EPA-450/3-73-003-b
SEPTEMBER 1974
EMISSIONS CONTROL
IN THE GRAIN
AND FEED INDUSTRY:
VOLUME II - EMISSION
INVENTORY
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
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EPA-450/3-73-003-b
EMISSIONS CONTROL
IN THE GRAIN
AND FEED INDUSTRY:
VOLUME II - EMISSION
INVENTORY
by
Dr. Larry J. Shannon, P. G. Gorman,
M. P. Schrag, and D. Wallace
Midwest Research Institute
425 Volker Boulevard
Kansas City, Missouri
Contract No. 68-02-0213
EPA Project Officer: Kenneth R. Woodard
Prepared for
ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Air Quality Planning and Standards
Research Triangle Park, N. C. 27711
September 1974
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This report is issued by the Environmental Protection Agency to report
technical data of interest to a limited number of readers. Copies are
available free of charge to Federal employees, current contractors and
grantees, and nonprofit organizations - as supplies permit - from the Air
Pollution Technical Information Center, Environmental Protection Agency,
Research Triangle Park, North Carolina 27711; or, for a fee, from the
National Technical Information Service, 5285 Port Royal Road, Springfield,
Virginia 22151.
This report was furnished to the Environmental Protection Agency by
Midwest Research Institute, in fulfillment of Contract No. 68-02-0213.
The contents of this report are reproduced herein as received from
Midwest Research Institute. The opinions, findings, and
conclusions expressed are those of the author and not necessarily those
of the Environmental Protection Agency. Mention of company or product
names is not to be considered as an endorsement by the Environmental
Protection Agency.
Publication No. EPA-450/3-73-003~b
11
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PREFACE
This report was prepared for EPA/OAQPS under Contract No. 68-02-0213,
which was monitored by Mr. Kenneth R. Woodard.
The program was centered in MRI's Physical Sciences Division, Dr. H.
M. Hubbard, Director. Dr. L. J. Shannon, Head, Environmental Systems Sec-
tion, served as program manager. Dr. L. J. Shannon, Mr. P. G. Gorman, and
Mr. M. P. Schrag were the principal authors of this report. Mr. D. Wallace
also contributed significantly to the program.
Approved for:
MIDWEST RESEARCH INSTITUTE
H. M. Hubbard, Directbr
Physical Sciences Division
September 1974
111
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age
CONTENTS
List of Tables
List of Figures vii
Summary 1
I. Introduction 5
II. General Methodology 7
III. Emission Calculations .................. 9
A. Grain Elevators 9
1. Country elevators 10
2. Inland terminal elevators 18
3. Export elevators. 23
B. Feed Mills 28
C. Alfalfa Dehydration 32
D. Wheat Mills 33
E. Durum Mills 36
F. Rye Milling 39
G. Dry Corn Milling 42
H. Oat Milling 46
I. Rice Milling 47
J. Commercial Rice Drying 50
K. Soybean Mills 51
L. Corn Wet Milling 58
v
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CONTENTS (Concluded)
IV. Projected Emissions. ...... 61
A. Elevators 63
1. Country elevators. 63
2. Terminal elevators .............. 64
3. Export elevators 65
B. Feed Mills 66
C. Alfalfa Dehydrating 67
D. Wheat Mills 68
E. Durum Mills 69
F. Rye Milling 70
G. Dry Corn Milling 71
H. Oat Milling 72
I. Rice Milling 73
J. Commercial Rice Drying 74
K. Soybean Mills 74
L. Corn Wet Mills 75
References. 76
Appendix A - Calculation of Projected Emissions 77
VI
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TABLES
Table . Title Page
1 Summary of Estimated Emissions* 2
2 Summary of Projected Emissions 4
3 Grain Dryer Emission Data—Rack Dryers. 13
4 Grain Dryer Emission Data—Column Dryers 15
5 Summary of Emission Factor Selection for Grain Dryers . . 16
FIGURES
Figure Title Page
1 Emission Factor Data for Rack Dryers as a Function of
Control Device Screen Size 14
vii
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SUMMARY
Volume I of this study reports on Emissions Control in the Grain and
Feed Industry and contains much or all available information on emission
sources within this industry. In addition, it contains a compilation of
questionnaire data on the extent of control that has been applied. The ob-
jective in Volume II is to evaluate this information, prepare an emission
inventory for this industry, and project emissions for the years 1975 and
1980.
Methodology employed in preparing the emission inventory consisted
of the following steps:
a. Identify (using information in Volume I) those operations within
each segment of the industry that represent major emission sources.
b. Determine production rate for each segment of the industry and
the portion of that rate associated with specific operations.
c. Evaluate data presented in Volume I and other references in order
to select the most representative emission factor for each operation.
d. Utilize questionnaire results presented in Volume I to identify
application of control on each operation and calculate average efficiency
of control.
e. Calculate annual emissions from each operation using factors ob-
tained in the preceding steps.
This sequence of steps, or variations thereof, was employed to calcu-
late emission quantities for all important sources within each segment of
the grain and feed industry. A summary of emissions for each segment is
presented in Table 1 and indicates the year for which these are applicable.
Some segments do not include all source operations because of lack of
information.
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Table I. SUMMARY OF ESTIMATED EMISSIONS
Source
Grain elevators
Country elevators (1971)
Terminal elevators (1971)
Export elevators (1971)
Feed mills (1969)
Alfalfa dehydration plants (1971)
Wheat mills (1971)
Durum mills (1971)
Rye mills (1971)
Dry corn mills (1970)
Oat mills (1970)
Rice mills (1970)
Commercial rice dryers
Soybean mills (1970)
Wet corn mills (1970)
Emissions
(tons/year)
357,000
117,000
140,000
174,000
16,000
45,600£/
649S/
408S/
3,550S/
875
4,260S/
b/
117,000
11,200
Confidence
Rating£/
B
A
B
B
B
C
C
C
B
C
C
B
C
a/ Emission quantity does not include all source operations
because of lack of information.
_b/ No estimate of emissions due to lack of information.
c/ A - Good reliability
B - Fair reliability
C - Poor reliability
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The emission estimates are subject to several limitations. Foremost
among these is the scarcity of data needed for determination of representa-
tive emission factors. In many cases estimates had to be based on only one
or two pieces of data and in certain cases controlled emission factors had
to be used. Accuracy of the emission calculations is also limited by the
reliability of the extent of control information taken from the question-
naires and the fact that these same data were used to calculate the aver-
age efficiency of control assuming 907<> efficiency for cyclones and 997o
efficiency for fabric filters. Reliance on meager data and the uncertainty
of assumptions limit the accuracy of results, as indicated by the con-
fidence ratings (Table 1), and emphasizes the need for additional testing
and information before more accurate estimates can be obtained.
The emission values given in Table 1 are believed to be the best esti-
mates that can be made within the limitations of the available data. These
estimates were prepared for more sources, and in more detail, than was pre-
viously possible. They are also based on the most complete information on
extent of control obtained from industry questionnaires and should there-
fore closely represent current status of applied control technology in
this industry.
Emission calculations were made for the latest year in which produc-
tion information was reported in Volume I. This ranged from 1969-1971.
These calculations were used as a basis for projecting emissions for 1975
and 1980. The processing rates for those years were estimated and the fol-
lowing assumptions were made concerning the future in the extent of control:
(1) larger operations located mainly in urban areas (e.g., export elevators)
will be subject to more control pressures so they would reach 100% applica-
tion of control, using the most efficient devices, by 1985; (2) a linear
relationship exists between the present and future level; (3) smaller
operations will reach 100% control by 1990 or 1995, depending on the type
of operation; (4) small operations in rural areas (e.g., country elevators)
should be under less control pressure, so the application of control will
increase at a fixed rate (e.g., 3% per year).
The accuracy of emission projections is limited primarily by these
assumptions, however, they are considered reasonable at this time.
Results of the emission projections for each segment of the grain and
feed industry are shown in Table 2.
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Table 2. SUMMARY OF PROJECTED EMISSIONS
Industry
Grain elevators
Country elevators
Terminal elevators
Export elevators
Feed mills
Alfalfa dehydration
Wheat millsS/
Durum mills^'
Rye mills^'
Dry corn mills^
Oat mills
Rice mills§/
Commercial rice dryers
Soybean mills
Wet corn mills
Estimated Emissions
(tons/year)
(and Base Year)
357,000 (1971)
117,000 (1971)
140,000 (1971)
174,000 (1969)
16,000 (1971)
45,600 (1971)
649 (1971)
408 (1971)
3,550 (1970)
875 (1970)
4,260 (1970)
y
117,000 (1970)
11,200 (1970)
Projected Emissions
(tons/year)
1975
376,000
126,000
132,000
156,000
13,000
37,400
628
338
2,870
1,000
3,730
b/
93,000
10,800
1980
339,000
115,000
82,000
127,000
9,200
29,000
507
262
1,980
1,000
2,420
y
61,400
9,300
a/ Emission quantities do not include all source
operations because of lack of information.
b/ No estimate of emissions due to lack of information.
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I. INTRODUCTION
Inventories of particulate emissions for grain and feed operations
have been conducted in the past by EPA and others, but the previous inven-
tories were usually directed primarily to grain elevators and were based
on very meager data on emission factors and estimates of extent of con-
trol. As part of EPA Contract No. 68-02-0213, recent test data as well as
previous data were compiled by MRI to up-date information on emissions
and emission factors for each operation within each segment of the grain
and feed industry. In addition, the emission inventory questionnaires
utilized in the study enabled a determination of the extent of control
for most industry operations.* The improved data base that resulted was
used to prepare an inventory of particulate emissions for the grain and
feed industry which is reported herein.
The segments of the grain and feed industry included in this emission
inventory are:
A. Grain Elevators
B. Feed Mills
C. Alfalfa Dehydrating Plants
D. Wheat Mills
E. Durum Mills
F. Rye Mills
G. Dry Corn Mills
H. Oat Mills
I. Rice Mills
* See Appendix C of Ref. 1.
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J. Commercial Rice Dryers
K. Soybean Mills
L. Wet Corn Mills
The above industry segments are the same as those covered in Volume
I,—' which included process descriptions, identification of emission
sources, presentation of emission data, and discussion of control methods,
etc. Much of that information has been utilized in this report.
The methodology used to make emission estimates and the data and
calculations pertinent to each operation are presented in this document.
Assumptions used and indications of the reliability of the estimates are
included with the calculations. Data required for calculating emissions
from some specific operations are still not available, therefore the emis-
sion inventory presented is not complete.
The emission inventory is primarily based on amounts of grain processed
by each segment of the industry in 1970 or 1971 (the most recent data com-
piled in Volume I).!./ Estimates of future grain production and emission
control have been used to project emissions for the years 1975 and 1980.
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II. GENERAL METHODOLOGY
In order to refine existing emission inventories, it is necessary
to upgrade the data base with respect to production rates, emission factors,
percentage of production capacity on which control equipment is installed,
and control equipment efficiency. Most of the available emission factor
data for the operations within each segment of the industry and statistics
on the amount of grain processed through each operation are presented in
Volume I as well as information on the type and on the number of control
devices installed on the various sources of interest.
The computation method used to calculate the emission was, in most
cases, the same procedure that had been applied in making the national
inventory of particulate emissions for the Particulate Pollutant System
Study.2/ The following equation was used to calculate emissions:
E= (P)(e.f.) (1/2,000) [l-(a)(e>] (1)
where E = Emissions in tons per year.
P = Process rate in tons per year.
e.f. = Emission factor in pounds per ton.
a = Application of control (expressed as the fraction of amount
processed that is equipped with control equipment).
e = Efficiency of control (a factor indicating the average effici-
ency of the control equipment applied to the process).
Details of the calculations and a summary of the calculated emissions
are presented in the following sections. All of the data necessary for the
calculation using Eq. (1) were not available for every operation in each
industry segment. For a few operations, so little information was avail-
able that it was not possible to estimate emissions. Some estimates were
made by somewhat different methods which are detailed in the text. Also,
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since more data were available for some sources than for others, a con-
fidence rating was assigned to the emissions quantity for each operation
as an indication of the accuracy of the calculated emissions.*
The estimated particulate emissions represent the total potential
emissions from handling of grain and other processing operations. Some
are generated from interior operations, such as tunnel belts and gallery
belts in grain elevators, and may not all reach the exterior of the
facility. Those emitted from operations that are primarily external (un-
loading, loading, drying, etc.) are emitted to the ambient air. There-
fore, the particulate emissions which actually enter the atmosphere could
range from a minimum of those associated only with external operations
up to a maximum of the total emission from all operations.
* A = Good reliability.
B = Fair reliability.
C = Poor reliability.
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III. EMISSION CALCULATIONS
A. Grain' Elevators
Grain elevators are one of the major sources of particulate emissions
within the grain and feed industry. This segment has been subdivided into
the three main categories of country, inland terminal, and export elevators.
Many of the grain handling operations or emission sources within these three
classes of elevators are similar and include:
Unloading
Loading
Drying
Cleaning
Garner and scale vents
Elevator legs
Transfer points
Bin vents
Emission estimates were made for most of the above sources within the
three types of elevators. Emission factors were derived from data compiled
in Volume I and were supplemented by data obtained in a recent study con-
ducted by MRI for EPA, at a terminal elevator in Kansas City.I/ An ex-
tensive analysis of available data on grain dryer emissions was necessary
in order to derive a representative overall emission factor for that source
because of the difficulties associated with sampling of dryers, the varia-
tions in dryer designs, and the spread in reported sampling results. Our
analysis of grain dryer emission factors is presented within the section
on country elevators.
One difficulty in making emission calculations for grain elevators
was determination of the amount of grain processed through each operation
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by each type of elevator. The first requirement was to ascertain the amount
of grain handled or unloaded in each type of elevator. It was then neces-
sary to analyze available information in order to estimate the amount of
grain processed through each operation. This is a complex problem because
only part of the grain that is unloaded is cleaned or dryed, while on the
other hand, more grain may be transferred internally than is unloaded.
The methodology used in estimating the amounts of grain processed through
each operation is discussed within the appropriate section of the emission
calculations for each type of elevator.
1. Country elevators; The major operations or sources within country
elevators for which emission quantities were calculated are:
a. Unloading
b. Turning
c. Loading
d. Drying
e. Cleaning
f. Headhouse
a. Unloading
(1) Processing rate; The annual receipts, or amount of
grain unloaded, at country elevators during the 1971-1972 crop year was
5.9 x 109 bushels (177 x 106 tons) (Vol. I, page 21).
(2) Emission factor; An emission factor of 0.64 Ib/ton,
for truck unloading, was taken from a study at a terminal elevator..!/
This is lower than previous factors for this source but is based on
quantitative results that are considered to be the most accurate available.
It is possible, however, that the emission factor for country elevators
could be higher than similar operations at terminal elevators because of
the field dust, etc., but definitive test results for country elevators
are not available.
(3) Extent of control; A 31% application of control was
determined from Table 177 in Vol. I. This same table was used to calculate
a 90% efficiency of control assuming 90% efficiency for cyclones and 997o
for fabric filters.
10
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(4) Calculation of emissions; Using Eq. (1) and the fac-
tors delineated above, one obtains the following estimate of particulate
emissions:
(177 x 106 tons) (0.64 Ib/ton) (ton/2,000 Ib) [l-(0.31)(0.90>]
=0.41 x 105 tons8
b. Turning
(1) Processing rate; The amount of grain turned was calcu-
lated using the amount of grain unloaded (177 x 106 tons). This was multi-
plied by 1/2.0, which is the ratio of storage capacity to amount received
(Vol. I, page 20), and by 1.5, which is the estimated number of times that
storage volume is turned based on the country elevator questionnaires dis-
cussed in Volume I.
(2) Emission factor; A value of 1.40 Ib/ton was used for
turning, based on expected similarity to the tunnel belt emissions factor
determined in Ref. 3 for a terminal elevator.
(3) Extent of control; Because grain is often turned at
a country elevator by returning it into the receiving pit, the same extent
of control as receiving was assumed.
(4) Calculation of emissions; Particulate emissions from
turning operations were estimated using Eq. (1) and the appropriate fac-
tors. As shown in the following calculations, emissions are estimated to
be about 6.7 x 10 tons/year.
(177 x 106 tons x 1/2.0 x 1.5)(1.40 lb/ton)(ton/2,000 lb)[l-(0.31)(0.90)]
=6.65 x 104 tons3
c. Loading
(1) Processing rate; It was assumed that over the long
term, the amount loaded equals the amount unloaded (177 x 10" tons).
(2) Emission factor; A factor of 0.27 Ib/ton was applied
to loading operations at country elevators. This factor is based on data
for car loading at a terminal elevator. No definitive data were available
for country elevators so the same factor was used as for terminal elevators
(see section on unloading).
11
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(3) Extent of control; Data in Vol, I (Table 177) were
utilized to calculate 22% application of control and 907» efficiency of
control.
(4) Calculation of emissions; Emissions are estimated to
be 19jOOO tons/year as indicated by the following calculation.
(177 x 106 tons)(0.27 lb/ton)(ton/2,000 lb)[l-(0.22)(0.90)] =0.19 x 10 tons?
d. Drying
- (1) Processing rate; Data in Volume I (page 23) indicated
that 25.47o of grain receipts are dried at country elevators. The survey
questionnaires used in deriving this figure also indicated that about
half of the dryers at country elevators were rack type and the other half
were column type. Based on this information, it was assumed that 12.77o
of grain receipts are dried in each type of dryer.
(2) Emission factor; A quantitative assessment of emis-
sions from grain dryers is difficult. The emission rate from any given
installation is probably dependent upon the dryer configuration, i.e.,
rack or column; the type of grain being processed, i.e., corn, soybeans,
wheat; the foreign material present in the incoming grain, i.e., dust,
chaff, "beeswing" hulls, etc.; and the amount of moisture removed which
affects throughput.
The large volumes of air passed through the grain, the
large cross-sectional area through which the air is exhausted and the
wide particle size distribution of the effluent contribute to sampling
difficulties. The absence of an acceptable test method makes comparisons
between reported dryer emission tests highly uncertain.
There are two main types of grain dryers (rack or column
type) and because the emissions from these two types are different, they
have been considered separately. Available data on rack dryer emissions
have been tabulated as shown in Table 3. Some of the data in Table 3 are
results of emission tests on dryers equipped with control devices employ^
ing some type of screen to reduce the emissions. The data and information
from Table 3 are depicted graphically in Figure 1. This figure indicates
that there may be a relationship between control device screen size and
the emission factor. The figure also indicates that the uncontrolled emis-
sion factor for rack dryers may approach an average value of about 3.0
Ib/ton. For this reason, the value of 3.0 Ib/ton has been selected as
the uncontrolled emission factor for rack dryers, for the purpose of esti-
mating emissions from rack dryers.
12
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Table 3. GRAIN DRYER EMISSION DATA—RACK DRYERS
A*/
B&/
c£/
D£/
Ed/
Fe/
Dryer
Throughput
(bu/hr)
2,750
1,000
1,033
4,000
2,000
1,000
Control Device
Screen Size
34 mesh
100 mesh
None
50 mesh
None
24 mesh
Emissions (Ib/ton)
Controlled Uncontrolled
1.3
0. 1 to 0.38
3.9
0.86
2.3
0.34 3.1
a/ Volume I, p. 134.
b/ Volume I, p. 136.
£/ Volume I, p. 137.
d/ Volume I, p. 139.
£/ Test report received from EPA.
13
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4.0
3.
Letter designations on data
points refer to Table 3.
0 10 20 30 40 50 60 70 80 90 100
SCREEN MESH SIZE
Figure 1 - Emission Factor Data for Rack Dryers as a Function of Control Device Screen Size
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Emission test data for column dryers are sparse, as can
be seen by the tabulation of data in Table 4. Only two sets of data were
available but they are in close agreement with an average of 0.22 Ib/ton.
However, other unpublished data for a column dryer (noncirculating) showed
an emission factor of 0.45 Ib/ton.* Therefore, these three pieces of data
were considered together and an emission factor of 0.3 Ib/ton was used
for the purpose of estimating emissions from column dryers.
Table 4. GRAIN DRYER EMISSION DATA--COLUMN DRYERS
AJL/
Bb/
Dr-yer
Throughput
(bu/hr)
1,000
400
Control
Device
None
None
Emissions (Ib/ton)
•Controlled Uncontrolled
0.21
0.23
a/ Volume I, p. 139.
b/ Volume I, p. 140.
In summary, the uncontrolled emission factors used in com-
puting dryer emissions are those shown in Table 5 (rack--3.0 Ib/ton, col-
umn--0.3 Ib/ton). However, it must be emphasized that because of the small
amount of available data, spread in these data, inadequate information
regarding specific test methods, use of different sampling trains, and
the lack of complete information regarding foreign material and moisture
differential, these emission factors should only be considered as indica-
tive of possible average emissions and not absolute numbers for individual
dryers.
(3) Extent of control; Data in Volume I (Table 177) showed
the application of control on all grain dryers to be 25%. It has been
assumed that the controlled dryers are primarily the rack type. As previ-
ously mentioned, half of the dryers are rack type, while the other half
are column type. Therefore, the application of control on rack type dryers
is 50%, while the application of control on column dryers is near 0%.
The associated efficiency of control was estimated to be 807o for the de-
vices that are used to control rack dryer emissions.
* Background Information for Federal Performance Standards - Grain
Handling and Milling, Report prepared for EPA by PEDCo-Environ-
mental, Cincinnati, Ohio, July 1971.
15
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Table 5. SUMMARY OF EMISSION FACTOR SELECTIONS FOR GRAIN DRYERS
Dryer Type Selected Emission Factor (uncontrolled)
Rack 3.0 Ib/ton
Column 0.3 Ib/ton
(4) Calculation of emissions; Based on the above factors,
particulate emissions from grain dryers were estimated as follows:
Rack dryers:
(177 x 106 tons x 12.7%)(3.0 lb/ton)(ton/2,000 Ib) [l-(0.50)(0.80)]
= 20.23 x 103 tons
Column dryers:
(177 x 106 tons x 12.7%)(0.3 lb/ton)(ton/2,000 Ib) [l-(0)]
= 3.37 x 103 tons
Dryer total 23.60 x 103 tonsC
e. Cleaning
(1) Processing rate; Data in Vol. I (page 23) indicated
that 7.8% of receipts at country elevators are cleaned.
(2) Emission factor; An emission factor of 6.0 Ib/ton was
selected based on data in Ref. 3. This is somewhat lower than the range
of 7-10 Ib/ton shown in Table 81 of Vol. I, but the former value is con-
sidered to be based on more definitive data
(3) Extent of control; Volume I (Table 177) showed 73%
application of control on cleaning operations at country elevators.* Data
from this same table were used to calculate an efficiency of control of
95%, assuming 90% efficiency for cyclones and 99% for fabric filters.
* In comparison with the application of control for drying in terminal
and export elevators, the 73% application figure appears to be quite
high. It is possible that data from questionnaires were not representa-
tive of the whole industry. Thus the confidence level of this figure
is quite low.
16
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(4) Calculation of emissions; Particulate emissions of
the order of 104 tons/year are estimated to result from grain cleaning as
shown in the following calculation:
(177 x 106 tons x 7.8%)(6.0 lb/ton)(ton/2,000 lb)[l-(0.73)(0.95)]
= 1.38 x 104 tonsc
f. Headhouse
(1) Processing rate; Amount of grain passing through the
headhouse (legs) is estimated to be the same as the total of all operations
because grain must pass through the headhouse at least once for each opera-
tion. Therefore, the amount passing through the headhouse was obtained by
summation of the amounts involved in each operation as described in the
preceding sections a through e, resulting in a total of 546 x 106 tons.
(2) Emission factor; An approximate emission factor of
1.5 Ib/ton was used for the headhouse (legs, etc.) based on data in Ref.
3.
(3) Extent of control; Volume I (Table 177) showed 59%
application of control on legs at country elevators. Almost all were con-
trolled with cyclones, so efficiency of control was estimated to be 9070.
(4) Calculation of emissions; Using Eq. (1) and the fac-
tors delineated for headhouse processes, one obtains the following estimate
of particulate emissions;
(546 x 106 tons)(1.5 lb/ton)(ton/2,000 lb)[l-(0.59)(0.90)] = 1.92 x 105 tonsB
g. Summary of estimated particulate emissions for country ele-
vators; A summary of the estimated particulate emissions for the major
sources at country elevators is presented below:
17
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Emission (1971) Confidence
Country Elevators (ton/year) Rating**/
a. Unloading 0.41 x 105 B
b. Turning 6.65 x 104 B
c. Loading 0.19 x 105 B
d. Drying 2.36 x 104 C
e. Cleaning 1.38 x 104 C
f. Headhouse 1.92 x IQ5^ B
Subtotal 3.57 x 105 B
a/ A = Good reliability.
B = Fair reliability.
C = Poor reliability.
2. Inland terminal elevators; The major individual sources within
inland terminal elevators for which emission quantities were calculated
are:
a. Unloading
b. Turning
c. Loading
d. Drying
e. Cleaning
f. Headhouse
g. Tripper
a. Unloading
(1) Processing rate; The annual receipts or amount of grain
unloaded at terminal elevators during the 1971-1972 crop year was 1.8 x 109
bushels (5.4 x 107 tons).!/
18
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(2) Emission factor; An emission factor of 1.00 Ib/ton
is estimated for unloading in terminal elevators. This is based on the
average of the emission factors for truck unloading (0.64 Ib/ton) and
car unloading (1.30 Ib/ton) found in Ref. 2. This estimate is supported
by data in Table 81 of Vol. I.
(3) Extent of control; A 59% application of control was
determined using Table 178 in Vol. I. This same table was used to deter-
mine an efficiency of control of 93%. This is based on a weighted average
of the control devices assuming 90% efficiency for cyclones and 99% ef-
ficiency for fabric filters.
(4) Calculation of emissions; Particulate emissions cal-
culated from Eq. (1) and the factors selected result in the following esti-
mate; .
(5.4 x 10? tonsXl.OO lb/ton)(l/2,000)[l-(0.59)(0.93)] = 1.22 x 104 tonsA
b. Turning
(1) Processing rate; The amount of grain turned was cal-
culated using the amount of grain unloaded (5.4 x 107 tons). This was
multiplied by 1/1.4 which is the ratio of storage capacity to amount
received (Vol. I, page 20) and by 1.0 which is the estimated number of
times that the storage volume is turned based on questionnaires discussed
in Vol. I.
(2) Emission factor; A factor of 1.40 Ib/ton was used and
was based on the tunnel belt emission factor of 1.40 determined in Ref, 3.
(3) Extent of control; A 92% application of control was
determined using Table 178 of Vol. I. The same table was used to determine
an efficiency of control of 93%, assuming 90% efficiency for cyclones and
99% efficiency for fabric filters.
(4) Calculation of emissions; Particulate emissions on
the order of 4,000 tons are estimated using Eq. (1) and the preceding
factors;
(5.4 x 107 tons x 1/1.4 x 1.0)(1.40 lb/ton)(l/2,000)[l-(0.92)(0.93)]
= 3.78 x 103 tonsA
19
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c. Loading
(1) Processing rate; It is assumed that .the amount loaded
is equal to the. amount unloaded (5.4 x 10 tons).
(2) Emission factor; The emission factor of 0.27 Ib/ton
for loading into cars was taken from Ref. 3.
(3) Extent of control; A 30% application of control was
obtained from Table 178 of Vol. I. Data from the same table were used to
calculate an efficiency of control of 92%.
(4) Calculation of emissions; Emissions of the order of
5,000 tons/year were estimated using Eq. (1).
(5.4 x 107 tons)(0.27 lb/ton)(l/2,000)[l-(0.30)(0.92)] = 5.25 x 103 tonsA
d. Drying
(1) Processing rate; Data in Vol. I (page 23) indicated
that 9.6%. of the grain unloaded is dried in terminal elevators. It was
also assumed that like country elevators half of the dryers at terminal
elevators were rack type and the other half were column type. On this
basis, it follows that 4.8% of the amount unloaded is dried in each type
of dryer (i.e., 2.59 x 106 tons).
(2) Emission factor; An emission factor of 0.3 Ib/ton
was used for column dryers and 3,0 Ib/ton for rack dryers (see Section
l.d.).
(3) Extent of centro1; A 24% application of control was
obtained from Table 178 of Vol. I and the efficiency of control was esti-
mated to be about 80% for the devices that are used to control dryer emis-
sions. However, the 24% application of control covers all dryers, half of
which ware assumed to be column type and half rack type. As in the case
of country elevators, it was also assumed that the controlled dryers are
primarily the rack type. It therefore follows that the application of
control on rack type dryers is 48%, while the application of control on
column dryers is near 0%.
(4) Calculation of emissions; Emissions have been cal-
culated based on the factors delineated above and in Eq. (1) as follows:
20
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Rack dryers:
(2.59 x 106 tons)(3.0 lb/ton)(ton/2,000 lb)[l-(0.48)(0.80)]
= 2.39 x 103 tons
Column dryers:
(2.59 x 106 tons)(0.3 lb/ton)(ton/2,000
= 0.39 x 10 .tons
Dryer total 2.78 x 103 tonsc
e. Cleaning
(1) Processing rate; From Vol. I (page 23) it was deter-
mined that terminal elevators clean 22.1% of their receipts. Using the amount
of grain unloaded (5.4 x 10^ tons) it was determined that the amount of
grain cleaned was 1.19 x 10 tons.
(2) Emission factor; An emission factor of 6.00 Ib/ton
is based on data from Ref. 3, which showed an emission factor of 5.78
Ib/ton for corn cleaning.
(3) Extent of control; A 43% application of control was
obtained from Table 178 of Vol. I. Data from this same table were used to
determine the efficiency of control of 92%.
(4) Calculation of emissions; The emissions from the clean-
ing process were calculated to be 2.18 x 104 tons.
(1.19 x 10? tons)(6.00 lb/ton)(l/2,000)[l-(0.43)(0.92)] = 2.18 x 104 tonsA
f . Headhouse
(1) Processing rate; The amount of grain passing through
the headhouse is estimated to be the total of all operations (16.4 x 10^
tons).
(2) Emission factor; The emission factor of 1.50 Ib/ton
was determined from Ref. 3 (1.49 Ib/ton) which included garner and scale.
(3) Extent of control; A 78% application of control was
obtained from Table 178 of Vol. I. This same table was used to determine
an efficiency of control of 92%.
21
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(4) Calculation of emissions; Below are the calculations
of total emissions from the headhouse process in terminal elevators (pri-
marily legs).
(16.4 x 107 tons)(1.50 lb/ton)(l/2,000)[l-(0.78)(0. 92)] = 3.44 x 104 tonsA
g. Tripper
(1) Processing rate; The amount of grain crossing the trip-
per is assumed to be at least equal to the amount unloaded plus the amount
turned (9.3 x 107 tons).
(2) Emission factor; The emission factor for the tripper
of 1.00 Ib/ton is a gross estimate based on factors for other sources and
observations of tripper emissions. No data are available for this source.
(3) Extent of control; A 22% application of control was
taken from Vol. I (Table 178). An efficiency of control of 94% was deter-
mined using data from the same table.
(4) Calculation of emissions; Emissions from the tripper
have been approximated at 3.67 x 10^ tons as calculated below;
(9.3 x 107 tons)(1.00 lb/ton)(l/2,000)[l-(0.22)(0.94)] = 3.67 x 104 tons5
h. Summary of the calculated emissions for terminal elevators;
A summary of the calculated emissions for the major sources at terminal
elevators is presented below;
Emissions (1971) Conf]Lde.nee
Terminal Elevators
a.
b.
c.
d.
e.
f.
g.
Unloading
Turning
Loading
Drying
Cleaning
Headhouse
Tripper
(tons/year)
1.22 x IO4
3.78 x IO3
5.25 x IO3
2.78 x IO3
2. 18 x IO4
3.44 x IO4
3.67 x IO4
Subtotal 1.17 x IO5
Ratinga/
A
A
A
C
A
A
B
A
a/ A = Good reliability.
B = Fair reliability.
C = Poor reliability.
22
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3. Export elevators; The major individual sources within export
elevators for which emissions quantities were calculated are:
a. Unloading
b. Turning
c. Loading
d. Drying
e. Cleaning
£. Headhouse
g. Tripper
a. Unloading
(1) Processing rate; The annual receipts or amount of
grain unloaded at export elevators during the 1971-1972 crop year was
2.7 x 109 bushels (8.1 x 107 tons) (Vol. I, page 21).
(2) Emission factor; The emission factor for export ele-
vators is assumed to be the same as that for terminal elevators, 1.0 lb/tqn.
(3) Extent of control; An application of control of 76%
was obtained from Table 179 of Vol. I. This same table was used to calcu-
late an efficiency of control of 957o. This was based on a weighted average
of the control devices, assuming 90% efficiency for cyclones and a 99% ef-
ficiency for fabric filters.
(4) Calculation of emissions; Using Eq, (1) and the fac-
tors delineated above, emissions from the unloading operation were deter-
mined as follows:
(8.1 x 107 tons)(1.00 lb/ton)(l/2,000)[l-(0.76)(0.95)] = 1. 13 x 104 tonsA
b. Turning
(1) Processing rate; The amount of grain turned was cal-
culated using the amount of grain unloaded (8.1 x 10^ tons). This was
multiplied by the ratio of the storage capacity to the amount received
(1/7.6) from Vol. I (page 20) and by the estimated number of times that
the storage volume is turned (0.5) based on data from the associated
questionnaires.
23
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(2) Emission factor; The emission factor for turning is
assumed to be the same as that for terminal elevators (1.40 Ib/ton).
(3) Extent of control; An 827, application of control was
determined by using Table 179 of Vol. I. This table was also used to de-
termine an efficiency of control of 93%.
(4) Calculation of emissions; The total emissions from
the turning of grain in export elevators has been determined to be about
900 tons.
(8.1 x 107 tons x 1/7.6 x 0.5)(1.40 lb/ton)(l/2,000)[l-(0.82)(0.93)]
=8.95 x 102 tonsA
c. Loading
(1) Processing rate; It is assumed that the amount loaded
is equal to the amount unloaded (8.1 x 10^ tons).
(2) Emission factor; The emission factor of 1.0 Ib/ton
for ship loading is based on one test of ship loading at a port elevator
in Seattle (EPA Emission Test Report 73-GRN-8).
(3) Extent of control; A 26% of application of control
is based on data in Table 179 of Vol. I. This same table was used to de-
termine an efficiency of control of 90%.
(4) Calculation of emissions; Emissions for the lopdingj
operations were calculated using Eq. (1) and the factors determined above
to be 3.12 x 104 tons.
(8.1 x 107 tons)(1.0 lb/ton)(l/2,000)[l-(0.26)(0.90)] =3.12 x 104 tons6
d. Drying
(1) Processing rate; Data in Vol. I (page 23) indicated
that 1.0% of the grain unloaded is dried in export elevators. Using the
amount of 8.1 x 10^ tons unloaded, the total amount dried is 8.1 x 10^
tons. However, it was again assumed that half the dryers are rack type
and half are column type. It was thus estimated that about 4.0 x 10 tons
are dried in each type dryer.
24
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(2) Emission factor; The emission factor and the assump-
tions on which it is based are the same for export elevators as for
country and terminal elevators (i.e., 3.00 Ib/ton for rack dryers and 0.3
Ib/ton for column dryers)^
(3) Extent of control; Based on the previously described
extent of control derived for country and terminal elevators, it was esti-
mated that the extent of control for rack type dryers in export elevators
is about 50%, while that .for column dryers is nearer 0%. The efficiency
of control was also estimated to be about 80%.
(4) Calculation of emissions; The emissions from drying
amount to about 400 tons.
Rack dryers;
(4.0 x 105 tons)(3.0 Ib/ton)(ton/2,000 lb)[l-(0.50)(0.80)] = 360 tons
Column dryers;
(4.0 x 105 tons)(0.3 lb/ton)(ton/2,000 lb)[l-(0)] = 60 tons
Dryer total 420 tonsc
e. Cleaning
(1) Processing rate; From Vol. I (page 23) it was deter-
mined that export elevators clean 14.6% of their receipts (8.1 x 107 tons).
It was thus calculated that the amount of grain cleaned was 1.18 x 107
tons.
(2) Emission factor; The emission factor for cleaning in
export elevators is assumed to be the same as that in terminal eleators
(6.00 Ib/ton).
(3) Extent of control; A 377o application of control was
obtained from Table 179 of Vol. I. Data from this same table indicated the
efficiency of control was 94%.
(4) Calculation of emissions; Emissions have been calcu-
lated to be 2.3 x 10^ tons using Eq. (1) and the factors determined above.
(1.18 x 107 tons)(6.00 lb/ton)(l/2,000)[l-(0.37)(0.94)] = 2.30 x 104 tonsA
25
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f. Headhouse
(1) Processing rate; The amount of grain passing through
the headhouse is estimated to be the total of the amounts involved in the
preceding five operations (18.0 x 10 tons).
(2) Emission factor; The emission factor of 1.5 Ib/ton
was assumed to be the same as that for the headhouse of a terminal ele-
vator.
(3) Extent of control; A 637o application of control was
determined from Table 179 Vol. I. 1. This same table was used to calculate
an efficiency of control of 96%.
(4) Calculation of emissions; The emissions total of 5.34
x 104 tons calculated below was determined using Eq. (1) and the factors
delineated above. The calculations are as follows:
(18.0 x 107 tons)(1.5 lb/ton)(l/2,000)[l-(0.63)(0.96)] = 5.34 x 104 tonsA
g. Tripper
(1) Processing rate; The amount of grain crossing the
tripper was assumed to be at least equal to the amount unloaded plus the
amount turned (8.6 x 10 tons).
(2) Emission factor; The emission factor of 1.0 was as-
sumed to be equal to the emission factor used for the tripper in a terminal
elevator.
(3) Extent of control; A 57% application of control was
obtained from Table 179 of Vol. I. An efficiency of control of 90% was de-
termined using data from this same table.
(4) Calculation of emissions; Tripper emissions of 2.02
x 10 tons have been calculated below.
(8,6 x 107 tons)(1.0 lb/ton)(l/2,000)[l-(0.57)(0.93)] = 2.02 x 104 tons6
h. Summary of calculated emissions for export elevators; A sum-
mary of the calculated emissions for the major sources at export elevators
is presented below:
26
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h. Summary of calculated emissions for export elevators; A sum-
mary of the calculated emissions for the major sources at export elevators
is presented below:
Emissions (1971) Confidence
Export elevators (tons/year) Rating—'
a. Unloading 1.13 x 10^ A
b. Turning 8.95 x 10^ A
c. Loading 3.12 x 10 B
d. Drying 4.20 x 10 C
e. Cleaning 2.30 x 10 A
f. Headhouse 5.34 x 10 A
g. Tripper 2.02 x 10 B
Subtotal 1.40 x 10 B
£/ A = Good reliability.
B = Fair reliability.
C = Poor reliability.
27
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B. Feed Mills
Feed mills convert grain and other ingredients into a mixed feed by
first changing the constituents to a desired form and size, then mixing,
and finally forming the feed into the desired shape and consistency. The
basic forms of the feed are mash, pellets, and crumbles. The operations
which are possible sources of emission in this process are as follows:
a. Receiving
b. Shipping
c. Handling operations (transfer points, garner and scale)
d. Grinding
e. Pellet coolers
The mixing stage and the pellet milling stage are not considered to
be major sources of emissions, thus they are not included in the calcula-
tions of emissions.
a. Receiving
(1) Processing ratet The total feed production for 1969
was reported to be 104 x 106 tons (Vol. I, page 29).
(2) Emission factor; Emission factor data for this opera-
tion are sparse, owing partly to the fact that many ingredients, whole
grain and other more dusty materials (bran, dehydrated alfalfa, etc.), are
received L^y both truck and rail, and several unloading methods are employed.
For these reasons, an average emission factor would be difficult, if not
impossible, to determine. However, the recovery operations are similar to
those in a grain elevator, at least as far as whole grains are concerned.
Therefore, an emission factor for the unloading operation only has been
estimated as 1.30 Ib/ton. This was the value determined for car unloading
(Ref. 3) and may be representative of feed mills since questionnaire in-
dicate that the majority of ingredients are received by rail cars. The value
hopefully reflects the fact that some ingredients tend to be more dusty
than whole grains.
(3) Extent of control; Data in Vol. I (Table 188) indicated
an average application of control of about 327». From this table the weighted
average of efficiency of control was calculated to be about 96%.
28
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(4) Calculation of emissions; Receiving operation emis-
sions in feed mills have been determined to be 4.66 x 104 tons using the
calculations below:
(104 x 106 tons)(1.30 lb/ton)(l/2,000)[l-(0.32)(0.96)] = 4.66 x 104 tonsB
b. Shipping
(1) Processing rate; The amount of feed shipping in 1969
was 104 x 106 tons and data in Ref. 4 indicate that about 78%, or 81 x 10
tons, is bulk shipment.
(2) Emission factor; Load out is a major source of dust
emissions but little emission factor data are available (Vol. I, page 166).
However, it is known that of the feed shipped from feed mills, most of the
bulk feed is shipped by truck. As a basis, an emission factor of 0.27 Ib/ton
was determined from car loading of grain in Ref. 3. However, because it is
assumed that bulk loading of feed mill products would tend to be more dusty
than whole grain, an emission factor of 0.5 Ib/ton has been assumed for
this operation.
(3) Extent of control; A 570 application of control is in-
dicated in Table 188 of Vol. I. This same table was used to calculate an
efficiency of control of 907» (most controlled by cyclones).
(4) Calculation of emissions; The calculations below have
been used to determine a yearly particulate emissions total for shipping
of 19,500 tons.
(81 x 106 tons)(0.5 lb/ton)(l/2,000)[l-(0.05)(0.90)] = 1.95 x 104 tons0
c. Handling operations
(1) Processing rate; The amount of material handled was
assumed to be the same as the amount received (104 x 10 tons).
(2) Emission factor; No emission factor data were avail-
able for the internal handling operations in feed mills. However, it would
be expected that they are somewhat similar to those of grain elevators.
Reference 3 showed that the most significant of these operations was the
legs, having an emission factor of 1.49 Ib/ton. The tunnel belt emission
factor of 1.40 Ib/ton is comparable but feed mill operations are such that
this may not be a comparable operation. However, all material would be ex-
pected to pass through a leg at least twice so an overall emission factor
for feed mills has been estimated at 3.00 Ib/ton.
29
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(3) Extent of control; A 35% application of control was
indicated by Table 188 of Vol. I. Data from this same table were used to
determine a 95% efficiency of control.
' ' • '
(4) Calculation of emissions; Particulate emissions in
the handling process were calculated as follows;
(104 x 106 tons)(3.0 lb/ton)(l/2,000)[l-(0.35)(0.95)] = 1.05 x 105 tons6
d. Grinding
(1) Processing rate; Data in Ref. 4 indicate that about
47% of feed ingredients are whole grains that require grinding. It was there
fore estimated that 47% of the total ingredients (104 x 10 tons) is ground,
which amounts to 49 x 10^ tons.
(2) Emission factor; Because of the wide variation in
grains and grinders used, an average emission factor would be difficult
to determine. A small amount of data indicate that controlled emissions
may range from 0.02-0.2 Ib/ton (Vol. I, page 163). Data from Table 188
of Vol. I indicate 56.3% application of control with some plants using
fabric filters to control grinder emissions. Considering these facts, and
a lack of other data, an average controlled emission factor of 0.1 Ib/ton
has been estimated.
(3) Extent of control; Since the emission factor is for
controlled emissions, the extent of control is not applicable.
(4) Calculation of emissions; Particulate emissions for
grinding were calculated as follows:
(49 x 106 tons)(0.1 lb/ton)(l/2,000) = 2.44 x 103 tonsC
e. Pellet coolers
(1) Processing rate; Data in Ref. 4 indicate that about
17%, of the feed is pelletized so the amount pelletized was calculated to
be 18 x 106 tons.
(2) Emission factor; The only available emission factor
data for this operation indicated that the uncontrolled emission factor
was quite high (5-50 Ib/ton) but that the cyclones were very efficient (92-
99.9%, Vol. I, page 164). The data also show considerable difference in
controlled emission factors for horizontal and column coolers. Distribu-
tion of these two coolers within the industry is not known but observa-
tions indicated that column coolers are quite common. For this reason, a
controlled emission factor of 0.1 Ib/ton has been estimated for the in-
dustry as a whole.
30
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(3) Extent of control; Since the emissions factor was for
controlled emissions the extent of control is unnecessary.
(4) Calculation of emissions; ' Pellet cooler emissions were
calculated to be 900 tons/year, as shown below:
(18 x 106 tons)(0.1 lb/ton)(l/2,000) = 0.90 x 103 tonsC
f. Summary of emissions for feed mills; A summary of the cal-
culated emissions for the major sources in the feed milling industry is
presented below:
Emissions (1969) Confidence
(tons/year) Rating^
4
a. Receiving 4.66 x 10, B
b. Shipping 1.95 x 105 C
c. Handling 1.05 x 10 B
d. Grinding 2.44 x 103 C
e. Pellet coolers 0.90 x 10 C_
Total 1.74 x 10 B
a/ A = Good reliability.
B = Fair reliability.
C = Poor reliability.
31
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C. Alfalfa Dehydration
/ Alfalfa dehydration plants are relatively small operations that re-
ceive fresh cut alfalfa from the fields and dehydrate it in rotary gas-
fired dryers. The most significant source of emissions in this process
is the primary drying cyclone, which accounts for about 75% of the emis-
sions. Since this one source is so dominant, emissions will be calculated
on a total rather than a source basis.
1. Processing rate; Data in Vol. I (page 45), indicated that the
dehydrated alfalfa production for the 1971-1972 crop year amounted to 1.6
x 10 tons of "meal.
2. Emission factors; The emission factors for alfalfa dehydration
plants are discussed extensively in Vol. I (pages 171-202). It was con-
cluded that the plant emission factor probably does not exceed 20 Ib/ton.
However, much of the data used in arriving at this figure were based on
testing at plants which were reportedly well "tuned" prior to testing or
in some cases were operated below rated capacity.* If the above emission
factor is too low, it means that the emission inventory calculation results
are too low. Nonetheless, this emission factor has been used because it
is based on analysis of all the data presently available.
3. Extent of control; Even though a few plants have now installed
control devices, the application of control was assumed to be 07».
4. Calculation of emissions; The total yearly emissions for the
alfalfa dehydrating industry have been calculated below to be 1.6 x 10
tons.
(1.6 x 106 tons meal)(20 lb/ton)(l/2,000)[l-0] = 1.6 x 104 tons3
* Smith, Ken D., EPA Report 650/2-74-007, based on Grant No. R801446
(January 1974).
32
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D. Wheat Mills
1 Processing operationsiin wheat mills are discussed in Vol. I (pages
203-213) and three major emission areas are identified: grain receiving
and handling, grain cleaning, and milling operations. These areas have been
divided into the following sources for which emissions were calculated:
a. Receiving
b. Precleaning and handling
c. Cleaning house
d. Mill house
a. Receiving
(1) Processing rate; Volume I (page 53), indicated that
in 1971 the amount of wheat received at mills was 555 x 10° bushels (16.6
x 106 tons).
(2) Emission factor; It would be expected that receiving
of wheat for wheat milling would be similar In emissions to that for
terminal grain elevators (0.64 and 1.30 lb/ton).—' Data in Vol. I, page
182, for flour mills present controlled emission factors for fabric filters
but it is difficult to use these data for estimating uncontrolled emission
factor. Therefore, the data from Ref. 3 were used to estimate an emission
factor of 1.0 lb/ton for receiving by trucks, cars, and barges.
(3) Extent of control; An application of control of 75%
was obtained from Table 201 of Vol. I. Data from this same table were used
to calculate a weighted average efficiency of control of 9570.
(4) Calculation of emissions; Equation (1) and the factors
explained above were used to calculate particulate emissions of about 3,000
tons/year in the equation below:
(16.6 x 106 tons)(1.0 lb/ton)(l/2,000)[l-(0.70)(0.95)] = 2.78 x 103 tonsB
b. Precleaning and handling
(1) Processing rate; The amount of grain involved in this
process is assumed to be the same as the amount received (16.6 x 10 tons)
The fact that some grain is handled more than once is taken into account
as part of the emission factor estimate.
33
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(2) Emission factor; Very little data on uncontrolled emis-
sions from precleaning were available. Precleaning was assumed to consist
of scalping type operations which should be a minor source in relation to
handling. Since usable data on uncontrolled emissions from handling sources
were lacking, data from handling sources in grain elevators in Ref. 3 were
used even though it does not include an emission factor for the tripper.
However, it did include a tunnel belt (1.40 Ib/ton) and legs (1.49 Ib/ton).
It is known that the grain passes through the leg at least twice in a flour
mill. Therefore, a cumulative emission factor of 5.0 Ib/ton was estimated
for all handling operations.
(3) Extent of control; An 85% application of control was
determined in Table 201 of Vol. I. These same data were used to calculate
an efficiency of control of 95%.
(4) Calculation of emissions; The yearly emissions have
been calculated below to be about 8,000 tons.
(16.6 x 106 tons)(5.0 lb/ton)(l/2,000)[l-(0.85)(0.95)] = 7.89 x 103 tons8
c. Cleaning house
(1) Processing rate; The amount processed was assumed to
be the same as amount received (16.6 x 10 tons).
(2) Emission factor; Cleaning is accomplished by a variety
of means but often includes air aspiration to remove lighter impurities
as well as disc separators and scourers. Each of these can be a source of
dust emission but only a small amount of data on controlled sources were
available. Therefore, it was not possible to determine an emission factor.
(3) Extent of control; Data were insufficient to determine
extent of control. However, Vol. I did infer that it is probably quite high
with controlled houses using 75% fabric filter and 25% cyclones.
(4) Calculation of emissions; Emissions could not be esti-
mated because of insufficient information.
d. Mill house
(1) Processing rate; The amount of grain processed is again
assumed to be 16.6 x 10$ tons.
(2) Emission factor; Operations in the mill house are complex
and again very little emission data are available. However, Vol. I, page
209, cites one report which indicated that dust generated in roller mills
may average 70 Ib/ton. This source and the purifiers might, therefore, ac-
count for more than 70 Ib/ton.
34
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(3) Extent of control; Due to the economic value of the
products, the extent of control is quite high. Table 201 of Vol. I indi-
cated a 96% application of control and was used to calculate 987o effici-
ency of control.
(4) Calculation of emissions; Mill house emissions were
determined to be 3.49 x 104 tons. The calculations are;
(16.6 x 106 tons)(70 lb/ton)(l/2,000)[l-(0.96)(0.98)] = 3.49 x 104 tonsB
e. Summary of calculated emissions for wheat mills; The emis-
sion figure for milling is higher than that for precleaning and handling
and may be erroneously high. However, the loading of bran and shorts,
which have not been included in any calculations, also is a source of
emissions. Therefore, the total emissions for wheat mills summarized below
may not be greatly exaggerated, but confidence in the calculated quantities
is low.
Emissions (1971) Confidence
(tons/year) Rat ing—'
a. Receiving 2.78 x 10 B
b. Precleaning and handling 7.89 x 10 B
c. Cleaning house Insufficient information C
d. Mill house 3.49 x 10 B
Total 4.56 x 104 C
a_/ A = Good reliability.
B = Fair reliability.
C = Poor reliability.
35
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E. Durum Mills
The sources of emissions in durum mills can be categorized into the
same three areas as wheat mills. The four sources of emissions which will
be discussed are:
a. Receiving
b. Freeleaning and handling
c. Cleaning house
d. Mill house
a. Receiving
(1) Processing rate: Volume I (page 57), indicates that
the amount of durum wheat ground at mills in 1971 was 32 x 10" bushels or
about 1 x 106 tons.
(2) Emission factor; Data on the rates of emissions for
durum mills are limited. However, since the process is so similar to that
of wheat milling, it was assumed that the same emission factors are applic-
able. Therefore the emission factor of 1.0 Ib/ton was used.
(3) Extent of control; The extent of control was assumed
to be the same as that for wheat mills. The application of control was thus
assumed to be 707<> and the efficiency of control 95%.
(4) Calculation of emissions; The yearly emissions from
the receiving operation in durum mills have been calculated below to be
168 tons.
(1 x 106 tons)(1.0 lb/ton)(l/2,000)[l-(0.70)(0.95)] = 1.68 x 102 tonsB
b. Precleaning and handling
(1) Processing rate; The amount of grain handled is assumed
to be the same as that received (1 x 10 tons).
(2) Emission factor; Since so little data are available
on emissions from durum mills, it is assumed that the factor is the same
as that for wheat milling (5.0 Ib/ton).
36
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(3) Extent of control; Again the extent of control is as-
sumed to be the same as that for wheat milling; an 85% application of con-
trol and 95% efficiency of control.
(4) Calculation of emissions; Below are the calculations
which set the yearly emissions for precleaning and handling at 481 tons.
(1 x 106 tons)(5.0 lb/ton)(l/2,000)[l-(0.85)(0.95)] = 4.81 x 102 tons3
c. Cleaning house
(1) Processing rate; The processing rate was again assumed
to be the same as the amount received (1 x 10" tons).
(2) and (3) Emission factor and extent of control; The
same problems were encountered at this point as those in the wheat milling
industry. Therefore, it was not possible to determine emission factors or
extent of control.
(4) Calculation of emissions; Emissions were not estimated
because of insufficient data.
d. Mill house
(1) Processing rate; The amount of grain milled is assumed
to be 1 x 106 tons.
(2) Emission factor; There are insufficient data to determine
an emission factor for the mill house in a durum mill. It could not be assumed
to be the same as in wheat mills because the purpose of durum mills is to
produce middlings rather than flour. For this reason, the break rolls are
different than in wheat mills and the 70 Ib/ton figure cannot be used. There-
fore, no emission factor could be estimated.
(3) Extent of control; Since it is impossible to determine
emissions factors there was no estimate made.
(4) Calculation of emissions; Emissions were not estimated
because of insufficient data.
37
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e. Summary of calculated emissions for durum mills; Due to in-
sufficient information it was not possible to calculate emissions for all
significant sources within durum mills. Those emissions that could be cal-
culated are summarized in the table below:
Emissions (1971) Confidence
(tons/year) Rat ing3./
a. Receiving 1.68 x 102, B
b. Precleaning and handling 4.81 x 10 B
c. Cleaning house Insufficient information C
d. Mill house Insufficient informATIOn C
Total 6.49 x 102 C
a/ A = Good reliability.
B = Fair reliability.
C = Poor reliability.
38
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F. Rye Milling
There is a great deal of similarity between wheat milling and rye
milling and the processing steps for rye milling are the same as those
for wheat milling. Major emission sources are listed below:
a. Receiving
b. Precleaning and handling
c. Cleaning house
d. Mill house
a* Receiving
(1) Processing rate; Volume I (page 58) indicates that
in 1971, the amount of rye ground for flour was 5.3 x 10° bushels or 1.5
x 10 tons.
(2) Emission factor; Very little emission factor data are
available for rye milling. Therefore, it was assumed that the emission
factor was the same as in wheat milling (1.0 Ib/ton).
(3) Extent of control; Again, little data were available
about rye milling, but it was considered reasonable to assume that the
extent of control is about the sameas for wheat milling (70% application
of control and 95% efficiency of control).
(4) Calculations of emissions; The emissions resulting
from the receiving operation in rye mills have been calculated below to
be 25 tons.
(1.5 x 105 tons)(1.0 lb/ton)(l/2,000)[l-(0.70)(0.95)] = 2.55 x 101 tons8
b. Precleaning and handling
(1) Processing rate; The amount of grain handled is as-
sumed to be the same as the amount received (1.5 x 10^ tons).
(2) Emission factor; Since the process is so similar to
that in wheat milling the emission factor was assumed to be the same (5.0
Ib/ton).
39
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(3) Extent of control; The control factors are assumed
to be the same as those for wheat milling (an 85% application of control
and a 95% efficiency of control).
(4) Calculation of emissions; Total emissions for pre-
cleaning and handling of about 72 tons have been calculated below using
Eq. (1) and the factors presented above.
(1.5 x 105 tons)(5.0 lb/ton)(l/2,000)[l-(0.85)(0.95)] = 7.22 x 101 tons5
c. Cleaning house
(1) Processing rate; The amount of grain cleaned is as-
sumed to be the same as amount received (1.5 x ICr tons).
(2) Emission factor; Since there was a lack of sufficient
data for cleaning operations for both wheat milling and rye milling, it
was not possible to determine an emission factor.
(3) Extent of control; The control factors for cleaning
house operations were not determined.
(4) Calculation of emissions; Emissions were not estimated
because of insufficient data.
d. Mill house
(1) Processing rate; The amount of grain milled was 1.5
x 105 tons.
(2) Emission factor; Some data on certain milling opera-
tions (Table 136, Vol. I) indicate a controlled emission factor of 1.0
Ib/ton. This is equivalent to an uncontrolled emission factor of 10 Ib/ton
assuming 90% cyclone efficiency. However, these data did not include break
rolls or other operations so the factor of 70 Ib/ton that was used for
wheat milling was assumed applicable to rye milling.
(3) Extent of control; Due to lack of sufficient data for
the rye milling process the control factors were assumed to be the same
as those for wheat milling (9670 application of control and 987o efficiency
of control).
(4) Calculation of emissions; Mill house emissions of ap-
proximately 300 tons have been calculated below;
(1.5 x 105 tons)(70 lb/ton)(l/2,000)[l-(0.96)(0.98)] = 3.11 x 102 tons3
40
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e. Summary of calculated emissions for rye milling; Due to the
fact that data for the cleaning house were unavailable and the assumptions
about the mill house emission factor have the same uncertainty as those
in wheat milling, the confidence in the total emissions summarized below
is low.
Emissions (1971) Confidence
(tons/year) Rating-/
a. Receiving 2.55 x 101 B
b. Precleaning and handling 7.22 x 101 B
c. Cleaning house Insufficient information C
d. Mill house 3.11 x 10 B
Total 4.09 x 10 C
a/ A = Good reliability.
B = Fair reliability.
C = Poor reliability.
41
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G. Dry Corn Milling
Corn is dry milled by two general systems, degerming and nondegerming.
The degerming system used in the United States will be the basis of this
report. The process includes the receiving operations, the drying and
cleaning of the corn, the preparation and degerming of the corn, the mill-
ing, and finally the shipping of the products. The main sources of emissions
in the process are listed below:
a. Receiving
b. Drying
c. Freeleaning and handling
d. Cleaning house
e. Degerming and milling
Shipping operations are not a major source because of the efforts to
minimize loss of products.
a. Receiving
(1) Processing rate; Volume I (page 59) shows that the
amount of corn milled to meal and grits in 1970 was 165 x 10° bushels
(approximately 4.6 x 10° tons).
(2) Emission factor; Using the same rationale as for
flour mills, an average emission factor of 1.00 Ib/ton has been used for
the receiving operation.
(3) Extent of control; A 70% application of control was
obtained from Table 210 of Vol. I. From this same table a weighted aver-
age efficiency of control of 97% was calculated.
(4) Calculation of emissions; Equation (1) and the factors
delineated above have been used to determine yearly emissions of 738 tons.
The calculations were performed as follows:
(4.6 x 106 tons)(1.0 lb/ton)(l/2,000)[l-(0.70)(0.97)] = 7.38 x 1Q2 tonsB
42
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b. Drying
(1) Processing rate; Questionnaire data from Vol. I indi-
cate that about 20% of the grain received may. be dried. This amounts to
0.9 x 106 tons.
(2) Emission factor; Data are insufficient to determine
the type of dryers (rack or column) used. However, about 50% use the Day-
Vac system. For this reason an emission factor of 0.5 Ib/ton was estimated.
(3) Extent of control; A 92% application of control was
obtained from Table 210 of Vol. I. Average efficiency of control was cal-
culated at 83% assuming 90% efficiency for Day-Vac units and 75% efficiency
for other control units.
(4) Calculation of emissions; Dryer emissions in the dry
corn milling industry have been calculated below to be approximately 53
tons.
(0.9 x 106 tons)(0.5 lb/ton)(l/2,000)[l-(0.92)(0.83)] = 5.32 x 101 tons3
c. Precleaning and handling
(1) Processing rate; It is assumed that the amount of
grain processed is the same as the amount received (4.6 x 10^ tons).
(2) Emission factor; As explained in the section on flour
mills, an average emission factor of 5.0 Ib/ton was used.
(3) Extent of control; Table 210 of Vol. I shows that the
application of control is about the same for each operation associated
with precleaning and handling. Using these data, the application of control
was calculated to be 82% and the efficiency of control 97%.
(4) Calculation of emissions; Equation (1) and the factors
described above have been used to calculate annual particulate emissions
of 2.35 x 10 tons as follows;
(4.6 x 106 tons)(5.0 lb/ton)(l/2,000)[l-(0.82)(0.97)] = 2.35 x 103 tonsB
43
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d. Cleaning house
(1) Processing rate; It was assumed, that all grain re-
ceived passes through the cleaning house (4.6 x 10" tons).
(2) Emission factor; As explained in Vol. I (page 218)
several steps are involved in grain cleaning, one of which includes air
aspiration and is a source which could generate considerable dust. This
type of source yielded an emission factor of 5.78 Ib/ton, which was
determined for grain elevator corn cleaning (Ref. 3). Also, Table 133
of Vol. I indicated an emission factor of 0.0015 Ib/bushel (0.05 Ib/ton)
for a cleaning house controlled by fabric filter. If the fabric filter
were 99% efficient the equivalent uncontrolled factor would be 5.0 Ib/ton
which agrees closely with the previous factor of 5.78 Ib/ton. Thus an
emission factor of 6.0 Ib/ton was used.
(3) Extent of control; Data from Vol. I (page 429) were
not sufficient to determine the percent of application of control, but did
indicate that it is probably quite high with considerable utilization of
fabric filters. For this reason the overall extent of control has been
estimated at 97%.
(4) Calculation of emissions; Using the above estimates
and Eq. (1) the calculations below indicated yearly emissions of approxi-
mately 400 tons.
(4.6 x 106 tons)(6.0 lb/ton)(l/2,000)[l-(0.97)] = 4.14 x 102 tons3
e. Degerming and milling
(1) Processing rate; The amount of grain through the de-
germing and milling operations was assumed to be the same as the amount
received (4.6 x 10° tons).
(2) Emission factor; Data were insufficient to determine
the emission factors for the various degerming and milling operations.
(3) Extent of control; Some data on the extent of con-
trol for these operations are available in Table 210 of Vol. I. However,
since calculations are not possible as a result of lack of emissions
data, the averages were not calculated.
(4) Calculation of emissions; Emissions were not estimated
because of lack of data. However, because of the product value it can
probably be assumed that this is not a major source compared with the
previous operations discussed.
44
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f. Summary of calculated emissions for dry corn milling; Emis-
sion quantities for those operations for which there was sufficient in-
formation to perform calculations are summarized in the table below:
Emissions (1970) Confidence
(tons/year) Rat ing—'
a. Receiving 7.38 x 102 B
b. Drying 5.32 x 101 B
c. Precleaning and handling 2.35 x 103 B
d. Cleaning house 4.14 x 102 B
e. Degerming and milling Insufficient information C
Total 3.55 x 103 B
a/ A = Good reliability.
B = Fair reliability.
C = Poor reliability
45
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H. Oat Milling
The initial stages for the milling process for oats are much the '
same as those in the wheat milling process. However, the separation
requirements in the oat milling process necessitate the use of aspirators,
and a forced draft is used in the cooling process. Neither of these possible
sources is a part of the wheat milling process. Also, the receiving and
handling process is reported.to be dustier for oats than for wheat.
Since there are insufficient emission data on the various operations
in the oat milling process and since comparisons with various operations
in the wheat milling process would be highly inaccurate, it is not pos-
sible to do an operational breakdown of the oat milling process emissions.
However, sufficient data are available to make an estimate of plant emis-
sions.
1. Processing rate; Volume I (page 60) states that the amount of
oats used for breakfast food in 1970 was 49 x 106 bushels (0.7 x 106
tons).
2. Emission factor; A controlled emission factor of 2.5 Ib/ton
(Vol. I, page 236) was calculated from the data available. It is not known
if these data (for one mill) include most major dust sources or if this
mill is representative of the industry; however, both are assumed to be
true.
3. Extent of control; Since the emission factor is for controlled
emissions, extent of control is not applicable.
4. Calculation of emissions; Oat milling industry emissions have
been estimated to be 875 tons as per the calculations below;
(0.7 x 106 tons)(2.5 lb/ton)(l/2,000) = 8.75 x 102 tonsc
46
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I. Rice Milling
Rice mills are of two types; conventional and parboil. In the
United States 85% are of the conventional type. Each type of mill has
three distinct stages: (1) rough rice receiving, cleaning, drying and
storages; (2) milling; and (3) milled rice and by-product bagging,
packaging, and shipping (Vol. I, page 235). The first two stages are the
main sources of emissions. These stages have been divided into the following
processes in order to calculate emissions:
a. Receiving
b. Handling and precleaning
c. Drying
d. Cleaning and mill house
a. Receiving
(1) Processing rate; According to Vol. I (page 82) the
amount of rough rice milled in 1970 was 77 x 106 cwt (3.85 x 106 tons).
(2) Emission factor; Emission factor data for all rice
milling operations are meager. Volume I stated that emission sources
associated with receiving, cleaning, and storage are similar to those
involved with all grain processing but it is not known if rice is more
or less dusty than other grains. However, estimates were made based
upon emission factors for other grains. Since data in Vol. I (Table 218)
indicated that most rice was received by trucks, the emission factor of
0.64 Ib/ton for truck unloading was used (Ref. 3).
(3) Extent of control; A 677<> application of control was
indicated in Table 218 of Vol. I. Data from this same table were used to
calculate a weighted average efficiency of control of 947o.
i (4) Calculation of emissions; Equation (1) and the factors
delineated above were used to calculate emissions of 456 tons for rice mill
receiving as follows:
(3.85 x 106 tons)(0.64 lb/ton)(l/2,000)[l-(0.67)(0.94)] = 4.56 x 102 tons
B
47
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b. Handling and precleaning
(1) Processing rate; The amount of grain handled was as-
sumed to be the same as the amount received (3.85 x 10° tons).
(2) Emission factor; As explained in the previous section,
emission factor data for rice milling are meager. Therefore, the cumula-
tive emission factor of 5.0 Ib/ton, determined in the wheat milling sec-
tion, has been assumed for similar operations in rice milling.
- (3) Extent of control; Extent of control for each han-
dling operation is not similar, as it was for wheat operations. There-
fore, average values have been calculated from the data in Table 218 of
Vol. I, resulting in a 637» application of control and a 96% efficiency of
control.
(4) Calculation of emissions; The calculations below
—•—^^™ —'- •' "• '» —^^ "i ^^^— «
were used to determine the yearly emissions of 3.80 x 10 tons for han-
dling and precleaning.
(3.85 x 106 tons)(5.0 lb/ton)(l/2,000)[l-(0.63)(0.96)] = 3.80 x 103 tonsB
c. Drying
(1) Processing rate; The amount of grain dried is assumed
to be 3.85 x 106 tons.
(2) Emission factor; Observation of rice dryers indicates
that the emission factor may be considerably higher than for other grains
but supporting data were not available. Thus, it was not possible to esti-
mate an emission factor.
(3) Extent of control; Since emission factors could not
be determined, control factors were not calculated.
(4) Calculation of emissions; Emissions were not esti-
mated because of insufficient data.
d. Cleaning and mill house; Because of lack of emission factor
data, no estimate of emissions could be made.
48
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e. Summary of calculated emissions for rice milling; Because
of a lack of emission factor data, estimates of emissions for some opera-
tions could not be made. Those operations for which estimates of emissions
were made are summarized in the table below:
Emissions (1970) Confidence
(tons/year) Ratine3./
a. Receiving 4.56 x 102 B
b. Handling and precleaning 3.80 x 103 B
c. Drying Insufficient information C
d. Cleaning- and mill house Insufficient information C
Total 4.26 x 103 C
a/ A = Good reliability.
B = Fair reliability.
C = Poor reliability.
49
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J. Commercial Rice Drying
A commerical rice drying facility has four basic operations: receiv-
ing, drying, storage, and shipping. The emission of pollutants results
primarily from rice handling, cleaning drying operations. The cleaning
step, if accomplished by aspiration, is a major source of emissions. The
grain dryer is the other major emission source (Vpl. I, page 243).
It was possible to determine the amount of rice processed in 1965-
1966 as 3.5 x 10^ tons (Vol. I, page 79). However, as was the case for
rice milling,, emission factor data for the dryers were not available. In
addition, there was no information available on extent of control for
these installations. Therefore, no estimate of emissions could be made.
50
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K. Soybean Mills
The sources of emissions in a soybean processing plant can be grouped
into three broad categories: (1) soybean receiving, handling and drying
operations; (2) soybean processing operations; and (3) soybean meal load-
out operations. In order to determine emissions from the various sources,
these categories have been divided into the following operations:
a. Receiving
b. Handling
c. Cleaning
d. Drying
e. Cracking (and dehulling)
f. Hull grinding
g. Bean conditioning
h. Flaking
i. Meal dryer
j. Meal cooler
k. Bulk loading
a. Receiving
(1) Processing rate; The amount of soybeans processed in
1970 was 760 x 106 bushels or 23 x 10 tons (Vol. 1, page 92).
(2) Emission factor; Data in Table 232 of Vol. I show
that soybeans are received by truck, hopper cars, and boxcars. Table 142
in the same report indicated an average controlled emission factor for a
truck dump pit of 0.017 Ib/ton, or an uncontrolled factor of 1.7 Ib/ton
assuming 9970 efficiency for fabric filters. This is in good agreement with
data obtained in Ref. 3 for soybeans which showed 1.63 Ib/ton for truck
unloading and 1.5 Ib/ton for car unloading. Therefore, an emission factor
of 1.6 Ib/ton was used for soybean receiving.
51
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(3) Extent of control; Table 232 of Vol. I showed that
extent of control for trucks and boxcars is about the same, but is consid-
erably lower for hopper cars although it is noted that some plants are
using choke unloading for hopper cars. Therefore, data from Table 232 on
extent of control for trucks and boxcars have been used to determine a
507o application of control and a 98% efficiency of control.
(4) Calculation of emissions; Emissions for the receiving
have been determined to be 9.38 x 10^ tons as shown below;
(23 x 106 tons) (1.6 lb/ton)(l/2,000)[l-(0.50)(0.98)] = 9.38 x 10^ tonsB
b. Handling
(1) Processing rate; The amount of grain handled was as-
sumed to be the same as the amount received or 23 x 10" tons.
(2) Emission factor; No specific information was avail-
able on emission factors for soybean handling operations. Even though
emissions for soybeans may be higher than for other grains, the 5.0 Ib/ton
emission factor discussed in the wheat milling section was used.
(3) Extent of control; A 767o application of control was
obtained from Vol. I, Table 232. This same table was used to calculate an
average 96% efficiency.
(4) Calculation of emissions; Handling emissions for soy-
bean mills were calculated, using the data delineated above and Eq. (1),
to be approximately 1.5 x 10 tons.
(23 x 106 tons)(5.0 lb/ton)(l/2,000)[l-(0.76)(0.96)] = 1.55 x 104 tons3
c. Cleaning
(1) Processing rate; It is assumed that all of the grain
is cleaned or 23 x 10° tons.
(2) Emission factor; Although no information was avail-
able on the cleaning of soybeans, it was assumed to be at least as much
as the 6.00 Ib/ton used for corn milling.
(3) Extent of control; Data were not available on ex-
tent of control for soybean cleaning. However, it was assumed to be
about the same as handling operations, or about 75%.
52
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(4) Calculation of emissions; Emissions were calculated
as shown below:
(23 x 106 tons)(6.0 lb/ton)(l/2,000)[l-0.75] = 1.73 x 104 tons8
d. Drying
(1) Processing rate; The amount of grain dried was as-
sumed to be 23 x 106 tons.
(2) Emission factor; Observations have indicated that
the emission factors for the drying of soybeans may be higher than the
average factors of 0.3 and 3.0 Ib/ton discussed in the section on dryers
at grain elevators. The only data available on soybean dryers (Vol. I,
Table 146) were used to calculate uncontrolled emission factors ranging
from 4.2 to 80 Ib/ton. The value of 80 Ib/ton is very high, but even
disregarding this figure, the average factor is 7.2 Ib/ton. This appears
to be a more reasonable number in comparison with other dryer factors,
so a value of 7.2 lb/ ton was used.
(3) Extent of control; A 42% application of control was
determined from Table 232 of Vol. I. Data from this same table were also
used to calculate an efficiency of control of 8070.
(4) Calculation of emissions; Dryer emissions of 5.5 x
10 tons for the year 1970 have been calculated below;
(23 x 106 tons)(7.2 lb/ton)(l/2,000)[l-(0.42)(0.80)] = 5.50 x 104 tons0
e. Cracking (and dehulling)
(1) Processing rate; The amount of grain cracked is as-
sumed to be 23 x 106 tons.
(2) Emission factor; Volume I (Table 147) indicated that
the controlled emission factor for the cracking and dehulling operations
is on the order of 0.01 Ib/bushel or 0.33 Ib/ton. Assuming 907,, efficiency
for cyclone control devices, the uncontrolled emission factor is 3.3 Ib/ton.
(3) Extent of control; A 967o application of control was
obtained from Table 232 of Vol I. This same table was used to calculate
a 937o efficiency of control.
53
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(4) Calculation of emissions; Emissions from the crack-
—^^-^— o
ing process have been determined to be 4.07 x 10 tons as shown below:
(23 x 106 tons)(3.3 lb/ton)(l/2,000)[l-(0.96)(0.93)] = 4.07 x 103 tonsC
f. Hull grinding
(1) Processing rate; The amount ground is again assumed
tons because the ei
grain rather than just the hulls.
to be 23 x 10 tons because the emission factor is based on the amount of
(2) Emission factor; Controlled emission factors for hull
grinding (Vol. I, Table 174) show an average, for three reported values,
of 0.0055 Ib/bushel or 0.18 Ib/ton. Again, assuming 90% efficiency for
cyclone control devices, the uncontrolled emission factor would be approxi-
mately 2.0 Ib/ton.
(3) Extent of control; Information from questionnaires
(Table 232 of Vol. I) showed 98% application of control and the average
efficiency of controls was computed to be 937».
(4) Calculation of emissions; Grinding emissions of about
2,000 tons have been calculated using Eq. (1) as shown below:
(23 x 106 tons)(2.0 lb/ton)(l/2,000)[l-(0.98)(0.93)] = 2.04 x 103 tonsB
g. Bean conditioning
(1) Processing rate; The processing rate is again as-
sumed to be 23 x 106 tons.
(2) Emission factor; Table 147 of Vol. I shows a cyclone
controlled emission factor of 0-r00"3~Tb/bushel or 0.01 Ib/ton. Assuming
907o cyclone efficiency, the uncontrolled emission factor would be 0.1
Ib/ton.
(3) Extent of control; A 79% application of control was
obtained from Table 232 of Vol. I. Data from this same table were used
to calculate a 91% efficiency of control.
(4) Calculation of emissions; Bean conditioning emissions
have been determined to be 3.23 x 102 tons. The calculations are shown
below:
(23 x 106 tons)(0.1 lb/ton)(l/2,000)[l-(0.79)(0.91)] = 3.23 x 102 tonsB
54
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h. Flaking
(1) Processing rate; The amount of grain flaked is as-
sumed to be 23 x 10 tons.
(2) Emission factor; A total of four controlled emission
factors presented in Tables 144 and 147 Vol. I shows an average of 0.0017
Ib/bushel or 0.057 Ib/ton. These were each cyclone controlled systems, so
assuming an efficiency of 907o, the uncontrolled emission factor is 0.57
Ib/ton.
(3) Extent of control; A 9670 application of control was
obtained from Vol. I (Table 232). Data from this same source were used to
calculate an efficiency of control of 91%.
(4) Calculation of emissions; The following calculations
resulting in an emission figure of 8.29 x 102 tons for flaking were made
using Eq. (1) and the data presented above.
(23 x 106 tons)(0.57 Ib/ton)(1/2,000)[l-(0.96)(0.91)] = 8.29 x 102 tons5
i. Meal dryer
(1) Processing rate; The amount of meal dried is assumed
to be 23 x 106 tons.
(2) Emission factor; Cyclone controlled emission factors
for meal dryers were presented in Tables 144 and 147 of Vol. I and showed
a range of 0.0003-0.0128 Ib/bushel with an average of 0.0045 Ib/bushel or
0.15 Ib/ton. Again, assuming a 90% cyclone efficiency, the uncontrolled
emission factor is estimated to be 1.5 Ib/ton.
(3) Extent of control; A 62% application of control was
determined from Table 232 of Vol. I. Data from the same table were used
to calculate a 90% efficiency of control.
(4) Calculation of emissions; Meal dryer emissions are
shown in the calculations below to be about 7.6 x 10^ tons.
(23 x 106 tons)(1.5 lb/ton)(l/2,000)[l-(0.62)(0.90)] = 7.62 x 103 tons3
j. Meal cooler
(1) Processing rate; The amount of meal cooled was assumed
to be the same as the amount of soybeans received, 23 x 10 tons.
55
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(2) Emission factor; Only one cyclone controlled emis-
sion factor was available (Table 144 of Vol. I); 0.0056 Ib/bushel or
0.18 Ib/ton. Assuming a 90% efficiency for the cyclone, the uncontrolled
emission factor would be 1.8 Ib/ton.
(3) E tent of control; A 94% application of control was
obtained from Table 232 of Vol. I. The same table was used to calculate
an efficiency of control of 91%.
(4) Calculation of emissions; Using the limited data pre-
sented above,- the cooler emissions were calculated in the following manner
to be about 3,000 tons.
(23 x 106 tons)(1.8 lb/ton)(l/2,000)[l-(0.94)(0.91)] = 2.99 x 103 tonsB
k. Bulk loading
(1) Processing rate; The amount loaded was assumed to be
about 23 x 10 tons.
(2) Emission factor; No emission factor data were avail-
able for meal loading. However, observation of these operations indicated
that it may be about the same as the loading of grain at elevators, or
about 0.27 Ib/ton. Although this is only an estimate it has been used to
calculate emissions.
(3) Extent of control; Data in Table 232 of Vol. I indi-
cated an application of control of 377o. This same table was used to calcu-
late a 977o efficiency of control.
(4) Calculation of emissions; The emissions for bulk load-
ing were determined to be 1.99 x 10 tons as shown below:
(23 x 106 tons)(0.27 lb/ton)(l/2,000)[l-(0.37)(0.97)] = 1.99 x 103 tons6
1. Summary of calculated emissions for soybean mills; The cal-
culated emissions for the soybean milling industry are summarized in the
table below.
56
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Emissions (1970) Confidence
(tons/year) Rat in&i'
a. Receiving 9.38 x 103 B
b. Handling 1.55 x 104 B
c. Cleaning 1.73 x 104 B
d. Drying 5.50 x 104 C
e. Cracking (and dehulling) 4.07 x 103 B
f. Hull grinding 2.04 x 103 B
g. Bean conditioning 3.23 x 102 B
h. Flaking 8.29 x 102 B
i. Meal dryer 7.62 x 103 B
j. Meal cooler 2.99 x 103 B
k. Bulk loading 1.99 x 103 B
Total 11.70 x 104 B
£/ A = Good reliability.
B = Fair reliability.
C = Poor reliability.
57
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L. Corn Wet Milling
The corn refining or wet milling industry has grown into one of the
most diversified grain processing industries. As a result of this diver-
sity, there are numerous and varied potential sources of emissions. Vol-
ume I divided these sources into three basic categories: (1) grain re-
ceiving, cleaning and storage; (2) separation process; and (3) conversion
process. The various sources within each category are delineated in Table
148 of Vol. I. As noted in Vol. I the main sources of emissions in the
separation and conversion processes are the various dryers. For the cal-
culations in these reports the various dryers have been grouped and will
be considered as one source. It should be noted that detailed emissions
data for these two processes are lacking. The assumptions that have been
made in order to calculate emissions are explained in the following sec-
tions concerning these emission sources:
a. Receiving
b. Handling
c. Cleaning
d. Dryers
a. Receiving
(1) Processing rate; The amount of corn processed by the
corn wet milling industry in 1970 was 225 x 10& bushels or 6.3 x 10° tons
(Vol. I, page 100).
(2) Emission factor; Corn is received by both cars and
trucks and the emission factor was assumed to be approximately the same
as that for similar operations in grain elevators, or about 1.0 Ib/ton.
(3) Extent of control; Data from Table 240 of Vol. I
was used to determine weighted averages for extent of control. A 67%
application of control and a 927, efficiency of control were determined.
(4) Calculation of emissions; Emissions from the receiv-
ing process of 1.21 x 103 tons are calculated below.
(6.3 x 106 tons)(1.0 lb/ton)(l/2,000)[l-(0.67)(0.92)] = 1.21 x 103 tons3
58
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b. Handling
(1) Processing rate; The amount of grain handled is as-
sumed to be the same as that received (6.3 x 10 tons).
(2) Emission factor; Emission factors specifically applic-
able to the handling of corn are not available. However, as was done in
the section on dry corn mills, an average cumulative emission factor of
5.0 Ib/ton was used.
(3) Extent of control; Extent of control for each han-
dling operation is different, but the largest contributor to the cumula-
tive emission is the legs. Therefore, the extent of control for the legs
was used. Table 240 of Vol. I indicated a 77% application of control and
a 96% efficiency of control.
(4) Calculation of emissions; Equation (1) and the data
determined above were used in the following calculation of emissions fqr
corn handling:
(6.3 x 106 tons)(5.0 lb/ton)(l/2,000)[l-(0.77)(0.96)] = 4.11 x 103 tons8
c. Cleaning
(1) Processing rate; The amount of corn cleaned was as-
sumed to be 6.3 x 10° tons.
(2) Emission factor; An emission factor of 6.0 Ib/ton,
as developed in the section on dry corn mills, was used to estimate emis-
sions.
(3) Extent of control; Data from Table 240 of Vol. I were
used to determine a 100% application of control and a 95% efficiency of
control.
(4) Calculation of emissions; Emissions of 945 tons for
cleaning are calculated below;
(6.3 x 106 tons)(6.0 lb/ton)(l/2,000)[l-(1.0)(0.95)] = 9.45 x 102 tons3
d. Dryers
(1) Processing rate; All data on emission rates for
dryers in wet corn mills are in units of pound per hour. Therefore, the
plant operating time has been estimated at 8,000 hr/year.
59
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(2) Emission factor; Feed, gluten, and germ dryers are
a major source of emissions from wet corn mills, but emission factor data
are lacking. Table 149 of Vol. I contains emission rate data (Ib/hr) for
dryers at five plants. The capacity of these dryers in relation to those
in the 17 plants in the industry is unknown. Neither is it known if it
included all the dryers at each plant nor their load at time of testing.
However, the only method of estimating emission rates for the industry
was to add the emission rates for these five plants (365 Ib/hr) and
multiply by the ratio of the number of plants — 17/5. This gives a con-
trolled emission rate of (17/5) x (365 Ib/hr) or 1,240 Ib/hr.
(3) Extent of control; Since the above emission factors
were controlled emission factors, this information was unnecessary.
(4) Calculation of emissions; Even though the above data
were somewhat uncertain, calculations were made for the emissions from the
dryers. Emissions were determined to be about 5,000 tons as shown below:
(8,000 hr/year)( 1,240 lb/hr)(l/2,000) = 4.96 x 103 tons0
e. Summary of calculated emissions for corn wet milling; The
emissions from the corn wet milling industry have been calculated using
the best data available. However, the lack of specific data for the vari-
oug emission sources within the separation and conversion processes,
especially the various drying processes, lowers the confidence level of
the calculated emissions of those processes. Below is a table summarizing
the calculated emissions:
._ Emissions (1970) Confidence
(tons/year) Rat ingji'
a. Receiving 1.21 x 103 B
b. Handling 4.11 x 103 B
c. Cleaning 9.45 x 102 B
d. Dryers 4.96 x 103 C
Total 1.12 x 104 C
£/ A = Good reliability.
B = Fair reliability.
C = Poor reliability.
60
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IV. PROJECTED EMISSIONS
Projected yearly emissions for various facets of the feed and grain
industry for the years 1975 and 1980 are delineated in this section of the
report. The projections are based on the general assumptions discussed in
the paragraphs below, and calculations were made using Eq. (1). Specific
assumptions for each industry and projections of emissions from indi-
vidual sources within the industry are presented in the appropriate sec-
tions of this report. Finally, specific estimated processing rates,
emissions factors, and extents of control for each process are contained
in the calculations, presented in Appendix A.
The general methods that follow were used to obtain the data that were
inserted into Eq. (1) to project emissions for 1975 and 1980.
Changes in processing rates have been estimated using production trends
in the industry. These trends have been determined through an analysis of
the production figures for each industry over the last 10 years, and pro-
jections that have been made by the U.S. Department of Agriculture.
It has been assumed that the uncontrolled emission factors for all
processes will remain the same over the projection period. A change in
extent of control for any process can be based on a change in either or
both of two factors: the efficiency of control or the application of con-
trol. Projections for changes in control have been based on the assumption
that most changes will occur as a result of pressure from governmental
control agencies. Therefore, the factors most likely to effect changes are
plant size and plant location. Those industries that are larger operations
and that are located in large urban areas (e.g., export elevators) were
assumed to be under the most pressure, and therefore it was assumed that
application of control would reach 100% by 1985. Other smaller industries
located in urban areas or large rural communities were assumed to be under
somewhat less pressure, and it was assumed that the application of control
would reach 100% by 1990 or 1995. Finally, smaller operations in rural
areas were assumed to be receiving the least pressure, so each of these
industries was assigned a certain percent increase in application of con-
trol per year (i.e., feed mill application of control will increase in-
crease 3% per year).
61
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Estimates of increases in efficiency of control were based on the
assumption that all processes would be equipped with "best control" de-
vices by the time they reached 100% application of control,. This means
that fabric filters with 99% efficiency would be used wherever possible.
The "best" type cyclone with an efficiency of 95% would be used on all
other sources.
The following pages contain the specific assumptions used for each
industry and summaries of projected emissions for 1975 and 1980 for the
major sources of emission within each industry.
62
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A. Elevators
1. Country elevators; Since country elevators tend to be smaller
operations, it was assumed that controls would not be applied as quickly
'nor would those controls be as efficient as those in terminal and ex-
port elevators. It was also felt that since many of the operations were
in smaller communities, there would not be as much public and agency
pressure to control emissions. For these reasons it was estimated that
the application of control would increase by 2% per year for every opera-
tion except drying, which would increase to 35% application of control by
1980. Efficiency of control for all operations but dryers was assumed to
reach 95% by 1980.
Previously described calculations for dryer emissions considered
rack and column dryers separately but assumed that half the dryers were
of each type. However, in making emission projections it is difficult to
estimate how the distribution of dryer types may change and where new
control devices will be applied in the future. Therefore, in calculating
projected emissions only one calculation was made, covering both types of
dryers, using an average emission factor of 1.65 Ib/ton [(3.0 + 0.3)/2]
with increases in the overall application of control as described above.
Dryer control efficiency was based on an average efficiency of 80% for
1971 and the assumption that all new devices will be 95% efficient.
Current and projected emissions for each source are presented in the
table below:
Emissions (tons/year) _^
a
Source 1971 1975 1980
Unloading 4.1 x 104 4.4 x 104 4.3 x 104
b. Turning 6.65 x 104 7.27 x 104 7.15 x 104
c. Loading 1.9 x 104 2.1 x 104 2.1 x 104
d. Drying 2.36 x 104 3.49 x 10^ 3.81 x 10^
e. Cleaning 1.38 x 104 1.17 x 104 0.81 x Id4
f. Headhouse 1.92 x 105 1.92 x 105 1.58 x 105
Total 3.57 x 105 3.76 x 1Q5 3.39
63
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2. Terminal elevators; Because terminal elevators tend to be larger
operations in more highly populated areas, it was felt that there would
be a greater pressure for controls than for country elevators. It was as-
sumed that application of control would reach 100% by 1995. It was also
assumed that all sources would be equipped with the best devices by 1995.
This indicates a 9970 efficiency for all operations except drying which would
be 957o efficient. Projected emissions for dryers were calculated using the
same methodology as for country elevators. Present and projected emissions
for the various sources in terminal elevators are listed in the table below:
Emissions (tons/year)
Source 1971 1975 1980
a. Unloading 1.22 x 104 1.31 x 104 1.20 x 104
b. Turning 3.78 x 103 4.32 x 103 3.96 x 103
c. Loading 5.25 x 103 5.68 x 103 5.12 x 103
d. Drying 2.78 x 103 3.76 x 103 3.54 x 103
e. Cleaning 2.18 x 104 2.28 x 104 2.12 x 104
f. Headhouse 3.44 x 104 3.72 x 104 3.38 x 104
g. Tripper 3.67 x 104 3.94 x 104 3.55 x 104
Total 1.17 x 105 1.26 x 105 1.15 x 105
64
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3. Export elevators; Export elevators are large operations and are
located in urban areas. Therefore, they will receive the most pressure to
control emissions. This leads to the assumption that export elevators will
have 100% application of control with highest possible efficiency of con-
trol by 1985. This also means a 99% efficiency of control on all operations
except drying which will have 95% efficiency. Projected emissions for
dryers were calculated using the same methodology as for country elevators.
The projected emissions for 1975 and 1980 for individual processes are in-
cluded in the table below:
Emissions (tons/year)
Source 1971 1975 1980
a. Unloading 1.13 x 104 1.07 x 104 0.68 x 104
b. Turning 8.95 x 102 8.38 x 102 5.12 x 102
c. Loading 3.12 x 104 2.96 x 104 1.82 x 104
d. Drying 4.20 x 102 3.90 x 102 2.60 x 102
e. Cleaning 2.30 x 104 2.19 x 104 1.34 x 104
f. Headhouse 5.34 x 10^ 4.94 x 10^ 3.10 x 104
g. Tripper 2.02 x 104 1.93 x 104 1.18 x 104
Total 1.40 x 105 1.32 x 105 0.82 x 105
65
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B. Feed Mills
Feed mills, like country elevators, are smaller operations in predomi-
nantly rural areas. Therefore, there is expected to be less pressure for
controls. Thus it has been assumed that the application of control will
increase by 37o per year. It has also been assumed that the efficiency of
control will reach 9770 by 1980. The emissions from those operations for
which a controlled emissions factor has previously been used will be cal-
culated using the same controlled emission factor. Current emissions and
emissions projected for 1975 and 1980 are listed in the table below:
Emissions (tons/year)
Source
a. Receiving
b. Shipping
c. Handling
operations
d. Grinding
e. Pellet coolers
Total
1969
4.66 x 104
1.95 x 104
10.5 x 104
2.44 x 103
0.90 x 103
1.74 x 105
1975
4.15 x 104
1.89 x 104
9.14 x 104
2.92 x 103
1.05 x 103
1.56 x 105
1980
3.36 x 104
1.72 x 104
7.15 x 104
3.29 x 103
1.19 x 103
1.27 x 105
66
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C. Alfalfa Dehydrating
Alfalfa dehydration plants are also small operations in rural areas.
However, several states are beginning to set standards and it has been
assumed that there will be increasing pressure for control on alfalfa
dehydrating plants. Therefore, it is estimated that there will be a 5%
per year increase in application of controls. It is also assumed that the
efficiency will be 95% on all installed controls.
Emissions data for alfalfa dehydration plants are for the total plant,
Therefore, estimated plant emissions for 1975 and 1980 and present plant
emissions are presented below:
Emissions (tons/year)
1971 1975 1980
1.6 x 104 1.30 x 104 0.92 x 104
67
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D. Wheat Mills
It has been assumed for these calculations that all operations for
which emission factors are available will reach 1007o application of con-
trol with the controls being 99% efficient, by 1990. Current and projected
emissions are contained in the table below:
Source
a. Receiving
b. Precleaning and
handling
c. Cleaning house
d. Mill house
Total
Emissions (tons/year)
1971 1975
2.78 x 103 2.24 x 1Q3
7.89 x 103 6.44 x 103
Insufficient information
3.49 x 104 2.87 x 104
4.56 x 104 3.74 x 1Q4
1980
1.54 x 103
4.47 x 103
2.30 x 104
2.90 x 104
68
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E. Durum Mills
Data on emission factors for some operations in durum mills are not
sufficient to calculate emissions. On those operations for which suffici-
ent emission factor data are available, it has been assumed that 100%
application of control will have been attained by 1990. It is also assumed
that all controls will be 997o efficient by this time. Projected emissions
for each source within the durum milling industry are listed in the table
below:
Emissions (tons/year)
Source
a. Receiving
b. Freeleaning and
handling
c. Cleaning house
d. Mill house
Total
1971
1.68 x 102
4.81 x 102
1975
1.62 x 102
4.66 x 102
1980
1.30 x 102
3.77 x 102
6.49 x 102
Insufficient information
Insufficient information
6.28 x 102
5.07 x 102
69
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F. Rye Milling
For those rye milling operations for which sufficient data were avail-
able to calculate emissions, it has been assumed that the application of
control will reach 100% with a 99% efficiency of control by 1990. Below
is a table containing present emissions and projected emissions for 1975
and 1980.
Emissions (tons/year)
Source
a. Receiving
b. Precleaning and
handling
c. Cleaning house
d. Mill house
Total
1971
2.55 x 101
7.22 x 101
3.11 x 102
4.08 x 10
1975
2.03 x 101
5.82 x 101
Insufficient information
2.59 x 1Q2
3.38 x 102
1980
1.39 x 101
4.04 x 101
2.08 x 102
2
2.62 x 10
70
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G. Dry Corn Milling
Those operations in the dry corn milling process for which sufficient
data were available to enable calculation of emissions were assumed to have
reached 100% application of control by 1990. All operations but drying were
assumed to have reached 997o efficiency by 1990. Drying was assumed to have
reached an efficiency of control of 95% by that date. Listed below are the
present calculated emissions and projected emissions for 1975 and 1980.
Emissions (tons/year)
a
Source 1970 1975 1980
Receiving 7.38 x 102 5.72 x 102 3.93 x 102
b. Drying 5.32 x 101 4.50 x 101 3.42 x 101
c. Precleaning and
handling 2.35 x 103 1.83 x 103 1.27 x 103
d. Cleaning house 4.14 x 102 4.23 x 102 2.82 x 102
e. Degerming and milling _ Insufficient information _
Total 3.55 x 103 2.87 x 103 1.98 x 1Q3
71
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H. Oat Milling
The only emission factor available for oat milling is a controlled
emission factor of 2.5 Ib/ton. For these calculations it is assumed that
this figure remains constant and only the production rate will increase.
Below are projections of estimated emissions for oat mills in 1975 and
1980.
Emissions (tons/year)
1970-
8.75 x 102 10.0 x 10^ 10.0 x
72
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I. Rice Milling
The only two operations in the rice milling process for which calcu-
lations were possible were receiving and precleaning and handling. It was
assumed that application of control on these operations would reach 100%,
with 99% efficiency, by 1990. Projected emissions for some of the rice
milling operations are listed below:
Emissions (tons/year)
Source 1970 1975 1980
a. Receiving 4.56 x 102 4.05 x 102 2.61 x 102
b. Precleaning and
handling 3.80 x 103 3.32 x 103 2.16 x 103
c. Drying Insufficient information
d. Cleaning and mill house Insufficient information
Total 4.26 x 1Q3 3.73 x 1Q3 2.42 x 103
73
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J. Commercial Rice Drying
Data are insufficient to estimate emissions for commercial rice dry-
ing.
K. Soybean Mills
It has been assumed that all operations in soybean mills will have
100% application of controls with the most efficient type of control device
by 1985. This means a 99% efficiency of control for all operations except
drying, bean conditioning, flaking, meal drying, and meal cooling which
will be 95% efficient. Projected emissions for the various sources in the
soybean milling operation are presented in the table below:
Emissions (tons/year)
Source 1970 1975 1980
a. Receiving 9.38 x 103 7.09 x 103 4.36 x 103
b.. Handling 1.55 x 104 1.19 x 104 0.75 x 104
c. Cleaning 1.73 x 104 1.32 x 104 0.82 x 104
d. Drying 5.50 x 104 4.47 x 104 2.99 x 104
e. Cracking (and
dehulling) 4.07 x 103 3.34 x 103 2.00 x 103
f. Hull grinding 2.04 x 103 1.54 x 103 1.21 x 103
g. Bean conditioning 3.23 x 102 2.69 x 102 1.93 x 102
h. Flaking 8.29 x 102 7.91 x 102 6.05 x 10
i. Meal dryer 7.62 x 103 6.00 x 103 4.38 x 103
j. Meal cooler 2.99 x 103 2.71 x 103 2.17 x 10
k. Bulk loading 1.99 x 103 1.49 x 103 0.93 x 103
Total 11.7 x 104 9.30 x 104 6.14 x 104
74
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L. Corn Wet Mills
It has been assumed that all operations except 'drying on corn wet
mills will have reached 100% application of control with 99% efficiency
of control by 1985. Estimated dryer emissions have been calculated using
a controlled emission factor of 1,241 Ib/hr and multiplying by the ratio
of increased production. Current process emissions and projected emissions
for 1975 and 1980 are contained in the table below:
Emissions (tons/year)
Source
a. Receiving
b. Handling
c. Cleaning
d. Drying
Total
1970
1.21 x 103
4.11 x 103
9.45 x 10
4.96 x 103
1.12 x 104
1975
0.97 x 103
3.20 x 103
8.76 x 10^
5.75 x 10
1.08 x 104
1980
0.55 x 103
1.97 x 103
4.80 x 102
6.30 x 103
4
0.93 x 10
75
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REFERENCES
1. Shannon, L. J., R. W. Gerstle, P. G. Gorman, D. M. Epp, T. W. Devitt,
and R. Anick, "Emission Control In the Grain and Feed Industry,
Volume I - Engineering and Cost Study," Final Report by Midwest
Research Institute prepared for Environmental Protection Agency,
Document No. EPA-450/3-73-003a (December 1973).
2. Vandegrift, A. E., L. J. Shannon, P. G. Gorman, E. W. Lawless, E. E.
Sallee, -and M. Reichel, "Particulate Pollutant Systems Study,
Volume I - Mass Emissions," prepared by Midwest Research Institute
for the Environmental Protection Agency under Contract No. EPA 22-
69-104 (May 1971).
3. Gorman, P. G., "Potential Dust Emission from a Grain Elevator in
Kansas City, Missouri," Final Report by Midwest Research Institute
prepared for Environmental Protection Agency (May 1974).
4. "Formula Feed Industry 1969 - A Statistical Summary," Statistical
Bulletin No. 485, Economic Research Service, U.S. Department of
Agriculture.
76
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APPENDIX A
CALCULATION OF PROJECTED EMISSIONS
77
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A. Elevators
1. Country elevators
a. Unloading
(1) 1975 -
(216 x 106 tons)(0.64 lb/ton)(l/2,000)[l-(0.39)(0.92)] = 4.4 x 104 tons
(2) 11980 -
(255 x 106 tons)(0.64 lb/ton)(l/2,000)[l-(0.49)(0.95)] = 4.3 x 104 tons
b. Turning
(1) 1975 -
(16.2 x 107 tons)(1.40 lb/ton)(l/2,000)[l-(0.39)(0.92)] i= 7.27 x 104 tons
(2) 1980 -
(19.1 x 107 tons)(1.40 lb/ton)(l/2,000)[l-(0.49)(0.95)] = 7.15 x 104 tons
c. Loading
(1) 1975 -
(21.6 x 107 tons)(0.27 lb/ton)(l/2,000)[l-(0.30)(0.92)] = 0.21 x 105 tons
(2) 1980 -
(25.5 x 107 tons)(0.27 lb/ton)(l/2,000)[l-(0.40)(0.95)] = 0.21 x 105 tons
d. Drying*
(1) 1975 -
(5.5 x 107 tons)(1.65 lb/ton)(l/2,000)[l-(0.28)(0.82)] = 3.49 x 104 tons
(2) 1980 -
(6.5 x 10? tons)(L.65 lb/ton)(l/2,000)[l-(0.35)(0.84)] = 3.81 x 1Q4 tons
* Original data obtained on the application of control for dryers were
given a low level of confidence. Therefore, these predictions based
on that data may be inaccurate.
78
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e. Cleaning
(1) 1975 -
(1.7 x 107 tons)(6.0 lb/ton)(l/2,000)[l-(0.81)(0.95)] = 1.17 x 104 tons
(2) 1980 -
(2.0 x 107 tons)(6.0 lb/ton)(l/2,000)[l-(0.91)(0.95)] = 0.81 x 104 tons
f. Headhouse
(1) 1975 -
(66.6 x 107 tons)(1.5 lb/ton)(l/2,000)[l-(0.67)(0.92)] = 1.92 x 105 tons
(2) 1980 -
(78.6 x 107 tons)(1.5 lb/ton)(l/2,000)[l-(0.77)(0.95)] = 1.58 x 105 tons
2. Terminal elevators
a. Unloading
(1) 1975 -
(6.9 x 107 tonsXl.O lb/ton)(l/2,000)[l-(0.66)(0.94)] = 1.31 x 104 tons
(2) 1980 -
(8.1 x 107 tons)(1.0 lb/ton)(l/2,000)[l-(0.74)(0.95)] = 1.20 x 104 tons
b. Turning
(1) 1975 -
(4.9 x 107 tons)(1.40 lb/ton)(l/2,000)[l-(0.93)(0.94)] = 4.32 x 103 tons
(2) 1980 -
(5.8 x 107 tons)(1.40 lb/ton)(l/2,000)[l-(0.95)(0.95)] = 3.96 x 103 tons
79
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c. Loading
(1) 1975 -
(6.9 x 107 tons)(0.27 lb/ton)(l/2,000)[l-(0.42)(0.93)] = 5.68 x 103 tons
(2) 1980 -
(8.1 x 107 tons)(0.27 lb/ton)(l/2,000)[l-(0.56)(0.95)] = 5.12 x 103 tons
d. Drying
(1) 1975 -
(0.66 x 107 tons)(1.65 lb/ton)(l/2,000)[l-(0.37)(0.83)] = 3.76 x 103 tons
(2) 1980 -
(0.78 x 107 tons)(1.65 lb/ton)(l/2,000)[l-(0.52)(0.86)] = 3.54 x 103 tons
e. Cleaning
(1) 1975 -
(1.5 x 107 tons)(6.00 lb/ton)(l/2,000)[l-(0.53)(0.93)] = 2.28 x 104 tons
(2) 1980 -
(1.8 x 107 tons)(6.00 lb/ton)(l/2,000)[l-(0.64)(0.95)] = 2.12 x 104 tons
f. Headhouse
(1) 1975 -
(20.9 x 107 tons)(1.5 lb/ton)(l/2,000)[l-(0.82)(0.93)] = 3.72 x 104 tons
(2) 1980 -
(24.6 x 107 tons)(1.5 lb/ton)(l/2,000)[l-(0.86)(0.95)] = 3.38 x 104 tons
g. Tripper
(1) 1975 -
(11.8 x 107 tons)(1.0 lb/ton)(l/2,000)[l-(0.35)(0.95)] = 3.94 x 104 tons
80
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(2) 1980 -
(13.9 x 107 tonsXl.O lb/ton)(l/2,000)[l-(0.51)(0.96)] = 3.55 x 104 tons
3. Export elevators
a. Unloading
(1) 1975 -
(10.5 x 107 tonsXl.O lb/ton)(l/2,000)[l-(0.83)(0.96)] = 1.07 x 104 tons
(2) 1980 -
(12.6 x 107 tons)(1.0 lb/ton)(l/2,000)[l-(0.91)(0.98)] = 0.68 x 104 tons
b. Turning
(1) 1975 -
(6.9 x 106 tons)(1.40 lb/ton)(l/2,000)[l-(0.87)(0.95)] = 8.38 x 102 tons
(2) 1980 - .
(8.3 x 106 tons)(1.40 lb/ton)(l/2,000)[l-(0.94)(0.97)] = 5.12 x 102 tons
c. Loading
(1) 1975 -
(10.5 x 107 tonsXl.O lb/ton)(l/2,000)[l-(0.47)(0.93)] = 2.96 x 104 tons
(2) 1980 -
(12.6 x 107 tonsXl.O lb/ton)(l/2,000)[l-(0.74)(0.96)] = 1.82 x 104 tons
d. Drying
(1) 1975 -
(1.05 x 106 tons)(1.65 lb/ton)(l/2,000)[l-(0.66)(0.84)] = 3.90 x 102 tons
(2) 1980 -
(1.26 x 106 tons)(1.65 lb/ton)(l/2,000)[l-(0.83)(0.90)] = 2.60 x 102 tons
81
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e. Cleaning
(1) 1975 -
(1.53 x 107 tons)(6.0 lb/ton)(l/2,000)[l-(0.55)(0.95)] = 2.19 x 104 tons
(2) 1980 -
(1.84 x 107 tons)(6.0 lb/ton)(l/2,000)[l-(0.78)(0.97)] = 1.34 x 104 tons
f. -Headhouse
(1) 1975 -
(23.3 x 107 tons)(1.5 lb/ton)(l/2,000)[l-(0.74)(0.97)] = 4.94 x 104 tons
(2) 1980 -
(28.0 x 107 tons)(1.5 lb/ton)(l/2,000)[l-(0.87)(0.98)] = 3.10 x 104 tons
g. Tripper
(1) 1975 -
(11.2 x 107 tonsXl.O lb/ton)(l/2,000)[l-(0.69)(0.95)] = 1.93 x 104 tons
(2) 1980 -
(13.4 x 107 tons)(1.0 lb/ton)(l/2,000)[l-(0.85)(0.97)] = 1.18 x 104 tons
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B. Feed Mills
a. Receiving
(1) 1975 -
(12.4 x 107 tons)(1.30 lb/ton)(l/2,000)[l-(0.50)(0.97)] =4.15 x 104 tons
(2) 1980 -
(14.0 x 1Q7 tons)(1.30 lb/ton)(l/2,000)[l-(0.65)(0.97)] = 3.36 x 104 tons
b. Shipping
(1) 1975 -
(9.68 x 107 tons)(0.5 lb/ton)(l/2,000)[l-(0.23)(0.94)] = 1.89 x 104 tons
(2) 1980 -
(10.9 x 107 tons)(0.5 lb/ton)(l/2,000)[l-(0.38)(0.97)] = 1.72 x 104 tons
c. Handling operations
(1) 1975 -
(12.4 x 107 tons)(3.0 lb/ton)(l/2,000)[l-(0.53)(0.96)] = 9.14 x 104 tons
(2) 1980 -
(14.0 x 107 tons)(3.0 lb/ton)(l/2,000)[l-(0.68)(0.97)] = 7.15 x 104 tons
d. Grinding*
(1) 1975 -
(5.82 x 107 tons)(0.1 lb/ton)(l/2,000) = 2.92 x Ifl3 tons
(2) 1980 -
(6.57 x 107 tons)(0.1 lb/ton)(l/2,000) = 3.29 x 103 tons
* A controlled emission factor was used to calculate emissions,
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e. Pellet coolers*
(1) 1975 -
(2.10 x 107 tons)(0.1 lb/ton)(l/2,000) = 1.05 x 103 tons
(2) 1980 -
(2.38 x 107 tons)(0.1 lb/ton)(l/2,000) = 1.19 x 103 tons
C. Alfalfa Dehydrating
(1) 1975 -
(1.6 x 106 tons)(20 lb/ton)(l/2,000)[l-(0.20)(0.95)] = 1.30 x 104 tons
(2) 1980 -
(1.6 x 106 tons)(20 lb/ton)(l/2,000)[l-(0.45)(0.95)] = 9.16 x 103 tons
D. Wheat Mills
a. Receiving
(1) 1975 -
(16.6 x 106 tonsXl.O lb/ton)(l/2,000)[l-(0.76)(0.96)] = 2.24 x 103 tons
(2) 1980 -
(16.6 x 106 tonsXl.O lb/ton)(l/2,000)[l-(0.84)(0.97)] = 1.54 x 103 tons
b. Freeleaning and handling
(1) 1975 -
(16.6 x 106 tons)(5.0 lb/ton)(l/2,000)[l-(0.88)(0.96)] = 6.44 x 103 tons
(2) 1980 -
(16.6 x 106 tons)(5.0 lb/ton)(l/2,000)[l-(0.92)(0.97)] = 4.47 x 103 tons
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c. Cleaning house
(1) 1975 - E = Insufficient information
(2) 1980 - E = Insufficient information
d. Mill house
(1) 1975 -
(16.6 x 106 tons)(70 lb/ton)(l/2,000)[l-(0.97)(0.98)] = 2.87 x 104 tons
(2) 1980 -
(16.6 x 106 tons)(70 lb/ton)(l/2,000)[l-(0.98)(0.98)] = 2.30 x 104 tons
E. Durum Mills
a. Receiving
(1) 1975 -
(1.2 x 106 tons)(1.0 lb/ton)(l/2,000)[l-(0.76)(0.96)] = 1.62 x 102 tons
(2) 1980 -
(1.4 x 10° tons)(1.0 lb/ton)(l/2,000)[l-(0.84)(0.97)] = 1.30 x 102 tons
b. Precleaning and handling
(1) 1975 -
(1.2 x 106 tons)(5.0 lb/ton)(l/2,000)[l-(0.88)(0.96)] = 4.66 x 102 tons
(2) 1980 -
(1.4 x 106 tons)(5.0 lb/ton)(l/2,000)[l-(0.92)(0.97)] = 3.77 x 102 tons
c. Cleaning house
(1) 1975 - E = Insufficient information
(2) 1980 - E = Insufficient information
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d. Mill house
(1) 1975 - E = Insufficient information
(2) 1980 - E = Insufficient information
F. Rye Milling
a. Receiving
(1) 1975 -
(0.15 x 106 tonsXl.O lb/ton)(l/2,000)[l-(0.76)(0.96)] = 2.03 x 10l tons
(2) 1980 -
(0.15 x 106 tons)(1.0 lb/ton)(l/2,000)[l-(0.84)(0.97)] = 1.39 x IQl tons
b. Precleaning and handling
(1) 1975 -
(0.15 x 106 tons)(5.0 lb/ton)(l/2,000)[l-(0.88)(0.96)] = 5.82 x 101 tons
(2) 1980 -
(0.15 x 106 tons)(5.0 lb/ton)(l/2,000)[l-(0.92)(0.97)] = 4.04 x 101 tons
c. Cleaning house
(1) 1975 - E = Insufficient information
(2) 1980 - E = Insufficient information
d. Mill house
(1) 1975 -
(0.15 x 106 tons)(70 lb/ton)(l/2,000)[l-(0.97)(0.98)] = 2.59 x 102 tons
(2) 1980 -
(0.15 x 106 tons)(70 lb/ton)(l/2,000)[l-(0.98)(0.98)] = 2.08 x 102 tons
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G. Dry Corn Milling
a. Receiving
(1) 1975 -
(4.7 x 106 tons)(1.0 lb/ton)(l/2,000)[l-(0.78)(0.97)] = 5.72 x 102 tons
(2) 1980 -
(4.7 x 106 tonsXl.O lb/ton)(l/2,000)[l-(0.85)(0.98)] = 3.93 x 102 tons
b. Drying
(1) 1975 -
(0.94 x 106 tons)(0.5 lb/ton)(l/2,000)[l-(0.94)(0.86)] = 4.50 x 101 tons
(2) 1980 -
(0.94 x 106 tons)(0.5 lb/ton)(l/2,000)[l-(0.96)(0.89)] = 3.42 x 101 tons
c. Freeleaning and handling
(1) 1975 -
(4.7 x 106 tons)(5.0 lb/ton)(l/2,000)[l-(0.87)(0.97)] = 1.83 x 103 tons
(2) 1980 -
(4.7 x 106 tons)(5.0 lb/ton)(l/2,000)[l-(0.91)(0.98)] = 1.27 x 103 tons
d. Cleaning house
(1) 1975 -
(4.7 x 106 tons)(6.0 lb/ton)(l/2,000)[l-0.97] = 4.23 x 102 tons
(2) 1980 -
(4.7 x 1QD tons)(6.0 lb/ton)(l/2,000)[l-0.98] = 2.82 x 1Q2 tons
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e. Degerming and milling
(1) 1975 - E = Insufficient information
(2) 1980 - E = Insufficient information
H. Oat Mills
(1) 1975 -
(0.8 x 106 tons)(2.5 lb/ton)(l/2,000) = 1 x 103 tons
(2) 1980 -
(0.8 x 106 tons)(2.5 lb/ton)(l/2,000) = 1 x 103 tons
I. Rice Milling
a. Receiving
(1) 1975 -
(4.4 x 106 tons)(0.64 lb/ton)(l/2,000)[l-(0.75)(0.95)] = 4.05 x 102 tons
(2) 1980 -
(4.4 x 106 tons)(0.64 lb/ton)(l/2,000)[l-(0.84)(0.97)] = 2.61 x 102 tons
b. Freeleaning and handling
(1) 1975 -
(4.4 x 106 tons)(5.0 lb/ton)(l/2,000)[l-(0.72)(0.97)] = 3.32 x 103 tons
(2) 1980 -
(4.4 x 106 tons)(5.0 lb/ton)(l/2,000)[l-(0.82)(0.98)] = 2.16 x 1Q3 tons
c. Drying
(1) 1975 - E = Insufficient information
(2) 1980 - E = Insufficient information
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d. Cleaning and mill house
(1) 1975 - E = Insufficient information.
(2) 1980 - E = Insufficient information
J. Commercial Rice Drying
Due to insufficient data, calculations are not possible.
K. Soybean Mills
a. Receiving
(1) 1975 -
(25.8 x 106 tons)(1.6 lb/ton)(l/2,000)[l-(0.67)(0.98)] = 7.09 x K)3 tons
(2) 1980 -
(30.6 x 106 tons)(1.6 lb/ton)(l/2,000)[l-(0.83)(0.99)] = 4.36 x 103 tons
b. Handling
(1) 1975 -
(25.8 x 106 tons)(5.0 lb/ton)(l/2,000)[l-(0.84)(0.97)] = 1.19 x 104 tons
(2) 1980 -
(30.6 x 106 tons)(5.0 lb/ton)(l/2,000)[l-(0.92)(0.98)] = 0.75 x 104 tons
c. Cleaning
(1) 1975.-
(25.8 x 106 tons)(6.0 lb/ton)(l/2,000)[l-0.83] = 1.32 x 104 tons
(2) 1980 -
(30.6 x 106 tons)(6.0 lb/ton)(l/2,000)[l-0.9l] = 0.82 x 10^ tons
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d. Drying
(1) 1975 - . . '.
(25.8 x 106 tons)(7.2 lb/ton)(l/2,000)[l-(0.61)(0.85)] = 4.47 x 104 tons
(2) 1980 -
(30.6 x 106 tons)(7.2 lb/ton)(l/2,000)[l-(0.81)(0.90)] = 2.99 x 104 tons
e. Cracking and dehulling
(1) 1975 -
(25.8 x 106 tons)(3.3 lb/ton)(l/2,000)[l-(0.97)(0.95)] = 3.34 x 103 tons
(2) 1980 -
(30.6 x 106 tons)(3.3 lb/ton)(l/2,000)[l-(0.99)(0.97)] = 2.00 x 103 tons
f. Hull grinding
(1) 1975 -
(25.8 x 106 tons)(2.0 lb/ton)(l/2,000)[l-(0.99)(0.95)] = 1.54 x 103 tons
(2) 1980 -
(30.6 x 106 tons)(2.0 lb/ton)(l/2,000)[l-(0.99)(0.97)] = 1.21 x 103 tons
g. Bean conditioning
(1) 1975 -
(25.8 x 106 tons)(0.1 lb/ton)(l/2,000)[l-(0.86)(0.92)] = 2.69 x 102 tons
(2) 1980 -
(30.6 x 106 tons)(0.1 lb/ton)(l/2,000)[l-(0.93)(0.94)] = 1.93 x 102 tons
h. Flaking
(1) 1975 -
(25.8 x 106 tons)(0.57 lb/ton)(l/2,000)[l-(0.97)(0.92)] = 7.91 x 102 tons
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(2) 1980 -
(30.6 x 106 tons)(0.57 lb/ton)(l/2,000)[l-(0.99)(0.94)] = 6.05 x 102 tons
i. Meal dryer
(1) 1975 -
(25.8 x 106 tons)(1.5 lb/ton)(l/2,000)[l-(0.75)(0.92)] = 6.00 x 103 tons
(2) 1980 -
(30.6 x 106 tons)(1.5 lb/ton)(l/2,000)[l-(0.87)(0.93)] = 4.38 x 103 tons
j. Meal cooler
(1) 1975 -
(25.8 x 106 tons)(1.8 lb/ton)(l/2,000)[l-(0.96)(0.92)] = 2.71 x 103 tons
(2) 1980 -
(30.6 x 106 tons)(1.8 lb/ton)(l/2,000)[l-(0.98)(0.94)] = 2.17 x 103 tons
k. Bulk loading
(1) 1975 -
(25.8 x 106 tons)(0.27 lb/ton)(l/2,000)[l-(0.58)(0.98)] = 1.49 x 103 tons
(2) 1980 -
(30.6 x 106 tons)(0.27 lb/ton)(l/2,000)[l-(0.79)(0.98)] = 0.93 x 103 tons
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L. Corn Wet Mills
a. Receiving
(1) 1975 -
(7.3 x 106 tonsXl.O lb/ton)(l/2,000)[l-(0.78)(0.94)] = 9.74 x 102 tons
(2) 1980 -
(8.0 x 106 tons)(1.0 lb/ton)(l/2,000)[l-(0.89)(0.97)] = 5.47 x 102 tons
b. Handling
(1) 1975 -
(7.3 x 106 tons)(5.0 lb/ton)(l/2,000)[l-(0.85)(0.97)] = 3.20 x 103 tons
(2) 1980 -
(8.0 x 106 tonsXS.O lb/ton)(l/2,000)[l-(0.92)(0.98)] = 1.97 x 103 tons
c. Cleaning
(1) 1975 -
(7.3 x 106 tons)(6.0 lb/ton)(l/2,000)[l-(l)(0.96)] = 8.76 x 102 tons
(2) 1980 -
(8.0 x 106 tons)(6.0 lb/ton)(l/2,000)[l-(l)(0.98)] = 4.80 x 102 tons
d. Drying
(1) 1975 -
(1,240 lb/hr)(7.3/6.3X8,000 hr)(l/2,000) = 5.75 x 103 tons
(2) 1980 -
(1,240 lb/hr)(8.0/6.3X8,000 hr)(l/2,000) = 6.30 x 103 tons
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