compared to other aspects of thermal device considerations,
scrubbers have the following disadvantages:
(1) Efficiency of removing hydrocarbons is less than for
all the combustion devices except the plume burner.
(2) Efficiency of removing carbon monoxide is essentially
zero.
(3) Air contaminants are transferred rather than destroyed,
and thus require additional treatment or result in
water pollution. This cost, however, is probably in-
cremental on existing facilities.
(4) For all practical purposes, heat recovery from the tail
gas is precluded.
Emission Controls on Product Fractionator Vent
1. Devices Currently Employed
(a) Water Scrubber
The product fractionator operates at sub-atmospheric pressure,
consequently the vent from that tower is normally through a stean
powered vacuum ejector or vacuum pump. Most respondents maximize
methanol recovery by cooling the suction line to the ejector or
pump. For the purpose of this report, the jet or pump suction
cooler is not considered a pollution control device. On this
basis then only one questionnaire respondent has reported the
use of a control device on this stream - operator 14-4. (Hcwever,
it is understood that at least one plant recycles the discharge
from the vacuum pump, which they utilize to effect the desired
product fractionator operating pressure.) The device reported by
respondent 14-4 consists of two water scrubbers in series, the
first is a bubble cap column and the second is a packed column.
Feed composition and flow are not available, thus efficiency cannot
be calculated; however, based on uncontrolled emissions reported
by other plants, efficiency is in the range of 79-97 percent.
Admittedly, this results in, at best, a crude estimate of
performance,, but the unit is old and newer units could undoubtedly
improve upon the actual performance. It does demonstrate that
control of this streati by this method is practical. However, it
suffers one drawback in that it transfers pollutants from one medium
to another (i.e., air to water).
-------
FS-27
TABLE FS-LO
WATER SCRUBBER
FOR
100 MM LB./YR. FORMALDEHYDE PLANT
ABSORBER VENT STREAM
OVERALL MATERIAL BALANCE - LB./HR.
Absorber
Scrubber
Liquid to
Component
Vent Gas
Vent Gas
Scrubber
Formaldehyde
7.4
0.4
Methanol
30.6
0.9
Hydrogen
123
123
Carbon Dioxide
558
558
Carbon Monoxide
64
64
Oxygen
38
38
Nitrogen
7147
7147
Water
178
178
12,500
Total
8146.0
8109.3
12,500
liquid frou
Scrubber
7.0
29.7
12,500
12,536,7
Demister
Pad
Demister
Pad
Scrubber
Vent Cas
ZZZZZ2Z
-¦^Tray No. 4
Tray No. 3
Tray No. 2
Tray No. ]
Vent Cas
from Absorber
(a ^/60° F
Vater to Scrubber
25 GPM @ Ambient Temp.
Waste Water
ex Scrubber
-------
FS-28
(b) Condenser
One respondent (14-8) reports a condenser on the scrubber
jet. It is not known if this is on the suction or effluent because
of incomplete data. It has been included in Table FS-7.
2. Feasible Devices Not Currently Employed
Total Recycle System
Table FS-11 presents a material balance and a rudimentary flow
diagram for a total recycle system that will recover all emissions
from the subject source. The primary disadvantage of this scheme
is the possibility that trace impurities might tend to concentrate
in the system. Further study appears to be warranted to determine
if such a build-up occurs, and whether or not it can be controlled
with a small pur^e.
-------
FS-29
TABLE FS-11
TOTAL RFCYCLE SYSTEM
FOR
100 MM LB./YR. FORMALDEHYDE PLANT
FRACTIONATOR VENT GAS
OVERALL MATERIAL BALANCE - LB./HR.
Component
Fractionator
Vent Gas
Steam to
E iector
E jector
Discharge
Gas to
Compressor
Condensate to
Absorber
Formaldehyde 4
Methanol 10
Air 50
Water 5_
Total 69
2500
2500
4
10
50
2505
2569
50
50
4
10
2505
2519
2500 lbs./hr. of 125 PSIG Steam
50 lb./hr.
air to
air compr.
suction
To
Reflux
and
Recycle
2519 lb./hr. -%¦
condensate to
absorber
Separator
Reflux
Drum
-------
FS-30
V. National Emissions Inventory
Based upon the emission factors shown in Table FS-5 , the total ap-
proximate emissions from existing silver process formaldehyde plants are
as follows:
Component
Average Emissions (a)
Lb./Lb. of 377- Formaldehyde
Total Emissions (k)
MM Lbs./Year
CO
Hydrocarbons
. 0040
.0180
.0220
23 .7
106.5
130.2
Since formaldehyde production has been reported as undergoing no seasonal
variation, emissions should be fairly constant throughout the year; unless
absorber tower top tray cooling capacity is marginal (or does not esist) .
In that case, emissions will tend to be somewhat higher during warm weather.
(a) Weighted average based on individual plant emission factors and formladehyde
production.
(b) Based on 5914 MM lbs./year silver process capacity and assuming production
rate equals capacity.
-------
FS-31
VI. Ground Level Air Quality Determination
A summary of air emissions data from the various surveyed formaldehyde
plants has been presented in Table FS-5. This table includes emissions
from absorber vent streams and fractionator ejector discharge plus the
emissions from various start-up vents.
Table FS-5 provides operating conditions and physical dimensions of
the various vent stacks. The EPA will use this information together with
the ai.r emission data to calculate ground level concentration for use in
subsequent reports.
-------
FS-32
VII. Cost Effectiveness of Controls
Table FS-12 presents a cost analysis for alternate methods of reducing
air pollution from the various vents. Economic data presented in this table
are for a new plant producing 100 MM lbs./year of 377„ formaldehyde and are
based on the following:
A. Investment (1973 Dollars)
1. Incinerators
Published data ^ were used to determine both thermal and
catalytic incinerator costs. It should be noted that these costs
are considerably lower than reported by respondent 14-10 (see
Table FS-7) for his thermal incinerator, The probable explanation
lies in the fact that the published data are for "off-the-shelf"
units, wnile tlie reported plant unit was specially designed for
the service.
2. Scruhbers
Investment data provided in questionnaire responses on both the
subject process and other processes were used to determine scrubber
costs.
3. Others
Investment and installation costs for the various packaged
units are estimated values based on previous experience in plant
construction. A major portion of this cost represents construction
labor.
P.. Operating Expenses (1973 Dollars)
1. Depreciation - 10 year straight line.
2. Interest - 67 on total capital.
3. Maintenance - If plant survey data vere not provided, maintenance
was set at 27 of investment, except for catalytic incinerators,
for which the maintenance was set at 47 of investment.
4. Labor - Virtually no operating labor is required for anv of the
devices listed in Table FS-13. A nominal 8 man hours/week was
assumed for the water scrubber and catalytic incinerator and
4 man hours/week labor was assigned to the other devices.
5. Utilities - Unit costs are based on typical value for the Culf
Coast area.
The criteria for functional adeauacy of emission control devices
cannot be fully established until the pertinent industry regulations are
promulgated. Never-the-less, a water scrubbing device Csee Table FS-12)
would appear to offer acceptable emission control for a modest price,
unless carbon monoxide emission regulations are particularly stringent.
Consideration must also be given to the fact that the scrubber transfers
pollutants from air to water, whereas combustion devices 'destroy' most
pollutants.
-------
TABLE FS-12
COST EFFECTIVENESS FOR ALTERNATE (h)
EMISSION CONTROL DEVICES
BASED ON 100 MM 1.B./YR. FORhALDEHYDE PRODUCTION Sheet 1 of 2
Stream
Absorber Vent Gas
Type of Emission Control Device
Water Scrubber
Thermal Incinerator
Catalytic Incinerator
Plume Burner
Boiler House Vent Gas Burner
Number of Units
I
1
1
1
7
Capacity of each unit - %
100
100
100
100
?
Feed
Total Flov, Lb./Hr.
8146
SCFM
2170
Composition, Ton/Ton HCHO (37%)
Hydrocarbons
—-
.0031
Particulates
0
SOx
0
0
Carbon Monoxide
.0052
Combined Effluent
1
*
Total Flov, Lbs./Hr.
8109
15132
22979
~15.000
SCFM
2163
3515
5244
^2200
3,500
Composition, Ton/Ton HCHO (377®)
Hydrocarbons
.0001
0
0
.0003
0
Particulates
0
0
0
0
NO*
0
(*)
(d)
(d)
(d)
S0X
0
0
0
0
Carbon Monoxide
.0052
0*
0*
.0005*
0*
Emissions Control Efficiency (i)
SE (%)
96.6
CCR {!)
100
100
90
100
SERR (Z)
94.6
99+
99+
89+
99+
Investment, $
Ulg)
(b)
(b)
(c)
(¦>
Purchased Cost
12,900
23,000
24,000
14,000
Installation
9,700
23,000
19,0(10
14,000
Total Capital
22,600
46,000
43,000
28,000
44,000
Operating Cost, $/Yr.
(a,g)
(b)
(b)
Depreciation '10 years)
2,300
4,600
4,300
2 ,800
4,400
Interest on Capital 167.)
1,400
2,800
2,600
1,700
2,600
Maintenance
1,400
900 (2%)
1,700 (47.)
600 (2Z)
900 (27.)
Labor,
-------
TABLE FS-12
COST EFFECT 1VENESS FOR ALTERNATE 00
EMISSION CONTROL DEVICE?
BASED ON 100 MM l.B./YR. FOPHALDEIfYDE PRODllCIIQN
Sheet 2 of 2
Stream
lype of Emission Control Device
Number of Units
Capacity of Each Unit, 7.
Feed
Total Flow, Lb./Hr.
SCFM
Composition, Ton/Ton HCHO (3770>
Hydrocarbons
PartIculates
N0X
S0X
Carbon Monoxide
Combined Effluent
Total Flov, Lbs./Hr.
SCFM
Composition, Ton/Ton HCHO (377)
Hydrocarbons
Part leulates
NO.
S0X
Carbon Monoxide
Emissions Control Efficiency (i)
SE - 7.
CCR - 7c
SERR - X
Investment - $
purchased Cost
Installation
Total Capital
Operating Cost, S/Yr.
Depreciation (10 years)
Interest on Capital (61)
Maintenance
Labor, 0 $A.85/IU .
Utilities
Pover, Ic/KVfH
Fuel, AOc/MM BTU
Procets Water lOc/M. Gal.
Total Utilities
Catalyst
Total Operating Cost - $/Yr.
FRACTIONATOR VENT CAS
Total Recycle System
Scrubber
1
1
100
100
2569
894
^ ' -
.0011
0
0
0
0
'
Nnt Applicable
56
No Emissions
. 00007
0
0
0
0
100
94
100
94
5500
(f,B)
600
300
100 (27,)
1000
100
2100
>2100
'f) These units are so small that estimates of Investment and cost are subject to more than normal error.
v Excludes water treatment cost.
(h) 1973 dollars.
(I) See Appendix for explanation.
-------
FS-35
Thermal incineration of the absorber vent gas stream offers the
most effective means of controlling emissions. Operating costs are
higher than for a scrubbing device, but only because depreciation and
interest on the more expensive incinerator are higher. Although
the caloric content of the absorber vent gas is high enough to sustain
combustion, a nominal amount of fuel vill be required (as indicated by
plant survey data) for pilots and device start-up. Unfortunately, the
caloric content of this stream is not high enough to justify the
coupling of a waste heat boiler with the incinerator. A thermal
incinerator could be incorporated with either existing or nev plants.
The installed cost of a catalytic incinerator (excluding catalyst
costs, which are considered as operating costs) is slightly less than
that of a comparable thermal incinerator. This results primarily from
its lower operating temperature, and the effect thereof on fabrication
and installation. Increased maintenance and catalyst charges result in
operating expenses 407„ higher than for non-catalytic incinerators.
Emission control capability has been depicted as being comparable to
that of thermal devices, although the possibility for catalyst failure
through poisoning, etc., always exists.
Supplementing boiler house fuels by burning tail gas in special
burners within the boiler fire box has many attractions, not the least
of which is a modest credit in operating costs. Cost data on this
device - as shown in Table FS-12, have been derived from plant surveys
and promotional literature by the prospective licensor. The licensor
made claims for better "pay-out" than is shown in Table FS-12, but these
could not be corroborated by the ('limited) available data. Note also
that licensening fees have not been included in the operating cost6.
The economic data presented for the various oombustion devices are
based on processing a typical absorber vent gas having a gross heating
value of 62 BTU/SCF. Should the heating value fall much belov 62
("as a result of different air/methanol ratios, catalyst selectivity,
absorber temperature, etc.) the tail gas could fail to sustain combustion
without the addition of supplemental fuel. This would, of course, increase
operating costs. Circumstances resulting in increased heating value
would affect the economics of only the boiler house burner, which would
show a proportionately larger operating credit.
Costs for installing the various absorber vent pollution control
equipment in existing plants would, for the most part, be the same or
only slightly higher than the figures shown in Table FS-12. The actual
cost differential would depend largely on space availability and location
relative to associated process equipment. The single exception is the
absorber vent gas water scrubber. The Table FS-12 cost data for this
unit are based on a "piggy-back" type close-coupled facility. Instal-
lation of this type of unit in an existing plant would be impractical.
Additionally, a non "piggy-back" type unit would require a vent gas
blower to overcome the increased AP caused by connecting piping. Thus,
investment and operating costs would be higher for installation of this
system in an existing plant.
The investment and operating cost for the two devices discussed for
control of fractionator vent gas emissions are based primarily on
in-house experience with similar equipment. However, the extremely
small size of the units involved makes accurate estimation difficult.
Both the investment and operating cost6 for either unit will be minimal.
-------
FS-36
Hovever, costs for the scrubber vill be higher than for the recycle
system. Thus, the cheaper system is more efficient, and is the preferred
method of emission control for this source.
-------
FS-37
VIII. Source Testing
It is recommended that source sampling should be carried out at one
or two of the plants employing absorber vent gas combustion devices.
Ideally, two sampling programs would be initiated. The first would include
a complete set of samples from either plant 14-6* or plant 14-9*, since both
utilize the type of equipment recommended for emission control in the most
feasible new plant.
It should be noted that the flue gas from the combustion type control
devices used in these plants (14-6 and 14-9) may not be segregated from the
flue gases of other burners in the boiler house. Thus, meaningful samples
could only be obtained when the other burners were shutdown - this may not be
practical.
The second sampling program would involve either plant 14-1 or plant
14-10. However, since the operator of plant 14-10* states that his 'fume
abatement1 unit "represents the latest technical art", then that unit would
seem to be the natural choice. Both the feed gases to the incinerator and
the flue gases from the incinerator should be sampled and analyzed. It should
be noted that the respondent (14-10) states that the flue gas stack is not
readily accessible.
It is recommended that the pertinent streams associated with the only
water scrubbing device reported fat plant 14-4) not be sampled because of the
age of the device. The respondent states that the scrubber was assembled
from second hand components and vould not be typical of modern installations.
*It may prove to be expedient to contact the operator of the designated plant
to determine whether or not his non-surveyed facilities employ the same type
devices-since both respondents operate a number of formaldehyde facilities.
Alternate locations may prove to be more convenient to either the operator or
the EPA.
-------
FS-38
IX. Industry Growth Projection
Total annual U.S. formaldehyde production is estimated (3,5) to increase
to somewhere around 16 billion pounds per year of 37% solution by 1985. If
the silver process maintains its present share of the market it will account
for the production of 12.5 billion pounds in 1985, see Figure FS-2.
More than half of all formaldehyde produced is consumed by the construction
industry. Urea-formaldehyde resins are used as an adhesive in the manufacture
of particle board, and consume 25 percent of formaldehyde production. Phenolic
resins are used as an adhesive for plywood and consume about 25 percent of
production. Melamine resins are used in decorative laminates (kitchen counters,
etc.) and consume about eight percent of total production. Demand in these
areas is expected to remain high, as housing starts maintain record levels.
Hexamine (hexamethylene tetramine) has been accounting for about six
percent of U.S. formaldehyde production the past few years as a result of the
use of large quantities of explosives in the Vietnam War. With the withdrawal
of U.S. Forces from that area, it is expected that hexamine consumption will
drop sharply.
Pentaerythritol (P.E.) accounts for about seven percent of formaldehyde
production. P.E. is used in the manufacture of alkyd resin surface coatings.
Consumption is expected to remain fairly steady.
Urea-formaldehyde fertilizers consume about five percent of formaldehyde
production. Good growth, up to nine percent per year, is expected for this
industry.
Polyacetal resins account for about eight percent of formaldehyde use.
This outlet is expected to maintain a growth rate of 10 percent per year.
Very little formaldehyde is either exported or imported due to the high
costs of transporting a water solution. Thus, fluctuations in the general
export/import market will not directly affect U.S. formaldehyde production.
The projected increase in formaldehyde production capacity will require
the construction of approximately 65 new 100 MM lbs./year silver catalyst
process plants between 1972 and 1985. This projection is based on the
assumption that the silver process will continue to account for 77 percent of
total formaldehyde capacity. It is doubtful that a ressurgence of the partial
oxidation or any other third process will develop during this period.
As shown in Table FS-13, methanol costs represents about 50 percent of
formaldehyde 'ex works' production costs. Therefore, formaldehyde selling
price is greatly influenced by methanol availability. This effect is
mitigated to some extent by the fact that the major formaldehyde producers
have captive methanol supplies. Methanol prices are currently very low as
a result of recent heavy expansions. The long-term outlook for natural gas
prices should eventually result in an upturn in methanol prices, but not
unitl methanol production catches up to capacity.
-------
FS-39
ion.
sc-
an.
FTG
' FORMAL JgRrpg
7-C-
3fcBteEF¥-E»ROJECfrlO
JCTION
en
Methanol shortage due to
strong demand and nev
plant start-up difficulties.-
A ¦ Formaldehyde production capacity-all processes.
J
|B = Formaldehyde production-all processes.
1
C = Formaldehyde production-silver catalyst process.—~
1980
1970
1960
1950
1940
-------
FS-40
X. Plant Inspection Procedures
Plant inspections will be conducted by the appropriate authorities, either
on a routine basis or in response to a complaint. The inspecting agent in
many cases may have only visual or olifactory observations at hiB disposal
although in some instances, stack monitoring equipment may be available or
it might be possible to sample the stack through an accessible sample point.
If the inspector has any reason to suspect that emissions are excessive,
some factors that he should consider and/or discuss vith plant officials are
itemized below:
A. During start-ups, some plants vent reactor feed to the amosphere
until the unit is stabilized. Other units vent absorber tail gases
to the atmosphere rather than to pollution control devices during
this initial on-stream period. A record should be kept as to when
and for how long this by-passing occurs. Obviously, an effort should
be made to minimize thi6 type of operation. Process economics
as well as air pollution considerations dictate that safeguards should
be taken to prevent inadvertent opening of the by-pass valves.
B. Proper operation of the absorber column is necessary to limit emissions
from the absorber vent ga6 in plants with no control device on this
stream. When the vent gas is discharged directly to the atmosphere
the only practical way hydrocarbon emissions can be controlled is by
manipulation of top tower temperatures. Many plants refrigerate the
top trays for this purpose. Most plants will keep a record of some or
all of the following operating variables and their design limits,
(1) Process and cooling water flow rates and temperatures.
(2) Formaldehyde and methanol concentration in top tray(s) liquid.
(3) Temperature and pressure of feed gas.
(4) Temperature of the (secondary absorber vent gas, especially
during warm weather operation.
C. A partially clogged or fouled mist eliminator can result in excessive
liquid entrainment.
D. When absorber vent gas is burned, proper operation of the combusting
device is essential if emissions are to be minimized. Two types of
problems may be expected to be encountered, (1) flame-outs and (2)
excessive smoking. Due to the low heating value of the tail gas the
first mentioned item is more likely. Plants are likely to periodically
record some or all of the following operating variables. Data vill
also be available on design limits.
(1) Combustion zone temperature.
(2) Quantity of excess air (too little will cause smoking, too much can
result in flame-outs), which might be indicated by measurements on
one or ail of the following-
a. Device draft - inches of vater.
b. Temperature of stack gases.
c. Air flow rate.
-------
FS-41
(3) Composition and flov rate of waste gas to the device.
<4) Quantity and heating value of supplemental fuel.
(5) Composition of Stack gases.
E. Periodic visual checks of flare stack opacity may be the only record
kept on the operation of this type of device. Hovever, some plants
may record the following data for comparison vith design limitations-
(1) Feed composition, temperature and flov rate.
(2) Occasional introduction of unusual materials into the flare
header.
(3) Plant up-sets causing changes in loading on the flare system or
carryover of liquids to the header.
The investigating operative should be cognizant of the fact that seemingly
similar plants may have had widely different design criteria, thus the flow,
temperature, pressure, composition, etc. characterizing a given stream in one
plant cannot necessarily be used as a basis for estimating like data for the
same stream in another plant. Nor can data from similar streams in separate
plants be used, in themselves, to estimate the comparative efficiencies of
related cor.trol equipment.
-------
FS-42
XI. Financial Impact
Table FS-13 presents economics for formaldehyde manufacture in a typical
100 MM lbs./yr. plant. This plant employs neither incineration nor scrubbing
devices, but relies solely on absorber tower temperature manipulation for
whatever emission control that is achieved. Two cases are shown; the first
for the current listed Gulf Coast methanol price of 12c/gal., and the second
for the Los Angeles area price of 17c/gal. As would be expected, this
results in an appreciable difference in return on investment. However,
even the operation with the more expensive feedstock is quite profitable.
Table FS-14 shows estimated economics for producing formaldehyde in a
new most feasible plant. This plant provides for burning absorber vent gas
in the boiler house plus total recycle of fractionator overhead vapors.
Table FS-14 indicates that total production costs for the new most
feasible plant will be only very slightly higher than the costs for existing
plants. The estimated difference is + ,004c/lb. of 37% formaldehyde. Return
on investment for the new most feasible plant is lower by 0.5 to 0.7 percent.
The difference in production costs is based on the assumption that the absorber
tail gas has a gross heating value of 62 BTU/SCF, and that it partly supplants
fuel having a value of 40?/MM BTU. Should either value be higher, then
manufacturing costs for the new most feasible plant would be proportionately
lower. In addition, uncertainties about the recycle system warrant investigation.
Table FS-15 shows that modifying existing plants by adding an absorber
tail gas plume burner adds only about .014c/lb. to the works costs of
formaldehyde.
Table FS-16 presents a proforma balance sheet for the following cases:
A. An existing plant - with no scrubbing, incineration or fractionator
recycle.
B. Existing with plume burner - which is the same as "A" (above) except
that the absorber tail gas is burned in a flare-like device.
C. Most feasible new - this plant burns absorber tail gas in the boiler
house and totally recycles fractionator overhead vapors.
It was assumed in developing these asset and liability positions that the
formaldehyde selling price would be held constant and the small increase in
total production costs would be taken out of the profit margin in order to
maintain sales at the same level. Capital requirement for the most feasible
new plant is estimated to be about $50,000 higher than for an existing plant
of the same capacity - 100 MM lbs./year.
An evaluation of the overall environmental impact of the most feasible
method of emission control described in this report is as important as the
financial impact. In addition to the obvious benefits of the diminution of
atmospheric pollution by hydrocarbons and carbon monoxide, one must consider
also the savings of both fuel and water effected by the recommended control
system. If all new silver process plants employ the described system, fuel
savings (as a result of burning tail gas) of the order of 3 x 10^2 BTU/year
will be realized. This is equivalent to three billion standard cubic feet per
year of natural gas. Also, as a result of recovering and reusing ejector
-------
FS-43
TABLE FS-13
FORMALDEHYDE MANUFACTURING COST
FOR A TYPICAL
EXISTING 100 MM LB./YR. FACILITY
C/Lb. $/Yr. c/T-b. $/Yr.
DIRECT MANUFACTURING COST
Raw Materials
Methanol
-------
TABLE FS-14
FORMALDEHYDE MANUFACTURING COST
FOR A TYPICAL NEW PLANT
WITH BOILER HOUSE INCINERATION
100 MM LB. /YR. FACILITY
C/Lb. $/Yr. c/lb>.
DIRECT MANUFACTURING COST
Raw Materials
Methanol @ 17c/gal. 1,136
@ 12c/gal. 0.802
Catalyst & Chemicals .070 .070
Labor .081 .081
Maintenance .101 .101
Net Utilities* .049 .04- 9
1.437 L.103
INDIRECT MANUFACTURING COST
Plant Overhead (110% of Labor)
FIXED MANUFACTURING COST
Depreciation (10 years)
Insurance & Property Taxes (2.370 of
MANUFACTURING.COST
GENERAL EXPENSES
Administration (370 of manufacturing
Sales (17. of manufacturing cost)
Research (27, of manufacturing cost)
Finance (67. of investment)
Cost ex works
Delivery
Total Delivered Cost
PRODUCT VALUE
.089 .08 9
.205 .205
Inv.) .049 .049
.254 .254-
1.78 0 1 .44 6
cost) .053 -043
.018 .014
.03 5 . 02 9
.123 .123
.22 9 - 209
2 . 00 9 1 - 655
.620 .62Q
2.629 2.275
377o formaldehyde - uninhibited
@ 3.5c/lb. (dlvd)
Profit before taxes
Profit after 527. tax
Cash Flow
ROI
ROI SENSITIVITY
3 . 50 0 3 , 500 , 00 0 3 . 500
.871 871 ,000 1. 225
.419 419,000 .589
624,000
20.5%
ROI with double capital charges of Table FS-12 19.67=
ROI with double capital and operating charges
less half operating credits of Table FS-12 19.47»
^Assumes .012c/lb. credit for boiler house fuel savings via utilization of
tail gas as supplemental fuel.
3,5 00,000
1,225,000
529,000
7 94,000
28. 87,
27. 11
-------
FS-45
TABLE FS-15
FORMALDEHYDE MANUFACTURING COST
FOR A TYPICAL
PLUME BURNER MODIFICATION TO EXISTING
100 MM LB./YR. FACILITY
c/Lb. $/Yr. c/Lb. $ iYr.
DIRECT MANUFACTURING COST
Raw Materials
Methanol @ 17c/gal. 1.136
@ 12c/gal. 0.802
Catalysts & Chemicals .070 .070
Labor .081 .081
Maintenance .101 .101
Utilities .062 .062
1.450 1.116
INDIRECT MANUFACTURING COST
Plant Overhead (1107= of Labor) .089 .089
FIXED MANUFACTURING COST
Depreciation (10 years) .203 .203
Insurance & Property Taxes (2.3% of inv.) .048 .048
.251 .251
MANUFACTURING COST 1.790 1.456
GENERAL EXPENSES
Administration (3% of manufacturing cost) .054 .044
Sales (1% of manufacturing cost) .108 .015
Research (2% of manufacturing cost) .036 .029
Finance (6%, of investment) . 121 .121
..229 .209
Cost ex works 2.019 1.665
Delivery .620 .620
Total Delivered Cost 2.639 2.285
PRODUCT VALUE
37% formaldehyde - uninhibited
@ 3.5c/lb. (dlvd) 3.500 3,500,000 3.500 3,500,00C
Profit before taxes .861 861,000 1.215 1,215,00(
Profit after 527„ tax .414 414,000 .584 584,00C
Cash flow 617,000 687,00C
ROI 20.4% 28.87.
ROI SENSITIVITY
ROI with double capital charges of Table FS-12 20.3% 28.6%
ROI with double capital and operating charges
of Table FS-12 20.2% 28.6%,
-------
TABLE FS-16
PROFORMA BALANCE SHEET
100 MM LB./YR. FORMALDEHYDE MANUFACTURING FACILITY
Current Assets
Cash (A)
Accounts Receivable (B'i
Inventories fC)
Fixed Assets
Plant
Buildings
Land
Total Assets
Current Liabilities CD')
Eauity & Long Term Debt
Total Capital
Existing
148,300
291,700
200,500
2,000,000
50,000
25,000
2,715,500
188,300
2,527,200
2,715,500
Existing vith
Plume Burner
149,200
291,700
201,900
2,028,000
50,000
25,000
2,745,800
188,100
2.557.700
2,745,800
New With Boiler
House Incinerator
148,300
291,700
200,900
2,049,500
50,000
25,000
2,765,400
187,700
2,577,700
2,765,400
(A) Based on one month's total manufacturing costs fvith methanol (3 17c'gal.).
(B) Based on one month's sales.
(C) Based on 10 MM lbs. of product valued at total cost (ex vorks).
(D) Based on one month's total cost (dlvd) less fixed manufacturing and finance costs.
(E) Also includes fractionator vent recycle system.
-------
FS-47
steam (see Diagram, Table FS-11), water consumption by the industry will
decrease by 130 million gallons per year. Admittedly, this is a negligible
amount but the effect is directionally desirable.
In order to determine the sensitivity of these pollution control cost
estimates, both Tables FS-14 and FS-15 show tha effect on ROI if investment
or operating costs were to double or if operating credits were to halve.
These adjustments all show a variation in R.O.I, of less than one percent.
All costs in these tables are based on 1973 estimates.
It should be further noted that the inclusion of a plume burner evaluation
for existing plants does not constitute a recommendation for its use. The
preferred solution, if possible, would be to use vent gases as a boiler house
supplement, even on existing plants. If not possible, some existing plant
operators might prefer a water scrubber which will control emissions nearly
as well as a plume burner with a slightly lower investment, a slightly
higher operating cost and no long term fuel gas demands.
-------
FS-48
XII. Cost to Industry
In the typical present day plant, as depicted in Table FS-13, very
little of the plant investment is directly attributable to the cost of air
pollution control. Although almost all plants employ mist eliminators on
the secondary absorber vent, moFt have little additional air pollution control.
A few pieces of equipment, used primarily for product recovery, do contribute
to emission control. It is difficult to categorize them, however, they
include the condenser in the fractionator ejector suction line and the
cooling coils in the uppermost trays of the absorber.
As noted in Section XI, the plume burner modification of existing
formaldehyde plants results in a minor effect on production costs (plus ,014c
per pound - Of 377„ formaldehyde). Therefore, the addition of plume burners
to existing plants should not pose a significant economic problem to the
industry. The total investment required to add this device to all existing
silver process plants would be on the order of $2,000,000. The addition of
a plume burner to existing plants might be classified as the "most feasible"
emission control, but if possible a boiler linuse incinerator should be
considered because it reduces emissions more effectively, saves energy and
would only require about 53,000,000 total investment. On the other hand,
water scrubbers would reduce emissions nearly as effectively as the plume
burner at a total investment of about $1,500,000.
In the "most feasible new plant" presented in Table FS-14, additional
air pollution control equipment represents about 2% percent of total plant
investment. The equipment consists of a boiler house incinerator and a
fractionator vent recycle. The resulting total production cost will be an
estimated ,004c/lb. higher than for the present day typical unit. Thus, the
costs involved should not reduce growth in demand via the requirement for
higher formaldehyde prices.
Assuming all new silver process plants built between now and 1980
incorporate these types of air pollution control equipment, the total
incremental capital cost will be on the order of $3,000,000.
The projected effect of the above expenditures on future air emissions
is shown in Table FS-17 where in:
The first column depicts 1985 emissions for the situation where no
pollution control devices (as defined in Section IV) are employed.
The total emission rate would be nearly 275 MM lbs./year.
The other three columns show the estinated 1985 emissions from
existing plants if they were to be equipped with water scrubbers,
boiler house incinerators or plume burners respectively, on the
absorber vent gas stream.
These three columns also indicate the total 1985 estimated emissions
under these three alternatives if all new plants are equipped with the "most
feasible new plant modifications" because emissions from these systems are
essentially nil.
-------
Type of Pollution Control
Plants Involved
Production Involved (MM Lbs./Year)
Emissions, Lbs./Lb.
Hydrocarbon
Carbon Monoxide
Total
Emissions, MM Lbs./Year
Hydrocarbon
Carbon Monoxide
Total
Weighted Emissions (2)
Hydrocarbons
Carbon Monoxide
Total
TABLE FS-17
ESTIMATED 1985 EMISSIONS
FOR ALTERNATIVE CONTROL SYSTEM
None
Existing & New
12,500
0.0040
0.0180
0.0220
50.0
225.0
275.0
4,000
225
4,225
Water Scrubber
Existing
5,914
0.0012
0.0180
0.0192
7.1
106.5
113.6 (1)
568
107
675 (1)
Boiler House
Incinerator
Existing
5,914
0.0009
0.0
0.0009
5.3
0
5.3 (1)
425
0
425 (1)
Plume Burner
Existing
5,914
0.0013
0.0018
0.0031
7.7
10.7
18.4 (1)
615
11
626 (1)
I
¦P-
VO
(1) If all new plants (6,586 MM Lbs./Year capacity) are equipped with boiler house incinerators and fractionator vent
recycle systems, the total existing and new 1985 emissions will be as shown. Obviously, the emission factors will
be somewhat less than half.
(2) Weighting factors are 80 for hydrocarbons and 1 for carbon nonoxide. See Appendix for explanation.
-------
FS-50
I. Emission Control Deficiencies
The control of formaldehyde plant emissions is affected by the
lowing technical considerations:
A. Process Chemistry and Kinetics
Production of formaldehyde by the silver catalyst process involves
a combination of dehyarogenation and oxidation reactions. The
amount of formaldehyde produced is influenced by air/methanol ratios,
converter residence time and operating temperature.
1. Converter Feed
(a) Methanol
Methanol feed must be pure. Impurities in the feed vill
generally end up as impurities in the product. Formic acid,
one of the more common formaldehyde contaminants, can be
produced through the use of impure methanol. Ion exchange
resins are normally used to remove aciuic contaminants from
the product. Regeneration of these resins may lead to acid
waste stream disposal problems. Therefore, in order to minimize
pollution, it is desirable to limit impurities in the feed.
(b) Air
Air provides the oxidizing agent for the oxidation
reaction, from which the necessary heat is derived to sustain
the endothermic dehydrogenation reaction. Sulfur compounds
present in the air, such as SO2, will poison the silver
catalyst and must be removed if the catalyst is to attain an
economical cycle life. Prevention of catalyst poisoning is
usually accomplished by raustic washing the air, which also
removes CO2.
(c) Air/Methanol Ratio
Because the major portion of the contaminants emitted by
a formaldehyde plant are those transported to the atmosphere
via the venting of the non-reactive portion of the feed air,
lesser amounts of air or lower air/methanol ratios'3 vill
decrease those contaminants. However, lower air/methanol
ratios will also result in lower methanol conversion and thus
overall yield may increase.(1) The economic feasibility of
this type of control has not been investigated.
2. Converter Operating Conditions
Converter operating conditions influence methanol conversion
rate and to some extent, the amount of non-selective products
formed. One of the non-selective products, carbon dioxide,
is a major component of the absorber vent gas stream. Converter
operating conditions are normally selected to obtain the
optimum balance between conversion and selectivity.
-------
FS-51
3. Catalyst
There are two basic types of catalysts used in the
subject process, silver crystal catalyst and silver gauze
catalyst. The newer crystal catalyst is reported to give
higher yields.It seems reasonable to surmize that the
higher yields are achieved through better selectivity, and
not merely through increased conversion. If so, the newer
catalyst would produce fewer emissions. Additionally, a
catalyst with a longer cycle life would require fewer shutdowns
and start-ups for regeneration or replacement and thus emissions
associated with these activities would be correspondingly lower.
Unfortunately, detailed performance comparisons of the various
silver catalyst are not readily available.
Process Equipment
1. Absorber
The absorber tail gas contains both gases and uncondensed
vapors. The uncondensed hydrocarbon vapors (methanol and
formaldehyde), because of their high 'weighted' value, constitute
the single most significant source of emitted pollutants in the
formaldehyde plant. More complete condensation of the hydro-
carbons is possible if the absorber pressure is increased or the
top temperature is decreased. Unfortunately, neither action
is practical. Increasing pressure to a level sufficiently high
to significantly affect vapor-liquid equilibria would result
in prohibitively high equipment and utility costs. Decreasing
the tower top temperature appreciably is impractical because
th« freezing point of the liquid on the top tray is close to
32° F; which, after allowing for a normal margin of safety,
is not significantly lower than the temperature at which many
producers actually operate their absorbers.
2. Product Fractionator
The product fractionator is operated at sub-atmospheric
pressure. This permits maintainence of the tower bottoms at
a temperature sufficiently low to avoid problems with formaldehyd
polymerization. Emissions are associated with the operation of
the vacuum system.
Control Equipment and Operations
The proposed combustion of absorber tail gas and recycling
of fractionator vent gas is one method of controlling formaldehyd
plant emissions. There are no apparent significant deficiencies
in this system, however, refer to Section IV for discussion of
this subject.
-------
FS-52
XIV. Research arid Development Goals
If the technological deficiencies discussed in Section XIII are to be
overcome, additional R & D is desirable in the following areas:
A. Existing Plants
1.. Improved Catalyst
It vould be desirable to have a more selective catalyst in order
to produce fever by-products and improve methanol utilization.
Published data state that the never crystalline catalysts
show better yields than the silver gauze catalysts. It is believed
that most nev plants do utilize the silver crystal catalysts.
Hovever, the vent gas composition reported by questionnaire
respondents utilizing the silver crystal catalyst indicates that
there is still room for improvement. Analyzing catalyst performance
via the technique described by Walker (D, one discerns ('from
questionnaire data) that catalyst selectivity for a typical 100
MM lb./yr. silver crystal plant is of the order of 94°/,. Improvement
beycnd that point could best be handled by the process licensors.
B. New Plants
In addition to the above R&D area, which has application to
both new and existing plants, the following items would require nev
facilities for utilization of gained technology:
1. Oxygen Source
A combination of pure oxygen feed in place of air, and recycling
of vent gas to the converter could reduce net emissions and improve
feed utilization. Additionally, the necessity of caustic scrubbing
the air feed would be negated due to the purity of standard merchant
oxygen.
The possibility of better feed utilization through improved
selectivity is enhanced by the observation that such benefits have
been claimed to accrue to tail gas recycling operations in metal
oxide process plants. Certainly this vould be a prime area for
investigation by any R&D program.
2. Tail Gas Combustion
The technology reauired for the efficient combustion of absorber
tail gas has been in existence for some time. Hovever, the
technology reauired for the economic utilization of tail gas as a
dependable boiler house fuel supplement is of a higher order. One
licensor claims to have perfected this methodology, but it vould
be desirable to have the performance of the required facilities
substantiated by the presentation of detailed economic and technical
data.
-------
FS-53
XV. Research and Development Program
The following proposed project relates to that area of R & D work
which seems to offer the best chance for obtaining a method of reducing
emissions from future formaldehyde plants:
PROJECT PROPOSAL
1. Title - Reduction of Vent Gas Emissions from the Silver Catalyst
Formaldehyde Process via Modifications in the Manufacturing
Procedure.
2. Object
To reduce vent gas emissions from the silver catalyst formaldehyde
process by modifying the manufacturing procedure.
3. Estimated Project Costs (see Table FS-18 for cost breakdown)
Capital Expenditures $ 63,900
Operating Costs
Unit Operation 62,500
Services 11,400
Process Engineering 9,100
Miscellaneous 5,800
Contingency 76,300
$229,000
4. Scope
This project would seek to reduce emissions in the vent gas from
the manufacturing of formaldehyde from methanol by modifying the
catalytic process. A small pilot plant would be constructed.
This pilot plant would be connected to an on-line gas chromatograph
which could sample the total effluent stream and the vent gases.
Data from the pilot plant would be used to develop a mathematical
model for the process.
5. Program
(a) Construction of Pilot Unit
The first phase in this program would be construction of a
small pilot unit. This unit would include a quench system and
product absorber to both simulate commerical operations and avoid
product decomposition. Effluent gases from the reactor and absorber
would be connected to an on-line gas chromatograph.
(b) Process Research
A number of process modifications will be explored to determine
their effect on methanol conversion, selectivity to formaldehyde,
and emissions in the vent gas. One of these modifications will be
substitution of oxygen for air in the feed. In the beginning a
standard silver catalyst will be used. However, large changes in
process conditions may require modifications in the catalyst.
(c) Process Engineering
Date from the process research will be used to develop a model
-------
FS-54
TABLE FS-18
DETAILED COSTS
FOR
R&D PROJECT
A. Capital Expenditures
Test Unit Construction $ 60,000
Unit Checkout
Professional, 2 weeks 1,800
Operator, 4 weeks 2,L00
Total 63,900
B. Operating Expenses
Unit Operation
Professional, 40 weeks 36,500
Operator, 50 weeks 26,000
Services
Computer Operator, 5 hrs./week x 50 weeks 3,200
Analytical, 5 weeks 3,200
Unit Maintenance, 1 day/week x 50 weeks 4,500
Physical and Catalyst Testing, 1 week 500
Total 73,900
C. Process Engineering
Professional, 10 weeks 9,100
Total 9,100
D. Miscellaneous
Computer Tine 2,000
Materials 2,000
Report Writing, Professional, 2 veeks 1,800
Total 5,800
E. TotaIs
Total of A through D 152,700
Contingency, 50°/ 76,300
Total Cost $229,000
-------
FS-55
for methanol oxidation to formaldehyde. This model will define
optimum conversions and selectivities as a function of vent gas
emiss ions.
6. Timetable
It is estimated that the above program will require a total of
17 months to complete.
-------
FS-56
XVI. Summary of Analytical Methods for Formaldehyde Plant Stack Emissions
1. Methods in Use
A total of fourteen plants were surveyed to obtain information on
emission measurement techniques, see Table FS-19 for summary. Of these,
four have performed no stack gas analyses and an additional four have
performed only Orsat analysis of the absorber vent gases to determine
inorganic constituents. Plant number 14-15 has performed "volumetric"
analyses for formaldehyde and methanol in addition to Orsat measurement,
but no details could be obtained on the actual procedure.
Plant number 14-1 uses a combination of Orsat analysis along -with a
sodium sulfite analysis for formaldehyde and chromic acid for methanol.
Plant 14-3 uses the same sodium sulfite analysis for formaldehyde, but
a Fisher gas partioner for inorganic gases and a gas chromatographic
technique for methanol. The sodium sulfite and chromic acid procedures
are referenced (1), but the details of the remaining methods are unknown.
Comprehensive analysis of absorber vent gases is performed at plant
14-8 by a combination of chromatographic and wet chemistry procedures.
A sample is drawn by vacuum through a train consisting of two batch
scrubbers, two 500 ml. glass bulbs and a wet test meter. The flow rate
is maintained to obtain a sample of approximately three cubic feet over
a one and one-half hour period. The scrubbers are filled with distilled
water and placed in an ice bath so as to promote condensation/absorption.
The scrubber liquid is weighted and an aliquot taken for methanol
analysis using an Aerograph Model 600 gas chromatograph. A 1/8" x 10'
aluminum coLumn packed with Porepak Q is combined with a hydrogen flame
ionization detector. Column temperature is maintained at 80° C. Carrier
gas is nitrogen at a flow rate of 35 ml per minute and the hydrogen flow
is 27 ml per minute. An injection port temperature of 150° C is maintained.
Calibration is maintained by the sequential injection of 1 ml of sample
followed by 1 ml of a mixture of 100 ml sample spiked with 1 ml of
reagent methanol.
The unused portion of the scrubber solution is analyzed for formaldehyde
using a modification of the talker sodium sulfite method (1) intended to
eliminate interference by CO2 in the sample. The modification consists
of adjusting the pH of both sample and sodium sulfite solutions to the
end point of thymophthalein prior to mixing and analysis.
Non-condensable gases from the bulb samplers are analyzed using a
Loenco thermal conductivity gas chromatograph with three columns. Hydrogen
and oxygen are run on a 1/4" x 7' aluminum column containing 5A molecular
sieve of 30-42 mesh size. The carrier gas is argon at a column pressure
of 10 PSIG, ambient temperature, detector current of 55 ma an d reverse
polarity. A 1 ml gas sample is used. Nitrogen and carbon monoxide are
measured using a 1/4" x 15' aluminum column packed with 13x molecular sieve
of 30-42 mesh size. Operating parameters include: helium carrier gas;
ambient temperature; 150 ma detector current and 3 ml sample size. Carbon
dioxide is determined using a 3/16" x 20' aluminum column packed with 12.5
percent hexamethylphosphoramide and 7,5 percent tributylphosphate on 60-80
mesh Chromosorb P. Operating conditions include: helium carrier gas at
30 ml/minute, ambient temperature, 150 ma detector current and 3 ml gas
sample size.
-------
TABIC FS-Jf
SUMJART OF
SAHPIING AND ANALYTICAL METHODS
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At plant 14-11, chromatographic techniques are used for complete
inorganic and organic gas analysis. Hydrogen, nitrogen, oxygen and
carbon monoxide are measured on a Varian Model 1700 thermal conducti.vi.t-y
instrument. A 3/16" x 15' aluminum column containing 50-80 mesh Porepak
Q is operated at 60° C using 30 ml/minute of helium carrier gas. For
carbon dioxide analysis, the column temperature is elevated to -I-650 C.
Organic absorber vent gas constituents analyzed include methane,
methanol, methylal, methyl formate, dimethyl ether, methoxymethylal. A.
Perkin-Elmer Model 154 chromatograph with 1/8" x 20' aluminum column and
thermal conductivity detector is used. Column packing consists of 20
percent 1,2,3 tris (cyanomethoxy) propane on 60-80 mesh Chromosorb W.
Nitrogen carrier gas at 30 ml/minute is used along with a column temperature
of 100° C.
2. Discussion
As may be noted from the previous section, stack gas analysis other
than the Orsat-type is the exception rather than the rule in the
formaldehyde industry. Even -where organic constituents are measured,
the frequency is low. Hoever, from the standpoint of analytical tech-
nology, adequate methods are available and are in use in several plants.
The sulfite and chromic acid methods (1) are simple and inexpensive to
perform and are acceptable for routine emissions monitoring. Through
gas chromatography, complete organic analyses are practical on either a
grab or continuous sample basis. No centralized effort is felt to be
warranted for further methods development.
-------
i' *J — ^
XVII. Emergency Action Plan for Air Pollution Episodes
A. Types of Episodes
The alleviation of Air Pollution Episodes as suggested by the. U.S.
Environmental Portection Agency is based on a pre-planned episode
emission reduction scheme. The criteria that set this scheme into
motion are:
1. Alert Status - The alert level is that concentration of pollutants
at which short-term health effects can be expected to occur.
2. Warning Status - The warning level indicates that air quality
is continuing to deteriorate and that additional abatement
actions are necessary.
3. Emergency Status - The emergency level is that level at which
a substantial endangerment to human health can be expected.
These criteria are absolute in the sense that they represent
a level of pollution that must not be allowed to occur.
B. Sources of Emissions
As outlined in the foregoing in-depth study of "Formaldehyde Manu-
facture by the Silver Catalyst Process" there are two continuous and
three intermittent vent streams to the atmosphere.
1. Continuous Streams
(a) Absorber Vent - The emissions from this source represent
by far the largest and most important atmospheric emission
associated with this process. The stream consists of
reaction by-products and varies in composition with
catalyst age or activity.
Except for a mist eliminator in the top of the secondary
absorber, most plants do not employ emission control
devices on the absorber vent. Those that do, usually
utilize some type of combustion system.
(b) Product Fractionator Vent - Reports indicate that the product
fractionators are usually operated at sub-atmospheric pressures
by using steam ejectors or vacuum pumps. The gaseous
effluent from this system is continuous in nature with
little change in composition provided tower operating
conditions (pressure, temperature and reflux) are maintained
at the normal operating levels.
2. Intermittent Air Emissions
(a) Converter Start-Up Vent - This stream represents the converter
feed during start-up and is usually vented to the atmosphere
ur.til stabilized conditions are obtained. It is then gradually
introduced to the converter for processing. The vent time
is reported to be 30 minutes per converter start-up. Another
type of start-up vent is employed when the absorber vent
stream is burned in a combustion device. In this case, the
absorber vent stream is directed to the atmosphere until
stabilized then it is routed to the incinerating device.
-------
FS-60
(b) Converter Emergency Vent - This vent is presumed to be an
explosion type of quick opening valve or bursting disc that
would operate only in event of sudden high pressure« Such
an occasion would be very infrequent and insignificant as
an emission source since flow would be of a short duration
(1-2 minutes).
C. Abatement Techniques
As the various levels of the pre-planned episode reduction scheme are
declared (Alert, Warning and Emergency) a progressive reduction in the
anount of air pollutants emitted must be made. This could ultimately
lead to total curtailment of pollutant emissions if the emergency level
becomes imminent.
The extent of the required cutback in emissions from formaldehyde
plants will be at the jurisdiction of the environmental governing agency.
It will depend on the relative amount of offending constituents contributed
by formaldehyde production to the overall emissions which resulted in the
pollution episode. This plus other factors will be used by the control
authorities in determining the amount of emissions to be tolerated during
various episodes.
Formaldehyde manufacturing facilities by the Silver Catalyst Process
generally consist of one or more converters with a common set of absorbers
(2) and a product fractionator. In plants with multiple converters in a
producting train of equipment, a certain degree of flexibility for a partial
reduction in air pollutant emissions is usually possible by shutting down
one or more converters. There is, in addition, the option of maintaining
operation of all converters and to "turndox^n" the plant capacity for the
required reduction. In the first instance if one or more catalytic
converters are taken out of service, a rebalance of flows through the
equipment is required. The polluting constituents, if they were discharged
directly to the atmosphere would be reduced by the percentage which the
air flow is reduced. In the second instance a "turndown" of plant
capacity would produce the same type of results. In both cases conversion
efficiency must be maintained.
In either of the options presented above for a partial reduction in
atmospheric pollutants, consideration must be given to the actual emission
into the atmosphere. For example, in plants that employ combustion devices
the reduction in plant capacity, whether by shutting down a converter or
turndown in capacity by reducing feed, would decrease the amount of
combustibles flowing to the incinerating devices. If the air rate is
not cut back proportionally, this could make it necessary to add
supplemental fuel to replace these combustibles in order to prevent
burner flame out. In the event the emissions are used in a steam
generating unit, supplementary fuel may also be required to maintain the
steam balance.
Two to four hours will be required to affect a partial reduction in
plant capacity with a similar period for return to normal operating levels.
Product fractionator vacuum producing equipment will remain in service
during the partial reduction. The sole requirement is for the maintenance
of satisfactory operating conditions on the tower.
-------
FS-61
The converter start-up vent should not be required during an alert
condition. If a "turndown" in capacity is used to reduce emissions
during an episode, converter venting will not be required upon resumption
to normal formaldehyde production levels. However, this vent is
necessary if individual converters are shutdown.
The same applies to the absorber vent in plants that use combustion
control devices. Ir> these units, the vent would be used only in the
event the entire train of equipment was starting up.
The converter emergency vent will presumably not be a source of
emissions during the alert condition. As the name implies, it would
emit pollutants only during an emergency. In this case, it is presumed
that the entire plant would be shutdown.
1. Declaration of Alert Condition - When an alert condition is
declared, the episode emission reduction plan is immediately
set into motion. Under this plan in addition to notifying the
manufacture of the alert condition, it may be deemed necessary
by the governing environmental protection agency to somewhat
reduce emissions from formaldehyde manufacture in order to
prevent further increases in pollution level which could result
in warning or emergency episodes. This reduction would be
accomplished by employing one of the foregoing options. This
will reduce the principal source of emission, represented
by the absorber vent, to a value approximately equivalent to
the reduction made in formaldehyde production. Usually the
alert condition can be expected to continue for 12 hours or
more.
2. Declaration c I r ,fcnaition - Vhen the air pollution
warning episode 3? ' oi'.iceii a substantial reduction of air
contaminants is desirable even to the point of assuring
reasonable economic hardship in Che cutback of production
and allied operations. This could involve a 50-60 percent
decrease in formaldehyde production.
3. Emergency Condition - When it appears that an air pollution
emergency episode is imminent, all air contaminants may ha\/e
to be eliminated immediately by ceasing production and allied
operations to the extent possible without causing ini'iry to
persons or damage to equipment.
The cessation of operation of the producing units whether wholly
or in part will not result in increased emissions. Start*>p
operations, however, will produce air pollutant emissions f.:r
short periods as previously outlined.
D. Economic Considerations
The economic impact on formaldehyde manufacturers of curtailing
operations during any of the air pollution episodes is based on the
duration and number of episodes in a given period. It is indicated that
the normal duration of air pollution episodes is usually one to seven
days with meteorology episode potentials as high as 80 per year.*? The
frequency of air pollution episodes in any given area is indicated as
being one to four per year. These data do not differentiate between
the episode levels. Normally since the alert level does not require a
-------
cutback in production, it will not influence plant economics. Therefore,
in discussing economic considerations resulting from the air pollution
abatement plant, it is necessary to estimate the frequency and number
of warning and emergency episodes. For the economic study, it has been
assumed that three warning and no emergency episodes occur per year.
Each warning episode is assumed to require a 50 percent reduction in
air contaminants for a period of 5^ days. This then equates to a complete
loss in plant production of about 8k days per year.
The financial impact resulting from this loss in production is shown
in Table FS-20. This table contains comparative manufacturing costs
for an existing 100 MM Lbs./Year facility without extensive pollution
control (Table FS-13) and for a most feasible new facility of the same
capacity (Table FS-14). Economics are shown for each of these plants
with methanol feed at 12 and 17 cents per gallon with and without
the financial impact accredited to the air pollution episodes. It
should be noted that whereas the proposed cutback in formaldehyde
production for emission control appears small (2.5 percent on a yearly
basis) it has a substantial influence on net profit (4.0 percent to
5.0 percent reduction) on the cases presented.
E. Summary of Estimated Emissions
In the foregoing it has been implied that a reduction in air
pollutant emissions is necessary for the various air pollution levels
that may be encountered. This was primarily predicated on existing
plants which do not have the most sophisticated pollution control
equipment. However, special consideration should be made in the EAP
for Air Pollution Episode Avoidance for new and existing plants that
employ incineration control equipment on the absorber vent. The
following presents estimated air emissions for a typical present day
system without incineration and the most feasible new plant with this
type of control plus recycle of fractionator vent gas.
Typical Present Most Feasible
Day System, Lb./Lb. New Lb./Lb. of
Pollutant of 37% Formaldehyde 3 7%, Formaldehyde
Hydrocarbons 0.0040 0
Carbon Monoxide 0.0180 £
Total 0.0220 0
As noted in the above, total emission of hydrocarbon and carbon
monoxide has been reduced to zero levels on the most feasible new plant.
However, it can be expected that some quantity of NOx will be made in
the incinerator. Despite this, one respondent reported that the normal
process emissions from his plant contained only oxygen, nitrogen, carbon
dioxide and uncombined water. In this particular case and on similar
facilities that can demonstrate the absence of polluting constituents
in their atmospheric emissions no steps would need to be taken during
any of the air pollution episodes.
The particular type and conenntration of pollutants in the atmosphere
at the time of the episode would dictate the degree to which a reduction
would be made on the most feasible new plant. If NOx is the offending
material, then a reduction in plant production should be made as outlined
-------
Direct Manufacturing Coat. M $/Yr.
Rav Material
Methanol @ 17c/Gal.
(3 12c/G«l.
Catalyst and Chemicals
Labor
Maintenance
Utilities*
Indirect Manufacturing Costs, M $/Yr.
Plant Overhead
Fixed Manufacturing Costs. M S/Yr.
Depreciation, Insurance & Prop. Taxes
TABLE IS-20
FINANCIAL IMPACT OF AIR POLLUTION EPISODES
ON MANUFACTURING COSTS
FOR 100 MM LBS./TEA! FORMALDEHYDE MANUFACTURING FACILITY
fSILVER CATALYST PROCESS)
Sheet 1 of 2
TYPICAL EXISTING PLANT
(TABLE FS-13)
Methanol @ 17c/Gal.
No Cut-
back In
Production
1,136
70
79
100
61
87
246
Assuming
8.5 Days
Lost
Product! on
1,108
68
79
100
59
87
246
Methanol (3 12c/Gal.
No Cut-
back In
Production
802
70
79
100
61
87
246
Assuming
8.S Days
Lost
Producti&n
782
68
79
100
59
87
246
MOST FEASIBLE NEW PLANT
(TABLE FS-14)
Mtchanol (a 17e/cal.
No Cut-
back In
Production
1,136
70
81
101
49
89
234
Assuming
9.5 Days
Lost
Production
1,108
66
81
101
48
89
254
Methanol (3 12c/Gal.
No Cut-
back In
Production
802
70
81
101
49
89
254
Assuming
8.5 Days
Lost
Production
782
68
81
101
48
89
234
*0ne formaldehyde manufacturer has commented that these utility charges are lov relative to the nixed oxide catalyst process utilities.
i
-------
Manufacturing Costs, M $/Yr.
General Expenses
Administration, Sales, Res. & Finance
Coat Ex Works
Delivery
Total DeLivercd Cost
Product Value, M j/Yr.
J7X Formaldehyde Uninhibited
@ 3.5p/Lb. (Dlvd.)
Profit Before Taxes
Profit After 52% T»v
Caah Flow
ROI
TABLE FS-30
FINANCIAL IMPACT OF AIR POLLUTION EPISODES
ON MANUFACTURING COSTS
FOR 100 MM LBS./YEAR FORMALDEHYDE MANUFACTURING FACILITY
(SILVER CATALYST PROCESS)
Sheet 2 of 2
TYPICAL EXISTING PLANT
(TABLE FS-13)
Methanol @ 17c/Ga1
No Cut-
back In
Production
1,779
226
2,005
620
2,62 5
3,500
875
420
620
21.0*
Assuming
8.5 Days
Lost
Production
1 ,74 7
226
1,973
605
2,578
3,413
835
AO 1
601
20. n
Methanol 12c/Gal.
fio Cut-
back }v.
Product ion
1,445
206
1,651
620
2,271
3,500
1,229
590
790
29.5*
Assuming
8.5 Days
Lost
Production
1,421
206
1,627
605
2,232
3,413
1,181
567
767
28.3*
HOST FEASIBLE NEW PIANT
(TABLE FS-14)
Methanol @ 17^/Cal.
No Cut-
back In
Production
1,780
229
2,009
620
2,629
3,500
871
419
624
20. 51
Assualng
8.5 Days
Lost
Production
1,749
229
1,9/8
*05
2,583
3,413
830
399
604
19.5*
Methanol (? 12c/Cal1
No Cut-
back In
Production
1,446
209
1,655
620
2,275
3,500
1,225
589
794
28. 8*
Aeauaing
8,5 Days
Lost
Production
1,423
204
603
2,21)
3,411
1,176
;s
27.6%
i
-------
FS-65
under "Declaration of Warning Status". In this case, NOx would be
reduced in proportion to the cutback in production and probably to a
greater percentage because of longer residence time and reduced
operating temperature of the incinerating device.
-------
FS-66
XVII. References
1. Walker, J. B., "Formaldehyde", ACS Monograph Series, Reinhold
Publishing Corporation, 1964.
2. "Own Your Ovn Formaldehyde Plant", Chemical Week, Tuly 10, 1965,
pages 81 - 84.
3. Stobaugh, R. E., et al: "Methanol: Hov, Where, Who -- Future";
Hydrocarbon Processing, June, July, August, September, 1970.
4. "A Lively Rivalry for Licensees", Chemical Week, November 19,
1969, pages 79 - 82.
5. "Formaldehyde Chemical Profile", Chemical Marketing Reporter,
May 1, 1972.
6. "Chemical Economics Handbook, Stanford Research Institution,
August, 1970.
7. Hahn, Albert. "The Petrochemical Industry: Markets and Economics",
McGrav-Hill Inc., 1970, pages 75 - 88.
8. Kirk-Othmer, "Encyclopedia of Chemical Technology", 2nd Edition,
1966, Volume 10, pages 86 - 90.
9. "Air Pollution Survey Production of Ten Petrochemicals", MSA
Research Corporation for Environmental Protection Agency,
Contract No. EHSD 71-12, Mod. I, Task II, July 23, 1971.
10. "Durez Synthesizes Formaldehyde", Chemical Engineering, February,
1949 pages 146 - 149.
11. "Formaldehyde from Methanol", Modern Chemical Processes, Volume III,
pages 79 - 80.
12. "Materials for Making Formaldehyde", Chemical Engineering,
January 15, 1968, pages 182 - 188.
13. "More - Methanol Formaldehyde Route Boasts Many Benefits",
Chemical Engineering, March 9, 1970, pages 102-- 104.
14. Rolke, R. W. et al, "Afterburner Systems Study", by Shell
Development Company for Environmental Protection Agency 'Contract
EHAS 71-3).
15. "Formaldehyde Producers Move to Ease Shortage of Materials;
Borden, Reichhold Expanding", Oil Paint and Drug Reporter,
April 7, 1969, pages 5 - 30.
16. "Directory of Chemical Producers", Stanford Research Institute.
17. "Guide for Air Pollution Episode Avoidance", Environmental Protection
Agency, Office cf Air Programs, Publication No. AP-73, June, 1971.
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1 I
APPENDIX I
BASIS OF THE STUDY
I. Industry Survey
The study which led to this document was undertaken to obtain information
about selected production processes that are practiced in the Petrochemical
Industry. The objective of the study was to provide data for the EPA to use
in the fulfillment of their obligations under the Clean Air Amendments of 1970.
The information obtained during the study includes industry descriptions,
air emission control problems, sources of air emissions, statistics on quantiti
and types of emissions and descriptions of emission control devices currently
in use. The principal source for these data was an Industry Questionnaire
but it was supplemented by plant visits, literature searches, in-house back-
ground knowledge and direct support from the Manufacturing Chemists Association
More than 200 petrochemicals are currently produced in the United States,
and many of these by two or more different processes. It was obvious that
the most immediate need was to study the largest tonnage, fastest growth
processes that produce the most pollution. Consequently, the following 32
chemicals (as produced by a total of 41 different processes) were selected
for study:
Acetaldehyde (two processes)
Acetic Acid (three processes)
Acetic Anhydride
Acrylonitrile
Adipic Acid
Adiponitrile (two processes)
Carbon Black
Carbon Disulfide
Cyclohexanone
Ethylene
Ethylene Dichloride (two processes)
Ethylene Oxide (two processes)
Formaldehyde (two processes)
Glycerol
Hydrogen Cyanide
Maleic Anhydride
Nylon 6
Nylon 6,6
"Oxo" Alcohols and Aldehydes
Phenol
Phthalic Anhydride (two processes)
Polyethylene (high density)
Polyethylene (low density)
Polypropylene
Polystyrene
Polyvinyl Chloride
Styrene
Styrene - Butadiene Rubber
Terephthalic Acid (1)
Toluene Di-isocyanate (2)
Vinyl Acetate (two processes)
Vinyl Chloride
(1) Includes dimethyl terephthalate.
(2) Includes methylenediphenyl and polymethylene polyphenyl isocyanates.
The Industry Questionnaire, which was used as the main source of informatio
was the result of cooperative efforts between the EPA, Air Products and the
EPA's Industry Advisory Committee,, After receiving approval from the Office of
Management and Budget, the questionnaire was sent to selected producers of
most of the chemicals listed above. The data obtained from the returned
questionnaires formed the basis for what have been named "Survey Reports".
These have been separately published in four volumes, numbered EPA-450/3-73-005
b, c, and d and entitled "Survey Reports on Atmospheric Emissions from the
Petrochemical Industry - Volumes I, II, III, and IV.
-------
1-2
The purpose of the survey reports was to screen the various petrochemical
processes into the "more" and "less - significantly polluting processes".
Obviously, significance of pollution is a term which is difficult if not
impossible to define because value judgements ar« involved. Recognizing this
difficulty, a quantitative method for Significant Emission Index (SEI) was
developed. This procedure is discussed and illustrated in Appendix II of
this report. Each survey report includes the calculation of an SEI for the
petrochemical that is the subject of the report. These SEl's have been
incorporated into the Emission Summary Table that constitutes part of this
Appendix (Table I). This table can be used as an aid when establishing
priorities in the work required to set standards for emission controls on
new stationary sources of air pollution in accordance with the terms of the
Clean Air Amendments of 1970.
The completed survey reports constitute a preliminary data bank on each
of the processes studied. In addition to the SEI calculation, each report
includes a general introductory discussion of the process, a process description
(including chemical reactions), a simplified process flow diagram, as well as
heat and material balances. More pertinent to the air pollution study, each
report lists and discusses the sources of air emissions (including odors and
fugitive emissions) and the types of air pollution control equipment employed.
In tabular form, each reports summarizes the emission data (amount, composition,
temperature, and frequency); the sampling and analytical techniques; stack
numbers and dimensions; and emission control device data (types, sizes, capital
and operating costs, and efficiencies).
Calculation of efficiency on a pollution control device is not necessarily
a simple and straight-forward procedure. Consequently, two rating techniques
were developed for each type of device, as follows:
1. For flares, incinerators, and boilers a Completeness of Combustion Rating
(CCR) and Significance of Emission Reduction Rating (SERR) were used.
2. For scrubbers and dust removal equipment, a Specific Pollutant
Efficiency (SE) and a SERR were used.
The bases for these ratings and example calculations are included in
Appendix III of this report.
II. In-Depth Studies
The original performance concept was to select a number of petrochemical
processes as "significant polluters", on the basis of data contained in
completed questionnaires. These processes were then to be studied "in-depth".
However, the overall time schedule was such that the EPA requested an initial
selection of three processes on the basis that they would probably turn out
to be "significant polluters". The processes selected in this manner were:
1. The Furnace Process for producing Carbon Black.
2« The Sohio Process for producing Aerylonitrile.
3. The Oxychlorination Process for producing 1,2 Dichloroethane
(Ethylene Dichloride) from Ethylene.
-------
TAP. IE I
EMISSIONS SUMMARY
I'nec i of 3
ESTIMATED CURRENT
AIR EMISSIONS,
MM LHS./YKAR
Hydrocarbons v '
Particulates )
Oxides of Nitrogen
Sul fur Oxu'eF
Carbon M^noxi il<-
I I't.T I
Total Veij
Acetaldehyde via Ethylene
1.1
0
0
0
0
1 . 1
8b
via Ethanol
0
0
0
0
27
21
27
Acetic Acid via Methanol
0
0
0.01
0
0
O.Oi
I
via Butane
4 0
0
0.04
G
14
v»
3,215
via Acctaldehyde
6.1
0
0
0
1.3
7.4
490
Acetic Anhydride via Acetic Acid
3.1
0
0
0
5 . 5
8.6
253
Acrylonitrile (9)
183
0
5.5
0
19m
385
15,000
Adipic Acid
0
0.2
29.b
0
0. 14
30
1 , 190
Adiponitrile via Butadiene
11.2
4.7
50.5
0
0
bh. 4
3 ,200
via Adipic Acid
0
0.5
0,04
0
0
0.54
30
Carbon Black
15b
8. 1
6.9
21.b
3.870
4 ,0o0
17,544
Carbon Disulfide
0.15
0.3
0. 1
4.5
0
5.1
120
Cyclohex-none
70
0
0
0
77.5
148
5,700
Dimethyl Terephthalate (+TPA)
91
1.4
0.1
1.0
53
146.5
7 ,460
Ethylene
15
0.2
0.2
2.0
0.2
i;. 6
1 ,240
Ethylene Dichloride via Oxychlorination
95.1
0.4
0
0
21.8
117.3
7,650
via Direct Chlorination
29
0
0
0
0
29
2,300
Ethylene Oxide
85.8
0
0.3
0.1
0
86.2
b. 880
Formaldehyde via Silver Catalyst
23.8
0
0
0
107.2
131
1 ,955
via Iron Oxide Catalyst
25.7
0
0
0
24.9
50. t>
2,070
Glycerol via Epichlorohydrin
16
0
0
0
0
lo
1 .280
Hydrogen Cyanide Direct Process
0.5
0
0.41
0
0
0.91
56
Isocyanates
1.3
0.8
0
0.02
8b
88
231
Maleic Anhydride
34
0
0
0
260
294
2 ,950
Nylon 6
0
1.5
0
0
0
1.5
90
Nylon 6,6
0
5.5
0
0
0
5.5
330
Oxo Process
3.25
0.0L
0.07
0
19.5
24.8
440
Phenol ,
24.3
0
0
0
0
24 .3
1,940
Phthalic Anhydride via O-Xylene
0.1
5.1
0.3
2.6
4 3.6
51.7
422
via Naphthalene
0
1.9
0
0
45
47
lbO
High Density Polyethylene
79
2.3
0
0
0
81.3
6,400
Low Density Polyethylene
75
1.4
0
0
p
7o. 4
6,100
Polypropylene
37.5
0.1
0
0
0
3 7.0
2,950
Polystyrene
20
0.4
0
1.2
0
21. b *
1,650
Polyvinyl Chloride
62
12
0
0
0
74
5 ,700
Styrene
4.3
0.07
0.14
0
0
4.5
355
Styrene-Butadiene Rubber
9.4
1.6
0
0.9
0
12
870
Vinyl Acetate via Acetylene
5.3
0
0
0
0
5.3
425
via Ethylene
0
0
TR
0
0
TR
TK
Vinyl Chloride
17.6
0.6
__0
_0
0
18.2
1,460
Totals
1 ,227.6
49.1
94.2
33.9
4,852.6
6,225.9 i7)
110,220
(1) In most instances numbers arc based on less than 100% survey. All based on engineering Judgement of best current control. Probahly has up to 10.. lov bias.
(2) Assumes future plants vilL employ best current control techniques.
(3) Excludes methane, includes H2S and all volatile organLcs.
(4) Includes non-volatile organlcs and inorganics.
(5) Weighting factors used arc: hydrocarbons - 80, particulates - 60, N0X - 40, S0X - 20, and CO - I,
(6) Referred to elsewhere in this study as "Significant Emission Index" or "SEl".
(7) Totals are not equal across and down due to rounding.
(9) Emissions based on what is now an ob»olete catalyst. See Report No. EPA-450/3-73-006 b for up-to-date information.
-------
TABLE T
EMISSION SUMMARY
Pa^c 2 of 3
ESTIMATED ADDITIONAL (2)
AIH EMISSION'S IN
1980, MM i.BS./YEAK
Hvdrocarbons
Part icu1ates
Oxides of Nitrogen
SuIfur Oxides
Carbon Monosicii'
I o t a 1
Total U'ci nht ed
Acctaldehyde via Ethylene
1.2
0
0
0
0
1 .2
96
via Ethanol
0
0
0
0
0
0
0
Acetic Acid via Methanol
0
0
0.04
0
0
0.04
2
via Butane
0
0
0
0
0
0
0
via Acetaldehyde
12.2
0
0
0
2.5
14.7
980
Acetic Anhydride via Acetic Acid
0.73
0
0
0
1.42
2.15
60
Acrylonitrile (9)
234
0
8.5
0
304
59o
23,000
Adipic Acid
0
0.14
19.3
0
0.09
19.5
779
Adiponitrile via Butadiene
10.5
4.4
47.5
0
0
b2.4
3*010
via Adipic Acid
0
0.5
0.04
0
0
0.54
30
Carbon Black
t/i
3.3
2.8
8.9
1 ,590
1 ,,260
Dimethyl Terephthalate (+TPA)
73.8
l.l
0.07
0.84
42.9
118.7
h,040
Ethylene
14.8
0.2
0.2
61.5
0.2
77
2,430
Ethylene Dichloride via OxychLorination
no
0.5
0
0
25
13<>
8,800
via Direct Chlorination
34.2
0
0
0
0
34.2
2,740
Ethylene Oxide
32.8
0
0. 15
0.05
0
33
2 ,650
Formaldehyde via Silver Catalyst
14.8
0
0
0
06. 7
81.5
1 ,250
via Iron Oxide Catalyst
17.6
0
0
0
1 7 ,0
34.6
I ,445
Glycerol via Epichlorohydrin
3.9
0
0
0
0
8.9
700
Hydrogen Cyanide Direct Process
0
0
0
0
0
0
0
Isocyanates
1.2
0.7
0
0.02
85
87
225
Maleic Anhydride
31
0
0
0
24 1
272
^,720
Nylon 6
0
3.2
0
0
0
3.2
194
Nylon 6,6
0
5.3
0
0
0
5.3
313
Oxo Process
3.86
0.01
0.05
0
14 .3
18.2
325
Phenol
21.3
0
0
0
0
21.3
1,704
Phthalic Anhydride via 0-Xylene
0.3
13.2
0.8
6.8
113
134
1,100
via Naphthalene
0
0
0
0
0
0
0
High Density Polyethylene
210
6.2
0
0
0
216
17,200
Low Density Polyethylene
262
5
0
0
0
2tv
21,300
Polypropylene
152
0.5
0
0
0
152.5
12, 190
Polystyrene
20
0.34
0
1.13
0
21.47
1 ,640
Polyvinyl Chloride
53
10
0
0
0
*3
4,840
Styrene
3.1
0.05
0.1
0
0
3.25
225
Styrene-Butadiene Rubber
1.85
0.31
0
0.18
u
2.34
170
Vinyl Acetate via Acetylene
4.5
0
0
0
0
4.5
360
via Ethylene
0
0
TR
0
0
TR
TR
Vinyl Chloride
26.3
0.9
0
0
0
27.2
2,170
Totals
1,547,2
55.9
79.5
00
o
2,588
4,351.9
134,213
(1) In most instances numbers are based on less than 1007, survey. Ail based on engineering judgement of best current control. l'robahlv has up to 10- lov bias.
(2) Assumes future plantr. will employ best current control techniques.
(3) Excludes methane, includes and all volatile organics.
(4) Includes non-volatile organics and inorganics.
(5) Weighting factors used are: hvdrocarbons - 80, particulates - 60, NOx - 40, S0X - 40, and CO - I.
(6) Referred to elsewhere in this study as "Significant Emission Index" or "SEI".
(7) TotaLs are not equal across and dowu duw to rounding.
(9) See sheet I of 3.
-------
TABLE I
EMISSIONS SUMMARY
Emissions MM Lbs,/Year
Total by 1980 Total Weighted <5) by 1980
Acetaldehyde via Ethylene
2.3
182
via Ethanol
27
27
Acetic Acid via Methanol
0.05
3
via Butane
54
3,215
via Acetaldehyde
22
1,4 70
Acetic Anhydride via Acetic Acid
10.8
313
Acrylonitrile (9)
980
3b, CO?
Adipic Acid
50
1,970
Adiponitrile via Butadiene
123.8
6,210
via Adipic Acid
1.1
bO
Carbon Black
5,730
24, 740
Carbon Disulfide
6.3
150
Cyclohexanone
310
ll,9b0
Dimethyl Terephthalate (+TPA)
265
13,500
Ethylene
9A
3,670
Ethylene Dichloride via Oxychlorination
253
lb,450
via Direct Chlorlnation
63
5,040
Ethylene Oxi^e
120
9,530
Formaldehyde via Silver Catalyst
212.5
3,205
via Iron Oxide Catalyst
85
3,515
Glycerol via Epichlorohydrin
25
2,000
Hydrogen Cyanide Direct Process
0.5 (10)
28
Isocyanates
175
456
Maleic Anhydride
566
5,u70
Nylon 6
4.7
284
Nylon b,b
10.8
650
Oxo Process
':!)
7b5
Phenol
46
3,640
Phthalic Anhydride via O-Xylene
18b
1, j22
via Naphthalene
47
160
High Density Polyethylene
297
23,600
Low Density Polyethylene
343
27,400
Polypropylene
190
15,140
Polyftyrene
43
3,290
Polyvinyl Chloride
137
10,540
Styrene
7.4
610
Styrene-Butadiene Rubber
14
1,040
Vinyl Acetate via Acetylene
9.8
785
via fcinyiene
TR
TR
Vinyl Chloride
45
3,b30
Totals
10,605 (7)
244,420
(1) In most instances numbers are based on less than 100% survey. All based on engineering judgement
(2) Assumes future plants vill employ best current control techniques.
(3) Excludes methane, includes H2S and all volatile organics.
(4) Includes non-volatile organica and inorganics.
(5) Weighting factors used are: hydrocarbons - 80, particulates - 60, NOx - 40, S0X - 20, and CO - 1.
(6) Referred to elsewhere in this study as "Significant Emission Index" or "SEI".
(7) Totals are not equal across and down due to rounding.
(8) By 1985.
Pn^c 3 of 3
Total Estimated Capacity
Estimated Number of N'ev plants MM I.hp./Year
( 1973 - 1980) Current Bv 1980
h
1 ,1 h0
2,4 60
0
966
9 6 6
u
4 00
1 ,800
0
1 ,020
500
3
875
2.015
3
I . 70-1
2, 100
5
I , I 05
3, 700
7
1 ,430
2,200
4
435
845
3
280
550
13
3,000
5,000
2
871
1 ,100
10
1 ,800
3 , 600
8
2 ,865
5 ,900
21
22.295
40,000
8
4,450
8,250
10
5,593
11,540
15
4,191
b, 800
40
5,914
9, COO
12
1 ,729
3.520
1
245
380
0
412
202
10
1 ,088
2 ,120
6
359
720
486
1 ,500
10
1 ,523
3 ,000
6
1 .727
3,000
1;
2, 3t>3
4 7.00
t
no
! ,800
0
603
528
31
2,315
8,500
41
5 ,269
21,100
32
1 .1 60
5.800
23
3,500
6,700
25
4.37S
8,000
9
5,953
10,000
4
14,4 hit
5,210
1
206
35'*
4
1 ,280
2,200
to
5,400
13,000
best current control. Prohnblv has up to 10' low bias.
-------
In order to obtain data on these processes, the operators and/or
licensors of each were approached directly by Air Products' personnel.
This, of course, was a slow and tedious method of data collection because
mass mailing techniques could not be used, nor could the request for" data
be identified as an "Official EPA Requirement". Yet, by the time that OMB
approval -was given for use of the Industry Questionnaire, a substantial
volume of data pertaining to each process had already been received. The
value of this procedure is indicated by the fact that first drafts of these
three reports had already been submitted to the EPA, and reviewed by the
Industry Advisory Committee, prior to the completion of many of the survey
reports.
In addition, because of timing requirements, the EPA decided that three
additional chemicals be "nominated" for in-depth study. These were phthalic
anhydride, formaldehyde and ethylene oxide. Consequently, four additional
in-depth studies were undertaken, as follows:
1. Air Oxidation of Ortho-Xylene to produce Phthalic Anhydride.
2. Air Oxidation of Methanol in a Methanol Rich Process to produce
Formaldehyde over a Silver Catalyst. (Also, the subject of a
survey report.)
3. Air Oxidation of Methanol in a Methanol-Lean Process to
produce Formaldehyde over an Iron Oxide Catalyst.
4. Direct Oxidation of Ethylene to produce Ethylene Oxide.
The primary data source for these was the Industry Questionnaire,
although SEI rankings had not been completed by the time the choices were
made.
The Survey Reports, having now been completed are available, for use in
the selection of additional processes for in-depth study.
-------
INTRODUCTION TO APPENDIX II AND III
The following discussions describe techniques that were developed for
the single purpose of providing a portion of ihe guidance required in the
selection of processes for in-depth study. It is believed that the underlying
concepts of these techniques are sound. However, use of them without sub-
stantial further refinement is discouraged because the data base for their
specifics is not sufficiently accurate for wide application. The subjects
covered in the Appendix II discussion are:
1. Prediction of numbers of new plants.
2„ Prediction of emissions from the new plants on a weighted
(significance) basis.
The subject covered in the Appendix hi discussion is:
Calculation of pollution control device efficiency on a variety of
bases, including a weighted (significance) basis.
It should be noted that the weighting factors used are arbitrary.
Hence, if any reader of this report wishes to determine the effect of
different weighing factors, the calculation technique permits changes in
these, at the reader's discretion,
-------
APPENDIX II
Number of New Plants*
Attached Table 1 illustrates the format for this calculation.
Briefly, the procedure is as follows:
1. For each petrochemical that is to be evaluated, estimate what
amount of today's production capacity is likely to be on-stream
in 1980. This will be done by subtracting plants having marginal
economics due either to their size or to the employment of an
out-of-date process.
2. Estimate the 1980 demand for the chemical and assume a 1980
installed capacity that will be required in order to satisfy
this demand.
3. Estimate the portion of the excess of the 1980 required capacity
over today's remaining capacity that will be made up by
installation of each process that is being evaluated.
4. Estimate an economic plant or unit size on the basis of today's
technology.
5. Divide the total required new capacity for each process by the
economic plant size to obtain the number of new units.
In order to illustrate, the procedure, data have been incorporated
into Table I, for the three processes for producing carbon black, namely
the furnace process, the relatively non-polluting thermal process, and
the non-growth channel process.
*The format is based on 1980, but any future year may be selected.
-------
Table
1. Number of
New Plants
by 1980
Chemical
Process
Current
Capacity
Marginal
Capacity
Current
Capacity
on-stream
in 1980
Demand
1980
Capacity
1980
Capacity
to be
Added
Economic
Plrtnt
Size
Number of
New
Units
Carbon Black
Furnace
4,000
0
4,000
4,500
5,000
1,000
90
11 - 12
Channel
100
0
100
100
100
0
30
0
Thermal
200
0
200
400
500
300
150
2
Notes: 1. Capacity units all in MM lbs./year.
2. 1980 demand based on studies prepared for EPA. by Pre ssoes Research, Inc. and MSA Research Corporation.
-------
II-3
Increased Emissions (Weighted) by 1980
Attached Table 2 illustrates the format for this calculation.
However, more important than format is a proposal for a weighting basis.
There is a wide divergence of opinion on which pollutants are more noxious
and even when agreement can be reached on an order of noxiousness, dis-
agreements remain as to relative magnitudes for tolerance factors. In
general pollutants from the petrochemical industry can be broken down into
categories of hydrogen sulfide, hydrocarbons, particulates, carbon monoxide,
and oxides of sulfur and nitrogen. Of course, two of these can be further
broken down; hydrocarbons into paraffins, olefins, chlorinated hydrccarbnns,
nitrogen or sulfur hearing hydrocarbons, etc. and particulates into a'h.
catalyst, finely divided end products, etc. It was felt that no usei'ui
end is served by creating a large number of sub-groupings because it wjld
merely compound the problem of assigning a weighting factor. Therefore,
it vasproposed to classify all pollutants into one cf five of the six
categories with hydrogen sulfide included with hydrocarbons.
There appears to be general agreement among the experts that carbon
monoxide is the least noxious of the five and that N0X is somewhat more
noxious than S0X. However, there are widely divergent opinions concerning
hydrocarbons and particulates - probably due to the fact that these are
both widely divergent categories. In recent years, at least two authors
have attempted to assign tolerance factors to these five categories.
Babcock (1), based his on the proposed 1969 California standards for
one hour ambient air conditions with his own standard used for hydrocarbons.
On the other hand, Walther (2), based his ranking on both primary
and secondary standards for a 24-hour period. Both authors found it
necessary to extrapolate some of the basic standards to the chosen time
period. Their rankings, cn an effect factor basis with carbon monoxide
arbitrarily used as a reference are as follows:
Babcock Walther
Primary Secondary
Hydrocarbons 2.1 125 125
Particulates 107 21.5 37.3
N0X 77.9 22.4 22.4
S0X 28.1 15.3 21.5
CO 111
Recognizing that it is completely unscientific and potentially subject
to substantial criticism itwas proposed to take arithmetic averages of the
above values and round them to the nearest multiple of ten to establish a
rating basis as follows:
Average Rounded
Hydrocarbons 84.0 80
Particulates 55.3 60
N0X 40.9 40
S0„ 21.6 20
CO 11
-------
S-r Table 2. Weighted Emission Rates
Chemical
Process
Increased Capacity
Increased Emissions Weighting Weighted Emissions
Pollutant Emissions, Lbs./Lb. Lbs. /Year Factors Lbs. /Year
Hydrocarbons
Particulates
N0X
sox
CO
80
60
40
20
1
Total
-------
II—5
Increased Emissions (Weighted) by 1980 (continued)
This ranking can be defended qualitatively, if not quantitatively for
the following reasons:
1. The level of noxiousness follows the same sequence as is obtained
using national air quality standards.
2. Approximately two orders of magnitude exist between top and bottom
rankings.
3„ Hydrocarbons should probably have a Lower value than in the
Walther analysis because such relatively non-nnxious compounds
as ethane and propane are included.
4. Hydrocarbons should probably have a higher value than in the
Babcock analysis because such noxious (or posionous) substances
as aromatics, chlorinated hydrocarbons, phenol, formaldehyde, and
cyanides are included.
5. Particulates should probably have a higher value than in the
Walther analysis because national air standards are based mostly
on fly ash while emissions from the petrochemical industry are
more noxious being such things as carbon black, phthalic anhydride,
PVC dust, active catalysts, etc.
6. N0X should probably have a higher value than in the Walther
analysis because its role in oxidant synthesis has been neglected.
This is demonstrated in Babcock's analysis.
Briefly, the procedure, using the recommended factors and Table 2, is
as follows:
1. Determine the emission rate for each major pollutant category in
terms of pounds of pollutant per pound of final product. (This
determination was madet on the basis of data reported on returned
questionnaires^in the Survey Reports^.
2. Multiply these emission rates by the estimate of increased production
capacity to be installed by 1980 (as calculated while determining
the number of new plants), to determine the estimated pounds of
new emissions of each pollutant.
3. Multiply the pounds of new emissions of each pollutant by its
weighting factor to determine a weighted pounds of new emissions
for each pollutant.
4. Total the v... .ghted pounds of new emissions for all pollutants to
obtain an estimate of the significance of emission from the process
being evaluated. It was proposed that this total be named
"Significant Emission Index" and abbreviated "SEI".
It should be pointed out that the concepts outlined above are not
completely original and considerable credit should be given to Mr. L. B. Evans
of the EPA for setting up the formats of these evaluating procedures.
-------
II-6
Increased Emissions (Weighted) by 1980 (continued)
Babcock, L. F., "A Combined Pollution Index for Measurement of Total
Air Pollution," JAPCA, October, 1970; Vol. 20, No. 10; pp 653-659
Walther, E. G., "A Rating of the Major Air Pollutants and Their Sources
by Effect", JAPCA, May, 1972; Vol. 22, No. 5; pp 352-355
-------
Appendix III
Efficiency of Pollution Control Devices
Incinerators and Flares
The burning process is unique among the various techniques for
reducing air pollution in that it does not remove the noxious substance
but changes it to a different and hopefully less noxious form. It can be,
and usually is, a very efficient process when applied to hydrocarbons,
because when burned completely the only products of combustion are carbon
dioxide and water. However, if the combustion is incomplete a wide range
of additional products such as cracked hydrocarbons, soot and carbon
monoxide might be formed. The problem is further complicated if the
hydrocarbon that is being burned is halogenated, contains sulfur or is
mixed with hydrogen sulfide, because hydrogen chloride and/or sulfur oxides
then become products of combustion. In addition, if nitrogen is present,
either as air or nitrogenated hydrocarbons, oxides of nitrogen might be
formed, depending upon flame temperature and residence time.
Consequently, the definition of efficiency of a burner, as a pollution
control device, is difficult. The usual definition of percentage removal of
the noxious substance in the feed to the device is inappropriate, because
with this definition, a "smoky" flare would achieve the same nearly 100
percent rating, as a "smokeless" one because most of the feed hydrocarbon
will have either cracked or burned in the flame. On the other hand, any
system that rates efficiency by considering only the total quantity of
pollutant in both the feed to and the effluent from the device would be
meaningless. For example, the complete combustion of one pound of hydrogen
sulfide results in the production of nearly two pounds of sulfur dioxide, or
the incomplete combustion of one pound of ethane could result in the
production of nearly two pounds of carbon monoxide.
For these reasons, it was proposed that two separate efficiency rating
be applied to incineration devices. The first of these is a "Completeness
of Combustion Rating" and the other is a "Significance of Emission Reduction
Rating", as follows:
1 . Completeness of Combustion Rating (CCR)
This rating is based on oxygen rather than on pollutants and is
the pounds of oxygen that react with the pollutants in the feed to
the device, divided by the theoretical maximum number of pounds that
wculd react: Thus a smokeless flare would receive a 100 percent
rating while a smoky one would be rated somewhat less, depending upon
how incomplete the combustion.
In utilizing this rar.ing, it is clear that carbon dioxide and water
are the products of complete combustion of hydrocarbons. However, some
question could occur as to the theoretical completion of combustion
when burning materials other than hydrocarbons. It ^as recommended
that the formation of HX be considered complete combustion of halogenated
hydrocarbons since the oxidation most typically does not change the
valence of the halogen. On the other hand, since some incinerators will
be catalytic in nature it was recommended that sulfur trioxide be
considered as complete oxidation of sulfur bearing compounds.
-------
III-2
Efficiency of Pollution Control Devices
1. Completeness of Combustion Rating (CCR) (continued)
Nitrogen is more complex, because of the equilibria that exist
between oxygen, nitrogen, nitric oxide, nitrogen dioxide and the
various nitrogen radicals such as nitrile. In fact, many scientists
continue to dispute the role of fuel nitrogen versus ambient nitrogen
in the production of N0X. In order to make the CCR a meaningful
rating for the incineration of nitrogenous wastes it vas recommended
that complete combustion be defined as the production of N2, thus
assuming that all N0X formed comes from the air rather than the fuel,
and that no oxygen is consumed by the nitrogen in the waste material.
Hence, the CCR becomes a measure of how completely the hydrocarbon
content is burned, while any N0X produced (regardless of its source)
will be rated by the SERR as described below.
2„ Significance of Emission Reduction Rating (SERR)
This rating is based primarily on the weighting factors that
were proposed above. All air pollutants in the feed to the device
and all in the effluents from the device are multiplied by the
appropriate factor. The total weighted pollutants in and out are
then used in the conventional manner of calculating efficiency
of pollutant removal, that is pollutants in minus pollutants out,
divided by pollutants in, gives the efficiency of removal on a
significance of emission basis.
Several examples will serve to illustrate these rating factors,
as follows:
Example 1 - One hundred pounds of ethylene per unit time is burned
in a flare, in accordance with the following reaction:
3C2H/4 + 7 O2 ~ C + 2 CO + 3 C02 + 6 H20
Thus, 14.2 lbs. of particulate carbon and 66.5 lbs. of carbon
monoxide are emitted, and 265 lbs. of oxygen are consumed.
Theoretical complete combustion would consume 342 lbs. of oxygen
in accordance with the following reaction:
C2H4 + 3 02 ^ 2 CO2 + 2 H2O
Thus, this device would have a CCR of 265/342 or 11,5%
Assuming that one pound of nitric oxide is formed in the reaction
as a result of the air ujied for combustion (this is about equivalent to
100 ppm), a SERR can a]so be calculated. It should be noted that the
formation of this NO is not considered in calculating a CCR because it
came from nitrogen in the air rather than nitrogen in the pollutant
being incinerated. The calculation follows:
-------
Ill—3
Efficiency of Pollution Control Devices
2. Significance of Emission Reduction Rating (SERR) (continued)
Pollutant
Hydrocarbons
Particulates
N0X
S0X
CO
Weighting
Factor
80
60
40
20
1
Pounds in
Pounds out
Actual
100
0
0
0
0
Weighted
8000
Actual Weighted
0
14.2
1
0
66.5
Total
SERR = 8000 - 958.5
8000
8000
852
40
66.5
958.5
x 100 = 558%
Example 2 - The same as Example 1, except the hydrocarbons are
burned to completion. Then,
CCR = 342
342
and
SERR = 8000 - 40
8000
x 100 = 100%
= 99.5%
Example 3 - One hundred pounds per unit time of methyl chloride is
incinerated, in accordance vLth the following reaction.
2 CHjCl + 3 02
: C02 + 2 H20 + 2 HC1
This is complete combustion, by definition, therefore, the CCR is
100%. However, (assuming no oxides of nitrogen are formed), the SERR
i.s less than 1007o because 72.5 lbs. of HCl are formed. Hence,
considering HCl as an aerosol or particulate;
SERR = 100 x 80 - 72.5 x 60
100 x 80
x 100 = 45.5%
The conclusion from this final example, of course, is that it is
an excellent combustion device but a very poor pollution control device,
unless it is followed by an efficient scrubber for HCl removal.
Example 4 - The stacks of two hydrogen cyanide incinerators, each
burning 100 pounds per unit time of HCN are sampled. Neither has any
carbon monoxide or particulate in the effluent. However, the first is
producing one pound of N0X and the second is producing ten pounds of
NOx in the same unit time. The assumed reactions are:
-------
III-4
Efficiency of Pollution Control Devices
2. Significance of Emission Reduction Rating (SERR) (continued)
4 HCN + 5 02 1 * ~ 2 H20 + 4 C02 + 2 N2
N2 (atmospheric) + X02 » ¦¦2 N0X
Thus, CCRi = 100% and CCR2 = 100% both by definition.
However, SERR^ ~ 100 x 80 — 1 x 40 100 ~ 99 51
100 x 80
and SERRo = 100 x 80 - 10 x 40
2 100 x 80 x 100 = 95l°
Obviously, if either of these were "smoky" then both the CCR and
the SERR would be lower, as in Example 1.
Other Pollution Control Devices
Most pollution control devices, such as bag filters, electrostatic
precipitators and scrubbers are designed to physically remove one or more
noxious substances from the stream being vented. Typically, the efficiency
of these devices is rated relative only to the substance which they are
designed to remove and for this reason could be misleading. For example:
1. The electrostatic precipitator on a power house stack might be
99% efficient relative to particulates, but will remove little
or none of the S0X and N0X which are usually present.
2. A bag filter on a carbon black plant will remove 99 + 7. of the
particulate but will remove none of the CO and only relatively
small amounts of the compounds of sulfur that are present.
3. A water scrubber on a vinyl chloride monomer plant will remove
all of the hydrogen chloride but only relatively small amounts
of the chlorinated hydrocarbons present.
4. An organic liquid scrubber on an ethylene dichloride plant will
remove nearly all of the EDC but will introduce another pollutant
into the air due to its own vapor pressure.
For these reasons, it was suggested again that two efficiency ratings be
applied. However, in this case, the first is merely a specific efficiency as
is typically reported, i.e., "specific to the pollutant (or pollutants) for
which it was designed", thus:
SE = specific pollutant in - specific pollutant out ^qq
specific pollutant in
The second rating proposed is an SERR, defined exactly as in the case
of incinerators.
Two examples will illustrate these ratings.
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III-5
Efficiency of Pollution Control Devices
Other Pollution Control Devices (continued)
Example 1 - Assume that a catalytic cracker regenerator effluent
contains 100 pounds of catalyst dust, 200 lbs„ of
carbon monoxide and 10 pounds of sulfur oxides per unit
time. It is passed through a cyclone separator where
95 pounds of catalyst are removed. Therefore,
SE = 100 - 5
100 ^ 100 — 95/»
and SERR = (100 x 60 + 10 x 20 + 200 x 1) - (5 x 60 + 10 x 20 + 200 x 1) x 100
(100 x 60 + 10 x 20 + 200 x 1)
= 6400 - 700 x 100 = 89%
6400
Example 2 - Assume that an organic liquid scrubber is used to wash a
stream containing 50 pounds of SO2 per unit time. All
but one pound of the SO2 is removed but two pounds of
the hydrocarbon evaporate into the vented stream. Then
SE = 5°5o 1 x100 = 98%
and SERR = (50 x 20) - (1 x 20 + 2 x 80)
(50 x 20) x 100
= 1000 - 180 100 = g27
1000
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before cvmpletip**
1. REPORT NO. 2.
EPA-450/3-73-006-d
3
4. TITLE AND SUBTITLE
Engineering and Cost Study of Air Pollution Control
for the Petrochemical Industry, Volume 4: Formaldehydi
Manufacture with the Silver Catalyst Prncess
5. REPORT DATE
March 1975
p. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
R. B. Morris, F. B. Higgings, Jr., J. A. Lee,
R. Newirth, J. W. Pervier
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Houdry Division/Air Products and Chemicals, Inc.
P. 0. Box 427
Marcus Hook, Pennsylvania 19061
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-02-0255
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Air Quality Planning & Standards
Industrial Studies Branch
Research Triangle Park, N.C. 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final Report
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
This document is one of a series prepared for the Environmental Protection
Agency (EPA) to assist it in determining those petrochemical processes for which
standards should be promulgated. A total of nine petrochemicals produced by
twelve distinctly different processes has been selected for this type of in-depth
study. Ten volumes, entitled Engineering and Cost Study of Air Pollution Control
for the Petrochemical Industry (EPA-450/3-73-006a throuqh j) have been prepared.
A combination of expert knowledge and an industry survey Was used to select
these processes. The industry survey has been published separately in a series of
four volumes entitled Survey Reports on Atmospheric Emissions from the Petrochemical
Industry (EPA-45Q/3-73-005a, b, c, and d).
This volume covers the manufacture of formaldehyde with the silver catalyst
process. Included is a process and industry description, an engineering description
of available emission control systems, the cost of these systems, and the financial
impact of emission control on the industry. Also presented are suggested air
episode procedures and plant inspection procedures.
17. KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
b. I D ENTI FI F RS/OPEN ENDED TERMS
c. COSATi 1 ield/Group
Air Pollution
Formaldehyde
Carbinols
Hydrocarbons
Carbon Monoxide
Petrochemical Industry
Methanol
7A
7B
7C
11G
13B
13H
13. DISTRIBUTION STATEMENT
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
94
20. SECURITY CLASS (This page)
Unclassified
22. PRI^C
EPA Form 2220-1 (9-73)
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