&ER&
United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EPA-450/3-80-040
November 1980
Air
Source Category Survey:
Starch Manufacturing
Industry
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EPA-450/3-80-040
Source Category Survey:
Starch Manufacturing Industry
Emission Standards and Engineering Division
Contract No. 68-02-3061
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air, Noise, and Radiation
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
November 1980
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This report has been reviewed by the Emission Standards and Engineering Division
of the Office of Air Quality Planning and Standards, EPA, and approved for publication.
Mention of trade names or commercial products is not intended to constitute endorsement
or recommendation for use. Copies of this report are available through the Library
Services Office (MD-35), U. S. Environmental Protection Agency, Research Triangle
Park, N. C. 27711, or from National Technical Information Services, 5285 Port Royal
Road, Springfield, Virginia 22161.
11
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TABLE OF CONTENTS
Section Page
1 SUMMARY 1-1
2 INTRODUCTION 2-1
3 CONCLUSIONS 3-1
4 DESCRIPTION OF INDUSTRY 4-1
4.1 Source Category 4-1
4.2 Industry Production 4-13
4.3 Process Description 4-22
4.3.1 Corn Wet Milling 4-22
4.3.2 Wheat Starch 4-26
4.3.3 Potato Starch 4-28
5 AIR EMISSIONS DEVELOPED IN SOURCE CATEGORY 5-1
5.1 Plant Process and Emissions 5-1
5.2 Total National Emissions From Source Category . 5-11
6 EMISSION CONTROL SYSTEMS 6-1
6.1 Control Approaches 6-1
6.2 Alternative Control Techniques 6-3
6.3 "Best System" of Emission Reduction 6-3
7 EMISSIONS DATA 7-1
7-1 Availability of Data 7-1
7.2 Sample Collection and Analysis 7-1
8 STATE AND LOCAL REGULATIONS 8-1
111
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LIST OF TABLES
Table Page
1-1 Quantity and Value of Shipments of Major Corn Wet Milling
Products in 1977 1-2
4-la Starch Manufacturing Operations — Corn 4-2
4-1b Starch Manufacturing Operations — Wheat 4-5
4-1c Starch Manufacturing Operations -- Potato 4-6
4-1d Starch Manufacturing Operations — Type Uncertain .... 4-7
4-2 List of Contacts 4-11
4-3 Quantity and Value of Shipments by all Producers in Wet Corn
Milling Industry (SIC 2046), 1963-77 4-14
4-4 General Statistics for Corn Wet Milling Industry (SIC 2046)
1958-77 4-17
4-5 Projected Production of Corn Wet Milling 4-18
5-1 Summary of Particulate Emission Stack Test Results From State
Emission Inventories 5-2
5-2 Summary of Particulate Emission Stack Test Results From EPA-
450/3-73-003a 5-3
5-3 Process Emissions Summary for Corn Wet Milling 5-5
5-4 Feed Dryer Emission Factors 5-6
5-5 Process Emissions Summary for Wheat Starch Manufacturing . 5-9
5-6 Procss Emissions Summary for Potato Starch Manufacturing . 5-10
6-1 Estimated National Emissions From Corn Wet Milling .... 6-5
IV
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LIST OF FIGURES
Figure Page
4-1 Corn Wet Milling Process Flow Diagram 4-23
4-2 Wheat Starch Process Flow Diagram 4-27
4-3 Potato Starch Process Flow Diagram 4-29
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1. SUMMARY
The starch manufacturing industry (.basically SIC 2046) was examined
during this survey to develop the background information necessary to
assess the need for the development of a new source performance standard
(NSPS). Starch is manufactured in the United States by the corn wet
milling, wet potato crushing, tapioca extraction, or dry wheat milling
processes; the corn wet milling process dominates the industry owing to
lower costs and greater product flexibility. Most of the 24 corn wet
milling operations in the U.S. are located near the source of raw materials
in Iowa (6), Illinois (5), and Indiana (4). In the corn wet milling
process the corn kernels are soaked in water with sulfur dioxide added,
then coarsely ground in a mill. The components are then divided using
various density separation techniques, processed, and dried. Potato and
tapioca (cassava) starches are produced by crushing the raw tuberous
vegetables and extracting the starch in water. Four of the eight existing
plants are located in Maine. The dry wheat milling procedure grinds the
grain into flour, adds water to make a batter, and extracts starch in a
combined beating/water spraying process. Three of the seven wheat
plants are located in Kansas. Each type of starch has certain characteristics
that make it useful for given applications; however, corn starch and its
by-products dominate the industry. In 1977, more than 9.8 x 10 Mg
(10.8 x 10 tons) of corn products valued at $1.9 billion were shipped,
4 4
while only 7.1 x 10 Mg (7.8 x 10 tons) of starches from other vegetables
with a value of $32 million were shipped.
The starch industry produces a variety of products with extremely
diversified applications. The corn wet milling industry produces common
and modified specialty starches; refined starch products: dextrins,
dextrose, glucose (corn) syrup, high-fructose corn syrup (MFCS), and
ethanol (grain alcohol); and by-products: corn oil and animal feeds.
Quantities and values of shipments of these major corn wet milling
products in 1977 are given in Table 1-1. The syrups are used as sweeteners
in a variety of food products with an increasingly large market for MFCS
in the-soft drink industry. The dextrins and modified specialty starches
are finding uses as filler in biodegradable plastics, rubber hardeners
1-1
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TABLE 1-1. QUANTITY AND VALUE OF SHIPMENTS OF MAJOR CORN WET MILLING
PRODUCTS IN 1977a
Product
Shipments
(billion kg)
Value
(Million $)
Common and modified
specialty starches
2.5
408
Refined starch products:
Dextri ns
Dextrose
Glucose (corn) syrup
High-fructose corn
syrup (HFCS)
Ethanol
By-products :
Corn oil
Animal feeds
0.063
0.57
2.1
1.5
Negligible
Indeterminate
3.1
25
139
284
251
Negligible
325
462
Extracted from Table 4-3; data from U.S. Department of Commerce
Census of Manufacturers.
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for tire manufacturing and super water absorbents for health care (disposable
diapers and bedsheets, sponges, etc.) or horticultural needs. Corn,
potato, and tapioca starches are also used in foods as thickeners, in
textile weaving to protect the yarn, and in paper products as filler or
to add texture and stiffness.
Total U.S. corn wet milling production capacity (generally expressed
in standard bushels - 56 Ib - of corn grind) has increased at about five
percent per year over the last 10 years. Actual production has been
more erratic, however, since the production of different co-products has
varied from minus three percent to greater than nine percent depending
on the different market situations in a given year. The production of
the more traditional co-products (e.g., starch and corn syrup) is expected
to continue to grow at about five percent and production of some other
co-products (e.g., dextrins and dextrose) is expected to stabilize or
decline. The production of MFCS is expected to increase sharply to meet
a shortage as MFCS captures from sugar an increasing share of the soft
drink sweetener market. Depending on government policy, corn wet
milling production of alcohol for gasohol will either increase utilization
of existing capacity or act as an incentive to add new capacity. As the
production of these starch and refined products (especially HFCS and
ethanol) increases, the production of the corn oil and animal feed by-
products will increase correspondingly. The markets for both of these
by-products are essentially unlimited, even though there may be stiff
competition from substitutes.
The starch manufacturing processes emit particulate, sulfur dioxide
and hydrocarbon pollutants to the atmosphere. Sulfur dioxide gas and
hydrocarbon vapors are evolved from the corn wet milling steeping and
steepwater evaporation procedures. In newer plants or processes, sulfur
oxide emissions may be absorbed in a caustic scrubber for recycle use
and emission control. The total annual SCL emissions are estimated at
700 Mg (800 tons). Hydrocarbon emissions have not been adequately
assessed, but are sometimes evidenced as odorous emissions. Odors that
are strong and offensive to neighbors of the plant are frequently incinerated.
Particulate emissions emanate from grain handling operations, grinding
mills, feed, germ, and starch dryers and product transfer to storage or
1-3
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bagging. The total annual parti oil ate emissions are an estimated 2900 Mg
(3200 tons). The dryers for starch, feed, and germ products are the
largest emissions sources. Controlled emissions from a corn wet milling
plant of average size (processing about 2500 m /day - 70,000 bu/day - of
corn) are estimated to be about 55-200 Mg/yr (60-220 tons/yr), 50 Mg/yr
(55 tons/yr), and 6.0 Mg/yr (6.6 tons/yr) from feed, starch, and germ
dryers, respectively. They are typically controlled by a cyclone,
cyclones in series, or a cyclone followed by a low-pressure drop wet
scrubber. These systems have collection efficiencies of 90 to 95+
percent. All other plant operations and some starch dryers have been
equipped with a fabric filter or have been retrofitted with a fabric
filter after an existing cyclone. The estimated control efficiency of
processes using this equipment is 99.9+ percent. There is limited stack
testing data available for dryers or other emission sources.
The present control level for feed dryers may be improved by addition
of a high-efficiency (90+ percent) wet scrubber after the cyclones.
Some plants have significant particulate emissions using only the cyclone
or cyclone/scrubber control methods. Emissions may be reduced with the
addition of a high-efficiency scrubber or a fabric filter.
Most corn wet milling facilities are in compliance with the emission
limitations under State regulations, which are generally in the form of
process weight rate equations. Raw material and product handling
emissions are generally controlled excellently by using fabric filters
with adequate explosion prevention equipment. Germ dryers appear to be
adequately controlled using cyclones due to the large particle size and
relatively low throughputs of the material. Controlled particulate
emissions in 1985 from new starch dryers are estimated, based on very
limited data, to be no greater than 470 Mg/yr (520 tons/yr), or as small
as 20 Mg/yr (20 tons/yr), depending on the prevalence of fabric filters
for product recovery and prevention of explosions in the ambient air.
Production of feed by-products will increase in conjunction with increases
in production of common, modified, and refined starches. Thus, 1985
particulate emissions from new feed drying sources are estimated to be
1800 Mg/yr (2000 tons/yr) if the control techniques currently in use are
still applied, or 910 Mg/yr (1000 tons/yr), if exhaust recirculation is
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applied for energy conservation and is effective in reducing particulate
emissions. The potential emission reduction of a new source performance
standard for animal feed dryers is estimated to be at least 700 Mg/yr
(800 tons/yr) or as much as 1600 Mg/yr (1800 tons/yr), depending on the
process and control technology in use in 1985.
1-5
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2. INTRODUCTION
A study of the starch manufacturing industry was performed in this
survey. The starch industry includes corn wet milling, potato starch,
and wheat milling processes. These are generally classed under standard
industrial classification (SIC) 2046, wet corn milling, by the U.S.
Department of Commerce. The corn wet milling industry is the largest of
these operations producing corn starch, specialty starches, corn syrup,
high fructose corn syrup, animal feed by-products and corn oil. Wheat
milling processes yield animal feed, starch, flour and wheat gluten for
making breads. The potato starch industry manufactures the desirable
cold water soluble potato starch and bulk animal feed.
The goal of this survey was to determine the need for a new source
performance standard (NSPS) for the starch industry. Starch is source
category number 53 out of 59 on the NSPS priority list. The Clean Air
Act (CAA), as amended in 1977, provides authority for the U.S. Environmental
Protection Agency (EPA) to control discharges of airborne pollutants.
The CAA contains several regulatory and enforcement options for control
of airborne emissions from stationary sources. Section 111 of the CAA
calls for issuance of standards of performance for new, modified, or
reconstructed sources which may contribute significantly to air pollution.
The standards must be based on the best demonstrated control technology.
Economic, energy, and non-air environmental impacts of control technology
must be considered in the development of standards.
To determine which processes and pollutants, if any, should be
regulated by national NSPS, the following information has been provided
in this survey:
1. Description of facilities included in source category,
2. Number and location of facilities,
3. Past and current volumes of production and sales, products,
and product uses,
4. Past and future growth trends in the industry,
5. Description of the processing operations and identification of
emission sources,
6. Characterization of emissions from processing operations,
7. Estimation of national emissions from source category,
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8. Identification and description of control techniques currently
used in the industry,
9. Identification of candidate "best systems" of control,
10. Description of state regulations applicable to the source
category, and
11. Preferred methods of sampling and analyzing the pollutants.
Several information sources were used in the development of this
report. Initially, a literature search was conducted to gather background
material on the starch manufacturing industry. This material provided a
basis for futher information gathering in the form of telephone and
letter.contacts with manufacturers engaged in the production of starch
and its co-products. Other individuals knowledgeable about the industry,
regional offices of EPA, and state and local air pollution control
agencies. The trade association for the corn wet millers, the Corn
Refiners Association, was also contacted. Visits were made to five corn,
two wheat, and two potato starch plants, using a variety of process and
control technology.
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3. CONCLUSIONS
The starch (wet corn milling) industry growth rate over the last
10 years has been approximately five percent per year. The soft drink
industry has recently begun to shift from sugar (sucrose) to high-
fructose corn syrup (MFCS) as a sweetener. The demand that could be
generated by the decision to allow MFCS usage in Coca-Cola is alone
greater than present industry MFCS capacity. Even higher capacity may
be needed if a crystallized MFCS is developed as a sugar substitute.
Government policy could favorably swing the economics toward production
of ethanol for gasohol by corn wet millers. Industry experts feel that
raw starch will first be diverted from the production of other co-
products to meet MFCS and alcohol demand before actual increases are
made in the total capacity (corn grind) of corn wet milling. The extent
of diverting raw starch to increase capacity utilization and profits
versus building new capacity will depend on the demand for the various
co-products and the configuration of existing plants. The industry will
most likely increase capacity to handle greater quantities of raw grain.
In addition, starch research and development is pointing out many new
uses for starches in tire manufacturing, biodegradable plastics, and
water absorbents (for horticultural or health care uses, e.g., disposable
diapers). These developments suggest that industry growth over the next
five to 10 years will increase to 15 percent or more per year.
The manufacture of starch from grain (e.g., corn or wheat) or
potatoes has several potentially significant emission sources. Grain
receiving and handling operations can emit significant amounts of particulate
pollutants if not properly controlled. The emissions from grain handling
operations are presently regulated under a new source performance standard
for grain elevators and appeared to be well controlled during survey
plant visits. Most facilities were using fabric filters to prevent
particulate emissions and achieve compliance with opacity regulations.
Starch drying procedures can also be a significant emissions source.
The economics of the industry necessitate efficient product recovery and
energy usage, forcing facilities to employ well designed dryers (especially
the newer flash dryers) equipped with efficient control devices. The
most common control system configurations are cyclones followed by
3-1
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another collector. The secondary collector is generally another cyclone
or a wet scrubber; however, some plants utilize fabric filters that are
protected against explosion hazards.
Feed drying processes at starch manufacturing plants are the other
major source of particulate emissions. The high moisture content of the
hot gases leaving these dryers has prevented control by fabric filter.
In the past these dryers have been controlled by cyclones with some
plants adding a scrubber for further emissions reduction. This operation
probably is best suited to control by a high-efficiency wet scrubber.
Recirculating dryer exhaust gases through dryers connected in series also
reduces emissions.
Particulate emissions test data was found only for starch, feed, or
germ dryers. These sources have been tested to meet state SIP requirements.
The test data indicates that feed dryers are the most significant particulate
emissions sources. The remaining sources of pollutant emissions have
been characterized for state emission inventories by material balance.
The tight control of process operations and product yields maintained
throughout the industry makes this material balance technique reasonably
reliable.
The control technology needed for reducing emissions from the
starch manufacturing industry is readily available. Control techniques
for the starch manufacturing industry are noted below in the order of
the process steps. Grain handling and product storage (bins and silos)
emissions are effectively controlled by small fabric filter modules.
The wet processing operations do not emit particulate pollutants but do
have S02 and hydrocarbon emissions. The limited data available indicate
that these emissions are extremely small. However, potential increases
in alcohol production could generate increased hydrocarbon emissions.
Hydrocarbon vapors from separation are being controlled to some
extent by energy and odor conscious operators who incinerate these
vapors and thus provide heat for drying operations. If greater control
is required, incineration can be augmented or replaced by absorption/adsorption
control. At least one plant is using a caustic scrubber to absorb SC^
emissions from steeping; however, other (older) plants consider capture
and control of steeping emissions to be excessively expensive. Starch
dryer emissions, which have traditionally been controlled by a cyclone or
3-2
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a series of cyclones, can be further reduced by the addition of a scrubber
or fabric filter baghouse. Feed dryers usually have cyclone or cyclone/scrubber
controls installed for abating particulate emissions. Energy conservation
programs have led some facilities to recirculate exhaust gases through
dryers or to operate dryers in series, thereby saving energy and reducing
emissions. Those plants using only cyclone controls may consider the
recirculation technique or high-efficiency scrubbers for emission reduction.
Fabric filters are not used for feed dryers owing to the high moisture
content of the effluent (presenting the likelihood of condensation in
the filter) and possible fire risks.
3-3
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4. DESCRIPTION OF INDUSTRY
4.1 SOURCE CATEGORY
The starch manufacturing industry is basically contained in Standard
Industrial Classification 2046, Wet Corn Milling. This category not
only includes plants manufacturing corn products, but also those manu-
facturing starch from other vegetable sources such as potatoes and
wheat. Plants known to produce starch and by-products from corn, wheat,
or potato are listed in Table's 4-la, b, and c, respectively. Plants
reported to be in the SIC, but which may not manufacture starch or which
may manufacture presumably small quantities of starch products from
undetermined raw materials, are listed in Table 4-ld. The majority of
the 24 corn wet milling operations are located in the Midwest with six
plants in Iowa, five in Illinois, and four in Indiana. Four of the
eight potato starch plants are located in Maine or in the western
states. Wheat starch production is concentrated in Kansas (three of six
reported plants). A list of individuals who are knowledgeable about
some aspect of the industry and were helpful during this survey is given
in Table 4-2.
Of the 54 plants currently listed in the Economic Information
System for SIC 2046, 24 of them employ 20 to 49 workers, nine plants
employ 50 to 99 workers, 12 plants employ 100 to 249 workers, one plant
employs 250 to 499 workers, five plants employ 500 to 999 workers, and
the three largest plants, A.E. Staley (Decatur, Illinois), CPC International
(Argo, Illinois), and Clinton Corn Processing (Clinton, Iowa), employ
1000 to 2499 workers with an average of 1,870 per plant. The total
employment level for SIC 2046 is 12,000.
In 1958, the four largest corn wet milling plants accounted for
approximately 75 percent of the total production and the eight largest
plants accounted for about 92 percent of the total. Currently, about
85 percent of the market is supplied by seven corporations with 19
plants with the largest market share of 24.7 percent being held by CPC
International which has only three plants. A.E. Staley represents
21 percent of the industry with five plants: three corn wet milling
operations and two small potato starch plants.
4-1
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TABLE 4-la. STARCH MANUFACTURING OPERATIONS — CORN
ADM Corn Sweeteners/Archer Daniels Midland
1350 Waconia Avenue S.W.
Cedar Rapids, Iowa 52406
(319) 398-0600
ADM Corn Sweeteners/Archer Daniels Midland
P.O. Box 1470
Decatur, Illinois 62525
(217) 424-5752
Amalgamaize Co., Inc./American Maize Products
Rt. 1 Alabama State Dock Road
Decatur, Alabama 35601
(205) 355-8815
American Maize Products Co.
113th & Indianapolis
Hammond, Indiana 46320
(219) 659-2000
Anheuser Busch, Inc.
2245 Sagamore Parkway
Lafayette, Indiana 47902
(317) 447-6911
Cargill, Inc.
1710 16th Street S.E.
Box 1467
Cedar Rapids, Iowa 52406
(319) 366-3591
Cargill, Inc.
411 N. Cherry
Mt. Pleasant, Iowa 52641
(319) 385-3103
Cargill, Inc.
Milling Division
3201 Needmore Road
Dayton, Ohio 45414
(513) 236-1971
Cargill Nutrena Feeds Division/Cargill, Inc.
4943 Stepherson Road
Memphis, Tennessee 38118
(901) 795-2660
Chemstar Products
McPherson, Kansas
4-2
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TABLE 4-1 a (Cont'd). STARCH MANUFACTURING OPERATIONS -- CORN
Clinton Corn Processing/Standard Brands, Inc.
1251 Beaver Channel Parkway
Clinton, Iowa 52732
(319) 242-1121
Clinton Corn Processing/Standard Brands, Inc.
Montezuma, New York 13117
(315) 776-4811
Colorcon
Indianapolis, Indiana
Corn Sweeteners, Inc./Archer Daniels Midland
900 19th Street
Granite City, Illinois 62040
(618) 452-2746
CPC International
64 & Archer Road
Argo, Illinois 60501
(312) 458-2000
CPC International
Corpus Christi, Texas
(reportedly sold to a petroleum refiner)
CPC International
1300 S. 2nd Street
Box 31
Peking, Illinois 61554
(309) 346-1121
CPC International
1001 Bedford
N. Kansas City, Missouri 64116
(816) 471-8000
CPC International
Stockton, California
(to be on line in 1981)
CPC International
Winston-Salem, North Carolina
(to be on line in 1982)
Dinmitt Corn/Amstar
E. Jones & 7th Streets
Box 169
Dimmitt, Texas 79027
(806) 647-4141
4-3
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TABLE 4-la (Cont'd). STARCH MANUFACTURING OPERATIONS — CORN
Grain Processing Corp./Kent Feeds, Inc.
1600 Oregon
Muscatine, Iowa 52761
(319) 263-1321
Holly Sugar Corp.
100 Chase Stone Center
Colorado Springs, Colorado 80901
Hubinger Company/H.J. Heinz Co.
1005 S. 5th Street
Keokuk, Iowa 52632
(319) 524-4641
Lincoln'Grain Co./General Life Co., Inc.
RR 3
Box 436
Atchison, Kansas 66002
(913) 367-1621
National Starch & Chemical
1515 Drover Street
Box 1084
Indianapolis, Indiana 46206
(317) 635-4455
A.E. Staley Mfg. Co., Inc.
2200 Eldorado
Decatur, Illinois 62525
(217) 423-4411
A.E. Staley Mfg. Co., Inc.
Lafayette, Indiana 47902
(317) 474-5474
A.E. Staley Mfg. Co., Inc.
Morrisville, Pennsylvania 19067
(215) 698-9402
4-4
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TABLE 4-lb. STARCH MANUFACTURING OPERATIONS — WHEAT
Centennial Mills
1464 N.W. Front Avenue
Portland, Oregon 97208
Centennial Mills
Spokane, Washington 99220
Henkel
410 Johnson Street
Keokuk, Iowa 52632
(319) 524-2323
Industrial Grain Products/Olgilvie Mills
Aiken, South Carolina
Midwest Solvents Co., Inc.
1300 Main Street
Atchison, Kansas 66002
(913) 367-1480
4-5
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TABLE 4-lc. STARCH MANUFACTURING OPERATIONS — POTATO
Boise Cascade
Stanfield, Oregon
Colby Cooperative Starch Co.
Water St.
Caribou, Maine 04736
(207) 492-5971
Frenchville Starch
Frenchville, Maine 04745
J.R. Simplot
Heyburn, Idaho 83336
A.E. Staley Mfg. Co., Inc.
Gary Mills
P.O. Box 786
Houlton, Maine 04730
(207) 532-9523
A.E. Staley Mfg. Co., Inc.
N. Washington
Box 911
Monte Vista, Colorado 81144
(303) 852-2412
Stein Hall & Co./National Starch and Chemical
Burleigh Street
Island Falls, Maine 04747
(207) 463-2288
Western Starch/Western Polymer
P.O. Box 488
Tulelake, California 96134
(916) 667-2269
4-6
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TABLE 4-ld. STARCH MANUFACTURING OPERATIONS -- TYPE UNCERTAIN
Adolph Coors Co.
Golden, Colorado 80401
ADM Corn Sweeteners/Archer Daniels Midland
Peoria, Illinois
American Maize Products
1602 16th Street
Central City, Nebraska 68826
(308) 324-5036
Anheuser Busch, Inc.
700 Edwards Avenue
New Orleans, Louisiana 70123
(504) 733-6740
Ashland Roller Mills
Highway 1 N.
Ashland, Virginia 23005
(804) 798-8329
Blue Magic of N.C. Inc.
509 South Lodge
Wilson, North Carolina 27893
(919) 237-3107
Boone Valley Co-Op
N. Commercial Street
Eagle Grove, Iowa 50533
Burrus Mills/Cargill, Inc.
2525 N. Field
Dallas, Texas 75215
(214) 748-5947
California Milling Corp.
Los Angeles, California 90055
Cargill, Inc.
Rt. 3
Grinnell, Iowa 50112
(515) 236-3522
Coeval, Inc.
St. Joseph, Illinois 61873
(217) 469-2213
Conagra, Inc.
Omaha, Nebraska 68108
4-7
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TABLE 4-ld (Cont'd). STARCH MANUFACTURING OPERATIONS
TYPE UNCERTAIN
Cre Mel Co., Inc.
1504 Forestdale Boulevard
Birmingham, Alabama 35214
(205) 798-6056
De Kalb Ag. Research, Inc.
1101 Darlington Avenue
Box 683
Crawfordsvill, Indiana 47933
(317) 362-2104
Dekalb Agresearch, Inc.
P.O. BDX 847
Sikeston, Missouri 63801
(314) 471-6995
Faultless Starch/Bon Ami Co.
1025 W. 8th Street
Kansas City, Missouri 64101
Gem, Inc.
Gem Boulevard
Byhalla, Mississippi 38611
Great Western Sugar Co./Hunt International Resources
9501 Southview Avenue
Brookfield, Illinois 60513
(312) HU5-2050
International Multifoods Corp.
Minneapolis, Minnesota 55440
Krause Milling Co.
Milwaukee, Wisconsin 53201
Johns Manville
Virginia
Marschall Division
Granite City, Illinois 62040
W.O. McCurdy & Sons
Fremont, Iowa 52561
(515) 933-4292
Menan Starch
P.O. Box Drawer N
Moses Lake, Washington 98837
(509) 765-1803
4-8
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TABLE 4-ld (Cont'd). STARCH MANUFACTURING OPERATIONS
TYPE UNCERTAIN
P.O. Mitchell & Brother, Inc.
Perryman, Maryland 21130
Moews Seed Co.
P.O. Box 214
Granville, Illinois 61326
(815) 339-2201
Monahan Co.
202 N. Oak Street
Arcola, Illinois 61910
(217) 268-4955
National Starch & Chemical
735 Battery
San Francisco, California 94111
(415) 981-1630
Olympic Corn Products, Inc.
No. 605 Fancher
Box 3627
Spokane, Washington 99220
(509) 535-0321
Pacific Resins & Chemicals, Inc.
1754 Thome Road
Tacoma, Washington 98421
Phil brick Starch Co.
Limestone, Maine 04750
(207) 325-3071
Pioneer Hibred Corn
816 N. Main Street
Princeton, Illinois 61356
(815) 875-2845
J.R. Short Milling Co.
Chicago, Illinois 60658
Unilever United States, Inc.
10 E. 53rd Street
New York, New York 10007
Union Oil Mill, Inc.
West Monroe, Louisiana 71291
4-9
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TABLE 4-Id (Cont'd). STARCH MANUFACTURING OPERATIONS
TYPE UNKNOWN
Univar Corp.
1600 Norton Building
Seattle, Washington 98104
Valley Lea Dairies, Inc.
South Bend, Indiana 46624
X Way Milling Co.
Rt. 1
Box 89
Laurinburg, North Carolina 28352
(919) 276-3488
4-10
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TABLE 4-2. LIST OF CONTACTS
Name
Affiliation
Phone Number
Allen, Jerry
Anderson, Lori
Brenner, Kyd
Erickson, Keith
Fink, Bob
Flowers, Eric
Glenn, Brian
Gorman, Paul
Gray, Fred
Hagroan, Bob
Harris, Paul
Hayward, Michael
Jobias, Dick
Keim, Carroll
Larson, Richard
Lewis, Dennis
Miller, Dwight
Pavlovich, James
Reape, Patty
Seitz, David
Selby, Roger
Snell, Russ
Tomevi, Gary
Willard, Wayne
Wells, Rofi
Wilson, Diane
A.E. Staley Mfg. Co., Inc.
Potato Promotion Board
Corn Refiners Association
Linn County (Cedar Rapids),
Iowa Health Dept.
Proctor & Schwartz, Inc.
(Dryers)
Tenn., Div. of Air Pollution
Control
Barr-Murphy, Ltd. (Dryers)
Midwest Research Institute
USDA (Sugars & Sweeteners)
Dedert Corp. (Dryers)
American Maize Products Co.
Iowa Dept. of Environmental
Quality
CE Raymond (Flash Dryers)
Carroll R. Keim Consultants,
Inc.
First Manhattan Co.
CE Raymond (Dryers)
USDA, Northern Regional
Branch Center
American Maize Products Co.
U.S. EPA Region V
Hammond Air Pollution Control
Flex Kleen (Baghouses)
CPC International
National Starch & Chemical
Company
Carter Day, R&D (Baghouses)
Hubinger Company
U.S. Dept. of Commerce
(SIC 2046)
(217) 423-4411
(303) 758-7783
(203) 331-1634
(310) 741-3931
(312) 358-5262
(615) 741-3931
(514) 337-9160
(816) 753-7600
(202) 447-7290
(312) 754-4690
(219) 659-2000
(515) 281-8853
(312) 236-4044
(203) 324-4366
(212) 949-8070
(312) 236-4044
(309) 685-4011
(219) 659-2000
(312) 353-2259
(219) 853-6306
(312) 648-5300
(312) 458-2000
(201) 685-5208
(612) 571-1000
(319) 52A-4151
(202) 377-4793
4-11
-------
Products manufactured by the corn wet milling process include
starch, corn syrups, corn oil, and animal feeds. There are four kinds
of commercial corn starch: unmodified, modified, oxidized, and dextrin.
Unmodified or common starch is the most widely utilized and its uses
include paper coating and sizing, adhesives, salad dressing, beers,
canned fruit, dry food mixes, and laundry starch. Starch may be modified
with acids or other chemicals in conjunction with heat treatments to
alter the starch characteristics. After acid modification, which reduces
viscosity, the starch is used mostly for sizing in the textile industry
and in starch-based gums. Starch also can be oxidized to reduce viscosity.
Oxidized starch is used by the paper industry and as an adhesives component.
Dextrins can be produced by cooking unmodified starch. The three different
kinds of dextrin vary in solubility and are used in pastes and adhesives.
Two-fifths of the corn starch produced is sold as corn starch, the
remaining three-fifths is converted into other products such as sweeteners.
There are five types of nutritive sweeteners made from starch which
include: (1) four grades of corn syrup (including high-fructose corn
syrup), (2) dried corn syrup, (3) maltodextrin, (4) dextrose monohydrate,
and (5) dextrose anhydrous. The major application of corn syrups, besides
MFCS, is confectionary. All of these sweeteners are used in a variety
of food products such as bakery goods, beverages, jellies, breakfast
food, liqueurs, fruit drinks, canned foods, salad dressings, sauces, and
syrups. Dextrose also can be used in the pharmaceutical, fermentation,
and chemical industries.
Two by-product groups of the corn wet milling process are animal
feeds and corn oil. There are four main feed products: (1) corn gluten
feed, which is composed of the bran and fibrous portions of the corn
kernel in combination with the starch and protein fractions not recovered
in the primary separation process; (2) corn gluten meal, which consists
of insoluble protein (gluten) separated in the corn wet milling process
in combination with minimal quantities of starch and fibrous fractions
not recovered in the primary separation process; (3) corn germ meal,
which is obtained from the corn germ fraction after the corn oil has
been removed; and (4) condensed fermented corn extractives, commonly
known as corn steepwater which consists of the soluble portions of the
4-12
-------
corn kernel, removed by the steeping process and concentrated to high
n
solids. The corn oil which is extracted from the germ is used, with or
without refining, in foods for human consumption.
4.2 INDUSTRY PRODUCTION
Corn wet milling lends itself to large scale production because of
the wide variety of food and industrial products obtained from one raw
material. In 1S70, the corn wet milling industry processed 125 million
bushels of shelled corn while in 1977 they processed almost 375 million
bushels. This amount represents about 10 percent of all corn sold on
the cash market (which is about one-half to two-thirds of the corn
grown). The cost of purchasing this quantity of raw materials may be
as high as 70 percent of the total cost of manufacturing starch and its
related products. In order to keep corn demand in line with increasing
production by farmers, industrial uses for corn must double in the near
future.5'6
During the 1950's and 1960's, corn starch shipments averaged 6 kg
(14 Ib) for each bushel* of corn processed. With current milling practices
which attain 98 percent recovery, the same 25 kg (56 Ib) standard bushel
of corn will yield approximately 15 kg (34 Ib) of starch, 1.0 kg (2 Ib)
of oil, and 5.9 kg (13 Ib) of feed. Full use must be made of all corn
wet milling by-products to make the process economically feasible and the
co-products must be relatively inexpensive to be competitive for general
industrial uses.
Shipments of the majority of the wet corn milling products increased
between 1963 and 1977 (see Table 4-3). According to the 1977 Census of
o
Manufacturers, the value of all wet corn milling products shipped from
38 plants was $1.9 billion. These figures for SIC 2046 include starch
products manufactured from vegetables other than corn. These other
starches (primarily wheat, potato, and tapioca) are used similarly to
corn starch in a variety of applications. The manufacture of all non-
corn starches decreased between 1972 and 1977 when shipments totaled
71 million kg (156 million Ib) with a value of $32 million.
*The corn wet milling industry defines a standard bushel as a quantity
of corn weighing about 25.4 kg (exactly 56 Ib).
4-13
-------
TABLE 4-3. QUANTITY AND VALUE OF SHIPMENTS BY ALL PRODUCERS IN WET CORN
MILLING INDUSTRY (SIC 2046), 1963-77*8
Quantity
Product (000,000 lb)
ALL VIET CORN MILLING TOTAL
Glucose syrup (corn syrup).
unmixed:
Type I (20 dextrose
equivalent up to 38)
Type II (33 dextrose
equivalent up to 58)
Type III (58 dextrose
equivalent up to 73)
Type IV (73 dextrose
equivalent and above:
High fructose corn
syrup
All other Type IV
Glucose syrup solids (dried
glucose syrup)
Dextrose monohydrate and
dextrose anhydrous
ranufactured starch:
Corn starch, including milo
Other starch, including
Irish potato, wheat, rice,
etc.
Dextrin (corn, tapioca, and
other)
Corn Oi 1 :
Crude "^
Once-refined V
Fully refined, including I
nargarine oil J
Wet process corn by-products:
Steepwater concentrate (50
percent solids basis)
Corn gluten feed
Corn gluten meal
Other wet process corn
by-products
Other wet com milling
products, n.s.k. . typically
for establishments with 15
employees or more (see
note)
Other wet corn milling
products, n.s.k., typically
for establishments with less
than 16 employees (see note)
(x)
207.7
2980.5
1175.5
•
3202.9
207.9
154.5
1266.7
5486.4
156.4
138.0
i/
135.5
4199.8
905.2
1564.0
(x)
(x)
1977
Value
($000,000)
1938.6
12.7
160.5
72.4
250. 5~)
12.3J
25.6
138.6
408.2
32.2
25.2
325.1
4.1
226.6
113.0
117.9
7.3
6.4
1972 1967 1953
Quantity Value Quantity Value Quantity Value
(000,000 lb) ($000,000) (000,000 lb) ($000,000) (000,000 lb) ($000,200)
(x) 786.7 (x) 646.6 (x) 547.2
385.2 14.4 210.5 10.5 89.4 4.5
1592.6 60.2 1598.0 74.9 1328.9 66.5
^
1630.4 68.1 871.4 43.2
843.0 42.5
519.9 22.4 60.6 2.8
84.2 7.8 127.1 10.4 110.4 3.8
1349.5 92.1 1227.9 81.6 1093.6 71.5
3588.3 208.8 3119.0 199.5 2565.1 '77.3
185.5 20.9 121.3 11.0 235.4 17.9
83.3 11.5 168.7 16.0 118.9 9.9
a/ 84.9 a/ 76.4 a/ 60.9
99.8 2.3 78.0 1.5 42.7 1.0
3050.8 76.4 2365.9 55.1 1316.8 27.4
783.0 51.3 875.2 36.6 1078.2 33.3
1076.0 50.5 341.4 16.9 N/A 17.2
(x) 13.4 (x) 9.9
(x) 8.6
\*/
(x) 1.7 (x) 0.3
-/Quantity data are withheld due to duplication arising from shipments between establishments in the same industry classification.
•Total shipments including interplant transfers.
4-14
-------
Corn starch production in 1977 totaled 2.5 billion kg (5.5 billion
Ib) at a value of nearly $410 million. Corn starch production increased
slightly from 1.4 billion kg (3.1 billion Ibs) in 1967 to 1.6 billion kg
(3.6 billion Ib) in 1972 and then increased nearly 900 million kg
(1.9 billion Ib) to 2.5 billion kg (5.5 billion Ib) between 1972 and
1977.8
Prior to 1969, from 450 to 680 million kg/yr (1 to 1.5 billion
Ib/yr) of starch were sold to the paper and related industries and
approximately 160 to 180 million kg/yr (350 to 400 million Ib/yr) to
Q
each of the food and textile industries. While the amounts sold to the
paper and food industries have increased, the amount sold to the textile
industry decreased to approximately 125 million kg/yr (275 million
Ib/yr) between 1972 and 1976. During 1969, 85 percent of the starch
produced was used for industrial uses, with 10 percent for food processing
industry uses and 5 percent for exportation. By 1977, over 80 percent
of all corn starch-based products (starches and syrups) have gone to the
4
food processing industry.
Increases in production of corn syrup and corn sugar continued
until 1972; thereafter production declined. In 1977, corn syrup production
totaled 3.6 billion kg (7.9 billion Ib) with a value of $534 million.
Between 1972 and 1977, high-fructose corn syrup production increased
substantially. In 1977, more high-fructose corn syrup (MFCS)
(1.5 billion kg (3.2 billion Ib)) was produced than the quantity of any
of the other three major types of corn syrup. The amount of dextrose
produced in 1977 was 570 million kg (1.2 billion Ib) with a value of
$139 million. Although the quantity of corn oil produced is undetermined,
the value was $325 million in 1977. From 1972 to 1977, the value of
corn oil increased from 11 to 17 percent of the total value of corn wet
Q
milling products.
Other wet process corn by-products, such as gluten feed and gluten
meal, totaled 3 billion kg (nearly 7 billion Ib). The value of the
shipments was $462 million. Shipments of animal feed by-products increased
by more than 600 million kg (1.3 billion Ib) between 1967 and 1972 and
by about 8QO million kg (1.8 billion Ib) between 1972 and 1977. These
increases amount to over 36 percent over each five-year period or an
annual growth rate of over six percent. Gluten feed production alone
4-15
-------
increased from approximately 1.4 to 1.9 billion kg C3 to 4 billion Ib)
over the period from 1967 to 1977. This greatly increased (nearly 38
percent over the five-year period) gluten feed production was accompanied
o
by a much smaller increase (about 16 percent) in gluten meal production.
Currently, the U.S. is importing starch and starch derivatives.
Eighty percent of all starch imports in 1960 to 1965 were tapioca starch,
as approximately 136 million kg/yr (300 million Ib/yr) was imported from
o
Brazil and Thailand. Dextrin, dextrose, dextrose syrup, and related
products also are imported, primarily from the Netherlands.
Exports of corn wet milling products have fluctuated over the past
20 years with a decrease in the early 1960's brought about by modernization
' 12
and expansion of plants in foreign countries. However, in 1977-78,
exports of corn wet milled feed products rose from 1.3 billion kg (2.9
billion Ib) in 1976-77 to 1.6 billion kg (3.5 billion Ib). This rise
was accompanied by a decrease in the export of substitutes such as
prepared feed and alfalfa and grain by-products which fell 3.1 billion
kg (6.8 billion Ib) in 1976-77 and 2.8 billion kg (6.2 billion Ib) in
1977-78. Currently, the European Economic Community is the recipient of
97 percent of all annual corn wet milling industry exports. In 1950,
the principal importer was Canada.
Employment and economic statistics for the wet corn milling industry
(SIC 2046) from 1958 to 1977 are given in Table 4-4. These data were
Q
compiled from the Census of Manufacturers and the Annual Survey of
14
Manufacturers and give general industry trends. Specific plant capacity
and product information is currently unavailable.
The projected production figures for each major co-product are
presented in Table 4-5. Historical production trends and projections of
future production were estimated based on information from industry
15 ?1
experts. In general, total U.S. corn wet milling production capacity
(usually expressed in standard bushels - 56 Ib - of corn grind) has
increased at about 5 percent per year over the last 10 years. Production
levels have been erratic, as the production of the different co-products
have varied from minus three percent to greater than nine percent over
the same time period, with greater variations depending on the different
4-16
-------
TABLE 4-4. GENERAL STATISTICS FOR CORNftWET MILLING
INDUSTRY (SIC 2046) 1958-77°'1H
All Employees
Number Payrol 1
(000) (5000,000)
1977 Census
1976 ASM3/
1975 ASM3/
1974 ASM5/
1973 ASH3/
1972 Census
1971 ASK3/
1970 ASM3/
1969 ASM3/
1968 ASM*-7
1967 Census
1966 ASM3/
3965 ASM3/
1964 ASM3/
1963 Census
1962 ASM3/
1961 ASM3/
1960 ASM3/
1959 ASM3/
1958 Census^/
10.8
11.0
10.9
11.1
11.7
12.1
13.0
13.5
13.5
14.1
14.1
13.9
12.9
12.5
13.2
13.9
13.9
13.7
13.3
13.8
189.2
179.8
162.9
151.4
143.7
137.7
134.0
143.9
129.8
120.1
116.1
106.6
98.4
95.3
89.7
91.8
87.4
83.2
79.5
78.8
Production Workers
Number Wages
(000) ($000,000)
7.7
8.0
7.9
7.7
8.2
8.4
9.0
9.3
9.4
9.9
9.8
9.9
9.3
9.2
9.8
10.2
10.3
10.1
7.9
10.4
131.0
126.1
112.7
92.5
94.1
88.6
86.7
89.3
82.2
78.4
75.2
73.6
70.3
66.0
65.3
63.0
60.2
57.2
55.6
56.3
Cost of
Materials
(SOOO.COO)
1322.2
1352.4
1274.8
1197.5
768.9
498.7
475.7
460.7
436.4
396.5
401.7
417.7
382.1
345.1
335.3
321.2
307.7
286.3
293.6
282.0
Value
Added 3y
Manufacture
(SOOO.OCO)
658.0
650.2
872.9
673.4
359.7
331.2
328.4
373.5
395.9
382.8
353.6
346.6
302.7
291.8
290.9
277.1
282.3
277.6
262.2
249.4
Value of
S'nioments
(3000,000)
1990.7
2002.5
2141.7
1852.1
1123.0
832.3
807.3
830.5
828.5
781.1
751.3
755.3
679.9
629.5
622.4
602.0
584.7
566.4
557.8
528.5
Capital
Expenditures
.'Jew
(3000,000)
223.8
164.7
157.8
82.1
67.3
59.7
35.8
4C.5
35.2
40.4
40.5
43.7
17.7
47.9
26.1
28.1
33.9
27.0
25.0
18.1
-'Based on a representative sample of establishments canvassed in the annual survey of manufacturers (ASM). These estimates may
differ from the results of a complete canvass of all manufacturing establishments. ASM publication shows percentage standard
errors. The percentage standard errors of the 1966/1965 relatives for employment and value added were 1 and 1, respectively.
-'Data prior to 1958 appear in Volume II, 1963 Census of Manufacturers, in Table 1 of the chapter devoted to this industry.
4-17
-------
TABLE 4-5. PROJECTED PRODUCTION OF CORN WET MILLING (109 lbs/yr)a
Product
Starches
Glucose (corn syrup)
Dextrose
High-Fructose Corn Syrup
(MFCS):
42% fructose
55% fructose
f Ethanol (alcohol)
oo
1980
4.5
5.0
1.5
3.0
1.6
0.2
1981
4.7
5.2
1.5
3.1
2.0
3.3
1982
5.0
5.5
1.5
3.2
2.6
5.1
1983
5.2
5.8
1.5
3.3
3.4
6.4
1984
5.5
6.1
1.5
3.4
4.5
8.0
1985
5.7
6.4
1.5
3.5
5.8
10.0
Remarks
Estimated 5%/yr growth rate
Estimated 5%/yr growth rate
Estimated 5%/yr growth rate
Expected to approachgmarket
saturation of ~ 10x10 Ibs by
1985
Estimated 4%/yr growth rate
Estimated 30%/yr growth rate
Estimated planned increases
through 1982, followed by
25%/yr growth rate
Total Starch & Refined
Products 15.8 19.8 22.9 25.6 29.0 32.9
Animal Feeds (gluten
feed, gluten meal,
germ meal) 7.2 8.9 10.3 11.5 13.0 14.8
Estimated as equal to 0.45 times
the Total Starch and Refined
Products
Total of Major Products 23.0
28.7
33.2
37.1
42.0
47.7
Total Grind — Millions
of Bushels of Corn Per
Year 500
620
720
810
910
1000
Estimated from 56 Ib standard
bushel containing 15.5% hLO &
98% (dry) product recovery
(i.e., 46 Ib total products/bu)
aBased on estimated current production and expected growth trends according to industry experts.
-------
market situations in any given year. While the production of the major
co-products (e.g., starch and corn syrup) is expected to continue to
grow at a rate of approximately five percent, production of other products
(e.g., dextrins and dextrose) is expected to stabilize or decline.
During the past 20 years there has been a dramatic change in the
whole corn wet milling industry brought about by new technologies and
new products. The new product that has had the greatest impact on the
industry is high-fructose corn syrup. The bulk of the 20th century
sweetener consumption was primarily sucrose from sugarcane and sugar
beets. In 1958, a shortage of sugar and other sweeteners as well as the
development of new corn syrup manufacturing processes created a surge in
corn syrup demand. The use of these high technology specialty syrups
continued to rise, thereby broadening the base for corn syrups in the
food industry. Around 1970, the introduction of HFCS created a new
surge in corn syrup sales in response to a severe sugar shortage. Since
55 percent fructose HFCS is virtually identical to sugar syrups, its
introduction has created substantial competition in the sweeteners
market, which has helped to keep sweetener prices down. In 1974, the
domestic consumption of sugar was 9.9 billion kg (22 billion Ib), while
in 1979 the consumption was 9.6 billion kg (21 billion Ib) with
771 million kg (1.7 billion Ib) of HFCS being consumed. Recently, the
sales of HFCS have been temporarily slowed by unrealistically low sugar
prices, but the use of HFCS will continue to rise steadily. In the long
run, HFCS will bring vast changes in two major crop economies and two
major food industries, sugar and corn wet milling.
Since the introduction of HFCS, corn processors have had a production
capacity of about 450 million kg (1 billion Ib) which is not enough to
supply all of the soft drink bottlers demands during a sugar shortage.
The capacity rate is expected to increase to 1.8 to 3.6 billion kg/yr
(4 to 8 billion Ibs/yr) in the 1980's and 4 to 4.5 billion kg/yr (9 to
10 billion Ib/yr) in the 1990's.22
By 1985, HFCS is expected to comprise one-third of the food and
beverage sweeteners. The industry experts contacted expect the market
for 55 percent HFCS to increase sharply as additional soft drink manufacturers
allow it to be used in their products. It is anticipated that HFCS will
have replaced sugar in all available liquid applications by about 1985.
4-19
-------
After 1985, growth is expected to approximate sugar's current growth
trends and level off at approximately five percent per year. Corn syrup
(glucose) production is expected to grow at slightly lower rates as MFCS
usage increases. Expansion of plant capacity to meet the MFCS demand
will continue at a slow rate because HFCS production is capital intensive.
The economics of production are also influenced by operating rates, and
the cost of energy, enzymes, and labor.
A second new production technology that will be undertaken by the
corn wet milling industry is the production of alcohol for gasohol. As
petroleum prices, energy demands for liquid fuels, pollution abatement
costs, and need? for rural assistance increase, alcohol (ethanol),
production will be developed. Production costs are highly dependent on
grain prices, conversion costs, and product value; however, as the
difference between gasohol and oil prices lessen, many plants will turn
to gasohol production to utilize excess grind (capacity) during reduced
demand for other products. Any new wet-mi 11 ing facilities constructed
primarily for alcohol production would be dependent upon government
policy; however, for the purposes of this study, a median growth scenario
was used.
The projected product growth rates would lead to a doubling of
total (grind) capacity by 1985 (see Table 4-5). The production of feed
and oil by-products will increase proportionally with increases in total
grind; however, the available markets for feed by-products are much
greater than for the other co-products and are continuing to grow with
an increased domestic demand for high-protein feed. In the past, the
biggest supplier of feed has been soybean meal which is a by-product of
the soybean oil industry. While soybean meal continues to hold the
largest market share, gluten meal and gluten feed use in pet, poultry,
and dairy food also has increased. Steepwater concentrates are also
being used as a protein additive.
Corn oil has sold at a premium on the retail market for years with
40 to 50 percent of total production being used for salads and frying,
and 30 to 35 percent being used for margarine. Currently, the soybean
industry produces 80 percent of the oil sold in the vegetable oil market.
Before a noticeable change in this market share would occur, there would
4-20
-------
have to be a significant increase in the price of soybeans. However,
demand for corn oil will continue to be strong, even if soybean oil
supply and prices remain the same. Thus, there will be no problem
marketing the increased supply of corn oil due to production of MFCS and
alcohol.23
The projected increase in total corn wet milling brought about by
increased production of starch and refined starch products will probably
result in 10 to 20 new plants or major modifications by 1985. Construction
of several new plants and several major modifications has been announced
or commenced. These new facilities generally include MFCS and/or alcohol
capacity. Other similar facilities presently are being considered.
Several recent or potential applications may also increase demand
for starch products in the longer-term future. Some of these products
are currently on the market while others are possible improvements on
current products or new products under development. During the 1960's,
the starch manufacturing segment of the industry developed new starch
derivatives to counteract the maturing of the traditionally large markets
in paper, textiles, and corrugating. These new starch derivatives are
low cost stabilizers and thickeners and are used extensively in the
newly engineered food products industry.
There has been expanded use of new products in the traditional
industries such as paper. For example, adding starch as a temporary
wet-strength agent allows repulping of treated paper, thereby decreasing
energy requirements. Also, starch is an excellent replacement for
petroleum-based polyols in the manufacture of rigid urethane forms since
modified starch has flame retardant properties. The manufacture of
plastics may become more economical while producing biodegradable products
by using starch as a filler. Using starch in plastics allows the plastics
to decompose and can shorten the time needed for biodegradation to one
year; such plastics also do not release toxic substances when burned as
petroleum-based plastics do. It can replace 30 percent of the nonrenewable
oil and gas currently used in plastics while cutting industry costs.
The rubber industry has used common starch as a reinforcement agent
partially replacing carbon black. The addition of starch also allows
4-21
-------
the rubber to be handled in a powdered form. Thus, rubber slabs, which
have high energy consumption and transportation costs, are not required.
A new development for the use of common starch is the manufacture
of a graft polymer capable of absorbing up to 1400 times its weight in
water. This property makes it an unusually versatile agent for prevention
of soil erosion, as an absorbent in diapers and bed pads, or as a moisture-
retention coating for agricultural purposes. It is also nontoxic,
25 ?fi
nonmutagenic, and biodegradable. '
A final new use for starch has been developed to remove metals from
water. By mixing a starch compound which does not dissolve in water
with water-containing metals, the charged metal ions are drawn to the
starch to form a sludge. The metal and starch are then removed by
nitric acid.
oo oq
4.3 PROCESS DESCRIPTION '
4.3.1 Corn Wet Milling30"33
The objective of the wet milling process (see Figure 4-1) is to
provide as complete a separation of the corn kernel components as possible
and practical. A corn kernel contains a germ (oil-rich center) surrounded
by starch (carbohydrate) and gluten (protein-rich) which are enclosed
within a fibrous hull. The large differences in the density of the
components provide for relatively easy separation.
The corn kernels are steeped (soaked) in water with sulfur dioxide
Q)* prior to wet milling. The sulfur dioxide prevents putrefaction
during steeping and aids in the swelling and dispersion of the protein.
The mixture is steeped for 30 to 50 hours at about 10°C (50°F).35 The
softened kernels are then coarsely ground in a cracking mi 11 ©freeing
the components from the hull. The first grind material is sent to
hydroclone separators(4)where the lighter germ is removed. The germ is
dried©and sold or processed into corn oil or corn germ meal (an animal
feed). The heavier hull, gluten, and starch fractions are sent through
a second, more thorough, milling procedure©to obtain free starch. The
fiber is separated from the starch by screening®. Water is removed
*Numbers in circles throughout corn wet milling process description
refer to steps in Figure 4-1, the process flow diagram, marked with
the same circled number.
4-22
-------
Shelled Corn
r
1
1 (T)
Steep Water Evaporation\^/
1
— Steepwater Concentrate
Corn C
©
Xl^teep
Degermi na
^—'Hydroclone
leaners-^ILoadout Emissions |
Tanks — > SO, Vapor
Fresh HjO
tor Hills(^2J
®1
,»K«I =wu. ^ -=.... Dryer — > Dust and Vapor
Starch, Gluten, Feed
ST\
Grinding Hills'
Washing Screens
I (a:
Centrifugal Separators
Oil Extraction
Germ Heal Corn 011
FeedN~-x GlutefC
• Slurry Starch
[Dust and Vapors\*— Dryers Dryers >JDust and Vapors)
-To Refining
— Acid or
Acid/Enzymes
Gluten Feed Gluten Meal
I OustL Dryer
Dextrose
Acid Roasting
ArU . -, >
Amines
Oxidation
^_^ Cookl ng
/T0\
Co
St«
no\
Dry Starch
Evaporation
DextrinsVi3/ Modified Stard
I
I Dust(-4 Dryer
CommorT Clarifler
Corn
Enzymes->
425 Fructose'
Ion-exchange ->
Resins
552 Fructose
Ion-exchange•
Resins
Storage and
Bagging-^
Storage and Storage and
-Bagging
Bagging-
90S FructoseV
Clarifier
I
HFCS
Figure 4-1. Corn wet milling process flow diagram.
4-23
-------
from the fiber @> which may be pressed into pellets or sold as bulk
animal feed (.corn gluten feed, 21 percent protein). Concentrated
steepwater(Dmay be added to the fiber or the germ meal to increase
protein content.
The fiber-free mixture of protein-rich gluten and starch is known
as mill starch @. The low-density gluten (1.1 specific gravity) is
separated from starch (1.5 specific gravity) in a centrifugal separation©.
The gluten is dewatered and dried. Starch is used to produce common
starch or diverted into processing streams for the manufacture of dextrin,
modified starches, refined corn products, or alcohol.
Common starchQj) is dried and prepared for use in foods or industry.
Both food-grade and industrial starches may be cooked for various time,
temperature, and agitation patterns in order to swell the starch granules
by breaking hydrogen bonds. Several characteristics such as viscosity
or gelatinization, can be modified by cooking; however, very good process
control is required to obtain specific characteristics. The preparation
and handling of food-grade starch must meet hygienic standards of the
Food and Drug Administration. Common corn starch is dried, sized, and
bagged, boxed, or shipped in bulk for use in foods or by industry,
primarily in the production of textiles and paper.
Dextrins Qj) are produced from dewatered common starch by
dry-heating or roasting the unmodified starch with an acid or alkaline
catalyst. The dry starch (five to seven percent moisture) is heated
with the catalyst in an agitated vessel. This process disrupts the
integrity of the starch granule allowing dextrins, which are later
suspended in water and reheated, to "peel" into layers. This process
QC
changes the viscosity and cold water solubility of the dextrins. The
degree of "peeling" of the dextrin determines whether it will be used
for adhesives, gums, or in gels.
Modified starches © are produced by acid or amine modification or
by oxidation of the common starch. The prime starch slurry is reacted
with the appropriate reagent to produce a modified starch with the
desired properties. The acid or amine modified starches possess firm
gelling properties which make them useful to confectioners for gum
4-24
-------
candies or to textile manufacturers as warp sizes, i.e., yarn adhesive
binders protecting the fibers during weaving. Oxidized starches have
high solids content with low viscosity. They are very useful in the
paper industry in tub, size press, and calendar size operations. In
37
addition, oxidized starches find uses in the food and textile industry.
Refined corn products @ - glucose (corn) syrup (which is actually
high-dextrose syrup) and high-fructose corn syrup - are produced by the
32
acid/enzyme conversion of prime starch. A colloidal starch solution
is reacted in a pressurized, heated converter vessel with acid or
acid/enzyme reagents at pH 2. The acid or acid/enzyme reaction breaks
down the starch molecule into the simple sugars, dextrose Q_§) and maltose.
The reaction is terminated by releasing the vessel pressure and neutral-
izing the liquor. The corn syrup (]j) is clarified to remove solids,
decolorized, and concentrated. If high-fructose corn syrup (MFCS) is
being made, the dextrose solution is further treated enzymatically,
producing a first generation (42 percent fructose) fructose/dextrose
syrup (£§). This 42 percent fructose syrup can be passed over ion-
exchange resins to concentrateQj) the solution to approximately
55 percent fructose (second generation MFCS). For specific market
purposes, the fructose concentration may be brought to as high as 90
percent (jj) for market purposes. The MFCS is clarified in the same
manner as regular corn syrup. These syrups have numerous uses in the
34
food and soft drink industries.
The corn wet milling industry is presently producing a limited
amount of ethyl alcohol by fermentation of the prime starch slurry.
Ethanol is distilled from the solution after the enzymatic reaction on
the slurry is completed. The economics of the procedure are difficult
to calculate precisely, therefore, the industry is proceeding cautiously
into this market. If the price of gasoline continues to rise, it is
expected that alcohol production will increase with more favorable
economics. Government policy regarding alcohol for gasohol production
will probably be a major factor in the economics.
The process flow diagram for corn wet milling points out the
sources of atmospheric emissions. There can be sulfur dioxide and
odorous vapor emissions from the steeping tanks and the feed, gluten,
4-25
-------
and germ dryers. Particulate emissions emanate from the loading and
storage sites and the numerous product dryers.
4.3.2 Wheat Starch28'38
Wheat starch can be used interchangeably with corn starch for most
applications; however, it is not as economic to modify wheat starch for
many uses as it is with corn or potato starch. Wheat starch may be
manufactured by several different processes. The preparation of starch
from wheat is one of the oldest starch manufacturing processes. The
early starch operations were interested only in the starch without
regard for the protein-rich gluten. The wheat was steeped to soften the
grain which was crushed and then fermented to destroy the gluten. The
starch was recovered and dried for sale. Today, the recovery of wheat
gluten is extremely important. It is used as a high-protein supplement
in baked goods and flour, adding protein without much flavor or odor.
Approximately 56 to 68 million kg (125 to 150 million Ibs) of wheat
starch are manufactured every year. This comprises 60 to 70 percent of
wheat manufacturing products, the other 12 to 16 percent is gluten, 6 to
9 percent process water solids, and 8 percent fiber.
The wheat gluten may be recovered through several procedures. The
Martin process involves grinding the dry wheat grain into flour, then
forming a stiff dough containing about 40 percent water. The hydrated
dough is then rolled between fluted rollers or kneaded in a trough with
water sprays to wash away the starch. Gluten and starch are dried
separately, bagged, and sold. The alkali process extracts wheat protein
from the flour using a 0.03 normal sodium hydroxide solution. Gluten
can also be obtained through the slack dough or batter process, either a
traditional process or a modified one such as the Raisio process. A
batter or slack dough is mixed by adding water to wheat flour. The
batter is then mechanically broken up while water is added to wash away
28
the starch. Gluten is recovered as fine curds. Starch liquor also is
recovered, evaporated, and dried. A generalized process flow diagram is
presented in Figure 4-2. Although handling and dry milling of wheat and
product handling can generate particulate emissions, the major emissions
from wheat starch operations are also expected to be from the dryers.
4-26
-------
Dust
Rail Car Delivered Wheat
I
S1lo Storage -*Dust
I
Flour Mil! Dry Grinding Process
F1
1 Fe
Stor
\
Load
ber
Flour
ed Dryer Wet M1
^ Fiber
age
\
out Coraroo
Dust-* Or
n Starch Common
ll-«-H20
Starch Gl
yers PreGel Steam Glute
Dryer
Dust -* Storage Gr1n<
jten
i Dryer -»-Dust
Mill — Oust Storage —*• Oust
I
Dust
Loadout
Figure 4-2. Wheat starch process flow diagram.
4-27
-------
4.3.3 Potato Starch28'39
Potato starch has become a specialty starch with unique gel properties
and excellent cold water solubility. These properties make it highly
desirable for sizing and coating quality paper products, warp sizing,
cotton yarns, instant food thickeners in baking items and puddings, and
40
producing flexible adhesive films. Potato starch uses in the traditional
industries are 60 percent in paper, 30 percent in textiles, and 10 percent
in food and adhesives. The biggest increase in the use of potato starch
has been in the paper industry where its properties are preferable to
those of other starches. Its cohesive strength and stringiness are
beneficial in paper coating. The higher degree of toughness and flexibility
of potato starch is important in the textile industry and is considered
. . 41
superior in warp sizing.
Currently, the starch output per bushel of potatoes ranges between
42
2.7 to 3.6 kg (6 to 8 Ib), or 10 to 12 percent of the weight of potatoes.
In the U.S., the manufacture of potato starch has lost its once strong
position to corn starch which can be made from abundant raw materials at
a lower price. The availability of potatoes as a raw material for
starch has declined as its use in food processing, especially frozen
potato products, has increased. Thus, potato starch raw materials have
41
become difficult to obtain at a reasonable price.
There are a great variety of procedures and equipment used in
manufacturing potato starch but all processes follow the same basic
steps. Fresh potatoes produce the best grade starches; therefore,
potatoes are quickly processed near production areas. Potatoes are held
in storage bins from which they are dropped into a running water flume.
The flume run removes stones and much of the dirt while delivering the
potatoes to a conveyor belt. The conveyor carries the potatoes to a
washer for a thorough cleaning. Clean potatoes are sent to a grinder/crusher
which disintegrates the cell structure liberating the water soluble
starch. Fiber and potato skin are separated by screening, or through a
rotary sieve. The starch solution is dewatered and the starch is then
dried and bagged. The fiber and skins are dried and sold as bulk animal
on
feed. The potato starch operation illustrated in Figure 4-3 has only
two significant points of emissions - the fiber dryer exhaust and the
starch dryer exhaust.
4-28
-------
Potato
Storage
Bin
H20-
. Flume
Potato Washer
-Grinder/Crusher
Waste •*— Decant Fiber
H.O and Starch
Screens
Oust
Fiber and
Skins
Dryer
-Cyclone
Starch
Slurry
V
Waste
H20
Oust
DewateHng
Steam
Evaporation
-Cyclone
Storage
I
Loadout
Storage
Bagging
Figure 4-3. Potato starch process flow diagram.
4-29
-------
4.4 REFERENCES FOR CHAPTER 4
1. Farris, Paul L. Economics and Future of the Starch Industry. In:
Starch: Chemistry and Technology Volume I. Whistler, R. L. and
E. F. Paschall (eds.). New York, Academic Press. 1965. p. 34-35.
2. Economic Information Systems, Inc. New York, New York. March 1980.
3. Properties and Uses of Feed Products from Corn Wet-Milling Operations.
Washington, Corn Refiners Association, Inc. 1975. p. 4.
4. Harness, John. The Corn Wet Milling Industry in 1978. In: Seminar-
Proceedings: Products of the Corn Refining Industry in Food. Washington,
Corn Refiners Association, Inc. May 9, 1978. p. 7.
5. Curry, John. .Corn Agriculture, USA. In: Corn Annual 1979 Edition.
Washington, Corn Refiners Association, Inc. 1979. p. 13-15.
6. Mitchell, Gerald M. 1980 Corn Annual Introduction. In: Corn Annual
1980 Edition. Washington, Corn Refiners Association, Inc. 1980. p. 4-5.
7. Kirk-Othmer. Encyclopedia of Chemical Technology: Volume 18.
New York, John Wiley and Sons, 1969. p. 681.
8. Census of Manufacturers. U.S. Department of Commerce. Washington, DC.
1963, 1967, 1972, 1977.
9. Reference 7, p. 684.
10. Russell, Charles R. Present and Potential Uses in Industry. In: Corn
Annual 1976 Edition. Washington, Corn Refiners Assocation, Inc. 1976.
p. 28.
11. Starch and Related Products in Selected Countries. U.S. Department of
Commerce. Washington, DC. 1967-
12. Reference 1. p. 40.
13. Hammer, Thomas A. U.S. Feed Ingredients and the E.G. In: Corn Annual
1979 Edition. Washington, Corn Refiners Association, Inc. 1979. p. 18-21.
14. Annual Survey of Manufacturers. U.S. Department of Commerce. Washington,
DC. 1958-1962, 1964-1966, 1968-1971, 1973-1976.
15. Plant Visit. Harris, Paul, American Maize Products with Siebert, Paul,
EEA. March 10, 1980. Operation of corn wet milling plant in Hammond,
Indiana.
16. Telecon. Gray, Fred, USDA Sugars and Sweeteners with Siebert, Paul,
EEA. March 17, 1980. Trends in corn starch production and emission
control.
4-30
-------
17. Telecon. Larsen, Richard, First Manhattan Co. with Siebert, Paul, EEA.
March 18, 1980, and April 1, 1980. Trends in corn starch production and
emissions control.
18. Telecon. Keim, Carroll, Carroll R. Keim Consultants, Inc. with
Siebert, Paul, EEA. March 19, 1980. Trends in corn starch production
and emissions control.
19. Telecon. Brenner, Kyd, Corn Refiners Association with Siebert,
Paul, EEA. March 24, 1980. Trends in corn starch production and
emissions control.
20. Telecon. Miller, Dwight, USDA Northern Regional Research Center with
Siebert, Paul, EEA. April 11, 1980. Trends in corn starch production
and emissions control.
21. Structural Change in the Sweetener System. In: Corn Annual 1980 Edition.
Washington, Corn Refiners Association, Inc. 1980. p. 26-31.
22. Lassus, L. High-Fructose is Here to Stay. Beverage World, p. 23-24.
October 1976.
23. Reiners, Robert A. Corn Oil. In: Seminar Proceedings: Products of the
Corn Refining Industry in Food. Washington, Corn Refiners Association,
Inc. May 1978. p. 18-22.
24. Plastics and Rubber. May 11, 1979.
25. Kohn, Philip. Starch Gains New Status as Filler, Raw Material.
Chemical Engineering. 84_:36,38. December 19, 1977.
26. Worthy, Ward. Super Slurper Gaining Commercial Application.
Chemical and Engineering News. 57^:23-24. November 5, 1979.
27. Butz, Earl. New Opportunities in Corn. In: Corn Annual 1975 Edition.
Washington, Corn Refiners Association, Inc. 1975. p. 5-6.
28. Whistler, Roy L. and Eugene F. Paschall (eds.). Starch: Chemistry and
Technology Volume II. New York, Academic Press, 1967. p. 1-101.
29. Radley, J.A. Industrial Uses of Starch and Its Derivatives.
London, Applied Science Publishers, Ltd., 259 p.
30. Seminar Proceedings: Products of the Corn Refining Industry in Food.
Washington, Corn Refiners Association, Inc., May 9, 1978. 79 p.
31 Corn Starch. Washington, Corn Refiners Association, Inc., 1979. 36 p.
32. Nutritive Sweeteners from Corn. Washington, Corn Refiners Association,
Inc., 1979. 31 p.
33. Reference 3. 16 p.
4-31
-------
34. Plant Visit. Wells, Ron, Hubinger Co. with Aldina, G.J., EEA.
March 11, 1980. Operation of the corn wet milling plant in Keokuk,
Iowa.
35. Reference 28. p. 32-38.
36. Reference 3. p. 26.
37. Reference 31. p. 17.
38. Plant Visit. Smick, Ken, Henkel Co. with Aldina, 6.J., EEA. March 12,
1980. Operation of the wheat milling plant in Keokuk, Iowa.
39. Plant Visit. Jeffrey, James, Colby Cooperative Starch Co. with
Aldina, G.J., EEA. March 13, 1980. Cooperation of the potato starch
processing plant in Caribou, Maine.
40. Reference 28. p. 98-100.
41. Treadway, R.H. Potato Starch. In: Potato Processing. Talburt, W.H.
and 0. Smith (eds.). Westport, CO., AVI Publishing Co. 1975. p. 546-561
42. Reference 1. p. 38.
4-32
-------
5. AIR EMISSIONS DEVELOPED IN SOURCE CATEGORY
5.1 PLANT AND PROCESS EMISSIONS
The corn wet milling industry can emit sulfur dioxide, hydrocarbon
and particulate emissions to the atmosphere. Particulate emissions have
been indicated by data in the state files as the major pollutant emitted
by the process. The state files contained a limited amount of data on
emissions from controlled process pollutant sources (Table 5-1); no data
was available for uncontrolled emission rates. A 1973 study by the EPA
was used to augment the state emissions information (Table 5-2) and
allow study objectives to be met. Uncontrolled emission factors presented
in this report were calculated from controlled emission rates and assumed
control device efficiencies based on those given in the state files.
Some effort has been made to measure S02 and hydrocarbon emissions, but
little reliable information exists. A summary of the process volumetric
flowrates, temperatures, stream compositions, and typical emission rates
is presented in Table 5-3.
The animal feed (gluten feed and gluten meal) dryers are the major
sources of particulate emissions. Gluten feed has a size distribution
of about 50 percent larger than 240 pm and only one percent smaller than
2
60 ym while gluten meal is somewhat smaller than gluten feed. The test
and production data presented in Tables 5-1 and 5-2 were used to calculate
a controlled emission factor for the animal feed dryers. The controlled
emission factor indicated for these dryer types is 0.36-1.3 kg/Mg (0.71-
2.6 Ib/ton) of product throughput (Table 5-4). This factor shows some
agreement with findings of the 1973 EPA report which listed an emission
factor of 0.2-0.6 kg/Mg (0.39-1.2 Ib/ton) of throughput. The uncontrolled
emission factor was calculated from the controlled emission factor
assuming a cyclone control device with 95 percent efficiency. Such a
high efficiency is possible since particles are large and the device is
carefully operated for product recovery (see Section 6). The uncontrolled
emission factor, thus calculated, is 7.1-26 kg/Mg (14.2-52 Ib/ton) of
product throughput. Due to the great variety of process, equipment, and
product mixes used in differing sizes and configurations at the different
wet milling operations, no one typical plant size or configuration
5-1
-------
TABLE 5-1. SUMMARY OF PARTICULATE EMISSION STACK TEST RESULTS FROM
STATE EMISSION INVENTORIES
Throughput Emission Rate
Plant Designation (ton/yr) Emission Point (Ib/hr)
Pulp feed.
Plant A -2,030 Dryer
Plant 3 11 Gouda Dryer
Pregel
12 Gouda Dryer
Pregel
Plant C 800,000 Steams-Rogers
Oryer
300,000 P4H Starch
Flash Oryers
Plant 0 Gluten Feed
Dryer
Gluten Meal
Dryer
Starch Dryer
Plant E Gluten Feed
Flash Dryer
Finish Feed
Dryer
Starch Dryer
8arr-Murphy
Dryer
Plant ? By-product Flash
Dryer
Starch Dryer
Plant G Peed Dryer
Feed Dryer
Starch Flash
Dryer
Starch Flash
Dryer
Starch Belt
Plant H F'°er Dryer
Feed Flash
Dryer
P&S Oryer
piant i Raymond Flash
Oryer »1
RFC IZ
Gluten Feed 11
Hell Dryer
Germ Oryer
Gluten Meal
Oryer
Gluten Meal
Oryer
Feed Oryer
7.08
0.2
0.1
16.9
27.6
0.068
0.034
0.062
30.8
0.288
0.033
0.049
7.3
7.4
22.2
10.7
7.5
0.09
4.4
14
6.3
25. 2
39.S
IS. 4
30.3
7.0
6.0
12.6
22.6
Flowrate
31 ,000 scfm
4,387 acfra
3.797 acfra
20,387 acfm
36,934 acfra
45.000
22.500 acfm
30,000
36,000 acfm
15.000 scfm
5.399
44.635 scfm
52,000
38.380 acfra
10,020 acfm
34,000 acfm
32.270
3.290
40.000 acfm
31,000
15,000 acfm
50,000 acfm
77,000 acfm
16,000 acfn
32,000 acfm
20,500 acfm
3,500
25,000
25,000
Operation
(hr/yr)
2.900
•8,200
-8,200
-8,600
-8.600
3,400 Est.
3,400 Est.
8,400 Est.
8,400 Est.
8,400 Est.
8.400 Est.
8,400 Est.
8.400 Est.
8,400 Est.
8,400 Est.
3.400 Est.
8.400 Est.
8,400 Est.
3,400 Est.
3.400 Est.
3.400 Est.
8.400 Est.
8,400 Est.
3,400 Est.
8.400 Est.
Emissions
(ton/yr)
10.3
0.32
0.4
72.5
118.6
0.3
0.14
0.26
129.4
1.2
0.14
0.21
30.66
31.1
68
33
23
2
1
18.5
58.3
26.5
105.3
166.3
64.7
129.4
29.4
25.2
52.9
94.9
Control
None
None
None
Cyclone
Cyclone
Cyclone/
Scrubber
Cyclone/
Scrubber
Cyclone/
Scrubber
Cyclone
Cyclone
Cyclone
None
Cyclone/
Scrubber
Scrubber
Cyclone
Cyclo-e
Cyclone
Scrubber
FF
Cyclone/
Scrubber
Cycl one
None
Cyclone/
Scrubber
Cyclone/
Rotoclone
Cyclone/
Rotoclone
Cyclone/
Rotocloni!
Cyclone/
Rotoclone
5-2
-------
TABLE 5-2. SUMMARY OF PARTICULATE EMISSION STACK TEST RESULTS FROM
EPA 450/3-73-003a'
Plant
Designation Source
Plant t& Gluten meal
dryer
2 Gluten
feed dryers
Proctor and
Schwartz
starch dryer
Proctor and
Schwartz
starch dryer
Flash starch
dryer
Flash starch
dryer
Syrup spray
dryer
Syrup spray
dryer
Germ dryer
Feed convey-
ing
Product
Recovery
Device
Cyclone
8 cyclones
per dryer
__
2 cyclones
2 cyclones
Cyclone
Cyclone
N/A
1 cyclone
(Aerodyne
Emission Rates from
Emission Rate Co"roirOevice Secondary Dust Control Device
Gas nfrom Pro
-------
TABLE 5-2 (Cont'd). SUMMARY OF PARTICULATE EMISSION STACK TEST
RESULTS FROM EPA 450/3-73-003a
Emission Rate
Plant
Designation
Plant 0^
Source
Gluten dryer
(Barr-Murphy
dryer)
Distillers,
dark grains
dryer (ro-
tary dryer)
Product
Recovery
Device
6 cyclones
in parallel
Cyclone
Gas
Vol ume
(cfm)
17,600
31 ,000
from Prc
Recovery
(gr/scf)
0.026-
0.077
0.03
)duct
Dev i ce
(lb/hr)
8.0-
8.7^
Emission Rates from
Secondary Dust Secondary Dust Control Device
Control Dev ice • •
On Product Inlet Dust Outlet Dust
Recovery Device Load Load
or Process Equipment (Ib/hr) (lb/hr)
Plant E Feed dryer
(Raymond flash) Cyclone 27,000 0.024 5.55
Feed dryer
(Raymond flash) Cyclone 27,000 0.028 6.58
Feed dryer
(Heil, rotary
finish drying) Cyclone 13,000 0.045 5.01
Gluten dryer
(Barr-Murphy
dryer) 8 cyclones 55,000 0.034 16.3
Plant F-'
Starch dryer
(Intensa flash
dryer) Cyclones 45,000
Wet scrubber
17.3
— Western Precipitation sampling equipment used for source testing.
— So product recovery device or dust control device installed on belt dryer.
— RAC sampling equipment used for source testing.
— Average of several individual tests.
5-4
-------
TABLE 5-3. PROCESS EMISSIONS SUMMARY FOR CORN WET MILLING
a,b
en
en
Range of Volumetric
Emission Point Flowrate (acfm)
Corn Loadout
Emissions
Steep Tanks
Germ Meal Dryer
Gluten Feed Dryer
Gluten Meal Dryer
Starch Dryer - Belt
Flash
Spray
Loadout Emission
Points
5,000-20,000
8,000-12,000
5,000-20,000
30,000-80,000
10,000-50,000
10,000-35,000
30,000-60,000
30,500-90,000
1,000-3,000
Exit
Stream Temperature Mean Controlled
Composition F Emission Rate
Parti cul ate Ambient 5 tons/yr
S02 Ambient 40 tons/yr
Particulate 220C 26 tons/yr
Parti cul ate 250C 80 tons/yr
Particulate 240C 30 tons/yr
Particulate 250-275° 20 tons/yr
Particulate Ambient 5 tons/yr
Measurement
Method
Material
Balance
Estimate
Material
Balance
EPA - RM 5
EPA - RM 5
EPA - RM 5
Material
Balance
Summary represents the limited data accessible within the Phase I survey time period. Data is extremely
limited in availability and applicability across the industry as a whole.
The data presented was obtained from emission test data in state files, plant information, and
EPA-450/3-73-003a, Emissions Control in the Grain and Feed Industry, Volume I -- Engineering and Cost Study.
cTemperature is carefully controlled to prevent cooking the product which can reduce saleable yield or
to present driving off organics which can produce a visible haze or odors.
-------
TABLE 5-4. FEED DRYER EMISSION FACTORS'
Plant
Designation
Plant A
Plant B
Plant C
Plant D
Controlled
Controlled Emission
Throughput Emission Factor
Emission Point (tons/yr) Rate (Ib/hr) (Ib/ton throughput) Control
Raymond Flash Dryer 35.6 25.2 0.71
Heil Dryer 11.9 30.8 2.6
Intensa (flash) Gluten 15.4 15.4 1.0
Feed Dryer
Gluten Feed Dryer 14.4 0.068 0.005
Steams-Rogers Gluten 17.4 16.9 0.97
Feed Dryer
Gluten Feed Flash Dryer 2.95 30.8 10.4
Cyclone
Cyl one
Cyclone
Cyclone
Cyclone
Cyclone
*Data from state files.
-------
exists that adequately represents the industry as a whole. However, an
average-sized plant (based on the literature and site visits ' ) would
process approximately 2500 m /day (70,000 bu/day) of corn kernels,
producing about 180 kg of animal feeds/m (14 Ib/bu). It usually would
operate 340 days/yr making 1.5 x 105 Mg of gluten feed/yr (1.7 x 10 tons/yr)
Based on these parameters, the average plant has controlled dryer emissions
of 55-200 Mg/yr (60-220 tons/yr); or a potential uncontrolled emission
rate - assuming a 95 percent efficient cyclone control device - of
1100-4000 Mg/yr (1200-4400 tons/yr).
The other emission points in the corn wet milling process emit much
lower amounts of particulate pollutants. The emissions from grain
loadout and from product handling and bagging operations have not been
tested. State data files contain emission estimates based on material
balance calculations. The EPA study on emissions control in the grain
and feed industry contains a controlled emission factor for grain
handling operations of 0.01 kg/Mg (0.02 Ib/ton) throughput or about
4.5 Mg/yr (5 tons/yr) emitted from each operation at the average plant.
In the past, cyclones with efficiencies of 95 percent or better were
used as control measures. The uncontrolled emission factor was back
calculated from this information as 0.2 Kg/Mg (0.41 Ib/ton) of product
throughput - about 98 Mg/yr (110 tons/yr) for the average plant. The
coverage of corn wet milling grain handling operations under the NSPS
for grain elevators has caused the widespread use of fabric filters on
these operations. In addition, the need for prevention of ambient air
explosions in the work environment and the incentives for product recovery
have led many plants to adopt fabric filter controls (99.9 percent
efficiency) for product handling operations. Emissions are thus being
reduced to less than 0.18 Mg/yr (0.2 ton/yr).
It is standard practice throughout the starch industry to install
double cyclones, cyclone/scrubber or cyclone/fabric filter control at
starch dryers.4'5 Corn starch granules vary in diameter from 5 to 25 ym.7
The state data files indicate that most plants expect 95-99.5 percent
control efficiency with these methods. A controlled emission factor was
estimated.from the emission rates available in state files by using
approximated throughputs for the plants with data. The calculated
5-7
-------
factor is 0.5 kg/Mg (1 Ib/ton) throughput - about 50 Mg/yr £55 tons/yr)
for the average plant. The uncontrolled emission factor (calculated
assuming a 95 percent control efficiency) is 9 kg/Mg (20 Ib/ton) starch
throughput. The average plant would be expected to have uncontrolled
emissions of 970 Mg/yr (1100 tons/yr).
The germ meal dryer controlled emission factor has been estimated
from the only operation listed in the collected state data which iden-
tifies the dryer, product, and tested emission rate. The controlled
emission factor for germ dryers is estimated as 0.5 kg/Mg (1 Ib/ton)
throughput, using an approximated throughput. The average plant has
controlled emissions estimated at about 10 Mg/yr (10 tons/yr). An
uncontrolled emission factor was calculated from the controlled emissions
data assuming a cyclone control device with 95 percent efficiency. The
uncontrolled emission factor is estimated at 9 kg/Mg (20 Ib/ton) product
throughput or about 240 Mg/yr (260 tons/yr) for an average plant.
The emissions from wheat and potato starch operations can be
assessed in a similar manner. Wheat and potato starch manufacturing
emits particulate matter from dryers and loading operations. Wheat
starch granules vary from about 3 to 75 ym in diameter, while potato
starch granules vary from 15 to 100 ym. The collected data indicate
that feed dryers, when used, are the only major sources of particulate
8 9
emissions. ' Two potato starch and two wheat starch plants were visited
during the survey. There is almost no data available on wheat or potato
starch, or tapioca operations owing to the dominance of the corn wet
milling industry for starch production. It is, therefore, not feasible
to estimate typical emission factors or total emissions for these plants.
Their specialty applications gives them small, but secure, niches in the
industry. The plants are generally small and use some air pollution
control, so emissions are expected to be low. Sample emissions data for
single plants are given in Table 5-5 for wheat starch and Table 5-6 for
potato starch manufacturing.
Most State implementation plans (SIP's) reviewed during this
survey, allow particulate emissions for sources that have production
capacities of up to 30 tons/hr, at a rate equal to:
5-8
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TABLE 5-5. PROCESS EMISSIONS SUMMARY FOR WHEAT STARCH
MANUFACTURING3'D
Range of Volumetric
Emission Point Flowrate (scfm)
Receiving, Storage,
and Clearance
Grinding Process
Mill Feed Dryer
Mill Feed Storage
Mill Feed Loadout
Starch Dryer
Starch Storage
Starch Loadout
Pre-gel Dryer
Pre-gel Grinding
Pre-gel Loadout
Gluten Dryer
Gluten Storage
Gluten Loadout
11,000-15,000
40,000
5,000
1,500
520
30,000
2,500
2,000
30,000
2,500
1,000
20,000
1,000
1,000
Exit
Stream Temperature
Composition f
Particulate
Particulate
Particulate
Particulate
Particulate
Particulate
Particulate
Particulate
Particulate
Particulate
Particulate
Particulate
Particulate
Particulate
Ambient
Ambient
212
Ambient
Ambient
500
Ambient
Ambient
500
Ambient
Ambient
500
Ambient
Ambient
Mean Controlled
Emission Rate
1.1 tons/yr
0.32 ton/yr
0.32 ton/yr
0.1 ton/yr
Negligible
4.9 tons/yr
0.3 ton/yr
Negligible
5.92 tons/yr
0.17 ton/yr
Negligible
5 tons/yr
0.1 ton/yr
Negligible
Measurement
Method
Material
Balance
Material
Balance
Material
Balance
Material
Balance
Material
Balance
Material
Balance
Material
Balance
Material
Balance
Material
Balance
Material
Balance
Material
Balance
Material
Balance
Material
Balance
Material
Balance
a B
Obtained through direct communication with Wheat Starch Manufacturer.
All baghouse controlled except for mill feed dryer which has wet scrubber. The summary presents the
emissions calculated by material balance for the wheat starch operation visited during the Phase I
survey. This is very limited data and does not have actual stack testing to support its validity.
5-9
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TABLE 5-6. PROCESS EMISSIONS SUMMARY FOR POTATO STARCH MANUFACTURING
en
o
Range of Volumetric
Emission Point Flowrate (acfm)
Fiber and Skins 53,750
Starch Steam
Dryer
Exit
Stream Temperature Mean Controlled Measurement
Composition F Emission Rate Method
Particulate 450 10 tons/yr Stack Test
Parti cul ate Negligible N/A
a 9
Obtained through communication with Potato Starch Manufacturer.
-------
c A , /production ratex0.67
L " 4<' l ton/hr ;
E = Ib emissions/ton throughput
The average plant described would have a production rate of approximately
19 Mg (20 tons) of feed per hour and 12 Mg 03 tons) of starch per hour
(nearly 45 Mg, or 50 tons of starch and refined products). The SIP
would allow emissions from the feed dryer of 15 kg/Mg (31 Ib/ton) and
from the starch dryer of 11 kg/Mg (23 Ib/ton). (Assuming there is only
one dryer; most plants have several parallel dryers, both for feed and
for starch with the production flow divided between the parallel units.)
The plant would be allowed controlled emissions of 2300 Mg/yr (2600 tons/yr)
and 1100 Mg/yr (1250 tons/yr), respectively. The plants surveyed were
usually within the allowable emissions and often were emitting far less
than the allowable amount.
5.2 TOTAL NATIONAL EMISSIONS FROM SOURCE CATEGORY
The starch manufacturing industry emits sulfur dioxide, hydrocarbons
and particulate pollutants. No data was found on hydrocarbon emissions.
They are assumed to be very small. Sulfur dioxide ($02) is emitted from
grain steeping and steepwater evaporation operations. Total national
S02 emissions were estimated by theoretical calculations and were confirmed
by industry information. The estimated national total particulate
emissions for the drying and material handling operations are calculated
using information on the industry capacity, proportion of product produced
from raw material and emission factors developed in the survey.
The estimated total national S02 emissions from the starch industry
are 700 Mg/yr (800 tons/yr). This estimate is based on the worst case
assumption that each bushel of corn is steeped in an equivalent volume
of three percent sulfurous acid in water (H2S03 = S02 + H20) and that
about half the S02 is emitted during steeping and evaporation of the
steepwater. Contact with industry suggested uncontrolled emissions of
over 100 ppm S02 (10 Ib/hr)10'11 which corresponds with emissions calculated
from the worst case assumptions. One company has estimated S02 emissions
based on equilibrium concentration reactions so that the calculated
emissions -are independent of production rates and only dependent on the
volume of aspirated air. This company, which uses about 800 g of
5-11
-------
S02/Mg corn (0.1 Ib S02/bu), also has measured S02 emissions from an
existing mill house scrubber of 160* ppm and 5389 scfm C8.7 Ib/hr) and
has two vendor quotes that will guarantee 10 ppm S09 emissions from
11 e-
scrubbers operated at the optimum pH.
The anticipated S02 emissions in 1985 from new sources only assuming
current (no) control is approximately 800 Mg/yr (900 tons/yr). In order
to comply with state and local regulations, especially in nonattainment
areas, new facilities would be expected to control S02 emissions to 10
ppm using scrubbers operated at optimum pH. Thus, estimated 1985 emissions
would be reduced to about 80 Mg/yr (90 tons/yr). These estimates are
•TO g
based upon a probable 1.8 x 10 m /yr (500 x 10 bu/yr) increase in corn
CO fi
grind (production capacity) and a 3.2 x 10 m /yr (90 x 10 bu/yr)
replacement of grind in existing facilities by 1985. A replacement rate
of 3.3 percent per year (18 percent from 1980-1985) of the total industry
grind capacity was used. This replacement rate assumes a 30 year equipment
life. Nevertheless, the current (500 x 10 bu/yr), rather than 1950-
1955 (130-170 x 10 bu/yr) grind was conservatively assumed as the
baseline for replacement of steeping equipment since limited information
on equipment life and historical production was readily available. (The
replacement baseline is the basis for calculating production capacity
needing replacement as it is the capacity installed one equipment life
in the past.)
The estimated total current national particulate emissions from
starch dryers is 1000 Mg/yr (1100 tons/yr). The present 1.8 x 10 m3/yr
fi fi
(500 x 10 bu/yr) raw material grind produces about 2.0 x 10 Mg/yr
(2.3 x 10 tons/yr) of starch (nearly 30 percent by weight of the total
starch and refined starch products). The emission factor for current
control developed during this study is 0.5 kg/Mg (1 Ib/ton) product
throughput. These data allow the calculation of the 1000 Mg/yr current
national emission estimate. The estimated emissions in 1985 from new
facilities (about 10-20 dryers due to both replacement and added capacity)
alone are 470 Mg/yr (520 ton/yr), assuming present control measures, a
5 percent per year production growth rate, a 5 percent per year dryer
replacement rate (i.e., a 20 year life), and the 1967 starch production
of 1.4 x 106 Mg/yr (1.6 x 10 tons/yr) as the replacement baseline. At
this time, cyclones in series (95 percent efficient) are the typical
5-12
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control measure for starch dryers. Although expensive explosion prevention
equipment is required in the system, fabric filter controls are being
installed after a product recovery cyclone in many new facilities in
order to increase product recovery and decrease emissions, thus reducing
the explosion hazard from uncoilected starch in the ambient air of the
workplace. These filters will most likely have a control efficiency of
99.9 percent thus reducing estimated 1985 emissions from new facilities
alone to 19 Mg/yr (21 tons/yr).
The starch industry presently produces 3.3 x 10 Mg/yr
(3.6 x 10 tons/yr) of animal feed. The emission factor developed for
feed drying is 0.5 kg/Mg (1 Ib/ton) of product through the dryer. Thus,
total national particulate emissions from feed drying are estimated at
1600 Mg/yr (1800 tons/yr). The anticipated growth in animal feed
production by 1985, coupled with a replacement rate of five percent per
year (i.e., an assumption of 20 year dryer life or a compounded replacement
rate of 28 percent in five years - 1980 to 1985) and a baseline for
replacement of the 1967 feed production, indicated new sources alone
producing 3.7 x 10 Mg/yr (4.1 x 10 tons/yr) of feed products. The
present particulate control is generally by product recovery cyclones
which have design control efficiencies of at least 95 percent. Particulate
emissions from new feed dryers (probably 10 to 20 units) are estimated
at 1800 Mg/yr (2000 tons/yr) in 1985 if current controls are used. If
the exhaust from half of the new dryers is recirculated into the combustor
of another dryer, net emissions projected in 1985 would be effectively
halved. Other available process or control modifications could further
reduce 1985 particulate emissions from new feed dryers.
The 1980 total national particulate emissions from germ dryers are
estimated at 130 Mg/yr (140 tons/yr). Data on shipments in 1977 and
12
1978 by members of the Corn Refiner Association support a production
ratio of 0.035:1 corn germ to corn starch (total starch and refined
starch products). The amount of germ processed in 1980 is, therefore,
approximately 2.5 x 10 Mg/yr (2.8 x 10 tons/year). The emission
factor for these dryers using current control methods is about 0.5 kg/Mg
(1 Ib/ton). product throughput. In 1985, the new germ dryers alone
(assuming the current control methods; dryer life of 20 years or a
compounded replacement rate over the five years of 28 percent of 1967
5-13
-------
5
estimated germ production; and new plant capacity of 2.7 x 10 Mg/yr -
3 x 105 tbns/yr) are expected to have total particulate emissions of
150 Mg/yr (170 ton/yr) from about 15 units.
Grain receiving and product bagging operations at starch facilities
have an emission factor of 0.01 kg/Mg (0.02 Ib/ton). The estimated
emissions from each operation at the average plant using cyclone controls
(95 percent efficiency) is 4.5 Mg/yr (5 tons/yr) or 9 Mg/yr (10 tons/yr)
total for both operations at the plant. The total estimated national
emissions from grain and product handling together are 180 Mg/yr (200 tons/yr).
New plants using fabric filter controls (99.9 percent efficiency) will
reduce total national emissions to 7 Mg/yr (8 tons/yr) in 1985.
The corn wet milling industry has total national 1980 particulate
emissions estimated at 2900 Mg/yr (3200 ton/yr). The total national
particulate emissions from new facilities in 1985 are estimated at
2600 Mg/yr (2900 tons/yr) with current control or 1100 Mg/yr (1200 tons/yr)
with expected control. A summary of the national emission estimates
developed in this study are presented in Table 6-1.
5-14
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5.3 REFERENCES FOR CHAPTER 5
1. Shannon, L.J., R.W. Gerstle, P.G. Gorman, D.M. Epp, T.W. Devitt,
and R. Amick. Emission Controls in the Grain and Feed Industry:
Volume I - Engineering and Cost Study. U.S. Environmental Protection
Agency, Research Triangle Park, NC. Publication No. EPA-450/3-73-003a,
December 1973. p. 99-106, 253-268.
2. Telecon. Allen, Jerry, A.E. Staley Manufacturing Co., with Siebert,
Paul, EEA. March 24, 1980. Air pollution control for wet corn
milling dryers and status of A.E. Staley starch manufacturing
facilities.
3. Reference 1, p. 265.
4. Plant Visit. Harris, Paul, American Maize Products, Co. with
Aldina, G.J., Energy and Environmental Analysis, Inc. (EEA).
March 10, 1980. Operation of Hammond, Indiana, corn wet milling plant.
5. Plant Visit. Wells, Ron, Hubinger, Co. with Aldina, G.J., EEA.
March 11, 1980. Operation of Keokuk, Iowa, corn wet milling plant.
6. Reference 1, p. 293-294.
7. Corn Starch. Washington, Corn Refiners Association, Inc., 1979. p. 7.
8. Plant Visit. Smick, Ken, Henkel Co. with Aldina, G.J., EEA.
March 12, 1980. Operation of the wheat milling plant in Keokuk, Iowa.
9. Plant Visit. Jeffrey, James, Colby Cooperative Starch Co. with
Aldina, G.J., EEA. March 13, 1980. Operation of the potato starch
processing plant in Caribou, Maine.
10. Telecon. Allen, Jerry, A.E. Staley, Co. with Siebert, Paul, EEA.
March 5, 1980. Emissions and emissions controls in corn milling
operations.
11. Letter and attachments from McWilliams, Paul, Cargill Corn Starch
and Syrup Processing Group, to Cohen, Eric, EPA Region V.
June 18, 1980. Air pollutant emissions report and applications for
permits for plant expansion.
12. Corn Annual 1979 Edition. Washington, Corn Refiners Association,
Inc., 1979. p. 6.
5-15
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6. EMISSION CONTROL SYSTEMS
6.1 CONTROL APPROACHES
The corn wet milling operations reviewed in this study employed
several types of participate control devices. The dryers were pre-
dominantly controlled by a cyclone or two cyclones in series. The
estimated efficiency of these cyclones is greater than 90 percent due to
the large particle size of the material throughput. Some plants used
various types of wet scrubbers, again with 90+ percent efficiency, for
parti oil ate control on the feed dryer. The rest of the operations
throughout the industry used small fabric filters (unit modules) to
control emissions and product losses. These units were estimated (very
little actual test data exists) to attain 99+ percent efficiency.
The industry is presently using efficient control techniques on
most process operations to assure economic product recovery. There are
several possible process and equipment changes, however, that may
decrease particulate emissions from the dryers or odorous emissions from
the steepwater operations. Several new feed dryer designs (flash-,
ring-, or rotary-type) are being manufactured which exhibit much better
energy efficiency and lower emission rates. Some installations are also
using the exhaust gases from one dryer to assist drying in downstream
devices, e.g., operating dryers in series, or recycling part of the
exhaust of a dryer, to maximize energy use and emissions control. These
dryer configurations reduce gas flows and emissions to some extent;
however, emissions control equipment could still be required to meet
state regulations. Other installations are using rotary steam tube
dryers in conjunction with coal-fired boilers to reduce both energy
costs and generation of particulate emissions. (A lower gas throughput
is used in rotary steam tube dryers than other dryer types, while effecting
the same drying.) The control efficiency for starch dryers has been
improved at newer facilities with the addition of a fabric filter after
the cyclone. Use of a fabric filter to control moist dryer exhaust can
become feasible through increased mechanical dewatering of the product
and improved explosion venting systems which allow location of fabric
filters within heated buildings. Along with these innovations, steepwater
6-1
-------
evaporative vapors can be recirculated through the dryers or burned in a
waste heat recovery boiler to incinerate odorous compounds and provide
heat recovery.
Steeping and steepwater emissions, consisting of both corn particulate
matter and sulfur dioxide (S02), are generally controlled with wet
scrubbers in the newer corn wet milling facilities. The removal of SC^
in a scrubber is an equilibrium reaction so that the outlet S02 concen-
tration is inversely proportioned to the pH. At one plant, S02 emission
concentration is 10 ppm when the pH in the caustic soda solution was about
eight. A pH higher than for this emission level will cause the formation
of insoluble calcium carbonates that will plug the scrubber spray nozzles.
New facilities are expected to use scrubbers with controls capable of
maintaining the optimum pH.
The flow diagram (Figure 4-2) for wheat starch manufacture points
out the sources of emissions from this process. The major emission
points again are the product dryers. In the traditional batter process
plant, the feed was not dried by forced air; the starch spray dryer was
controlled with a baghouse. The Raisio modified batter process plant
visited during this survey controlled the mill feed dryer emissions
with a wet collector; all other emission points (including loading
fugitive emissions) were controlled with small fabric filter modules.
The efficiency of all control equipment (for this relatively new plant)
was estimated by the equipment manufacturer/installer at 99+ percent.
No emission test data on this equipment is available at this time,
although typical efficiencies for these control methods is well
established.
The potato starch process diagram (Figure 4-3) shows emission
points from this type operation. The fiber/skins dryer is the only
major emission point for the process visited during the survey. The
dryer was tested in 1974 and exhibited an emission rate of 3.2 kg/hr
(7 Ib/hr; 9 Ib/ton throughout). Control at the plant was by a single
cyclone. A new facility has been planned, reportedly with modern
processing and control methods. Construction of the facility has not
begun and no specific information is available at this time.
6-2
-------
6.2 ALTERNATIVE CONTROL TECHNIQUES
The starch industry strives for efficient particulate control on
most operations to assure economic product recovery. The use of fabric
filter controls wherever possible and the process changes such as
recirculation of vapors or hot exhaust gases illustrate the industry's
approach to product recovery, energy conservation, and emissions control.
These procedures should receive more examination by the industry in the
near future especially if production capacity expands for alcohol manufacture.
The other possibility for increased emissions control is the
addition of a high-efficiency (90+ percent for 2 to 10 pm particles)
cleaning device (a moderate or high pressure drop scrubber or fabric
filter) after the cyclone(s) on the dryer exhaust. The present use of
cyclones on the dryers has given good product recovery and emissions
control, but a high-efficiency scrubber could reduce emissions further.
A fabric filter offers even better control than most high-efficiency
scrubbers and has the added advantage of dry product recovery; however,
it could be blinded (i.e., partially or totally blocked due to water) by
the high moisture effluent from animal feed dryers.
6.3 "BEST SYSTEMS" OF EMISSION REDUCTION
The starch manufacturing industry is extremely competitive. It is
a capital intensive process with a relatively low profit margin. The
entire process is carefully monitored for product yield per unit raw
material input. The necessity of good product yield in conjunction with
protection from explosion hazard has led to the industry's adoption of
effective dust control measures by the industry. The plants visited
during the survey employed fabric filter particulate control devices at
all storage bin emission points, loading operations, dry product grind-
ing processes, and most starch dryers. A typical feed dryer is controlled
with a cyclone (sometimes two cyclones in series) or cyclone/scrubber
thus providing reasonable control efficiency. Feed dryer control may be
improved with the addition of a high-efficiency wet collector; however,
process and control modifications for improved heat and product recovery,
which are currently available and will also reduce emissions are likely
to be installed at most new facilities. These process changes probably
will result in reducing emissions by at least half, but at a net cost
6-3
-------
savings. The following plants, which have been recently built or are
currently being planned, generally incorporate some of these features:
A.E. Staley Manufacturing Co. Lafayette, Indiana
CPC International Stockton, California
CPC International Winston-Sal em, North Carolina
Amalgamaize Decatur, Alabama
Clinton Corn Processing Montezuma, New York
Cargill, Inc. Dayton, Ohio
ADM Corn Sweeteners Decatur, Illinois
Also, some plants in Canada have employed state-of-the-art drying
process and control technology.
A preliminary selection of the "best" control systems which are
currently available, based on recently constructed or currently planned
facilities, would include the following systems. Fabric filter baghouses
or cyclones followed by baghouses are feasible and very effective for
controlling grain and product handling, starch dryers, and germ dryers.
Cyclone/scrubber combinations are feasible and effective for animal feed
dryers, while baghouses could be used if potential moisture problems can
be overcome. Scrubbers with an absorbent slurry such as caustic have
been effectively used to control sulfur dioxide emissions from steeping.
The estimated national emissions from the various corn wet milling
process sources are given in Table 6-1 for the present and for 1985.
Emissions estimates for 1985 are presented for the continued use of
current control techniques, the control techniques expected to be in
use, and the use of the best control techniques currently available.
6-4
-------
TABLE 6-1. ESTIMATED NATIONAL EMISSIONS FROM CORN WET MILLING
CTI
O1
Source Pollutant Type
Grain Handling Part icul ate
Steeping and Steepwater Sulfur Dioxide
Starch Dryers Parti cul ate
Germ Dryers Part icul ate
Animal Feed Dryers Parti cul ate
Product Handling Part icul ate
Total Sulfur Dioxide
Total Part icul ate
Current
Emissions
Mg/yr
(tons/yr)
90
(100)
730
(800)
1,000
(1,100)
130
(140)
1,600
(1,800)
90
(100)
730
(800)
2,900
(3,200)
1985 Emissions from New
Mg/yr (tons/yr)
Current
Control
90
(100)
820
(900)
470
(520)
150
(170)
1,800
(2,000)
90
(100)
820
(900)
2,600
(2,900)
Expected
Control
4
(4)
80
(90)
20
(20)
150
(170)
910
(1,000)
4
(4)
80
(90)
1,100
(1,200)
Sources
Best
Control
4
(4)
80
(90)
20
(20)
15
(17)
180
(200)
4
(4)
80
(90)
230
(250)
-------
7. EMISSIONS DATA
7-1 AVAILABILITY OF DATA
Emission test data for the starch manufacturing industry is available
for some of the product dryers. An examination of state emissions data
files collected during this survey revealed that starch manufacturing
operations were usually required to test particulate emissions from the
gluten feed and gluten meal dryers. The limited test data indicated
that some dryers using the typical cyclone product recovery/particulate
control method had particulate emissions of 45 Mg/yr (50 tons/yr) or
greater. No uncontrolled emission test data was found. The testing
required was typically performed using EPA Reference Method 5 (Federal
Register, August 18, 1977) test procedures. Many plants did not have
actual emissions test data for the dryers or any other process emissions.
The only sulfur dioxide emissions data found was that acquired during
plant visits. No hydrocarbon emissions data was located.
Particulate emissions from process sources other than the gluten
feed/meal dryers were calculated by material balance. The material
balance emissions calculations were made in conjunction with the control
equipment efficiency stated by the manufacturer. The starch industry
conducts relatively precise material balance calculations for process
control and marketing reasons which lends credibility to the estimated
emissions. The material balance computations did not show other emissions
points in the process as significant particulate emitters. Additional
test data, including some data for sulfur dioxide emissions, should
become available after the compliance testing of new plants and expansions
currently under construction.
7.2 SAMPLE COLLECTION AND ANALYSIS
The typical method used for sampling particulate emissions for the
sources tested was EPA Reference Method 5. This method is described in
the August 18, 1977, Federal Register and has been the required test
method by state agencies. The procedure requires the extraction of a
representative gas/particulate sample from the effluent emitted to the
atmosphere. A pitot tube is used in conjunction with a sampling nozzle
and probe to assure that a representative sample is taken. The gas
7-1
-------
sample is extracted from equal sampling areas as prescribed in the EPA
reference method. The sample is filtered to catch participate matter on
a glass mat filter substrate then sent through a condenser to dry the
gas. The dry gas volume is measured with a calibrated dry gas meter.
The actual volume is later corrected to standard conditions (20°C and
760 mm Hg). The standard volume of gas sampled is used with the measured
particulate catch from the test to calculate the particulate mass concen-
tration per standard cubic volume in the effluent. The standard flowrate
of the effluent (calculated from the gas velocity data and effluent
cross-sectional area) can then be employed to calculate the pollutant
mass emission rate. This method is recommended for all particulate
sampling when properly conducted within the required 90-110 percent
isokinetic rate1.
7-2
-------
8. STATE AND LOCAL REGULATIONS
Relatively minor hydrocarbon, nitrogen oxide, and carbon monoxide
can be emitted from corn wet milling operations; however, these emissions
generally are not regulated except when nuisance odors are present.
Particulate emissions occur at various stages throughout the corn
wet milling process. These stages include grain handling and storage,
and separation and subsequent processing (e.g., drying) of starch and
fiber, and gluten feeds.
Grain elevators, including those at wet corn mills, are already
federally regulated under a new source performance standard. Emissions
cannot be greater than 0.025 g/sm (0.01 gr/scf) or greater than zero
percent opacity. Certain grain drying operations must meet the zero
percent opacity requirement. Fugitive emissions from truck or rail car
unloading, grain handling, truck loading, and barge or ship loading are
not to exceed 5, 0, 10, and 20 percent opacity, respectively. Work
practice requirements are specified for barge or ship unloading. There
are state regulations for grain elevators, specifically Indiana, which
are similar to the federal regulations.
Emissions from most starch manufacturing operations are covered by
process weight regulations. There are a variety of process weight
formulas with the most common being E=4.10P for process weights up
to 27 Mg/hr (30 tons/hr), and E = 55.OP0'11 for weights of 27 Mg/hr
(30 tons/hr) or greater, where E equals the allowable emissions in
pounds per ton of throughput and P equals the process weight rate in
tons per hour. Illinois has one of the strictest sets of formulas for
0 53
new sources; E = 2.54P * for process weights up to 410 Mg/hr (450 tons/hr)
and E = 24.68P0'16 for weights over 410 Mg/hr (450 tons/hr). Starch and
related products manufactured from potatoes and wheat are usually also
regulated by the same process weight rate formulas that would be used
for corn wet milling in the particular state. For those states with
potato and wheat starch operations, the most common formula is E = 3.59P0*62
for under 27 Mg/hr (30 tons/hr) and E = 17.31P0*16 for 27 Mg/hr (30 tons/hr)
or greater.
8-1
-------
Iowa has specific processing and handling regulations which are the
most restrictive state regulations applicable to starch manufacturing.
Section 4.4(7) states that equipment operated for the processing or
handling of grain, grain products, and grain by-products cannot dis-
charge particulate matter into the atmosphere at a concentration exceeding
0.25 g/sm3 (0.1 gr/scf) of exhaust gas. Illinois also specifically
regulates wet corn milling by limiting emissions from feed and gluten
3
dryers to 0.74 g/sm (0.3 gr/scf) rather than using the general process
weight regulation. All other processes in new plants are regulated by
process weight. Existing sources are regulated by the less restrictive
process weight formula.
The majority of the states have a visible emission regulation with
the upper limit being 20 percent opacity. This opacity level corresponds
to number one on the Ringelmann scale.
Fugitive emissions, when mentioned in the state regulations, are
usually controlled by requiring the installation and use of hoods, fans,
fabric filters, and other devices to enclose and vent areas used in the
handling of dusty materials. Also, fugitive emissions should not be
visible beyond the property line.
8-2
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA 450/3-80-040
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
5. REPORT DATE
_Novemb er_l 980.
Source Category Survey: Starch Manufacturing Industry
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
8. PERFORMING ORGANIZATION REPOI
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Energy and Environmental Analysis, Inc.
3101E Guess Road
Durham, North Carolina 27705
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-02-3061
12. SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Emission Standards and Engineering Division
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA/200/04
15. SUPPLEMENTARY NOTES
16. ABSTRACT
This report documents a study assessing the need for new source performance standards
(NSPS) for the starch manufacturing industry. This industry is basically contained
in SIC 2046, Wet Corn Milling, and includes the manufacture of corn starch, corn oil,
corn syrups, wheat starch, wheat gluten (protein), potato starch, and by-product animal
feeds. Starches can also be refined to produce ethanol alcohol for gasohol. Information
and assessments concerning the products, processes, product uses, plants, historical
statistics, and growth potential of the industry are presented. Air pollution emissions
are identified and quantified as feasible with the limited data. Animal feed and starch
dryers are the major sources of particulate emissions. Present methods of air pollutior
control and their effectiveness are examined. State regulations applying to the industi
are summarized. Based on the estimated industry growth in new sources and the emission
reduction attainable using the best available control, an estimate of the total emissior
reduction achievable through a NSPS is presented.
17.
KEY WORDS AND DOCUMENT ANALYSIS
a.
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATi Field/Group
Starch Manufacturing
Wet Corn Milling
Wheat Starch
Potato Starch
Animal Feeds
Gluten
Dryers
Air Pollution
Particulate Matter
Pollution Control
Control Equipment
Standards of Performance
Air Pollution Control
13 B
18. DISTRIBUTION STATEMENT
Release Unlimited
19. SECURITY CLASS (This Report I
Unclassified
21. NO. OF PAGES
66
20. SECURJTY CLASS (Tutspage)
I Un r 1 a«; <; i -Fi pH
22. PRICE
EPA Form 2220-1 (Rev. 4-77) PREVIOUS EDITION is OBSOLETE
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