; n u»2
vsei;ss uy
of Conventional
o
rn
the Iron rind Stee
Indusry
Office of Rfcsearch «nd Monitorinn
US Frivironipent?*! Protection Agency
Washington. D.C 20460
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EPA-R2-73-192
Systems Study of Conventional
Combustion Sources
in the Iron and Steel Industry
by
J. Goldish, G. Margolis,
J. Ehrenfeld, and R. Bernstein
Walden Research Corporation
359 Allston Street
Cambridge, Massachusetts 02139
Contract No. EHSD 71-21
Program Element No. 1A2014
EPA Project Officer: G. B. Martin
Control Systems Laboratory
National Environmental Research Center
Research Triangle Park, North Carolina 27711
Prepared for
OFFICE OF RESEARCH AND MONITORING
U. S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D. C. 20460
April 1973
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This report has been reviewed by the Environmental Protection Agency
and approved for publication. Approval does not signify that the
contents necessarily reflect the views and policies of the Agency,
nor does mention of trade names or comnercial products constitute
endorsement or recommendation for us.
11
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TABLE OF CONTENTS
Section Title Page
I SUMMARY 1
A. Background, Definitions and Assumptions 1
B. Boiler Inventories 4
C. Fuel Consumption and Boiler Emissions 4
D. Process Emissions 8
E. Comparison of Boiler and Process Emissions 12
F. Control Strategi es 12
G. Cost Effectiveness 15
H. Conclusions and Recommendations 17
1. Conclusions 17
2. Recommendations 17
II INTRODUCTION 20
III INVENTORIES OF BOILER CAPACITIES, FUEL USE, AND
EMISSIONS 22
A. Definitions 22
1. Size 22
2. Regions 22
3. Fuels 24
4. Firing Type 24
5. Age 25
B. Methodology 25
1. The Boiler Sample 25
2. The 1970 Boi 1 er Inventory 25
3. Operating Factors 26
4. Projections 26
5. Fuel Use 28
6. Emissions 28
C. Results 28
1. 1970 Boiler Inventory and Fuel Consumption .. 29
2. Projected Boiler Inventories and Fuel
Consumption 33
3. Current and Projected Boiler Emissions 39
IV PROCESS EMISSIONS 44
A. Introduction 44
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TABLE OF CONTENTS (Cont.)
Section Title Page
IV B. Methodology 45
1. Conventional Process Emissions 45
2. Fuel Based Emissions 53
C. Results and Discussion 64
V COMPARISON OF BOILER EMISSIONS TO PROCESS
EMISSIONS 70
VI STRATEGIES FOR EMISSION CONTROL 74
A. Introduction 74
B. Fuel Switching 74
1. General Approach 74
2. Fuel Pri ces 75
3. Capital Costs Involved in Fuel Switching ... 75
C. Fl ue Gas Treatment 76
1. Particulate Control 76
2. Sulfur Oxide Removal 80
3. NO Removal and Recovery 90
X
D. Combustion Design 90
1. Combustion Additives 90
2. Combustion Design 92
E. Control Strategies of Special Application to the
Iron and Steel Industry 95
VII COST EFFECTIVENESS AND ANALYSIS 98
A. Introduction 98
B. Results 99
1. Fuel Switching 99
2. Flue Gas Treatment 99
3. Maximum Reduction - Reasonable Cost
Strategy 101
VIII CONCLUSIONS AND RECOMMENDATIONS 105
A. Conclusions 105
B. Recommendations 105
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Section
VIII
APPENDIX A
APPENDIX B
APPENDIX C
APPENDIX D
1.
2.
TABLE OF CONTENTS (Cont.)
Title
Improvements of the Present Study
Implementation of Fuel Switching .
DATA ANALYSIS AND BOILER INVENTORY
PROJECTIONS OF BOILERS TO THE YEAR 1980
PROCESS EMISSIONS
EMISSION FACTORS AND BOILER EMISSIONS
Page
105
106
A-l
B-l
C-l
D-l
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I. SUMMARY
A. BACKGROUND, DEFINITIONS AND ASSUMPTIONS
Process emissions from the iron and steel industry have been
studied in the past, with little attention given to the contribution to
air pollution of the conventional fossil fuel combustion equipment cur-
rently installed in steel mills. This study determines this contribution,
compares it to process emissions and considers potential means to control
the boiler emissions.
The study identified the pollutant sources according to equipment
size, regional distribution, fuel, firing type, age and other factors of
significance to air pollution emissions. Estimates of installed capacity
were made for the base year, 1970, and projections were made for 1975
and 1980.
This study includes only watertube boilers (WT). The data-base
was obtained from a variety of sources. Sales data were made available
by the American Boiler Manufacturers Association (ABMA) [1-1] and several
individual boiler manufacturers. Statistics compiled from the yearly
boiler surveys, published by Power magazine [1-2] were used for checking
purposes. Data on the boilers actually in operation were obtained
from government agencies and telephone interviews with about 70 iron
and steel plants across the country. The data were summarized by six
regions (Figure 1-1).
These geographical regions are similar to those used in the
Intermediate Size Boiler Study [1-5]. The rationale behind the choice
of these regions was two-fold. First, the states in these areas are
considered to have similar air pollution conditions, and secondly, such
a regional grouping allowed comparison with air pollution resulting from
boilers in U.S. industries in general.
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Figure 1-1. Regional Boundaries
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Assumptions
(1) In order to obtain a complete 1970 inventory from this sample, the
assumption was made that employment in the iron and steel industry
was proportional to the boiler capacity in the industry.
(2) It was assumed that the number of units and the wide scope of the
study permitted the application of average operating characteristics,
emission factors, fuel prices, etc.
(3) No controls for S(L and NO were assumed in developing the emission
£- s\
estimates. The process particulate emissions are shown partially
controlled, based on estimates and available statistics. The boiler
particulate emissions are shown uncontrolled.
(4) In developing projections one of the main assumptions used was that
the ratio of the boiler capacity used for non-power purposes to the
total tons of raw steel produced in 1970 [1-3] would remain constant
over the years. Projected production figures were obtained from
the BatteHe study of the integrated iron and steel industry Il-4].
(5) The energy required to produce the projected raw steel [1-4] for
1975 and 1980 was determined by means of linear regression of
historical data [1-3]. The fraction of the total energy generated
in-house was used to arrive at the boiler capacity required for
power generation.
(6) Fuel distribution for the projected years was based on the fuel
patterns developed in the Walden study of intermediate-size
boilers [1-5] and projections of raw steel requirements made by
Battelle [1-4].
(7) No changes in boiler operating factors, such as boiler efficiency,
load factor, fuel sulfur content, were assumed in the boiler
projections.
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B. BOILER INVENTORIES
The total estimated capacity of boilers installed in the iron
and steel industry in 1970 was 103.5 million pounds of steam an hour
(pph), representing approximately 1,600 units. Table 1-1 shows a sum-
mary of this inventory by region and fuel.
Projections of boiler capacities were made in the following
manner. The energy required to produce the raw steel projected by the
BatteHe Systems Study of the Integrated Iron and Steel Industry [1-4]
was determined. The total energy required for the iron and steel in-
dustry was derived from this figure. The estimated boiler capacity
required to produce this energy was obtained by projecting the percentage
of the total power generated in-house. This gave 1975 and 1980 figures
for the boiler capacity to be used for power generation. The assumption
was then made that the ratio of boiler capacity used for non-power
purposes to the total tons of raw steel produced in 1970 would remain
constant over the years. Using the Battelle projections of raw steel
production [1-4] the boiler capacity needed for process and space heating
was derived for 1975 and 1980. By summing the capacities required for
power generation and for process and space heating the total projected
boiler capacities were found to be 116.8 and 125.0 million pounds per
hour for 1975 and 1980, respectively. Regional projections of fuel use
and the various boiler sizes were derived from the Walden study of in-
termediate-size boilers [1-5]. The projected boiler inventories are shown
in Table 1-2.
C. FUEL CONSUMPTION AND BOILER EMISSIONS
The annual fuel consumption of boilers was calculated by using
the following formula:
R , _ capacity (Ib/hr) x load factor x 8760 (hours/yr) x 975 (Btu/lb)
Btu/yr efficiency
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TABLE 1-1
1970 BOILER CAPACITY IN THE IRON AND STEEL INDUSTRY*
(103 pph)
Boilers
WT<_100,000 pph
WT1 00, 001 -250, 000 pph
WT>250,000 pph
TOTAL
Fuels
CL
RO
GS
BFG
COG
CL
RO
GS
BFG
COG
CL
RO
GS
BFG
COG
AT
1,729
2,247
5,013
5,878
2,420
1,317
1,712
3,820
4,478
1,844
1,070
1,391
3,104
3,639
1,498
41,160
GL
3,956
1,148
2,425
3,829
1,404
4,698
1,364
2,879
4,546
1,667
3,709
1,077
2,273
3,589
1,316
39,880
WS
73
182
1,277
1,131
985
42
106
739
655
570
77
192
1,344
1,190
1,037
9,600
SE
1,439
135
1,170
1,260
495
864
81
702
756
297
1,810
170
1,470
1,584
622
12,855
Total
7,197
3,712
9,885
12,098
5,304
6,921
3,263
8,140
10,435
4,378
6,666
2,830
8,191
10,002
4,473
103,495
*
Regions CU and RN were not included because of negligible participation in the
primary iron and steel industry.
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TABLE 1-2
PROJECTED BOILER CAPACITY IN THE IRON AND STEEL INDUSTRY BY SIZE
(106 pph)
WT
WT
WT
£100,000 pph
100,001-250,000 pph
>250,000 pph
AT
1975
21.1
14.4
11.3
46.8
1980
23.5
15.6
11.2
50.3
GL
1975
15.6
16.5
12.7
44.8
1980
17.0
17.9
12.6
47.5
WS
1975
4.5
2.3
4.0
10.8
1980
4.7
3.7
4.0
12.4
SE
1975
5.5
2.9
6.0
14.4
1980
5.8
3.1
5.9
14.8
Total
1975
46.7
36.1
34.0
116.8 1
1980
51.0
40.3
33.7
25.0
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The 1970 fuel consumption pattern is shown in Figure 1-2. It is noted that
almost half of the fuel used consists of fuels generated elsewhere in the
iron and steel plant.
Coke Oven Gas
119.7
Blast Furnace Gas
275.4
Figure 1-2. 1970 Fuel Consumption by Boilers in the Iron and
Steel Industry in 10^2 Btu.***
Uncontrolled boiler emissions were calculated according to the
following equations:
cn /. x fuel consumption (Btu/yr) x emission factor (Ib/Btu) x % sulfur
bU2 uonsj 2000 Ob/ton)
wn t+n \
MUX itons;
(tons)
fuel consumption (Btu/yr) x emission factor (Ib/Btu)
2000 ( ID/ ton)
- fuel consumption (Btu/yr) x emission factor Qb/Btu) x % ash**
- - - * - ynnn M k /-I-««A - -
2000 (Ib/ton)
For the conventional fuels the emission factors, sulfur and ash
contents used for industrial intermediate-size boilers, were applied [1-5].
**
***
Only in the case of coal- or oil-fired boilers
V
Only in the case of coal-fired boilers
Ir
Distillate oil use in the iron and steel industry is negligible.
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The corresponding factors for blast furnace gas and coke oven gas were
obtained by studying the process which creates these gases (see Appendix
C). The estimated air pollution emissions for 1970 and the projected
figures for 1975 and 1980 are summarized in Tables 1-3, 1-4 and 1-5.
From these results it is clearly evident that the combustion of
the fossil fuels (as compared to the non-conventional fuels) produce the
major fraction of the emissions. Blast furnace gas and coke oven gas
are relatively clean fuels when compared to coal and fuel oil.
D. PROCESS EMISSIONS
Process emissions in the iron and steel industry emanate from
two distinct types of sources:
(i) emission produced during the handling of raw materials
and the subsequent processing of these materials to pro-
duce steel, i.e., the conventional process emissions.
(ii) emissions resulting from non-boiler fuel combustion needed
to meet the energy demands during the manufacturing steps
(i) Conventional Process Emissions
The conventional process emissions were determined by calculating
the emissions for each of the following processes in the iron and steel
industry:
(1) Sinter plants
(2) Pellet Plants
(3) Coke manufacture
(4) Blast furnaces
(5) Steel furnaces
- Open hearth
- Basic oxygen furnace (EOF)
- Electric arc furnace
(6) Scarfing
(7) Materials handling
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TABLE 1-3
SUMMARY
OF PROJECTED S02 EMISSIONS (TO3 tons)
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T3
O
X)
AT
GL
WS
SE
TOTAL
Fossil
Fuels
81.2
206.9
6.0
49.0
343.1
1970
Non-
Conventional
Fuels
37.7
28.5
16.8
9.2
92.2
Total
118.9
235.4
22.8
58.2
435.3
Fossil
Fuels
67.8
228.3
7.3
42.9
346.3
1975
Non-
Conventional
Fuels
36.8
35.2
9.1
11.0
92.1
Total
104.6
263.5
16.4
53.9
438.4
Fossil
Fuels
76.1
249.9
8.1
45.0
379.1
1980
Non-
Conventional
Fuels
39.6
37.1
9.7
11.7
98.1
Total
115.7
287.0
17.7
56.7
477.2
TABLE 1-4
AT
GL
WS
SE
TOTAL
Fossil
Fuels
73.2
227.6
4.0
67.9
372.7
SUMMARY
1970
Non-
Conventional
Fuels
2.4
1.9
.7
.6
5.6
OF PROJECTED PARTICULATES EMISSIONS (103
Total
75.5
229.5
4.7
68.5
378.3
Fossil
Fuels
51.2
247.8
5.5
62.4
366.9
1975
Non-
Conventional
Fuels
2.1
2.1
.1
.7
5.4
Total
53.3
249.9
6.0
63.1
372.3
tons)
Fossil
Fuels
55.3
276.4
6.1
65.6
403.4
1980
Non-
Conventional
Fuels
2.1
1.9
.6
.6
5.2
Total
57.4
278.3
6.7
66.2
408.6
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TABLE 1-5
SUMMARY OF PROJECTED NOV EMISSIONS (103 tons)
X
AT
GL
WS
SE
TOTAL
Fossil
Fuels
32.4
49.8
4.4
15.8
102.4
1970
Non-
Conventional
Fuels
12.9
10.4
5.2
3.3
31.8
Total
45.3
60.2
9.6
19.1
134.2
Fossil
Fuels
36.1
56.0
6.8
15.9
114.8
1975
Non-
Conventional
Fuels
12.4
12.2
3.0
4.0
31.6
Total
48.5
68.2
9.8
19.9
146.4
Fossil
Fuels
41.8
62.4
8.5
17.0
129.7
1980
Non-
Conventional
Fuels
12.4
12.1
3.3
4.0
31.8
Total
54.2
74.5
11.8
21.0
161.5
O
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the emission calculations were based on the input/output data for each
source [1-4], and where reliable statistics were available, controlled
particulate emissions were calculated. Thus the particulate process
emissions, as shown in this report, may be considered partially controlled,
whereas no control was assumed for process emissions of S09 and NO .
C- s\
Process emission projections were based on projections of pro-
duction figures obtained from the Battelle report [1-4] and analysis of
the various manufacturing steps which cause them. The results are sum-
marized in Table 1-6.
TABLE 1-6
CONVENTIONAL PROCESS EMISSIONS OF THE IRON AND STEEL INDUSTRY
CIO3 tons)
1970 1975 1980
S09 Part. N0v S09 Part. NO SO- Part. NO
L- X L, X £ X
Sirter Plants
Pellet Plants
32
*
Coke Manufacture *
Blast Furnaces
Steel Furnaces
Open Hearth
B.O.F.
Electric Arc
Scarfing
Materials
Handling
TOTALS
*
Emissions less
(ii) Fuel
*
35
2
*
*
*
69 1
than 500
Combustion
96
*
152
*
312
28
28
63
446
,125
tons
24
*
*
*
25
*
*
*
*
49
Process Emi
39
*
*
*
31
2
*
*
*
72 1
ssions
117
*
155
*
189
36
15
73
533
,118
29
*
*
*
22
*
*
*
*
51
42
*
*
*
25
3
*
*
*
70
124
*
159
*
8
46
20
86
612
955
31
*
*
*
18
*
*
*
*
49
Five fuels are extensively used in the iron and steel industry
to supply process energy: fuel oil, natural gas, tar and pitch, coke oven
gas and blast furnace gas. The latter three fuels are produced within
11 WALDEN RESEARCH CORPORATION
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the steel mill as by-products and their production depends on the coke
rate and ultimately on pig iron requirements.
1970 fuel oil and natural gas consumption figures were available
in the annual reports of the American Iron and Steel Institute (AISI) [1-3].
Future consumption of these fuels was determined by projecting time series
available in the AISI reports as well as the ratios between fuel and pig
iron, open hearth steel and raw steel production.
A summary of the calculated emissions is shown in Table 1-7.
E. COMPARISON OF BOILER AND PROCESS EMISSIONS
Figure 1-3 shows the boiler and process emissions in the iron
and steel industry from 1970 to 1980.
It must be emphasized that S09 and NO emissions are shown un-
^ A
controlled, representing the actual situation in 1970. The particulate
emissions are shown uncontrolled for boilers and partially controlled for
process emissions. This is due to the lack of data on air pollution con-
trol equipment installed on boilers in the iron and steel industry. The
comparison between boiler and process particulate emissions is therefore
not as straightforward as the comparison for the other two pollutants.
The fact remains, however, that the boilers in the iron and steel in-
dustry are major contributors to the total S09 and NO emissions, and
£ X
represent a significant portion of the total particulate emissions.
F. CONTROL STRATEGIES
The analysis of control of emissions from boilers was approached
in terms of strategies for both control of the separate three pollutants
and also in terms of combined emissions. The principal control approaches
examined were:
1. Fuel Switching
2. Flue Gas Treatment
Particulate Collectors
S02 Removal Systems
NO Removal Systems
J\
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TABLE 1-7
PROCESS EMISSIONS FROM NON-BOILER FUEL COMBUSTION IN THE IRON AND STEEL INDUSTRY
(tons)
Blast Furnace Area
Coke Oven Underfiring
Heating and Annealing
Furnaces and Heating
Ovens for Wire Rods
TOTALS
1970
S02 Part.
2,220
106,725 2,515
194,000 7,170
300,725 11,905
NOX SO,
160
5,900 95,000
5,600 196,500
11,660 291,500
1975
Part.
2,400
2,300
8,300
13,000
N0x
170
6,000
6,700
12,870
1980
S02 Part.
2,200
97,000 2,500
205,500 9,300
302,500 14,000
NOX
170
6,000
7,700
13,870
-------
805
370
850
435
xx
364
X
438
373
X
477
1970 1975 1980
S00
195
210
225
61
69
146
63
L162
1970 1975 1980
NO..
1,515 l5
1970 1975 1980
Particulates
= Boilers
Figure 1-3. Boiler and Process Emissions 1970-1980 (103 tons).
14
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3. Combustion Design
Fuel Additives
Combustion Modifications and Control
Low Excess Air (LEA)
Flue Gas Recirculation (FGR)
4. Strategies of Particular Application to the Iron and Steel
Industry
Estimates of the applicability, pollution reducing potential and
cost of implementing each control strategy were obtained.
G. COST EFFECTIVENESS
The cost effectiveness of applying the following three control
strategies were examined:
1. Fuel Switching
2. Flue Gas Treatment - Alkaline Scrubbing
3. Maximum Reduction-Reasonable Cost Total Program, i.e.,
combination of fuel switching, fuel additives and combus-
tion modifications.
Fuel switching emerged as the most effective strategy. However,
flue gas treatment approximates fuel switching in its combined effect on
the simultaneous removal of all of the pollutants, although the initial
capital costs of flue gas treatment are much higher than fuel switching.
These results are shown in Table 1-8.
The relative effectiveness of fuel switching depends on the price
of fuel, which in turn depends on its availability. No models for avail-
ability were introduced in the cost effectiveness analysis.
Should, however, the price of fuel increase rapidly due to demand,
so that fuel switching would not become as attractive, it was concluded
that the iron and steel industry was in a fairly favorable position to
adopt other control strategies because of the high load factors of the
boilers and the general level of maintenance available in the industry.
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TABLE 1-8
ALTERNATIVE STRATEGIES FOR BOILERS IN THE IRON AND STEEL INDUSTRY
SO,
NO.
Particulates
Emissions
Emissions
Emissions
10 tons/Y Reduction 10 tons/Y Reduction 10 tons/Y Reduction
Cost
$ 106
Annual
Capital Operating
1975 Projected Base
Level 438
Fuel Switching 134
Flue Gas Treatment 22
69
95
146
129
117
11
20
372
17
17
95
95
11.6
238
39.0
137
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H. CONCLUSIONS AND RECOMMENDATIONS
1. Conclusions
Three major conclusions emerge from this study:
(a) Steam raising boilers are a significant source of air
pollution in the iron and steel industry. These boilers
emit about 1/3 the particulate loadings of the process
emissions but produce annually about half of the total
S0? and two thirds of the NO .
^ /\
(b) A significant fraction of the particulate and S0?
emissions from the boilers result from the combustion
of conventional fossil fuels. This is a result of the
relative cleanliness (with respect to particulates and
sulfur) of coke oven gas and blast furnace gas as com-
pared to the conventional fossil fuels.
(c) Mainly as a consequence of (b), it is concluded from
the control strategy cost effectiveness analyses that
fuel switching would be the most effective means of
control.
2. Recommendations
Examination of the results of the development of emission
estimates and projections and analysis of control strategies point to two
principal sets of recommendations:
(1) Improvement on the present study
(2) Implementation of fuel switching
a. Improvements of the Present Study
The first set reflects uncertainties and limitations
resulting from assumptions, idealizations and imperfect data inputs in-
herent in the analytic procedures employed in the study.
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Anticipating that strategy evaluation appears more meaning-
ful on the basis of combined effects on all three pollutants, it would be
valuable to develop a parallel means to combine the emissions into a single
quantity using some weighting factor to account for permissible levels of
exposure.
Other improvements are more direct. The study should be
updated and checked against actual future developments. More fine
structure should be introduced. There is need to improve the emission
factor data and the information concerning the fraction of units controlled.
This information is required particularly for the process emissions where
very little information is available and yet these "rough" emission esti-
mates would suggest that the iron and steel industry is a significant in-
dustrial polluter.
The fuel switching analysis depends on several key as-
sumptions regarding fuel price and availability. Re-examination considering
supply price forecasts should be made.
b. Implementation of Fuel Switching
Fuel switching was shown to be the preferred control
strategy as long as fuel prices do not increase. However, recent trends
in prices, particularly for low sulfur fuels, would suggest rapid increases
in the near future. Because fuel switching has many attractive features
other than low annual operating cost, it is important to seek means to
maintain the price of fuel and the adequacy of supply at levels where
this strategy remains effective.
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REFERENCES TO SECTION I
1-1. American Boiler Manufacturers Association, Annual Reports on Water-
tube Boiler Sales, 1947-1970.
1-2. Annual Boiler Surveys by Power Magazine, 1940-1970.
1-3. Statistical Reports, American Iron and Steel Industry, 1968-1970.
1-4. A Systems Analysis Study of the Integrated Iron and Steel Industry,
BatteHe Memorial Institute, Columbus, Ohio, 1964".
1-5. Systematic Study of Air Pollution from Intermediate-Size Fossil-
Fuel Combustion Equipment,'Balden Research Corporation, Cambridge,
Mass., 1971.
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II. INTRODUCTION
This report describes the results, methodology, and data base for a
study of air pollution from conventional combustion sources in the pri-
mary iron and steel industry. This work has been carried out under Con-
tract No. EHS-D-71-21, sponsored by the Office of Research and Monitor-
ing (OR&M) of the U.S. Environmental Protection Agency.
The purpose of this systems study was:
(1) to obtain a complete and current inventory of conventional
stationary fossil fuel combustion equipment installed in the iron and
steel industry,
(2) to project into the future the boiler inventory installed in
this industry,
(3) to calculate SO , NO , and particulate emissions resulting
/\ J\
from these types of conventional fossil fuel combustion equipment for
the present and future,
(4) to compare these emissions to total process emissions in the
iron and steel industry,
(5) to study the cost effectiveness and program required of con-
trol strategies, applicable to the boilers in the iron and steel in-
dustry.
The work was divided into the following phases:
I. Identification of the 1970, 1975, and 1980 boiler inventories,
and calculation of the fuel consumed by these boilers and the air pol-
lution resulting therefrom.
II. Identification of the 1970, 1975, and 1980 process emissions.
III. Comparison of the emissions from conventional boilers to pro-
cess emissions.
20 WALDEN RESEARCH CORPORATION
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IV. Techno-economic evaluation of air pollution control.
V. Program planning outline.
The boiler data for this study were obtained from a variety of
sources, including the American Boiler Manufacturers Association (ABMA),
Power magazine's yearly boiler surveys, government agencies, and tele-
phone interviews with approximately 70 iron and steel plants. Fuel con-
sumption and emission figures were derived from these boiler capacity
data, using operating characteristics gathered in the above-mentioned
sample.
The process emissions were calculated in two steps:
(1) Emissions produced during the handling of raw materials and
the subsequent processing of these materials to produce steel were de-
termined. Where it was possible to estimate the degree of controls the
emissions were reduced accordingly. The calculations were performed by
considering each of the following separate processing operations:
(a) Sinter plants
(b) Pellet plants
(c) Coke manufacture
(d) Blast furnaces
(e) Steel furnaces
(f) Scarfing
(g) Materials handling
(2) The emissions resulting from the combustion of fuel needed to
meet energy demands during the above manufacturing steps were estimated.
The comparison between these partially controlled process emissions and
the uncontrolled emissions resulting from the boilers in the industry in-
dicated the need to control both sources. Alternate control strategies
are suggested at the end of this report to control the significant emis-
sions from the conventional fossil fuel combustion equipment in the iron
and steel industry. A guideline to the determination of the cost effec-
tiveness of each strategy is given.
21 WALDEN RESEARCH CORPORATION
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III. INVENTORIES OF BOILER CAPACITIES, FUEL USE. AND EMISSIONS
A. DEFINITIONS
This section defines the various categories used to identify
and classify fossil fuel burning equipment and to note some of the cod-
ing used in this report. Fossil fuel burning equipment is broken down
according to:
(1) Size
(2) Region
(3) Fuel
(4) Firing type (for coal only)
(5) Age
1. Size
The watertube boilers have been reported in three size
classes: less than or equal to 100,000 Ib per hour (pph), between
100,000 and 250,000 pph and greater than 250,000 pph.
2. Regions
Four regions were used in this study (Figure 3-1). A sum-
mary description of these four regions follows:
The Atlantic region (AT) includes New York, Pennsylvania,
Delaware, Maryland, Connecticut, and Massachusetts. This is a very dense,
nearly continuous band of large, mature, urban areas. The urbanization
is supported by an exceptionally broad economic base including a wide
variety of types and sizes of manufacturing enterprises as well as the
nation's educational, financial, and government centers. The region ex-
periences moderately cold winters and uses oil for most of its space
heating. The pollution problem is aggravated by shallow atmospheric
mixing depths but relieved by relatively high wind speeds and the in-
frequency of low-level stability.
The Great Lakes region (GL) includes Michigan, Illinois,
Indiana, Ohio, Minnesota, and Missouri. A second group of large, mature,
22 WALDEN RESEARCH CORPORATION
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Figure 3-1. Regional Boundaries
-------
urban areas, different only in degree from the Atlantic coastal megalop-
olis, having slightly less dense surroundings, somewhat wider spacing of
urban centers, and an economy more characterized by large, mass-production
industry. The two regions also differ in fuel use, with the Great Lakes
region dividing its consumption among coal, oil, and gas. Although the
region is characterized by relatively favorable atmospheric dilution,
the population and industrial load results in high pollution levels.
The Southeast region (SE) includes Alabama, Georgia,
Kentucky and West Virginia. This region has medium-size, widely separ-
ated, mature metropolitan areas, surrounded by a fairly dense statewide
population. The cities are supported by manufacturing. The warmer
climate reduces space heating emissions, but frequent atmospheric stag-
nation concentrates the pollutants which are emitted.
The Far West and South region (WS) includes Texas, Utah
and California. This region has a group of large, new, fast-growing
urban areas which are widely scattered over the otherwise sparsely-
settled territory. Relatively little manufacturing and a warm climate
tend to mitigate pollution from stationary combustion units. The large,
disperse urban areas, however, generate high volumes of automobile exhaust,
which in several areas are concentrated by poor atmospheric conditions.
Other states are not included in this survey because of a
negligible participation in the primary iron and steel industry.
3. Fuels
The fuels considered were the conventional fossil fuels,
coal (CL), residual oil (RO), and natural gas (GS) and the derived fuels:
blast furnace gas (BFG) and coke oven gas (COG). Distillate oil use by
industrial watertube boilers in the iron and steel industry is negligible.
4. Firing Type (for coal only)
No specific data on firing methods were collected for this
study, and it was decided to distribute the coal firing methods according
to the nationwide distribution of firing types of coal-burning intermediate-
24 WALDEN RESEARCH CORPORATION
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size watertube boilers £3-1]. This is necessary because the firing types
reflect differences in emissions as well as control costs. The types con-
sidered were: pulverized coal (PV), cyclone firing (CY), overfed stoker
(OF), spreader stoker (SS), and underfed stoker (UF).
5. Age
From the Wai den sample, age data were collected in two
categories: less than or equal to 20 years old, and older than 20 years.
In the emission calculations, age was not taken into account, because
the information required for this adjustment to the emission factors
would really be too detailed for the scope of this study.
B. METHODOLOGY
This section indicates briefly the methodology used to arrive
at the boiler inventories, the fuel consumed by these boilers and the
resulting emissions. For a more detailed explanation, the reader is
referred to Appendices A, B and D.
1. The Boiler Sample
The Walden sample of boilers in the iron and steel industry
was obtained from the following major sources: The American Boiler Manu-
facturers Association, several boiler manufacturers, yearly boiler sur-
veys published by Power magazine (1940-1970), government agencies, tele-
phone interviews with approximately 70 iron and steel plants across the
country, and detailed boiler data provided by three of the four largest
integrated steel producers in the country: U.S. Steel, Bethlehem Steel,
and Jones & Laughlin.
2. The 1970 Boiler Inventory
This sample represented about two thirds of the total employ-
ment in the iron and steel industry. In order to arrive at a complete
inventory, the sample was summarized by state. Statewide employment in
the iron and steel industry as obtained from County Business Patterns [3-2],
and individual plant employment figures as obtained from the Dun & Bradstreet
25 WALDEN RESEARCH CORPORATION
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Metal working Directory [3-3] were used to proportion the sample in order
to arrive at a complete 1970 inventory. The smaller cast iron and fire-
tube boilers, used at some plants, were excluded from the totals (see
Appendix A). This hardly affected total capacity figures in each region
and only reduced the number of boilers slightly.
3. Operating Factors
77%.
The load factor of the boilers in the sample averaged about
The weighted efficiencies for the various boiler sizes were: 73%,
78% and 84%, respectively for watertube boilers less than or equal to
100,000 pph, between 100,000 and 250,000 pph, and greater than 250,000
pph. The firing method distribution was that of intermediate-size water-
tube boilers in general [3-1]. This distribution is shown in Table 3-1.
TABLE 3-1
PERCENTAGE OF WATERTUBE BOILERS USING VARIOUS
FIRING METHODS FOR COAL COMBUSTION
^100
WT1 00-250
lfT>250
Pulverized Coal
20
59
92
Cyclone
0
2
5
Overfired
47
29
0
Stokers
Spreader
Stoker
20
8
2
Under
Fired
13
2
1
4. Projections
It was found that about 500 kwh of energy is needed to pro-
duce a ton of steel in electric furnaces [3-4]. Using the projections of
raw steel production published in the Battelle Systems Study of the Inte-
grated Iron and Steel Industry [3-5], the energy required for these produc-
tion figures was derived for 1975 and 1980. The ratio between energy
used for production of raw steel to the total electric power consumed
was linearly projected to 1975 and 1980 and the projected electric power
26
WALDEN RESEARCH CORPORATION
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consumed was calculated. The total was then split into energy purchased
and generated, and the estimated boiler capacities required for power gen-
eration was derived from the latter figure.
To determine the boiler capacity needed for non-power pur-
poses (process and space heating), the assumption was made that the ratio
of non-power boiler capacity to the total tonnage of raw steel production
in 1970 would remain constant at a value of .65 pph/ton of raw steel.
Using the Battelle projections of raw steel production the boiler capacity
needed for process and space heating was derived for 1975 and 1980. By
summing the boiler capacities required for power generation and for
process and space heating, the total projected boiler capacities were
determined for 1975 and 1980. For further details, the reader is re-
ferred to Appendix B.
It is interesting to note at this point that our projections
showed that purchased energy as a percentage of the total energy consumed
in the iron and steel industry has been increasing significantly. In
1970 this percentage was about 76% and in 1975 and 1980 it is expected
to be 85% and 93%, respectively, of the total required energy.
Regional fuel distributions were obtained for the fossil
fuels from the growth projections of regional coal, oil and gas use of
industrial intermediate boilers [3-1]. For the non-conventional fuels,
the projected amounts were determined by studying the processes which
creates them, using the Battelle projected figures as input to these
processes (see Appendix C, Section II). The national proportion between
blast furnace gas and coke oven gas in 1975 and 1980 was maintained for
each region due to lack of regional projections in the Battelle study.
The relative growth of the various size groups for inter-
mediate boilers as a whole was applied to the projected iron and steel
boilers on a total basis £3-1].
27 WALDEN RESEARCH CORPORATION
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The firing types for the projected years were assumed to be
unchanged from the 1970 figures, due to lack of better data.
5. Fuel Use
Fuel use was calculated for the 1970, 1975 and 1980 boiler
inventories by using the formula:
n. ,, _ capacity (Ib/hr) x load factor x 8760 (hours/yr) x 975 (Btu/lb)
Btu/yr efficiency
6. Emissions
Uncontrolled boiler emissions were calculated for the 1970,
1975 and 1980 boiler inventories according to the following equations:
en (+c\ - fuel consumption (Btu/yr) x emission factor (Ib/Btu) x % sulfur*
bU2 It0ns; 2000 (Ib/ton)
Mn /, \ _ fuel consumption (Btu/yr) x emission factor (Ib/Btu)
NUx itons; 2000 (Ib/ton)~
D ,. , . _ fuel consumption (Btu/yr) x emission factor (Ib/Btu) x % ash**
(tws) = 2000 lib/ton)
The emission factors and sulfur and ash contents used are listed in Ap-
pendix D. The coal, oil, and natural gas emission factors are the same
as those used for industrial intermediate-size boilers in the Intermediate
Boiler Systems Study £3-1J. An explanation of the derivation of the emis-
sion factors for blast furnace and coke oven gas is found in Appendix D,
Section II.
C. RESULTS
This section describes the results of the current and projected
boiler inventories, fuel consumption patterns, and emissions, accompanied
by a short discussion.
Only in the case of coal- or oil-fired boilers
**
Only in the case of coal-fired boilers
28 WALDEN RESEARCH CORPORATION
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1. 1970 Boiler Inventory and Fuel Consumption
The summary results of the 1970 boiler inventory are shown
in Table 3-2.
TABLE 3-2
1970 REGIONAL ESTIMATES OF WATERTUBE BOILERS IN
THE IRON AND STEEL INDUSTRY
Region
Atlantic
Great Lakes
West and South
South East
TOTAL
No. of Boilers
783
514
123
172
1,592
Capacity (103 pph)
41,160
39,880
9,600
12,855
103,495
Av. Capacity (pph)
53,000
77,600
78,000
74,700
(65,000)
The relatively lower average capacity of watertube boilers
in the Atlantic region is due to a relatively higher number of small
watertube boilers used here. This may be due to several factors:
(1) The age of industry in that region combined with the
longevity of watertube boilers justifies the finding of smaller units
which were used pre World War II.
(2) Expanding plants in the Atlantic region merely added
additional small units, and have only recently started substituting one
or two larger watertube boilers for the many small ones in use so far
(see Appendix A, page A-4).
A more detailed inventory of the boiler capacity installed
in the iron and steel industry in 1970 is shown in Table 3-3.
WALDEN RESEARCH CORPORATION
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TABLE 3-3
1970 BOILER CAPACITY IN THE IRON AND STEEL INDUSTRY
(TO3 PPh)
Boiler Size
WT<100
WT1 00-250
^250
TOTAL
Fuel
CL
RO
GS
BFG
COG
CL
RO
GS
BFG
COG
CL
RO
GS
BFG
COG
AT
1,729
2,247
5,013
5,878
2,420
1,317
1,712
3,820
4,478
1,844
1,070
1,391
3,104
3,639
1,498
41,160
GL
3,956
1,148
2,425
3,829
1,404
4,698
1,364
2,879
4,546
1,667
3,709
1,077
2,273
3,589
1,316
39,880
VIS
73
182
1,277
1,131
985
42
106
739
655
570
77
192
1,344
1,190
1.037
9,600
SE
1,439
135
1,170
1,260
495
864
81
702
756
297
1,810
170
1,470
1,584
622
12,855
Total
7,197
3,712
9,885
12,098
5,304
6,921
3,263
8,140
10,435
4,378
6,666
2,830
8,191
10,002
4,473
103,495
The 1970 fuel use estimates of boilers in the iron and
steel industry are shown in Table 3-4.
It is interesting to compare these fuel figures to fuel
consumption figures derived from the American Iron and Steel Institute
(AISI) annual statistics [3-6]. It must be noted, however, that:
30 WALDEN RESEARCH CORPORATION
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OJ
I
30
m
in
rn
o
I
o
o
30
TJ
O
30
TABLE 3-4
1970 FUEL CONSUMPTION BY BOILERS IN THE IRON AND STEEL INDUSTRY
Fuel*
CL
RO
GS
BFG
COG
Total
*
CL =
RO =
GS =
BFG =
COG =
*
units
1,350
314
102
1,256
98
n.a.
coal in
residual
natural
AT
10
1
1
12
35
45
01
19
49
350
103
oi
gas
Btu
.1
.5
.7
.3
.0
.6
GL
* 12
units 10
4,008 104.
208 30.
64 63.
1,062 100.
74 37.
n.a. 336.
Btu
2
2
9
9
0
2
WS SE Total
units* 1012 Btu units* 1012 Btu units* 1012 Btu
65 1.7 1,327 34.5 6,750 175.5
28 4.0 22 3.2 572 82.9
28 28.2 28 27.9 222 221.7
263 25.0 318 30.2 2,899 275.4
44 21.8 24 11.9 240 119.7
n.a. 80.7 n.a. 107.7 n.a. 875.2
tons
1
i
blast furnace
coke oven gas
in 10
n 109
gas
in 1
barrels
cubic feet
g
in 10 cubic feet
g
0 cubic feet
-------
(1) The AISI covered only those plants included in SIC
3312 whereas this study covers all of SIC 331. Our AlSI-derived figures
are, therefore, 1.16 times higher than the published figures for fossil
fuels. This factor is based on employment figures.
(2) Only for coal is the amount of fuel used for steam
raising specified by the AISI; for other fuels estimates had to be made
as to the amount of fuel used under boilers (Appendix A, page A-10).
(3) The AISI fuel use figures are based on a less complete
sample than their steel production figures [3-7].
Table 3-5 shows the Walden and the AISI derived fuel con-
sumption figures.
TABLE 3-5
VERIFICATION OF 1970 FUEL USE RESULTS FOR BOILERS IN THE
IRON AND STEEL INDUSTRY (1012 Btu/yr)
Coal
Residual Oil
Natural Gas
Blast Furnace Gas
Coke Oven Gas
Total
Walden-AISI innw
Walden
176
83
222
275
120
876
AISI-Derived
143
55
203
236
127
764
Percentage
Difference*
23%
53%
9%
17%
6%
15%
AISI
Note that the sum of the three gases is off by a mere B%.
The discrepancy for residual oil seems quite high. Walden studied the
possibility of the boiler sample having included too many plants located
in areas where residual oil is used a lot.
3?
0 WALDEN RESEARCH CORPORATION
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Table 3-6 shows that this was not the case. Over half of the
actual employment was represented by the sample of boilers for the Atlantic
region, whereas over two thirds of the actual employment was included in the
sample for each of the three other regions. If anything, the bias would have
worked the other way, i.e., Walden's figures for residual oil consumption
would have been lower, not higher, due to the relatively low sample in the
Atlantic region. In view of the above and of the admitted lack of confi-
dence in the AISI fuel statistics, the Walden figures were accepted. Walden's
total 1970 boiler fuel consumption figure is within 15% of the AISI total,
and it is felt that these results are satisfactory.
TABLE 3-6
REGIONAL COMPLETENESS OF WALDEN BOILER SAMPLE (103 pph)
AT
GL
WS
SE
Sample
21,407
31,670
6,190
8,513
67,780
Total
41,160
39,880
9,600
12,855
103,495
%
52
79
64
66
65
2. Projected Boiler Inventories and Fuel Consumption
The results of the 1975 and 1980 boiler inventories are shown
respectively in Tables 3-7 and 3-8.
Figure 3-2 shows the projected regional fuel use patterns for
fuel burned under boilers in the iron and steel industry.
Tables 3-9 and 3-10 show the projected fuel use for boilers
in the iron and steel industry in more detail.
Most boilers can be fired by two or three fuels. This is most
commonly the case when plants have coke ovens or blast furnaces. One of the
tasks of the fuel combustion engineers at these plants is to minimize the
cost of fuel to the plant by maximum use of the coke oven and blast furnace
gases, which would otherwise be wasted.
33 WALDEN RESEARCH CORPORATION
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TABLE 3-7
1975 BOILER CAPACITY IN THE IRON AND STEEL INDUSTRY
(TO6 pph)
Boiler Size
WT<100
WT100-250
^250
TOTAL
Fuel
CL
RO
GS
BFG
COG
CL
RO
GS
BFG
COG
CL
RO
GS
BFG
COG
AT
1.3
2.5
9.1
5.7
2.5
.9
1.7
6.2
3.9
1.7
.6
1.4
4.9
3.0
1.4
46.8
GL
4.7
1.4
3.4
4.2
1.9
5.0
1.5
3.6
4.4
2.0
3.8
1.2
2.8
3.4
1.5
44.8
WS
.1
.2
2.4
1.2
.6
.1
.1
1.2
.6
.3
.1
.2
2.1
1.1
Jj.
10.8
SE
1.4
.2
1.7
1.5
.7
.8
.1
.9
.8
.3
1.6
.2
1.9
1.6
.7
14.4
Total
7.5
4.3
16.6
12.6
5.7
6.8
3.4
11.9
9.7
4.3
6.1
3.0
11.7
9.1
4.1
116.8
34 WALDEN RESEARCH CORPORATION
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TABLE 3-8
1980 BOILER CAPACITY IN THE IRON AND STEEL INDUSTRY
no6 Pph)
Boiler Size
WT<100
^100-250
WT
Wl>250
TOTAL
Fuel
CL
RO
GS
BFG
COG
CL
RO
GS
BFG
COG
CL
RO
GS
BFG
COG
AT
1.4
3.0
11.3
4.9
2.8
.9
2.0
7.5
3.3
1.9
.7
1.5
5.4
2.4
1.3
50.3
GL
5.4
1.4
4.6
3.6
2.0
5.7
1.4
4.8
3.8
2.2
4.0
1.0
3.4
2.7
1.5
47.5
WS
.1
.2
2.8
1.0
.6
.1
.2
2.2
.8
.4
.1
.2
2.4
.8
.5
12.4
SE
1.6
.2
2.1
1.2
.7
.8
.1
1.1
.7
.4
1.6
.2
2.1
1.3
.7
14.8
Total
8.5
4.8
20.8
10.7
6.1
7.5
3.7
15.6
8.6
4.9
6.4
2.9
13.3
7.2
4.0
125.0
35 WALDEN RESEARCH CORPORATION
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inn
SO-
SO.
40.
20.
n
15
inn
sa
60
40.
2a
n
Coke Oven Gas
Blast Furnace Gas
Natural Gas
- ___
~-____Resjdual Oil
uoal
370 1975 19
Year
ATLANTIC REGION
Coke Oven Gas
Blast Furnace Gas
-"^"^ Natural Gas
100,
80.
60.
40.
20.
0
80 19
TOO,.
80.
60
40.
2CL
Residual
Oil
Pnal 0.
Coke Oven Gas
Blast Furnace Gas
.
Natural Gas
Residual Oil
Coal
70 197"5 193
Year
GREAT LAKES REGION
Coke Oven Gas
Blast Furnace Gas
Natural Gas
Coal
1970 1975
Year
WEST AND SOUTH REGION
1980
1970 1975
Year
SOUTH EAST REGION
Residual
1980
Figure 3-2. Fuel Burned Under Boilers in the Iron and Steel
Industry, 1970-1980.
36
WALDEN RESEARCH CORPORATION
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TABLE 3-9
1975 FUEL USE IN THE IRON AND STEEL INDUSTRY
(1012 Btu)
Boiler Size Fuel
WT<100 CL
RO
GS
BFG
COG
^100-250 CL
RO
GS
BFG
COG
^250 CL
RO
GS
BFG
COG
TOTAL
AT
11.7
22.5
82.0
51.4
22.5
7.6
14.3
52.3
32.9
14.3
4.7
11.0
38.4
23.5
11.0
400.1
GL
42.3
12.6
30.6
37.8
17.1
42.2
12.6
30.4
37.1
16.9
29.8
9.4
21.9
26.6
11.7
379.0
WS
.9
1.8
21.6
10.8
5.4
.8
.8
10.1
5.1
2.5
.8
1.6
16.4
8.6
3.9
91.1
SE
12.6
1.8
15.3
13.5
6.3
6.7
.8
7.6
6.7
2.5
12.5
1.6
14.9
12.5
5.5
120.8
Total
67.5
38.7
149.5
113.5
51.3
57.3
28.5
100.4
81.8
36.2
47.8
23.6
91.6
71.2
32.1
991.0
37 WALDEN RESEARCH CORPORATION
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TABLE 3-10
1980 FUEL USE IN THE IRON AND STEEL INDUSTRY
(1012 Btu)
Boiler Size
WT
Wl<100
WT1 00-250
WT>250
TOTAL
Fuel
CL
RO
GS
BFG
COG
CL
RO
GS
BFG
COG
CL
RO
GS
BFG
COG
AT
12.6
27.0
101.8
44.1
25.2
7.6
16.9
63.2
27.8
16.0
5.5
11.7
42.3
18.8
10.2
430.7
GL
48.6
12.6
41.4
32.4
18.0
48.1
11.8
40.5
32.0
18.5
31.3
7.8
26.6
21.1
11.7
402.4
WS
.9
1.8
25.2
9.0
5.4
.8
1.7
18.5
6.7
3.4
.8
1.6
18.8
6.3
3.9
104.8
SE
14.4
1.8
18.9
10.8
6.3
6.7
.8
9.3
5.9
3.4
12.5
1.6
16.4
10.2
5.5
124.5
Total
76.5
43.2
187.3
96.3
54.9
63.2
31.2
131.5
72.4
41.3
50.1
22.7
104.1
56.4
31.3
1062.4
38
WALDEN RESEARCH CORPORATION
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3. Current and Projected Boiler Emissions
The national boiler emissions are shown graphically in
Figure 3-3 and summarized by region in Table 3-11. The figures shown
are for uncontrolled emissions. This is accurate for S09 and NO .
L, A
There is some control of particulate boiler emissions, but data on con-
trols were not available for this study, causing the particulate emissions
from boilers reported here to be slightly higher than they are in reality.
The Great Lakes region shows continuously increasing emis-
sions from all three pollutants, and is by far the region most seriously
affected by air pollution resulting from boilers in the iron and steel
industry. Looking back at Table 3-2, the reader will note that this is
not the region with the largest number of boilers or boiler capacity.
The high emissions can be attributed to the intensive use of industrial
coal in the Great Lakes region. The other three regions more or less
follow the national trend (see Figure 3-3) with a slight decrease in
particulate emissions during the period of 1970 to 1975, followed by
a slow increase thereafter. The decrease is explained by a certain amount
of fuel switching to cleaner fuels (see Figure 3-2) and the increase
between 1975 and 1980 is due to the fact that the growth of the iron and
steel industry will eventually counteract the effect of cleaner boiler
fuels and cause a growth in air pollution emissions in those regions as
well. NO emissions increase steadily in all four regions.
/\
Table 3-12 shows the emissions by equipment size.
There is no very significant emphasis on any particular
boiler size group as far as emissions are concerned. We can say, how-
ever, that boilers burning coal are the main sources for all three air
pollutants. They represented 64%, 45% and 97%, respectively, of the
total S0?, NO and particulate emissions from boilers in the iron and
L A
steel industry in 1970.
39 WALDEN RESEARCH CORPORATION
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5
m
en
m
3)
o
I
o
o
3)
s
435.3
438.4
477.2
1970 1975 1980
S00
134.2
146.4
161.5
1970 1975 1980
NO..
378.3
372.3
408.6
1970 1975 1980
Particulates
Figure 3-3. Projected Air Pollution from Boilers in the Iron and Steel Industry
(thousand tons)
-------
o
m
z
30
m
en
30
O
I
O
O
30
t)
O
3D
TABLE 3-11
CURRENT AND PROJECTED EMISSIONS FROM BOILERS IN THE IRON AND STEEL INDUSTRY
(thousand tons)
Region
AT
GL
WS
SE
Total
1970
118.9
235.4
22.8
58.2
435.3
so2
1975
104.6
263.5
16.4
53.9
438.4
1980
115.7
287.0
17.7
56.7
477.2
1970
45.3
60.2
9.6
19.1
134.2
NOX
1975
48.5
68.2
9.8
19.9
146.4
1980
54.2
74.5
11.8
21.0
161.5
Parti culates
1970 1975 1980
75.6
229.5
4.7
68.5
378.3
53.3
249.9
6.0
63.1
372.3
57.4
278.3
6.7
66.2
408.6
-------
TABLE 3-12
1970 BOILER EMISSIONS BY BOILER SIZE
Watertube
Watertube
Watertube
<_ 100,000 pph
100,001-250,000 pph
> 250,000 pph
so2
167.0
143.7
124.6
435.3
N0x
41.6
45.9
46.7
134.2
Particulates
118.9
132.1
127.3
378.3
It is interesting to note that the 1970 boiler emissions in
the iron and steel industry represent about 10%, 15% and 16%, respectively,
of S0?, NO and particulate emissions from industrial boilers in 1967 [3-1],
L. A
For more detailed breakdowns of the emissions from boilers
in the iron and steel industry, the reader is referred to Appendix D.
WALDEN RESEARCH CORPORATION
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REFERENCES TO SECTION III
3-1. Systematic Study of Air Pollution from Intermediate-Size Fossil-
Fuel Combustion Equipment, Walden Research Corporation, Cambridge,
Mass., 1971.
3-2. County Business Patterns, U.S. Bureau of Labor, 1969.
3-3. Dun & Bradstreet Metal working Directory, 1971, Dun & Bradstreet, Inc.,
New York.
3-4. The Making, Shaping and Treating of Steel, 8th Edition, U.S. Steel
Corporation, Pittsburgh, Pa., 1964.
3-5. A Systems Analysis Study of the Integrated Iron and Steel Industry,
Battelle Memorial Institute, Columbus, Ohio, 1964.
3-6. Statistical Report, American Iron and Steel Institute, 1970.
3-7. Personal communication with Mr. Eckel of the American Iron and
Steel Institute.
43 WALDEN RESEARCH CORPORATION
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IV. PROCESS EMISSIONS
A. INTRODUCTION
The production of iron and steel is a complex process requiring
many intermediate steps. During each of these steps, process emissions
are produced from two distinct types of sources. First, handling of
raw materials and subsequent processing of these materials produce emis-
sions which fall within the conventional definition of process emissions.
However, in order to meet its energy demands during the manufacturing
steps, the iron and steel industry combusts significant quantities of
fuel. This combustion forms the second source of process emissions.
These two different types of process emissions will be discussed
separately.
In general, the following major processing operations can be
identified in the iron and steel industry:
(1) Sinter Plant
(2) Pellet Plants
(3) Coke Manufacture
(4) Blast Furnaces
(5) Steel Furnaces
Open Hearth
Basic Oxygen Furnace
Electric Arc Furnace
(6) Scarfing
(7) Materials Handling
An estimation of process emissions from the above mentioned
operations requires an understanding of the separate processes and
the places of potential emissions. Appendix C briefly describes the
operations, but for a more detailed description, the reader is directed
to The Making, Shaping and Treating of Steel [4-1], and Battelle's
Systems Study of the Integrated Iron and Steel Industry [4-2].
The following sections summarize the basic methodology used
in estimating process emissions and also present the results of the
44
WALDEN RESEARCH CORPORATION
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use of the above mentioned methods. Detailed descriptions of the com-
putations can be found in Appendix C.
B. METHODOLOGY
1. Conventional Process Emissions
Base Year 1970
Conventional uncontrolled process emissions (which do not
include emissions resulting from fuel combustion associated with the
process) were estimated from production figures taken from the AISI
Statistical Report [4-3] and emission factors obtained from both the
Nationwide Emission Factor Compilation [4-4] and Battelle's Systems
Study of the Integrated Iron and Steel Industry [4-2]. The 1970 pro-
duction figures and the emission factors are shown in Tables 4-1 and
4-2. Table 4-3 summarizes the control collection efficiencies utilized
for estimation of the controlled conventional process emissions.
Uncontrolled and controlled emissions v/ere obtained by
multiplication of the relevant production figures, emission factors
and collection efficiencies.
Projections to 1975 and 1980
Except in the case of the electric furnace, identical
uncontrolled emission factors (Table 4-2) as those previously used,
were utilized in estimation of projected emission. The particulate
emission factor for the electric furnace was changed to 18 Ib/ton
product to reflect an expected increase in the average size of the
steel change.
Only in the case of particulate emissions were changes in
control (as compared to the base year 1970) considered. These changes
reflected not changes in collection efficiencies, but rather expected
changes in the fraction of units controlled. In the case of SO and
A
45 i WALDEN RESEARCH CORPORATION
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TABLE 4-1
1970 PRODUCTION OF RAW MATERIALS USED IN PRODUCTION
Production or Raw Materials Used
in Production
Operation (tons)
Sinter Plant
Coke Plant
Blast Furnace
45.6 x TO6
Coal 87.2 x
Iron Ore
Agglomerates
106
38.2
109.0
Sinter
x 106
x 106
Steel Making
Open Hearth 48.0 x 106 Raw Steel
Basic Oxygen Furnace 63.3 x 10 Raw Steel
Electric 20.2 x 106 Raw Steel
Source: AISI Statistical Reports [4-3]
46
WALDEN RESEARCH CORPORATION
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TABLE 4-2
UNCONTROLLED EMISSION FACTORS - CONVENTIONAL PROCESS EMISSIONS
Operation
Particulate
SO
NO.
I
33
m
C/5
m
>
33
O
X
O
O
33
-o
O
33
Sinter Plants
Coke Manufacture
Blast Furnace
Open Hearth Furnace
Basic Oxygen Furnace
(BOF)
Electric Arc Furnace
Scarfing
Material Handling
Windbox 20 Ib/ton sinter
Discharge 22 Ib/ton sinter
By-product 3.5 Ib/ton coal
coking
F = 70X + 40 Ib/ton pig iron
ton arc
where X =
ton arc + ton agglomerates
With 0? lancing 22 Ib/ton pig iron
Without Op lancing 12 Ib/ton pig iron
46 Ib/ton steel produced
With 02 lancing 11 Ib/ton steel produced
Without 02 lancing 7 Ib/ton steel produced
3 Ib/ton steel produced
10 Ib/ton steel produced
1.42 Ib/ton sinter 1.04 Ib/ton sinter
1.40 Ib/ton steel
produced
0.06 Ib/ton steel
produced
0.02 Ib/ton steel
produced
For fuel oil:
250 lb/200 ton
steel batch
For nat. gas &
coke oven gas:
150 lb/200 ton
steel produced
-------
TABLE 4-3
PARTICULATE CONTROL EFFICIENCIES AND PERCENT OF OPERATIONS
CONTROLLED - CONVENTIONAL PROCESS EMISSIONS
00
o
m
m
t/j
m
o
X
o
O
3)
-o
O
30
Operation
Sinter Plants
Coke Manufacture
Blast Furnace
Open Hearth
Basic Oxygen Furnace
Electric Furnace
Scarfing
Material Handling
Control Efficiency
Windbox: Dry cyclone
Electrostatic precipitator
(in series with dry cyclone)
Discharge Dry cyclone
MEAN
1. Preliminary cleaning
settling chamber or dry cyclone
2. Primary cleaning
gas washers & wet scrubbing
3. Secondary cleaning
electrostatic precipitator or
high energy washers
Electrostatic precipitator
Venturi scrubber
Bag house
MEAN
Electrostatic precipitator
High efficiency scrubber
Electrostatic precipitator
Bag house
MEAN
Precipitators
Precipitators
90%
95%
93%
90%
60%
90%
90%
98%
85-98%
99%
98%
98%
98%
92-97%
98-99%
95%
90%
95%
Percent
Controlled
100%
0%
100%
41%
100%
79%
75%
32%
-------
NO emissions, however, no attempt was made to estimate how much of the
y\
emissions would be controlled in future years. This decision was based
simply on the speculative nature of the answer that would have been ob-
tained.
Table 4-4 summarizes the fraction of units controlled that
were used for estimation of the projected emissions.
Projected production figures for 1975 and 1980 were ob-
tained from BatteHe [4-2] and these figures are summarized in Tables
4-5, 4-6 and 4.7.
Additional computation had to be performed in order to
estimate sinter production and coke production.
BatteHe [4-2] reports, as shown in Table 4-5, the physi-
cal form of iron ore consumed in the U.S. and estimates to 1980. In
order to estimate the total sinter production (as opposed to the pro-
duction of sinter emanating only from iron ore) extrapolations were used
of the fraction of additional material to iron ore utilized in the pro-
duction of sinter. This fraction was calculated from AISI statistical
data. It was found that over the last several years, this fraction has
been constant at 0.075 and thus it was assumed that this fraction would
hold constant to 1980.
Utilizing this fraction the following total sinter productions
were calculated:
1975: 55.5 x 106 tons
1980: 59.1 x 106 tons
Coke rates (Ib coke/T pig iron) were obtained from extrapo-
lation of historical data in conjunction with an estimate of expected
changes in blast furnace technology which would affect the coke rate
(direct fuel oil and natural gas injection into the tuyeres which re-
duces the coke rate).
49
WALDEN RESEARCH CORPORATION
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TABLE 4-4
PROJECTED PERCENT OF OPERATIONS CONTROLLED FOR PARTICIPATE
EMISSIONS - CONVENTIONAL PROCESS EMISSIONS
Percent Controlled
Operation 1975 1980
Sinter Plants 100% 100%
Coke Manufacture 0% 0%
Blast Furnace 100% 100%
Open Hearth 62% 100%
Basic Oxygen Furnace 100% 100%
Electric Furnace 100% 100%
Scarfing 75% 75%
Material Handling 32% 32%
WALDEN RESEARCH CORPORATION
50
-------
TABLE 4-5
PHYSICAL FORM OF IRON ORE CONSUMED IN THE U.S. AND ESTIMATES TO 1980
en
Year 1
1960
1967
1975
1980
alncludes
Lump
O6 tons
62.0
46.7
31.7
34.9
Ore
54.
35.
20.
19.
only iron ore
1
3
0
5
used
Sinter
106 tons
41.5
42.2
46.0
48.3
for making
a
36.3
31.9
29.0
27.0
sinter
Pell
106 tons
11.0
43.4
80.8
95.8
ets
9.
32.
51.
53.
Total
106 tons %
6
8
0
5
114
132
158
179
.5
.3
.5
.0
100.0
100.0
100.0
100.0
I
O
rn
30
O
I
n
o
30
-o
o
33
-------
TABLE 4-6
PIG IRON REQUIREMENTS FOR THE U.S. IN 1960 AND 1967
AND PROJECTIONS TO 1980
Year
1960
1967
1975
1980
Raw Steel
Production
(105 tons)
99.3
127.2
157.0
180.0
Apparent Pig Iron
Consumption
(106 tons)
66.5
87.0
106.8
122.4
TABLE 4-7
PRODUCTION OF RAW STEEL IN THE U.S. BY TYPE OF FURNACE
AND PROJECTIONS TO 1980
Year
1960
1967
1975
1980
Open Hearth
(103 tons)
86,368
70,690
44,000
36,000
Bessimer
(103 tons)
1,189
--
--
--
Basic Oxygen
Furnace
(103 tons)
3,346
41 ,434
80,000
99,000
Electric
Furnace
(103 tons)
8,379
15,089
33,000
45,000
Total
(103 tons)
99,282
127,213
157,000
180,000
52
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The following estimated coke rates were used for emission
computations:
1975: 1145 Ib coke/T pig iron
1980: 1020 Ib coke/T pig iron
It was assumed, however, that both in 1975 and 1980, 1.4
tons of coal would still be required to produce one ton of coke.
Emissions were obtained by multiplication of the relevant
projected production figures, emission factors and control efficiencies.
2. Fuel Based Emissions
Five fuels are extensively used in the iron and steel in-
dustry to supply process energy. These are fuel oil, natural gas, tar
and pitch, coke oven gas and blast furnace gas. The latter three fuels
are produced within the steel mill as by-products and their production
is dependent on the coke rate and ultimately on pig iron requirements.
Fuel oil and natural gas, on the other hand, are purchased fuels whose
usage is tied into the process in a fairly complex fashion.
In estimating emissions from fuels used in process areas
it is necessary first to determine fuel consumption and then to apply
emission factors. Fuel consumptions are available [4-3] but extrapola-
tion to 1975 and 1980 will have to be made based on an understanding of
how fuel usage is related to process requirements.
The AISI Statistical Reports [4-3] break down fuel con-
sumption into the following "use" categories:
(1) Blast Furnace Area -
(ii) Steel melting furnaces
(iii) Heating and annealing furnaces
(iv) Heating ovens for wire rods
(v) Other
53 WALDEN RESEARCH CORPORATION
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In addition, included under other uses in the blast furnace
area, are reported the quantity of fuel used for coke oven underfiring.
Discussions with AISI officials [4-5] indicated that:
(i) Steel melting furnaces refer to fuel usage in open
hearth furnaces
(ii) The category of "other" could be considered to refer
mainly to the use of a particular fuel in steam
raising boilers.
Base Year 1970
Table 4-8 summarizes fuel consumption data for 1970 extracted
from the AISI Statistical Report [4-3].
Table 4-9 summarizes the uncontrolled emission factors used
in estimation of the fuel based emissions. Detailed discussion of the
sources of these emission factors can be found in Appendix C.
No data could be found on controls relating to the fuel
based emissions and as such ALL ESTIMATIONS OF FUEL BASED PROCESS EMIS-
SIONS REFER TO UNCONTROLLED EMISSION LOADINGS.
Uncontrolled emission loadings were computed by multiplica-
tion of the relevant fuel consumption rates and uncontrolled emission
factors.
Projections to 1975 and 1980
As discussed in the brief introduction to the fuel based
process emissions, fuel oil and natural gas are purchased fuels whose
usage is tied into the process in a fairly complex fashion. On the other
hand, coke oven gas, tar and pitch and blast furnace gas production rates
are dependent on the coke rate and ultimately on pig iron requirements.
These tv/o groups of fuels will therefore be discussed separately.
54
WALDEN RESEARCH CORPORATION
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TABLF 4-8
FUEL CONSUMPTION 1970
en
en
|
5
m
m
in
33
o
T
Fuel
Fuel Oil
103 gals
Tar & Pitch
103 gals
Natural Gas
106 scf
Coke Oven
Gas
106 scf
Blast Fur-
nace Gas
106 scf
Liquid Pet.
Gas
Q
10 gals
Purpose
Blast Furnace Area stfiel Heating & Heating
Other Coke Oven Melting Annealing Ovens for
Furnaces Uses Underfiring Furnaces Furnaces Wire Rods Other
146,031 19,801 5,000 416,822 377,593 1,648 273,558
42,500 -- - 176,902 -- 41,503
44,474 10,262 4,000 57,797 306,097 4,403 170,483
9,177 319,628 274,603 22,056 363,899 4,217 208,959
1,592,038 1,246,894 286,402 - 164,693 - 1,519,250
6,555 -- 12,220
h
Steam0
Raising Total
288,359 1,235,453
41,503 260,905
176,745 593,516
253,984 927,936
2,479,742 4,522,875
12,220 18,775
8 Includes coke oven underfiring
" h
o Steam raising = Z other - coke oven underfiring
O
z.
-------
TABLE 4-9A
UNCONTROLLED EMISSION FACTORS - FUEL BASED PARTICULATES AND SO PROCESS EMISSIONS
X
Fuel
Participates
SO.
Fuel Oil
Natural Gas
Blast Furnace Gas
Coke Oven Gas
0.42 x 103 lb/103 barrels
15 lb/106 scf
2.4 lb/106 scf
15 lb/106 scf
0.68 x 104 x % sulfur (Ib SO/103 barrels)
0
0
0.77 Ib SO/100 scf
/\
en
cn
TABLE 4-9B
UNCONTROLLED NO.. EMISSION FACTORS - PROCESS BASED
NO Emission Factors
I
o
m
in
o
X
o
o
XI
-a
o
30
Blast Furnace
Coke Manufacture
Heating and Annealing Furnaces
0.4 lb/10 scf blast furnace gas
0.135 Ib/ton coal
0.086 Ib/ton steel
-------
Fuel Oil and Natural Gas
Fuel oil and natural gas are used throughout the steel mill
as is evidenced by the 1970 fuel consumption shown in Table 4-8. Pro-
jections of fuel usage for future years were based on understanding of
how fuel oil and natural gas were utilized in the different process areas.
The following underlying logic was used in these pro-
jections:
(i) Fuel oil and natural gas used in the blast furnaces
are injected through the tuyeres [4-6]. As such these fuels reduce the
blast furnace coke burden and lead to more efficient performance of the
furnace. Since these fuels ultimately produce blast furnace gas, esti-
mation of their consumption in future years is necessary in order to
determine blast furnace gas production. The fuels used in the blast
furnace area are dependent on required pig iron production and thus
their consumption was correlated with pig iron production.
(ii) As indicated earlier, steel melting furnaces refer
to open hearth furnaces. Thus fuel oil and natural gas consumption
used in steel melting furnaces was correlated with open hearth pro-
duction.
(iii) Heating and annealing furnaces are mainly utilized
in steel production and thus fuel oil and natural gas consumption in these
areas was correlated with raw steel production.
Using extrapolations of AISI Statistical Report data 14-3]
and the above assumptions, ratios of fuel oil and natural gas consumptions
relative to production were obtained for 1975 and 1980. These ratios
are listed in Table 4-10. Actual fuel consumptions were then obtained
by multiplication of the ratios listed in Table 4-10 and projected productions
taken from Tables 4-6 and 4-7. Table 4-11 summarizes the projected fuel
oil and natural gas consumptions for 1975 and 1980.
57 WALDEN RESEARCH CORPORATION
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TABLE 4-10
EXTRAPOLATED RATIOS* OF FUEL CONSUMPTION
RELATIVE TO PRODUCTION
Fuel Oil:
1. Blast Furnace Area
Steel Melting Furnaces
(Open Hearth)
Heating and Annealing
Furnaces
1975: 3.7 gals/ton pig iron
1980: 10 gals/ton pig iron
1975: 8.3 gals/ton open hearth steel
1980: 8.3 gals/ton open hearth steel
1975: 2.2 gals/ton raw steel
1980: 2.2 gals/ton raw steel
Natural Gas:
1.
2.
3.
Blast Furnace Area
Steel Melting Furnaces
(Open Hearth)
Heating and Annealing
Furnaces
1
1
1
1
1
1
975:
980:
975:
980:
975:
980:
0.
0.
1.
1.
2.
3.
5
5
1
1
7
05
x 1
x 1
x 1
x 1
x 1
X
0
0
0
0
0
1
o
3
3
3
3
O3
ft0
ft3
ft3
ft3
ft3
ft
/ton
/ton
/ton
/ton
/ton
3/ton
pig iron
pig iron
open hearth
process
open hearth
process
raw steel
raw steel
Extrapolated from historical data in Table C-12
58
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TABLE 4-11
PROJECTED FUEL OIL AND NATURAL GAS CONSUMPTION
FOR 1975 AND 1980
Fuel
Year
Purpose
Blast Steel Heating & Steam
Furnace Melting Annealing Raising
Fuel Oil 1975
103 gals
Fuel Oil 1980
103 gals
Natural Gas 1975
106 scf
Natural Gas 1980
105 scf
396,000 366,000 396,000 377,000
1,224,000 300,000 396,000 377,000
53,400 49,500 424,000 210,000
61,400 39,400 549,000 278,000
59
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Identical emission factors to those previously used (Table
4-9) were used in the estimation of UNCONTROLLED emissions for 1975 and
1980. Due to lack of information, no attempt was made to estimate what
controls would be implemented by 1980.
Coke Based Fuels - Coke Oven Gas, Blast Furnace Gas and
Tar and Pitch
Coke oven gas, blast furnace gas and tar and pitch are
dependent on the coke rate. However estimation of process emissions
resulting from the combustion of these fuels are dependent in certain
cases (i.e., NO emissions) on the burning rates of these fuels in the
/\
different processes using the fuels. Thus, as was done with fuel oil
and natural gas it is necessary to estimate the fuel quantities com-
busted in the different processes.
Estimates of the projected coke based fuel consumptions
were obtained by the following sequence of steps:
1) Coke rates for 1975 and 1980 were estimated to be
respectively 1145 and 1020 Ib coke/ton pig iron. (For detailed calcu-
lations see Appendix C)
2) Based on historical data, which showed little varia-
tion with time, the total volumetric production rate of coke oven gas/ton
coke was estimated to be 15,000 scf/ton coke. Thus using the coke rate,
the volumetric production rate and Battelle's [4-2] estimated pig iron
requirements, projected coke oven gas production rates could be calculated.
These are shown in Table 4-12.
3) Blast furnace gas production rate, on the other hand,
varies with the coke rate. The data of Heynert [4-7], reproduced in
Figure 4-1 were used to estimate blast furnace production rates/ton
coke. However, comparisons between reported data from the AISI Statistical
Reports [4-3] and data from Heynert's correlation showed that the cor-
relation predicted about a 40% higher blast furnace gas production than
was reported by AISI. Part of this disparity could probably be attributed
60
WALDEN RESEARCH CORPORATION
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TABLE 4-12
PROJECTED TOTAL PRODUCTIONS OF COKE "BASED" FUELS
Fuel 1975 1980
Coke Oven Gas 9.2 x 1011 scf 9.35 x 1011 scf
Blast Furnace Gas 5.07 x 1012 scf 4.56 x 1012 scf
Tar and Pitch 2.!4 x 108 gals 1.62 x 108 gals
to losses which are unaccounted for in the AISI data, although complete
understanding for the differences was not discovered. Consequently, a
conservative attitude was taken and estimates of blast production rates/
ton coke were calculated as 60% of the values obtained from Figure 4-1.
For further discussion on this subject, see Appendix C.
In estimating blast furnace gas production, equivalent
coke rates of 1175 and 1100 Ib coke/ton pig iron were used for 1975 and
1980. This equivalent coke rate corresponds to the sum of the actual
coke rate (1145 and 1020 Ib coke/ton pig iron) plus the fuel oil and
natural gas injected into the tuyeres/ton pig iron. This approach was
taken since the fuel oil and natural gas are also partially combusted
to form blast furnace gas. The results are shown in Table 4-12.
3) Tar and pitch production rates were obtained from ex-
trapolations of historical data which indicated that 3.5 and 2.6 gals/ton
coke would respectively be produced in 1975 and 1980. Total productions
are shov/n in Table 4-12.
4) Fractional allocation of the total fuel production among
the different process units was performed by assuming that the frac-
tional fuel consumption as obtained from historical data would re-
main constant through to 1980. The fractional allocations are shown
in Table 4-13 for coke oven gas, blast furnace gas,and tar and pitch.
61 WALDEN RESEARCH CORPORATION
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en
a
m
JO
m
in
m
>
73
O
X
8
73
s
30
Total Gas Volume
Table For
Other Use
1000
1200 1400 1600 1800 2000
Coke Rate, pounds per net ton of hot metal
2200
Figure 4-1. Effect of Coke Rate on Volume of Blast Furnace Gas Produced.
-------
5
r
o
33
m
CO
33
O
I
O
O
33
-a
o
33
TABLE 4-13
FRACTIONAL ALLOCATION OF COKE "BASED" FUELS
Fuel
Blast
Furnaces
Coke Oven
Underlying
Steel
Melting
Furnaces
Heating &
Annealing
Furnaces
Comments
en
CO
Blast Furnace Gas 0.345
Coke Oven Gas 0.01
Tar and Pitch
0.076
0.269
0.03
0.66
.038
0.40
Rest in steam raising
Rest in steam raising
Rest injected in blast fur-
nace and used in steam
raising
-------
Fuel consumptions in the different process units were ob-
tained by multiplication of the total production by the fractions sum-
marized in Table 4-13.
5) Uncontrolled emissions were estimated by multiplica-
tion of the appropriate fuel and emission factor (summarized in Table
4-9).
C. RESULTS AND DISCUSSION
Base Year 1970
Table 4-14 summarizes the process emissions - both conventional
and fuel based - for 1970.
Three sources of process emission data were available for com-
parison. The results of the Midwest Research Institute [4-8] show
1,442,000 tons of particulate process emissions. This compares very
favorably with the estimates of this study.
Battelle's [4-2] estimates on sulfur emissions from the iron
and steel industry can be shown to correlate well with the results of
this study on SO emissions.
X
Similarly, Esso's [4-9] calculations on NO emissions agree
X
fairly well with the results of Table 4-14.
Perusal of the results displayed in Table 4-14 show that about
1/2 of all the particulate emissions emanate from material handling. An
accurate estimate of the particulate. emission factor for material handling
was not possible and the emissions from materials handling should there-
fore be considered in the light of this difficulty.
Furthermore, the results show that most of the particulate and
NO emissions come from conventional process emissions, whilst most of the
A
SO emanates as a result of the fuel combusted to the heat in the process.
54 WALDEN RESEARCH CORPORATION
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TABLE 4-14
SUMMARY OF 1970 PROCESS EMISSIONS
(tons)*
cr>
en
I
o
m
z
33
m
33
O
I
O
o
33
TJ
O
33
Sinter Plants
Coke Manufacture
Blast Furnaces
Steel Furnaces
(Open Hearth)
B.O.F.
Electric Arc
Heating &
Annealing
Furnaces
Scarfing
Material
Handling
TOTAL
*
Tons rounded to
Non-Fuel
S0x
32,000
35,000
2,000
negl.
69,000
the nearest
Process Emissions
Part. NO
J\.
96,000 24,000
152,000
312,000 25,000
28,000
28,000
63,000
446,000
1,125,000 49,000
thousand
Fuel Process Emissions
From Combustion
SOX Part. N0x S0x
32,000
107,000 3,000 6,000 107,000
2,000 negl.
35,000
2,000
negl .
194,000 7,000 6,000 194,000
301 000 12'000 12,000 370,000
Total
Part.
96,000
155,000
2,000
312,000
28,000
28,000
7,000
63,000
446,000
1,137,000
N0x
24,000
6,000
negl .
25,000
6,000
61,000
-------
Projections to 1975 and 1980
Tables 4-15 and 4-16 summarize the projected estimates of
process emissions in 1975 and 1980.
Once again it is emphasized that except partially in the case
of participate emissions, the emission results shown in Tables 4-15 and
4-16 are uncontrolled emission loadings. In addition, the reader is re-
minded of the problems associated with estimating an emission factor for
materials handling.
KG
OU WALDEN RESEARCH CORPORATION
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TABLE 4-15
SUMMARY OF 1975 PROCESS EMISSIONS
(tons)
cr>
1
o
[N RESEARCH CORPORA"
Sinter Plants
Coke Manufacture
Blast Furnaces
Steel Furnaces
(Open Hearth)
B.O.F.
Electric Arc
Heating &
Annealing
Furnaces
Scarfing
Material
Handling
TOTAL
*
Tons rounded to
Fuel Process Emissions
Non-Fuel Process Emissions From Combustion
SOV Part. NO SO Part. NOU
X XX X
39,000 117,000 29,000
155,000 95,000 2,000 6,000
2,000 negl.
31,000 189,000 22,000
2,000 36,000
negl. 15,000
196,000 8,000 7,000
73,000
533,000
72,000 1,118,000 51,000 291,000 12,000 13,000
the nearest thousand
Total
SOX Part.
39,000 117,000
95,000 157,000
2,000
31,000 189,000
2,000 36,000
negl. 15,000
196,000 8,000
73,000
533,000
363,000 1,130,000
N0x
29,000
6,000
negl.
22,000
7,000
64,000
-------
TABLE 4-16
SUMMARY OF 1980 PROCESS EMISSIONS
(tons)
CTt
CO
I
o
m
m
c/j
m
o
x
o
o
;0
3
Sinter Plants
Coke Manufacture
Blast Furnaces
Steel Furnaces
(Open Hearth)
B.O.F.
Electric Arc
Heating &
Annealing
Furnaces
Scarfing
Material
Handling
TOTAL
Fuel Process Emissions
Non-Fuel Process Emissions From Combustion
SO Part. NO SO Part. NO
X XX X
42,000 124,000 31,000
159,000 97,000 2,000 6,000
2,000 negl.
25,000 8,000 18,000
3,000 46,000
negl. 20,000
205,000 9,000 8,000
86,000
612,000
70,000 955,000 49,000 302,000 13,000 14,000
S0x
42,000
97,000
25,000
3,000
negl .
205,000
372,000
Total
Part.
124,000
161,000
2,000
8,000
4,600
20,000
9,000
86,000
612,000
968,000
NOX
31 ,000
6,000
negl .
18,000
8,000
63,000
Tons rounded to the nearest thousand
o
2
-------
REFERENCES TO SECTION IV
4-1. The Making, Shaping and Treating of Steel, 8th Edition, U.S. Steel
Corporation, Pittsburgh, Pa., 1964.
4-2. A Systems Analysis Study of the Integrated Iron and Steel Industry,
Battelle Memorial Institute, Columbus, Ohio, 1964.
4-3. Statistical Report American Iron and Steel Institute, 1970.
4-4. McGraw, M. J. and Duprey, R. L., Compilation of Air Pollution Emis-
sion Factors, Preliminary Document EPA, Research Triangle Park,
N.C., April 1971.
4-5. Private conversation with Mr. Eckel, American Iron and Steel
Institute, New York, N.Y.
4-6. A Systems Analysis Study of the Integrated Iron and Steel Industry,
Battelle Memorial Institute, Columbus, Ohio, 1964.
4-7. Heynert, Von G., et al., "Charge Preparation and Its Effect on
Operating Results of the Blast Furnace," Stahl und Eisle 81, 1,
1961.
4-8. Systems Study on Particulate Emissions, Midwest Research Institute;
Information obtained from R. C. Lorentz, EPA, Durham, N.C.
4-9. Systems Study of Nitrogen Oxide Control Methods for Stationary
Sources, Esso Research and Engineering Co., Government Research
Laboratory.
WALDEN RESEARCH CORPORATION
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V. COMPARISON OF BOILER EMISSIONS TO PROCESS EMISSIONS
Table 5-1 summarizes the current and projected national air pollu-
tion emissions from the iron and steel industry, resulting from the cal-
culations in Sections III and IV of this report.
TABLE 5-1
SUMMARY OF AIR POLLUTANTS IN THE IRON AND STEEL INDUSTRY
(103 tons)
so2
Boilers
1970 435
1975 438
1980 477
Process
370
363
372
N0x
Boilers
134
146
162
Process
61
64
63
Parti culates
Boilers
378
372
409
Process
1,137
1,130
968
The emission figures shown for boilers represent uncontrolled emis-
sions, since insufficient data were available to determine the fraction
of the emissions which were controlled. The uncontrolled figures are
realistic for S0~ and NO emissions from boilers. The particulates
C. A
resulting from fuel combustion under boilers, however, are partially
controlled, but the emission figures shown have not been adjusted
accordingly.
The figures shown for process emissions represent partially con-
trolled emissions for particulates (see Table 4-3) and uncontrolled SO,,
and NO emissions.
A
The above table shows that boilers are the source of a significant
fraction of the S09 and NO emissions in the iron and steel industry,
£. A
and further that they emit a fair portion of total particulates as well
Figure 5-1 was obtained by summing the 1970 percentages of con-
tribution to air pollution for each source and air pollutant type.
WALDEN RESEARCH CORPORATION
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BOILERS
Process
Figure 5-1. Relative Contribution of Boiler Emissions in the Iron
and Steel Industry in 1970.
The particulate emissions from boilers are slightly overstated due to
the fact that they are shown uncontrolled. From this figure it is con-
cluded that the air pollution control priorities in the iron and steel
industry should be as follows:
(1)
(2)
(3)
(4)
(5)
(6)
Control further the particulate emissions resulting from
the manufacturing processes
Control S0? emissions resulting from boilers
Control NO emissions resulting from boilers
/\
Control S02 emissions resulting from the manufacturing processes
Control NO emissions resulting from the manufacturing processes
X
Control further the particulate emissions resulting from boilers
It has been found that almost 40% of the process particulate emissions
result from material handling (see Appendix C, Table C-24). It should be
stressed that this is a rough estimate and that in reality these emissions
71
WALDEN RESEARCH CORPORATION
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may be lower. Even under those circumstances, however, the process particu-
late emissions are of first importance.
In the case of S09 and NO emissions, the boilers contribute the most
£ A
significant portion of the total emissions. It is furthermore found that
boiler emissions of S09 and NO in the iron and steel industry are also
c~ X
significant in comparison to total SO- and NO emitted by industrial
boilers [5-1] (see Table 5-2).
TABLE 5-2
1975 AND 1980 BOILER EMISSIONS
IRON AND STEEL AS A PERCENTAGE OF ALL INDUSTRY
(103 tons)
so2
N0x
Iron and
Steel
438
146 '
1975
All
Industry %
3,800 ' 12
1,127 13
Iron and
Steel
477 '
162
1980
All
Industry
3,988
1,268
%
12
13
In short, the above comparisons indicate the need to control air
pollution resulting from boilers in the iron and steel industry.
Suggested strategies and their cost effectiveness are discussed in
the following sections.
72 WALDEN RESEARCH CORPORATION
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REFERENCES TO SECTION V
5-1. Systematic Study of Air Pollution from Intermediate-Size Fossil-
Fuel Combustion Equipment, Walden Research Corporation, Cambridge,
Mass., 1971.
73 WALDEN RESEARCH CORPORATION
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VI. STRATEGIES FOR EMISSION CONTROL
A. INTRODUCTION
The development of an inventory of boiler equipment and fuel
by various categories and their derivation of combustion emissions and
projections has been presented and discussed. Attention is now directed
to possible means to control these emissions. In general, some methods
are effective by preventing or reducing the formation of certain pollu-
tants where others work to remove from the flue gases undesirable pro-
ducts of combustion that were generated in the boiler.
Considered in sequence below are the following broad groups:
(1) Fuel switching to reduce formation of particules, S0?
and NO during combustion
/\
(2) Mechanical methods for removal of particulates from
flue gas
(3) Chemical process controls for removal of S07 (and NO )
C. A
from flue gas
(4) Changes in combustion design to reduce formation of
particulates and NO
/\
(5) Other control strategies of particular application to
the iron and steel industry.
The evaluation of control means, singly or combined into broad
based strategies requires inputs relevant to the overall applicability of
the approaches, the state of development of the approach and specific
operating and cost data. This section of the report presents such data
pertinent to each of the major classes of potential control approaches.
B. FUEL SWITCHING
1. General Approach
The parameters of fuel switching are well known and do not
warrant explanation in great detail. Without restriction of cost,
availability or boiler design, the following generalizations can be
employed as guidelines in examining possibilities of fuel switching:
74
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a. Natural gas, now and in the foreseeable future, is the
closest approach to a perfect fuel; very low in particulate and SCL emis-
sions; not nearly so advantageous in NOV emissions, but better than other
A
fuels in most cases.
b. Distillate oil is lowest of all liquid fuels considered
to particulates,
tant somewhat higher than gas.
with respect to particulates, SCL and NO emissions, but for each pollu-
£ y\
c. Low-sulfur residual oil and residual oil are considered
equal in emissions factors for particulates and NO , but differ by a
X
factor of about 4 to 5 with respect to sulfur content and, therefore, in
S0? emissions. The emission of all three pollutants is greater than for
the above fuels.
d. Coal has generally the highest pollutant potential of
any fossil fuel with respect to particulates, S09 and NO , when un-
L. X
controlled. Even with particulate control equipment, it still may rank
highest in this category.
2. Fuel Prices
Table 6-1 shows the 1967 prices in dollars per million
Btu of various fuels used in the industrial sector according to region [6-1].
3. Capital Costs Involved in Fuel Switching
The capital costs of conversion consist of the cost of
(1) new equipment and alterations at the furnace for satisfactory com-
bustion of the fuel and (2) storage, handling, pumping and piping of
the fuel .
The capital costs developed below were converted into an
annual basis assuming a useful life of 20 years. Inclusion of the cost
of money, taxes, insurance, etc., resulted in annualization at the rate
of 14.3% of capital cost.
75 WALDEN RESEARCH CORPORATION
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TABLE 6-1
FUEL RATES
(1967 Basis)
Region ,jf*
Gas
(F)*
Residual Oil Distillate Coal
S<.5 S<1. S>1. Oil S£l. S>1.
USER GROUP IS INDUSTRIAL
AT
GL
WS
CU
SE
RN
0.45
0.38
0.37
0.28
0.36
0.37
1.03
0.58
0.52
0.54
0.50
0.70
0.59
0.62
0.63
0.53
0.63
0.58
0.51
0.54
0.55
0.45
0.55
0.50
0.40
0.53
0.37
0.42
0.37
0.40
0.84
0.81
0.79
0.76
0.77
0.80
0.43
0.38
0.50
0.45
0.36
0.46
0.37
0.34
0.38
0.38
0.35
0.38
I = Interruptible
F = Firm
Data in $/106 Btu
There appears to be no limit on types of coal burning in-
stallations which can be replaced by gas/oil burners, assuming the age
and condition of the existing unit is such that a new package type
boiler would not be a more practical replacement.
Table 6-2 lists the total cost of converting coal fired
boilers and includes both the cost of conversion and cost for fuel
handling equipment [6-2].
C. FLUE GAS TREATMENT
1. Particulate Control
a. Equipment Type
There are four types of categories of particulate
control equipment in general use today. These are:
76
WALDEN RESEARCH CORPORATION
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TABLE 6-2
TOTAL CAPITAL COST OF CONVERTING COAL-FIRED BOILERS
Year - 1975
Size
WT1
WT2
WT2
WT3
WT3
FT
CI
Average
Capacity
37,000
163,900
163,900
274,900
274,900
4,600
625
Type of
Burner
Stoker
Stoker
Pulverized
Stoker
Pulverized
Stoker
Stoker
Cost of Conversion to
Gas Oil/Gas
$ 25,000
107,000
50,000
152,000
65,000
8,000
1,000
$ 35,000
170,000
120,000
260,000
165,000
20,000
4,000
Cost of New Boiler
Gas Oil /Gas
$221 ,000
652,000
652,000
830,000
830,000
17,500
3,000
$255,000
725,000
725,000
940,000
940,000
27,500
5,000
5
r~
O
m
z
33
m
in
33
O
I
O
O
33
~0
O
33
-------
(1) Dry Cyclone
1. Employs centrifugal forces to separate by dif-
ferential density.
2. May consist of single unit, or multiples in
parallel or series.
3. Except on the largest particulates, not capable
of the highest efficiencies.
(2) Wet Scrubber.
1. Depends on intimate mixing of scrubbing liquid
to impinge on and entrap particulates carried by gas stream.
2a. Low to medium pressure drop characteristic
of very many designs involving liquid sprays, fixed or movable packing
in towers.
2b. Medium to high pressure drop characteristic
of a number of venturi designs which, except for fabrication details,
are very similar.
3. Can be designed for very high efficiencies.
4. Likely to have the greatest maintenance expense
due to erosion and corrosion.
(3) Electrostatic Precipitator
1. Generates an electric field to charge the par-
ticulates which are then attracted to elements of opposite polarity in
the precipitator.
2. Capable of the highest efficiency.
3. Will generally have the lowest pressure drop
of any design; may be limited in some cases by certain flue gases which
do not have favorable ionization characteristics.
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4. Usually the highest cost method.
5. Efficiency can be affected by gas characteristics,
e.g., adversely by low S02 concentration.
(4) Fabric Filter
1. Generally consists of multiple parallel cloth
enclosures as bags or tubes through which the gas passes, leaving the
particulates trapped on the cloth medium.
2. As with the electrostatic, capable of high
efficiency: above 99% for submicron particles.
3. Greatest limitation of application is design
and selection of proper filter medium for adequate life span.
b. . Cost Analysis
The capital cost of a specific type of collector of
given size depends on the manufacturer, location, and types of process
for which it is designed. Examination of data from manufacturers and
in the literature showed that reasonable general cost curves could be
used to represent typical installations.
The annual operating costs of the four types of con-
trol equipment are listed below in general equation form [6-3]:
Dry Cyclone (or DC)
G = S[(A x C) + (117.0 x 10"6) ^ + (M x C)]
Wet Scrubber (or wS)
G = S[(A x C) + (117.0 x 10"6) £jf£ + (188.0 x 10"6) ^- + WHL + (M x C)]
Electrostatic Precipitator (or ESP)
G = S[(A x C) + (117.0 x 10"6) + OHK + (M x C)]
79 WALDEN RESEARCH CORPORATION
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Fabric Filter (or FF)
G - S[(A x C) + (117.0 x 10"6) + (M x C)]
where
G = dollars/year
P = flue gas pressure drop DC 4.3 in. W.C.
WS (hi AP) 20 in. W.C.
WS (lo AP) 6 in. W.C.
ESP 1 in. W.C.
FF 5 in. W.C.
Q = liquor circulation rate 0.50 gal/hr-acfm
h = total liquor head requirement 70 ft FLO
W = make-up liquor requirement 0.05 gal/hr-acfm
_3
J = power requirements 0.26 x 10 kw/acfm
S = design capacity of collector, acfm of flue gas
H = annual operating time, hours
L = liquor cost, collars/gal
E = fan efficiency
F = pump efficiency
A = annual capital cost factor, per year
M = annual maintenance factor, per year
K = power cost, dollars/kwhr
C = capital cost, dollars/acfm
Values for the variables in the equations can be ob-
tained from Reference [6-2].
2. Sulfur Oxide Removal
a. Process Description
(1) General
A preliminary review of air pollution abatement
processes which would remove S09 and NO individually or simultaneously
£ X
80 WALDEN RESEARCH CORPORATION
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from the boiler flue gases revealed that there are presently no processes
demonstrated for NOV removal but that several exist for SCL abatement.
* d.
About two dozen SCL removal processes at various
stages of development are now under investigation [6-4]. Most of the
removal systems are of the regenerative type in which a sulfur by-product
is recovered and the reactive chemicals are recycled. A few of the systems
are the non-regenerative or throw-away type, where the reacted sulfur and
additive are discarded.
There is no process that is applicable to all
boilers. Location and fuel are considerations which make one process
more applicable than others. Detailed economic evaluations are not
available for most of the processes and the few that have been published
are incomplete and are based on different assumptions.
(2) Throw-away Processes
(a) Nahcolite Dry Process (NaHC03)
The nahcolite process is being promoted by
the Precipitation Pollution Control Company. The process uses the
mineral nahcolite to remove the SCL from the flue gas. Powdered
nahcolite is injected into the flue gas where upon the reaction to sul-
fate occurs and the product is removed from the flue gas in a dry dust
collector.
The process can be easily applied to small
boilers and has the attractive advantage of producing a dry but soluble
inert, inorganic waste product.
(b) Na2C03 Wet Process
The wet sodium carbonate process utilizes a
solution of NapCCL to absorb the SCL. The solution is sprayed into a
wet scrubber for reaction with the SCL. A process is being developed
by the Chemico Co. that is capable of regenerating the waste solution.
° ' WALDEN RESEARCH CORPORATION
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The advantage of the soda ash scrubbing system
is that is is simple, easy to operate and the waste disposal is not ex-
pected to be a major operating cost.
(c) TVA Dry Limestone Process
In this process, finely divided limestone is
injected into a high temperature region of the furnace for calculation
and reaction with the SCL [6-5]. The additive containing reactive sulfur
is swept through the furnace and removed in some particulate collector.
The applicability of the dry TVA process de-
pends on limestone costs, disposal costs and air quality regulations.
The disadvantage of the TVA dry lime system is that great quantities of
waste are produced due to the low chemical efficiency. Nevertheless,
the dry TVA process has the lowest net annual operating cost for the
pulverized coal fired boilers, because the combined spent additive and
ash are handled and discarded in a dry state.
(d) Combustion Engineering Dolomite Process
The process promoted by Combustion Engineering,
Inc. is one of the only two systems which have been tested on a proto-
type installation [6-6,6-7,6-8].
In this process, the SCL is absorbed in a lime
slurry in a wet scrubber precipitating calcium sulfate and sulfite. The
lime is obtained by the injection of finely pulverized dolomite lime-
stone into the boiler where it is calcined.
The precipitate and fly ash are separated
from the scrubbing liquor by a settling tank and the supernatant
liquor is recycled to the scrubber. Primarily the C-E process applic-
ability depends on the cost of the limestone, disposal cost and boiler
design of existing units.
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(c) CaC03 Scrubbing
An alternative to the above is to keep the
sorbent out of the furnace and employ it in the scrubber only. This
appeals especially to the boiler operator who generally is not anxious
to put anything other than fuel and air into the furnace.
(3) Recycle Processes
Four recovery processes appear to be most promising
as recycle type processes. These are:
(a) Chemico Process
The Chemico Process is presently being dev-
eloped jointly by Chemical Construction Company and Basic Chemicals Co.
[6-9]. The Chemico process is a wet system which uses a slurry of
magnesium oxide to absorb the SOp* forming a precipitate of MgSO^/MgSCL.
The scrubbing liquor is concentrated and crystallized for shipment to a
central recovery plant. At the recovery plant the MgSCu/MgSO. is de-
composed in a kiln to produce concentrated gaseous S0? and powdered
MgO. The MgO is returned to the scrubbing system.
The disadvantage of the Chemico system is
that the MgSCu/MgSCL solution is relatively dilute and, to minimize
shipping costs, should be concentrated and crystallized before it can
be shipped to the central recovery plant, necessitating a filter, crystal!izer
and dryer at the boiler. However, the regenerated MgO is in a dry
phase which is easily shipped back to the users. Overall, the Chemico
process is one of the more practical systems that can be readily utilized
in the regional centralized concept for small boilers.
(b) Stone & Webster/Ionics Process
The Stone & Webster/Ionics Process, which is
being developed jointly by Stone & Webster Engineering Corporation and
Ionics Company, is one of the most technologically advanced and promising
S02 recovery processes [6-10]. The process was operated at a pilot plant
83 WALDEN RESEARCH CORPORATION
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in Tampa, Florida, and a prototype plant is now being designed. The
pilot plant tests indicated satisfactory levels (>90?0 of SCL removal
were feasible and that further demonstration of the process was war-
ranted.
The SW/I Process is based on sodium hydroxide
absorption of the SCL. The formed sodium sulfite-bisulfite solution is
reacted with sulfuric acid (ILSO.), generated internally, to form sulfur
dioxide and sodium sulfate solution. The sodium sulfate is processed in
the electrolytic cell to general sodium hydroxide and sulfuric acid which
are recycled to process. The SCL, which is recovered as pure gas, can
be used to manufacture sulfuric acid or elemental sulfur.
The disadvantage of the SW/I Process is that
relatively dilute solutions have to be transported between the boiler
and the recovery plant. The solutions could be concentrated and crystal-
lized but it would mean higher capital expenditure at each boiler site
and at the recovery plant.
(c) Wellman-Lord Process
The Wellman-Lord Process is also a wet scrub-
bing process; the absorbing solution is K7SCL [6-11]. In the scrubber,
£ O
KHSCL is formed which will crystalize and precipitate upon cooling.
The metabisulfate crystals (K^S^CL) when
heated with steam will give up one mole of SCL per mole of Ko^O,- and
forms an aqueous solution of K^SCL. The K^SCL is recycled.
The Wellman-Lord Process has the same dis-
advantage as all the other aqueous regenerative processes; that is,
relatively weak solutions have to be handled both to and from the re-
covery plant or concentrated and crystallized at the respective sites.
The Wellman-Lord Process is being developed with minimum public dis-
closure of results and progress.
84 WALDEN RESEARCH CORPORATION
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TABLE 6-3
S02 REMOVAL SYSTEMS
Designation
Description
Chem.
Feed
Developer Rate*
S02
Removal
Efficiency
C
D
Dry Sodium Carbonate (Nahcolite
(Na2C03) and fabric Alternative)
filter
Sodium Carbonate
(Na2C03) Scrubbing
Dry Calcium Car- TVA
bonate (CaCO,)
O
Dry Calcium Car- C.E.
bonate (CaC03)
and Scrubber
Calcium Carbonate
(CaCCL) Scrubbing
110
110
200
no
no
60
95
40
90
60
£
Percent of stoichiometric requirement of the sulfur in the fuel.
85
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(d) The Molten Carbonate Process
The molten carbonate process being developed
by the Atomics International Division of North American Rockwell is still
in the bench scale development stage and design details are sparse [6-12],
However, the molten carbonate process appears to be one of the most adapt-
able processes to the regional recovery plant concept for new installations.
In this process the SOp is adsorbed in a molten
salt at approximately 800°F. The molten salt solution is regenerated by
reducing the sulfate to sulfide and reacting the sulfide with CCL to pro-
duce carbonate salt and HLS gas. The HpS can be used to manufacture ele-
mental sulfur.
There is a substantial drawback to this process
in that the high operating temperature of the unusual adsorbent would al-
most completely preclude all boilers except those operating continually
throughout the year. Thus, only large boilers in process industries are
likely candidates for consideration.
b. Cost Information
Detailed cost information were available from the In-
termediate-Size Boiler Study £6-2] for the five SCL removal systems de-
tailed in Table 6-3.
Table 6-4 indicates estimates of capital cost for each
process at a new installation and at an existing boiler plant. For
schemes A and C, oversize particulate collection equipment was included
because of the great increase over normal combustion-associated loads.
For the schemes B, D, and E at a new boiler plant, it was assumed that
the wet scrubber installed for S0? control would also be adequate for
particulate control. Therefore, credit was given for omission of a
particulate collector that would otherwise have been installed.
Table 6-5 shows total annual operating cost for each
SCL control scheme. This includes all operating costs such as labor,
maintenance, utilities, chemicals, etc. Also included was an allowance
WALDEN RESEARCH CORPORATION
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TABLE 6-4
SULFUR DIOXIDE REMOVAL FROM FOSSIL FUEL BOILER FLUE GAS
(CAPITAL COST IN $1000)*
Size and Fuel
275,000 Ib/hr
Coal , Pulverized
Coal , Stoker
Oil
164,000 Ib/hr
Coal , Pulverized
Coal , Stoker
Oil
37,000 Ib/hr
Coal , Pulverized
Coal , Stoker
Oil
A
Na2C03 (Dry)
New
510
510
610
355
355
425
190
Conver-
sion
730
730
710
485
485
470
206
B
Na2C03 (Wet)
New
285
285
268
188
188
182
no
88
Conver-
sion
480
480
375
320
320
250
152
105
.C
CaC03 (Dry)
New
360
356
263
328
169
Conver-
sion
520
550
365
400
190
D
CaC03 (Dry) &
Wet Scrubber
New
275
377
187
258
Conver-
sion
471
470
312
320
E
CaC03 (Wet)
New
275
275
377
187
187
258
135
Conver-
sion
471
471
470
312
312
320
158
F
CaO (Wet)
New
275
275
377
187
187
258
110
135
Conver-
sion
471
471
470
312
312
320
150
158
OO
z
33
'(/)
m
33
O
X
O
O
33
O
33
For comparison, new boiler costs alone are
size, and $230,000 for the 37,000 pph size
approximately $900,000 for the 275,000 pph size, $700,000 for the 164,000 pph
O
-------
TABLE 6-5
SULFUR DIOXIDE REMOVAL FROM FOSSIL FUEL BOILER FLUE GAS
(TOTAL ANNUAL OPERATING COST IN $1000)
Assuming 3% Sulfur
Size and Fuel
275,000 Ib/hr ]
Coal , Pulverized
Coal , Stoker
Oil
164,000 Ib/hr2
Coal , Pulverized
Coal , Stoker
Oil
37,000 Ib/hr3
Coal , Pulverized
Coal , Stoker
Oil
A
Na2C03 (Dry)
New
422
420
385
345
242
230
76
77
Conver-
sion
480
475
410
280
280
245
85
81
B
Na2C03 (Wet)
New
350
320
260
190
180
150
60
46
Conver-
sion
408
390
290
230
232
170
55
51
C
CaC03 (Dry)
New
230
200
142
135
55
Conver-
sion
270
232
170
155
61
D
CaC03 (Dry) &
Wet Scrubber
New
285
230
165
145
Conver-
sion
335
255
195
160
E
CaC03 (Wet)
New
275
260
220
160
149
137
55
52
Conver-
sion
330
305
248
191
180
157
63
58
F
CaO (Wet)
New
305
275
240
170
158
145
56
54
Conve
sion
360
365
270
210
193
167
64
60
Divide costs by 13 to obtain cents/106 Btu
Divide costs by 5.0 to obtain cents/106 Btu
-------
for annual capitalization expense, taken at 21% of total capital cost.
The basic information used in the computation of these figures can be
found elsewhere [6-2].
Application of these operating costs to a control cost
effectiveness study on boilers in the iron and steel industry may at
first appear unrealistic because of differences in percent of sulfur
in the fuel and load factors. As is noted at the head of Table 6-5,
the operating costs were calculated for a 3% sulfur fuel. The percent
sulfur in the fuel affects mainly the raw material and disposal costs
and as such the annual operating costs vary with percent sulfur in
fuel.
Perusal of Table D-2 indicates that the coal and
oil used in process boilers in the iron and steel industry contained
on the average about 1.8% sulfur.
Furthermore, the data presented in Table 6-5 were
calculated assuming that the boilers had the following load factors:
Capacity Load Factor
<100,000 pph boiler 21%
100,001-250,000 pph boiler 35%
>250,000 pph boiler 55%
Comparison of the above load factors to the average load factor of 77%
for process boilers in the iron and steel industry (see page 26)
indicates that on the average the iron and steel boilers nave load
factors about twice those used in the estimation of the data in
Table 6-5.
Fortunately, these two disparities between the two
sulfurs result in approximately compensating effects so that as a sim-
plifying conclusion it will be assumed that the annual operating costs
of the various S0? control schemes as shown in Table 6-5 can be applied
for cost effectiveness studies to the process boilers in the iron and
89
WALDEN RESEARCH CORPORATION
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steel industry. It is recognized that with the smaller boilers this
compensating effect may not be quite as good because of their lower load
factor.
3. NO Removal and Recovery
J\
The normal range of NO concentration in the flue gas is
J\
approximately 300 to 700 ppm. At these low concentrations, other flue
gas constituents such as CO,,, S02 and 02 interfere with NOX removal
processes using sorption, scrubbing and catalytic conversion techniques.
Several NO removal processes are being investigated. However, all of
J\
them are still at the laboratory bench stage of development and are
not available for full scale installation.
Perhaps the most sophisticated process approach to the
problem has been presented by Tyco Laboratories [6-8], In their process
both S0? and NO are removed from the flue gases by a process similar
L~ /\
in nature to the old "chamber process" for the production of sulfuric
acid. However, this process, too is still in the laboratory stage of
development.
D. COMBUSTION DESIGN
The following two major types of control techniques will be
considered in this section:
(i) Use of combustion additives
(ii) Changes in combustion design
1. Combustion Additives
As an approach to improving combustion and reducing pol-
lutants, total effort in the field of combustion additives has been
small when measured against development programs in equipment and fuels.
WALDEN RESEARCH CORPORATION
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Perhaps it is because the concept has often been viewed as black art,
in this case changing obnoxious chemicals into harmless ones. However,
in today's view of the pollution situation, the use of chemical additives
to reduce particulate, sulfur oxide and nitrogen oxide emissions from
furnaces is a concept which deserves to be evaluated, particularly for
small and medium size installations where flue gas treatment systems
requiring substantial capital expenditure are not likely to be econ-
omically feasible.
The purpose here is to survey and evaluate additives pre-
sently used or proposed for use in furnaces.
The organometallic additives (e.g., methyl cyclopentadienyl
manganese tricarbonyl) are claimed to reduce carbonaceous particulate
emissions from furnaces by functioning as combustion catalysts.
Reliable data on additive loading and effectiveness in re-
ducing particulate emissions is sparse. About the only information gen-
erally available are manufacturer's claims of additive effects and
recently work done at NAPCA [6-13,6-14]. Published results [6-14]
indicate that with only about 10% of the over 200 additives tested
were reductions in particulate emissions observed.
Generally the suggested additive loadings could result
in considerable emissions of toxic metallic particulates [6-14].
A second class of additives, presently used to reduce soot
emissions, function by changing the pumping and atomizing characteristics
of heavy fuel oils.
There are no additives which are currently in commercial
use to reduce nitric oxide emissions from stationary combustion equip-
ment. However, the injection of liquid water into the flame to act
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WALDEN RESEARCH CORPORATION
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as an inert diluent has been tried [6-15]. The results indicate a de-
crease in NO with a simultaneous increase in particulate emissions.
J\
Perhaps the most effective use of additives, at the present
time has been demonstrated in the reduction of sulfur oxide emissions.
Successful additive action has been experienced in residual
oil fired large boilers wherein finely divided MgO additive suspended
in light oil is simultaneously injected at a controlled rate into the
furnace. The SCL emission is decreased, corrosion is reduced substan-
tially, and the ash found on tubes is soft, dry and easily removed [6-16],
Many of the manganese containing additives which are ef-
fective in reducing particulate emissions, have also been demonstrated
to reduce SO, production [6-17,6-18].
Emission Control and Cost Data
From the foregoing discussion it can be concluded that the
control effects and cost of additive addition are not well established.
Nevertheless, based on rough estimates of the Intermediate
Boiler Study [6-12], it will be assumed that the following values will
be attainable in 1975:
(1) 50% reduction in particulate emissions
(2) 0.3 cents per million Btu cost
2. Combustion Design
a. Process Description
Based on present knowledge and technology, the attack
is likely to be different from that on particulat
SO . For the latter two, present sources and foreseeable progress
on NO emissions is likely to be different from that on particulates and
A
WALDEN RESEARCH CORPORATION
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appears to lie in fuel switching and/or flue gas treatment, although a
certain amount of unburned carbon particulate emissions and SCL pro-
3
duction probably will be reduced by redesign of the combustion package.
For NO , on the other hand, redesign of the combustion package offers
/\
the greatest promise of improvement and will probably include changes
in fuel/air mixing and metering, burning mechanisms, the furnace en-
velope and combustion controls.
The study done by Esso Research and Development Company
for NAPCA "Control Techniques for Nitrogen Oxide Emissions from Sta-
tionary Sources" is the most recent and comprehensive view of the sub-
ject and the recommendation and analysis generally follows that work [6-19],
In general , three combustion modifications are cur-
rently considered as effective in reducing NO emissions. These are
/\
Low Excess Air (LEA), Flue Gas Recirculation (FGR) and Two Stage Com-
bustion.
Low excess air, as the name implies, requires the use
of 5% or less excess combustion air, rather than the usual 20-30% to
markedly reduce the production of nitrogen oxides. Experimental data
from large boilers indicates that a reduction of 33% in NO emissions
X
is possible and it has been assumed that this reduction can be obtained
for all boiler sizes.
The mechanics of implementing low excess air involve
carefully metering combustion air and fuel, measuring either CO^ or 02
in the flue gas and introducing some feedback mechanism from this
last measurement to effect control over the fuel/air ratio. Excellent
fuel/air mixing at each burner and uniformity across the furnace is
of greatest importance.
A second technique for reducing NO involves bringing
/\
a portion of the combustion flue gas back to the combustion chamber
as part of the combustion air [6-19]. This approach appears to reduce 0-
concentration and temperature with effects as described above and also to
93 WALDEN RESEARCH CORPORATION
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reduce flame temperatures which has been shown to be an effective mechanism
for NO reduction.
Implementation of this strategy is not too difficult,
needing only flue gas recirculation fan, duct work and controls.
Extension of the above techniques have led to develop-
ment of boiler operation with both low excess air and flue gas recircula-
tion. This has been successfully demonstrated in commercial equipment and
as a result of the compound effect a reduction of NO emissions by 50% has
A
been assumed for the combined strategy [6-19].
Finally one of the advanced concepts summarized by Esso
is that of two-stage combustion [6-19]. Work on commercial units has gone
forward and a West Coast utility with an NO emissions problem has made
A
considerable progress, aided by their boiler manufacturer.
b. Economic and Operating Characteristics
The Intermediate Boiler Study [6-2] presents the follow-
ing capital cost estimates: (Table 6-6)
TABLE 6-6
ADD-ON COST OF COMBUSTION MODIFICATION
Cost Per Boiler
Boiler Size LEA FGR Both
WT-1 (<100,000 pph)
WT-2 & 3 (100,001-
500,000 pph)
Firetube and cast iron
$3,000
4,000
3,000
$ 6,000
20,000
3,000
$ 8,000
22,000
4,200
A low annualization factor of 10% has been applied
against the above capital cost because of the effects of assuming the
life of such accessories will equal that of the boiler and because of
94
WALDEN RESEARCH CORPORATION
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low maintenance requirements. However, it will be assumed that LEA
will realize enough savings through fuel economy that the annualized
capital costs will be offset in the WT2 and WT3 boilers, but not in
the WT1 boilers where the annualized capital costs was set equal to
the total operating cost.
E. CONTROL STRATEGIES OF SPECIAL APPLICATION TO THE IRON AND STEEL
INDUSTRY
A brief survey was undertaken of the possibilities of using
some of the currently employed process particulate removal systems to
assist in removal of particulates from boiler emissions. It was con-
cluded that the process removal systems were operating at their design
load and as such had no addition capacity for other particulate laden
gas. Furthermore, the cost of transportation of the large volumes of
boiler flue gas would generally be prohibitively high.
95 WALDEN RESEARCH CORPORATION
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REFERENCES TO SECTION 6
6-1. Based on The Fuel of Fifty Cities, Ernst & Ernst, November 1968.
6-2. Systematic Study of Air Pollution from Intermediate-Size Fossil-
Fuel Combustion Equipment, Walden Research Corporation, Cambridge,
Mass., 1971.
6-3. Anon., Control Techniques for Particulate Air Pollutants, NAPCA
Pub. No. AP-51, U.S. Dept. of HEW, Public Health Service, Con-
sumer Protection and Environmental Health Service, 1969.
6-4. Dennis, R. and Bernstein, R.H., Engineering Study of Removal of
Sulfur Oxides from Stack Gases, Report for Committee for Air and
Water Conservation, American Petroleum Institute, August 1968.
6-5. Sulfur Dioxide Removal from Power Plant Stack Gas, Conceputal
Design and Cost Study, Sorption by Limestone or Lime Dry Process,
TVA Report, 1968.
6-6. Maurin, P.G. and Jonakin, J., "Removing Sulfur Oxides from Stacks",
Chemical Engineering, April 27, 1970.
6-7. Plumley, A.L., Whiddon, O.D., Shutko, F.W. and Jonakin, J.,
"Removal of S02 and Dust from Stack Gases", presented at American
Power Conference, Chicago, Illinois, April 25-27, 1967.
6-8. McLaughlin, J.F. and Jonakin, J., "Operating Experience with
Wet-Dolomite Scrubbing", Annual Meeting of APCA, June 1969.
6-9. Willett, H.P., Quig, R.H., and Shah, I.S., "Venturi Scrubbing for
SO? and Fly Ash Removal at Power Plant Sites with Centralized Re-
aclant Reprocessing", presented at New England Section, APCA, Hart-
ford, Connecticut, April 16, 1969.
6-10. Humphries, J.J., Zdonik, S.B. and Parsi, E.J., "Economic Factors
in the Capital and Operating Costs of the Stone & Webster/Ionics
SO? Removal and Recovery Process", presented at AIChE Symposium,
Chicago, Illinois, November 29-December 1, 1970.
6-11. Terrana, J.D., and Hi Her, L.A., "New Process for Recovery for
S02 from Stack Gases", Wellman-Lord, Inc., Florida.
6-12. Qldenkamp, R.D., and McKenzie, D.E., "The Molten Carbonite
Process for Control of Sulfur Oxide Emissions", North American
Rockwell Corp., Atomic International Div.
6-13. Martin, G.B., "Use of Fuel Additives and Combustion Improving
Devices to Reduce Air Pollution Emissions from Domestic Oil
Furnaces", presented at the Third New and Improved Oil Burner
Workshop of NOFI, Hartford, Conn., September 23-24, 1970.
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WALDEN RESEARCH CORPORATION
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REFERENCES TO SECTION 6 (Cont.)
6-14. Martin, G.B., Wasser, J.H. and Hanegebrauck, R.P., "Status
Report on Study of Effects of Fuel Oil Additives on Emissions
from an Oil-Fired Test Furnace", presented at Annual Meeting of
APCA, St. Louis, Mo., June 14-19, 1970.
6-15. "The Treatment of Residual Fuel Oils", Dearborne Chemical Divi-
sion, W.R. Grace Co., Merchandise Mart, Chicago, 111., Technical
Bulletin 12101.
6-16. Exley, L.M. Tamburrino, A.E. and O'Neal, A.J., Jr., "LILCO
Trims Residual Oil Problems", Power, April 1966, pp 69-73.
6-17. Belyea, A.R., "Manganese Additive Reduces SO.,", Power,
November 1966.
6-18. Kukin, I., "Advances in the Use of Chemical Treatment in Air
Pollution Reduction Programs", presented at the Rocky Mountain
Regional Meeting, National Petroleum Refiners Association,
October 2-3, 1968.
6-19. Bartok, et al., Systems Study of NQX Control Methods for Sta-
tionary Sources, Esso R&D Co. (NAPCA Contract No. PH 22-68-55),
November 1969.
97 WALDEN RESEARCH CORPORATION
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VII. COST EFFECTIVENESS AND ANALYSIS
A. INTRODUCTION
Lack of funding precluded a thorough cost effectiveness analysis
of the application of many of the different control strategies discussed
earlier. However, following the general guidelines of the Intermediate
Boiler Study [6-1], cost effectiveness analyses were made for the applica-
tion of the following three broad control strategies to the steam raising
boilers in the iron and steel industry.
(i) Fuel Switching
(ii) Flue Gas Treatment
(iii) Maximum Reduction - Reasonable Cost Total Program,
i.e., combustion of fuel switching, fuel additives
and combustion modification
The economic impact of the strategies has been examined in
terms of both capital cost and also annual cost. The latter quantity in-
cludes such operating costs as fuel, labor, maintenance, water, etc.,
and the annualized capital cost. The latter factor represents the de-
preciation and depends on the number of years of useful life assumed
and on the cost of money.
Exercise of judgment in assessing the multitude of strategies
leads one quickly to the many positive aspects of fuel switching. The
major advantage is the fact that this approach can very largely eliminate
simultaneously, emissions of SOp and particulates and make a good showing
in total NO emissions.
A
The control of all emissions, comparable to the results of
fuel switching, can be accomplished by means of a flue gas treatment.
Wet scrubbing employing a sodium carbonate solution was selected as
being optimal.
Under maximum pressure or incentive to bring emissions to the
lowest practical level over the short term say 1975, it is conceivable
that a combination of individual strategies could be implemented, resulting
98 WALDEN RESEARCH CORPORATION
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in a maximum reduction - reasonable cost total program. Such an all en-
compassing program was comprised of the following strategies:
(1) Fuel switching from coal to low sulfur residual oil,
distillate oil or gas according to size and region for re-
duction of particulates and SCL and some NO .
u. /\
(2) Fuel additives for all oil firing in all sizes for
additional particulate reduction
(3) Combustion modification by LEA, staged combustion, and
FGR for significant NO reduction.
A
B. RESULTS
1. Fuel Switching
Fuel switching was based on the gross regional assumptions
that coal-fired equipment would be converted to low sulfur residual oil
firing in the Atlantic (AT) and Southeast (SE) areas and to gas firing
in the balance of the 48 states. In addition, all units firing residual
oil were switched to low sulfur residual. These assumptions were based
on those used in the Intermediate Boiler Study [7-1].
The results obtained are shown in Table 7-1.
It should be emphasized, however, that variation in fuel
prices due to supply and demand were not taken into account.
2, Flue Gas Treatment
Even though furnace gas contains no sulfur, flue gas treat-
ment strategy was applied to all units in the cost effectiveness analysis.
The rational behind this was that boilers in the iron and steel industry
tend to use many different fuels during their operation, so that flue
gas treatment would be required when other fuels were used.
Estimation of capital investment and annual operating
costs were obtained simply by dividing separately the total boiler
WALDEN RESEARCH CORPORATION
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TABLE 7-1
FUEL SWITCHING STRATEGY
1975
Parti culates
WT1
WT2
WT3
TOTAL
so2
WT]
WT2
TOTAL
N0x
WT1
WT2
WT3
TOTAL
Includes a 14.3%
**
Cost to reduce al
**
Emissions Cost
(103 tons/yr) % ^^^ $ TO6
Projections Reduction Pollutant Capital Annual
124.6
130.6
117.1
372.3
176.5
143.5
118.4
438.4
49.1
49.5
47.8
146.4
writing
1 three
115.7 ^
126.5
113.1 i
355.3 95 |
119.0
5.8 16.6
103.5 V 3.0 11.1
82.0
304.5 69
5.7
4.9
6.0
16.6 11 ,
off of the capital cost.
pollutants.
/ 2,8 11.0
11.6 38.7
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WALDEN RESEARCH CORPORATION
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capacity in each of the three size groupings WT1, WT2 and VTT3 by the average
boiler sizes for which data were presented in Tables 6-4 and 6-5. This was
a rough estimate of the total number of units in each size category. Costs
were then obtained by multiplying these number of units by the average
(by fuel and type of burner) conversion costs presented in Tables 6-4 and
6-5.
The results are shown in Table 7-2.
3. Maximum Reduction - Reasonable Cost Strategy
As discussed earlier this strategy consists of the combined
application of three strategies. The results of the fuel switching strategy
are presented in Table 7-1. Table 7-3 presents the cost effectiveness of
applying combustion modifications and additives.
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TABLE 7-2
FLUE GAS TREATMENT BY CONVERSION OF EQUIPMENT
Emissions
(103 tons/yr) % Auction
1975 Projections Reduction
Particulates
WT1
WT2
WT3
TOTAL
so2
WT1
WT3
TOTAL
NOX
WT1
WT2
WT3
TOTAL
124.6
130.6
117.1
372.3
176.5
143.5
118.4
438.4
49.1
49.5
47.8
146.4
115.7 >
126.5
113.1
355.3 95
167.5
136.0
113.0
416.5 95
9.8
9.9
9.6
29.3 20 /
Cost
$ 106
Annual
Capital Operating
1
125 52
60 42
' 53 43
238 137
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TABLE 7-3
COST EFFECTIVENESS OF APPLYING COMBUSTION MODIFICATIONS (LEA AND FGR)
AND ADDITIVES TO ALL RESIDUAL OIL BOILERS
Emissions
Cost
% Reduction
of Each
1975 Projections Reduction Pollutant
(10° tons/yr)
$ 10b
Capital Annual
Parti culates
WT] 124.6
WT2 130.6
WT3 117.1
TOTAL 372.3
2.5
.7
.8
4.0 1
0
0
0
0
2.0
1.4
1.2
4.6
SO,
TOTAL
438.4
N.A.
NO
WT1
WT2
WT3
TOTAL
49.1
49.5
47.8
146.4
21.7
22.3
20.9
64.9 44
8.3
4.4
2.6
15.3
.8
0
0
.8
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REFERENCES TO SECTION VII
7-1. Systematic Study of Air Pollution from Intermediate-Size Fossil-
Fuel Combustion Equipment, Wai den Research Corporation, Cambridge,
Mass., 1971.
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VIII. CONCLUSIONS AND RECOMMENDATIONS
A. CONCLUSIONS
Three major conclusions emerge from this study:
(1) Steam raising boilers are a significant source of air
pollution in the iron and steel industry. These boilers
emit about 1/3 the particulate loadings of the process
emissions, about 1/2 of the total S02 and 2/3 of the
total NO .
A
(2) A significant fraction of the particulate and S02 emis-
sions from the boilers result from the combustion of
conventional fossil fuels. This is a result of the rela-
tive cleanliness (with respect to particulates and sul-
furs) of coke oven gas and blast furnace gas as compared
to the conventional fossil fuels.
(3) Mainly as a consequence of (2), it is concluded from
the control strategy cost effectiveness analyses that
fuel switching would be the most effective means of
control.
B. RECOMMENDATIONS
Examination of the results of the development of emission
estimates and projections and analysis of control strategies point to
two principal sets of recommendations.
(1) Improvement on the present study
(2) Implementation of fuel switching
1. Improvements of the Present Study
The first set reflects uncertainties and limitations
resulting from assumptions, idealizations and imperfect data inputs in-
herent in the analytic procedures employed in the study.
105 WALDEN RESEARCH CORPORATION
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Anticipating that strategy evaluation appears more meaning-
ful on the basis of combined effects on all three pollutants, it would be
valuable to develop a parallel means to combine the emissions into a
single quantity using some weighting factor to account for permissible
levels of exposure.
Other improvements are more direct. The study should be
updated and checked against actual future developments. More fine struc-
ture should be introduced. There is need to improve the emission factor
data and the information concerning the fraction of units controlled. This
information is required particularly for the process emissions where very
little information is available and yet these "rough" emission estimates
would suggest that the iron and steel industry is a significant industrial
polluter.
The fuel switching analysis depends on several key assump-
tions regarding fuel price and availability. Re-examination considering
supply price forecasts should be made.
2. Implementation of Fuel Switching
Fuel switching was shown to be the preferred control
strategy as long as fuel prices do not increase. However, recent trends
in prices, particularly for low sulfur fuels, would suggest rapid increases
in the near future. Because fuel switching has many attractive features
other than low annual operating costs, it is important to seek means to
maintain the price of fuel and the adequacy of supply at levels where
this strategy remains effective.
06 WALDEN RESEARCH CORPORATION
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APPENDIX A
DATA ANALYSIS AND BOILER INVENTORY
From the various sources, state-by-state totals were compiled of
the available capacity in the boiler data base. From the Dun & Brad-
street Metalworking Directory [A-l], the number of employees for each
plant for which data were available were recorded. Where no employ-
ment figures were available, estimates were made. Table A-l lists
the capacities and number of boilers obtained for each state, and the
approximate percentage this would represent of the total, based on em-
ployment. The percentage was arrived at for each state by using the
ratio between the employment figures for the plants for which data were
available and the total employment figure for SIC 331, as reported in
the 1969 County Business Pattern publication for each state [A-2].
Exceptions were those cases where it was known that one or two large
plants made up most of the total state capacity and where information
on the boilers in use in these plants were available, i.e., in Maryland
and Michigan.
Except for New Jersey, the states not listed have a negligible
number of people employed in the iron and steel industry (less than
0.5% of the total U.S. employment in SIC 331). Based on a rough
capacity/employment ratio of 250 (obtained by averaging some of the
available data), we estimated New Jersey to have about 15 boilers with
a total capacity of 1 million Ib/hr. The other state totals were ob-
tained by multiplying the reciprocal of the employment ratio, described
before, by the capacity available in Wai den's sample data. The results
are listed in Table A-2 and add up to 103,495,000 Ib/hr and 2,269 boilers.
The total sample obtained represents about 64% of the total employment
in the iron and steel industry.
In order to make a rough check of these estimates, the following
exercise was performed. An age profile was drawn up from the sample of
boilers where the boiler age was available. Assuming a two-year lag
between the boiler sales as reported by the ABMA [A-3] and the date of
A-l WALDEN RESEARCH CORPORATION
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TABLE A-l
SAMPLE OF BOILERS IN THE IRON AND STEEL INDUSTRY
State
Alabama
California
Colorado
Connecticut
Delaware
Georgia
Illinois
Indiana
Kentucky
Maryland
Massachusetts
Michigan
Minnesota
Missouri
New York
Ohio
Pennsylvania
Texas
Utah
West Virginia
No.
87
29
22
3
2
2
60
97
1
422
13
12
23
4
30
187
285
8
23
20
Capacity (103 pph)
6,063
2,151
1,445
49
100
50
4,594
8,874
negl .
4,980
104
4,120
389
240
2,303
13,453
13,871
1,002
1,592
2,400
66,256
% of Total
62
55
100
6
50
100
80
93
negl .
100
21
82
66
80
64
73
46
39
99
80
A-2
WALDEN RESEARCH CORPORATION
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TABLE A-2
1970 ESTIMATE OF BOILERS IN THE IRON AND STEEL INDUSTRY
State
Alabama
Cal i form' a
Colorado
Connecticut
Delaware
Georgia
Illinois
Indiana
Kentucky
Maryland
Massachusetts
Michigan
Minnesota
Missouri
New Jersey
New York
Ohio
Pennsylvania
Texas
Utah
West Virginia
No.
140
53
22
53
4
2
75
105
13
425
60
52
51
8
15
48
255
700
21
28
21
2,269
Capacity (103 pph)
9,800
3,900
1,500
860
200
50
5,750
9,580
5
5,000
500
5,000
850
300
1,000
3,600
18,400
30,000
2,600
1,600
3,000
103,495
A-3 WALDEN RESEARCH CORPORATION
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actual installment, the boilers sold between 1965 and 1968 should have
been installed between 1967 and 1970. Furthermore, the assumption was
made that the age profile of the sample is representative of the national
age profile of the boilers sold by the ABMA members to the primary
metals industry. Using these assumptions, the capacity installed be-
tween 1911 and 1970 was found to be 7.09 times as large as the capacity
installed in the four-year period of 1967 to 1970. Multiplying the
1965 to 1969 ABMA sales by this factor should give an approximation of
the boilers sold to the primary metals industry between 1911 and 1970.
This calculation results in a total capacity of 120,885,000 Ib/hr.
Assuming that 90% of this capacity was sold to the iron and steel in-
dustry reduces the figure to 108,796,000 Ib/hr. Subtracting about 5%
for retired boilers [A-4] results in the final figure of 103,356,000
Ib/hr of installed boiler capacity in the iron and steel industry.
This compares very favorably with the total capacity obtained from the
state-by-state approach, which was 103,495,000 Ib/hr. The two approaches
differ by less than 1%, giving us confidence in the methodology and the
results.
Ranking the states according to installed capacity, we find Penn-
sylvania to be far ahead of all other states, with Ohio, Indiana, and
Alabama in the second, third, and fourth places (see Table A-3).
The boiler inventory is summarized in Table A-4. It was decided to
leave out the small cast iron and firetube boilers used in some iron and
steel plants. This reduced the number of boilers significantly, but did
not affect the total boiler capacities when reported in thousand pounds
of steam per hour (see Table A-5).
The age distribution of the boilers in the iron and steel industry
available from the Walden sample shows that the Southeastern region of
the U.S. has the largest proportion of boilers older than 20 years (see
Table A-6). This region has had iron and steel plants since the end of
the 19th century and, contrary to the Atlantic states, it has not ex-
panded its iron and steel plants by putting in a larger number of small
A-4 WALDEN RESEARCH CORPORATION
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TABLE A-3
1970 STATE RANKING BY BOILER CAPACITY IN THE
IRON AND STEEL INDUSTRY
Rank
1
2
3
4
5
6/7
6/7
8
9
Pennsylvania
Ohio
Alabama
Indiana
Illinois
Maryland
Michigan
Cal i form' a
New York
Capacity (10 pph)
30,000
18,400
9,800
9,580
5,750
5,000
5,000
3,900
3,600
TABLE A-4
1970 REGIONAL ESTIMATES OF BOILER CAPACITY IN
THE IRON AND STEEL INDUSTRY
Region
Atlantic
Great Lakes
West and South
South East
No. of
Boilers
1,305
547
124
176
2,152
Capacity
(103 pph)
41,160
39,880
9,600
12,855
103,495
A-5 WALDEN RESEARCH CORPORATION
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TABLE A-5
1970 REGIONAL ESTIMATES OF WATERTUBE BOILERS IN
THE IRON AND STEEL INDUSTRY
Region
Atlantic
Great Lakes
West and South
South East
No. of
Boilers
783
514
123
172
1,592
Capacity
(103 pph)
41,160
39,880
9,600
12,855
103,495
Average
(pph)
53,000
77,600
78,000
74,700
(65,000)
TABLE A-6
1970 AGE DISTRIBUTION OF WATERTUBE BOILERS IN
THE IRON AND STEEL INDUSTRY
Less Than or Equal Older Than
Region to 20 Years 20 Years
Atlantic 49% 51%
Great Lakes 49% 51%
West and South 31% 69%
South East 10% 90%
. g WALDEN RESEARCH CORPORATION
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boilers. In some cases, larger boilers were ordered to replace the older
ones, and it is assumed that the 10% new boilers are mostly those greater
than 250,000 pph. In very many cases, however, the iron and steel in-
dustry has turned to purchasing steam and electricity, instead of gen-
erating steam for process heating and power purposes. The TVA complex
in this region has facilitated this process. Summarizing, it may be
said that the percentage of new boilers is quite small in iron and
steel plants in the Southeast, because this is an old industry for the
region, and because many expanding and new plants have eliminated their
own boiler plants by buying outside steam and electricity.
From the Walden sample of boilers in the iron and steel industry,
the following fuel distributions were obtained: (Table A-7)
TABLE A-7
1970 FUEL DISTRIBUTION OF BOILERS IN THE
IRON AND STEEL INDUSTRY
(percentages)
Region
Atlantic
Great Lakes
West and South
South East
Coal
10
31
2
32
Residual
Oil
13
9
5
3
Natural
Gas
29
19
35
26
Blast Furnace
Gas
34
30
31
28
Coke
Oven Gas
14
11
27
11
From all the above distribution tables, we arrive at the boiler in-
ventory summarized in Table A-8.
From the sample a weighted average was calculated for the load fac-
tor of the boilers in the iron and steel industry. This average was
about 77%. Boiler efficiencies were not requested on the questionnaire
form, but were requested in the telephone interviews. From this smaller
sample, the range of efficiencies was found to be from 60% to 92% with
an average of about 78%. The larger boilers usually had a higher
A-7 WALDEN RESEARCH CORPORATION
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TABLE A-8
1970 BOILER CAPACITY IN THE IRON AND STEEL INDUSTRY
(103 pph)
Boiler Size Fuel
"T^OO CL
RO
GS
BFG
COG
WT1 00-250 CL
RO
GS
BFG
COG
WT>25Q CL
RO
GS
BFG
COG
TOTAL
AT
1,729
2,247
5,013
5,878
2,420
1,317
1,712
3,820
4,478
1,844
1,070
1,391
3,104
3,639
1,498
41,160
GL
3,956
1,148
2,425
3,829
1,404
4,698
1 ,364
2,879
4,546
1,667
3,709
1,077
2,273
3,589
1,316
39,880
WS
73
182
1,277
1,131
985
42
106
739
655
570
77
192
1,344
1,190
1,037
9,600
SE
1,439
135
1,170
1,260
495
864
81
702
756
297
1,810
170
1,470
1,584
622
12,855
Total
7,197
3,712
9,885
12,098
5,304
6,921
3,263
8,140
10,435
4,378
6,666
2,830
8,191
10,002
4,473
103,495
A-8 WALDEN RESEARCH CORPORATION
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efficiency than the smaller ones. It was decided to use the following
average boiler efficiencies by size group:
Watertube <100,001 Ibs/hr - 73%
Watertube 101,001-250,000 Ibs/hr -78%
Watertube >250,000 Ibs/hr - 84%
Since no specific data on firing methods were collected for the
study, it was decided to use the coal firing method distribution charac-
teristic of intermediate size watertube boilers in general [A-4]. This
distribution is shown in Table A-9.
TABLE A-9
PERCENTAGE OF WATERTUBE BOILERS USING VARIOUS
FIRING METHODS FOR COAL COMBUSTION
Boiler
Size
^100
WT1 00-250
WT>250
Pulverized
Coal
20
59
92
Cyclone
0
2
5
Overfired
47
29
0
Stokers
Spreader
Stoker
20
8
2
Under
Fired
13
2
1
Stokers are used mostly for the smaller watertube boilers; the large
boilers tend to utilize pulverized coal.
In order to check the 1970 fuel use results, Walden used the AISI
statistical reports. The data only showed coal used for steam raising,
so that this is the only direct comparison that could initially be made.
It also breaks down the consumption of the other fuels into the fol-
lowing use categories:
A-9 WALDEN RESEARCH CORPORATION
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! Blast Furnace
Other Uses
(including coke over underfiring)
Steel Melting Furnaces
Heating and Annealing Furnaces
Heating Ovens for Wire Rods
Other
Discussions with AISI (Mr. Eckel) indicates that the category "other"
could be considered to refer to fuel usage for steam raising. Con-
sequently, fuel oil, natural gas, coke oven gas, and blast furnace gas
consumption in steam raising were each estimated by summing the fuel
quantities listed under "other" (subtracting out in each case the fuel
used for coke oven underfiring). Tar and pitch consumption which are
also tabulated by AISI were added to the fuel oil figures for this
estimated.
WALDEN RESEARCH CORPORATION
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REFERENCES TO APPENDIX A
A-l. Dun & Bradstreet Metalworking Directory, 1971. Dun & Bradstreet,
Inc., New York.
A-2. County Business Patterns. U.S. Bureau of Labor Statistics, 1969.
A-3. American Boiler Manufacturers Association, Yearly Reports on Boiler
Sales.
A-4. Systematic Study of Air Pollution from Intermediate-Size Fossil-
Fuel Combustion Equipment, Maiden Research Corporation, March 1971.
A-11
WALDEN RESEARCH CORPORATION
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APPENDIX B
PROJECTIONS OF BOILERS TO THE YEAR 1980
It was found that about 550 kwh of energy is needed to produce a ton
of steel in electric furnaces [B-l]. Using this figure and the produc-
tion figures published by the AISI, we arrived at the actual energy
needed for steel production in electric furnaces, shown in the left-
hand column of Table B-l.
TABLE B-l
POWER UTILIZATION IN IRON AND STEEL PLANTS
Energy Used for
Production of
Raw Steel in
Total Electric
Power Consumed
by the Iron and
1964
1965
1966
1967
1968
1969
1970
L- i <=u ui iv* luiiiauci.
(106 kwh)
A
6,973
7,592
8,179
8,299
9,248
11,073
11,089
a ULCCI j
(106
Generated
B_
12,816
12,151
12,096
11,954
12,685
11,702
11,749
Liiuua ui y
kwh)*
Purchased
C_
26,049
28,006
29,891
30,557
33,470
36,691
37,833
Column A
Ratio B+C"
D.
.179
.189
.195
.195
.200
.229
.224
"Source: AISI - 1970 Annual Statistical Report
The BatteHe Systems Study of the integrated iron and steel industry
reports projections of raw steel production by type of furnace, see
Table B-2.
B-l
WALDEN RESEARCH CORPORATION
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TABLE B-2
PROJECTIONS OF RAW STEEL PRODUCTION BY TYPE OF FURNACE
(1000 net tons)
Year
1975
1980
*
Source:
Open
Hearth
44,000
36,000
Battell e
Basic-Oxygen
Bessimer Furnace
80,000
99,000
Memorial Institute
Electric
Furnace
33,000
45,000
Total
157,000
180,000
Corresponding to the production of steel in electric furnaces,
using the factor of 550 kwh/ton of steel, are the figures of respectively
18.150 x 10 kwh and 24.750 x 10 kwh for energy used for this production
in 1975 and 1980 respectively. A linear projection of the ratio in column
D of Table B-l results in the ratio of .275 for 1975 and .320 for 1980.
Using these ratios we arrive at the projected figures for total energy
required shown in the lefthand column of Table B-3. Purchased energy
as a percentage of the total has been increasing significantly [B-3].
In 1970 this percentage was about 76%. Our projections for 1975 and
1980 show that 85% and 93% respectively of the total required energy
will be purchased as opposed to generated in-house. The boiler capacity
needed for this in-house generation was calculated based on a load fac-
tor of 77% and assuming 1 kilowatt to be approximately equivalent to
10 Ibs of steam per hour. The results are shown in Table B-3.
Boilers in the iron and steel industry are used to raise steam
for power generation, process heating and space heating. The assump-
tion is made below that the amount of steam generated for non-power
purposes will remain the same per ton of steel produced during the
coming decade. This boiler capacity required for process and space-
heating in 1975 and 1980 was arrived at by using the Battelle pro-
jections of total steel production shown in Table B-2. The 1970 total
R 2
WALDEN RESEARCH CORPORATION
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TABLE B-3
PROJECTIONS OF POWER REQUIREMENTS IN THE
IRON AND STEEL INDUSTRY
(TO6 kwh)
Total
Year Energy
A_
1975 66,000
1980 77,340
Purchased Generated
B C
56,000 9,900
71,926 5,414
Boiler Capacity in Use
for Power Generation
D
14.7 x 106 pph
8.0 x 106 pph
3
production of raw steel was 131,514 x 10 tons, corresponding to a boiler
capacity of 103,495 x 103 pph. Table B-l shows that 11,749 x 106 kwh
of energy were generated in iron and steel plants in 1970. The boiler
capacity required for this would be 17.4 x 10 pph, which is about 17%
of the total boiler capacity installed in the iron and steel industry
in 1970. The remaining 86.1 x 10 pph are used for space and process
heating. The 1970 ratio between the capacity used for non-power pur-
poses and the total tons of raw steel is .65 pph/ton. The assumption
is made that this ratio will remain fairly constant through the fol-
lowing decade, since no drastic decreases in steam generated for process
and space heating use per ton of steel produced is expected, as opposed
to the expected decrease in in-house power generation. Consequently
the 1975 boiler capacity required for process and space heating is ex-
pected to be .65 x 157 x 10 = 102 x 10b pph, and the corresponding
f.
1980 figure is projected to be 117 x 10 pph. These results are sum-
marized in Table B-4.
It was decided to use the industrial fuel projections obtained in
the Intermediate-Size Boiler Study as guidelines for the respective de-
creases and increases in relative use of the conventional fossil fuels
in the iron and steel industry in each region [B-4]. These projections
are shown in Table B-5. The 1970 fuel use distribution in the iron
and steel industry is shown in Table B-6.
WALDEN RESEARCH CORPORATION
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TABLE B-4
PROJECTIONS OF BOILER CAPACITIES IN THE
IRON AND STEEL INDUSTRY
(106 pph)
Year
1970
1975
1980
Boiler Capacity
Used for
Power Generation
17.4
14.7
8.0
Boiler Capacity
Used for Process
and Space Heating
86.1
102.1
117.0
Total
Boiler Capacity
103.5
116.8
125.0
The growth and decline rates derived from Table B-5 are shown in
Table B-7. These ratios are applied to the 1970 fuel distribution for
the iron and steel industry, and the distribution in Table B-8 is ob-
tained for the three conventional fossil fuels. The total projected
percentage made up by these three fossil fuels is calculated as follows;
(1) Total projected capacities for 1975 and 1980 are respectively
116.8 x 106 pph and 125.0 x 106 pph (see Table B-4).
(2) Total projected consumption in 1975 and 1980 of blast furnace
*
and coke-oven gas are:
1 o
In 1975: blast furnace gas 2.8 x 10 cu. ft., coke-
oven gas 2.46 x 10 cu. ft.
In 1980: blast furnace gas 2.34 x 1012 cu. ft., coke-
oven gas 2.51 x 10 cu. ft.
(3) The approximate Btu values corresponding to the total capacities
are:
In 1975: 985 x 1012 Btu/yr
In 1980: 1.062 x 1012 Btu/yr
These estimates are discussed in Appendix C, pages C-
B-4
WALDEN RESEARCH CORPORATION
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CD
I
in
o
m
z:
m
C/5
rn
O
X
o
o
50
~a
o
TABLE B-5
PROJECTIONS OF INDUSTRUAL FUEL DISTRIBUTION
AT
GL
WS
SE
CL
38.9
59.5
1.8
59.5
1967
RO
42.0
10.1
19.3
10.4
(X)
DO
12.8
5.3
1.2
2.3
GS
6.3
25.1
77.7
27.8
CL
28.2
58.8
1.8
46.3
1975
RO
53.8
8.7
10.7
12.0
(X)
DO
2.9
1.6
1.4
1.0
GS
15.1
30.9
86.2
40.7
CL
23.9
56.5
1.6
44.2
1980
RO
56.8
7.6
9.7
12.4
(X)
DO
2.7
1.5
1.4
1.0
GS
16.6
34.3
87.3
42.4
-------
TABLE B-6
1970 FUEL DISTRIBUTION IN THE IRON AND STEEL INDUSTRY
(percentages)
AT
GL
WS
SE
AT
GL
WS
SE
CL RO GS BFG COG
AT 10 13 29 34 14
GL 31 9 19 30 11
WS 2 5 35 31 27
SE 32 3 26 28 11
TABLE B-7
PROJECTED FUEL GROWTH RATES - 1967-1980
(percentages)
%A/yr 2A/5 years
1967 - 1975 1975 - 1980
CL RO DO GS CL RO DO
-3.4 +3.5 -9.7 +17.5 -15.2 +5.6 -6.9
-0.1 -1.7 -8.7 +2.9 -3.9 -12.6 -6.3
0 -5.6 +2.1 +1.4 -11.1 -9.3 0
-2.8 +1.9 -7.1 +5.8 -4.5 +3.3 0
TABLE B-8
PROJECTED FUEL RATIOS IN THE IRON AND STEEL INDUSTRY
(percentages)
1975 1980
CL RO GS CL RO
8.3 15.3 54.4 7.9 16.2
29.5 8.2 21.8 28.3 7.2
2.0 3.6 37.5 1.8 3.3
27.5 3.3 33.5 26.3 3.4
GS
+9.9
+11.0
1.3
+4.2
GS
59.8
24.2
38.0
34.9
B-6
WALDEN RESEARCH CORPORATION
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(4) The approximate Btu values corresponding to the projected use
of blast furnace gas and coke-oven gas are:
In 1975: blast furnace gas 266 x 1012 Btu/yr, coke-oven
gas 123 x 1012 Btu/yr
In 1980: blast furnace gas 222 x 1012 Btu/yr, coke oven
gas 126 x 1012 Btu/yr
(5) The percentages of the total Btu value taken up by blast
furnace gas and coke oven gas are:
In 1975: 27% blast furnace gas and 12% coke oven gas
In 1980: 21% blast furnace gas and 12% coke oven gas
(6) The remaining 61% in 1975 and 67% in 1980 are taken up by
the fossil fuels.
(7) By reducing the ratios on the previous page to add up to
these percentages, we obtain the final fuel distribution for the pro-
jected years as indicated in Table B-9.
TABLE B-9
PROJECTED FUEL DISTRIBUTION IN THE IRON AND STEEL INDUSTRY
(percentages)
1975
CL RO
AT
GL
WS
SE
6 1
30
3
26
*
Insufficient
2
9
5
3
data
GS
43
22
53
32
are
BFG*
27
27
27
27
availabl
COG*
12
12
12
12
e to
CL
6
32
3
27
vary these
RO
13
8
5
4
1980
GS
48
27
59
26
percentages
BFG*
21
21
21
21
regi
COG*
12
12
12
12
onally
g_7 WALDEN RESEARCH CORPORATION
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The growth of the installed capacity of the various watertube
boiler sizes is obtained from the Systems Study of Intermediate-Size
Boilers. (See Table B-10) [B-4].
In 1970 the capacity distribution by size and region was as shown
in Table B-ll. Applying the relative growth of the various size groups
for intermediate boilers as a whole [B-4] to the iron and steel boilers
on a total basis results in Table B-12. The proportions for each re-
gion within a size group are assumed to remain the same as in 1970.
From the distribution tables developed above, the boiler inven-
tories for 1975 and 1980 in the iron and steel industry are derived
and summarized below in Tables B-13 and B-14.
B-8 WALDEN RESEARCH CORPORATION
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TABLE B-10
PROJECTED BOILER CAPACITIES BY SIZE - INTERMEDIATE BOILERS
(106 pph)
Watertube
Watertube
Watertube
£100
100
>250
,000
,001
,001
pph
-250,000
-500,000
pph
pph
1970
921
658
259
1975
1.045
700
286
1980
1 .123
745
282
TABLE B-ll
1970 BOILER CAPACITY IN THE IRON AND STEEL INDUSTRY BY SIZE
(106
pph)
AT
Watertube <100,000 pph
Watertube 100,001-250,000 pph
Watertube >250,000 pph
1
1
1
7
3
0
41
,287
,171
,702
,160
GL
12
15
11
39
,762
,154
,964
,880
WS
3
2
3
9
,648
,112
,840
,600
SE
4
2
5
12
,499
,700
,656
,855
Total
38
33
32
103
,196
,137
,162
,495
B-9
WALDEN RESEARCH CORPORATION
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0
a
m
m
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o
X)
TABLE B-12
PROJECTED BOILER CAPACITY IN THE IRON AND STEEL INDUSTRY BY SIZE
(106 pph)
1975 1980
WT £100,000 pph
WT 100,001-250,000 pph
WT >250,000 pph
21.1 23.5
14.4 15.6
11.3 11.2
46.8 50.3
1975 1980
15.6 17.0
16.5 17.9
12.7 12.6
44.8 47.5
1975 1980
4.5 4.7
2.3 3.7
4.0 4.0
10.8 12.4
1975 1980
5.5 5.8
2.9 3.1
6.0 5.9
14.4 14.8
1975
46.7
36.1
34.0
116.8
1980
51.0
40.3
33.7
125.0
D3
I
-------
TABLE B-13
1975 BOILER CAPACITY IN THE IRON AND STEEL INDUSTRY
(106 pph)
WT<100 CL
RO
GS
BFG
COG
WT1 00-250 CL
RO
GS
BFG
COG
^250 CL
RO
GS
BFG
COG
TOTAL
AT
1.3
2.5
9.1
5.7
2.5
.9
1.7
6.2
3.9
1.7
.6
1.4
4.9
3.0
1.4
46.8
GL
4.7
1.4
3.4
4.2
1.9
5.0
1.5
3.6
4.4
2.0
3.8
1.2
2.8
3.4
1.5
44.8
WS
.1
.2
2.4
1.2
.6
.1
.1
1.2
.6
.3
.1
.2
2.1
1.1
.5
10.8
SE
1.4
.2
1.7
1.5
.7
.8
.1
.9
.8
.3
1.6
.2
1.9
1.6
.7
14.4
Total
7.5
4.3
16.6
12.6
5.7
6.8
3.4
11.9
9.7
4.3
6.1
3.0
11.7
9.1
4.1
116.8
B-n
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TABLE B-14
1980 BOILER CAPACITY IN THE IRON AND STEEL INDUSTRY
(TO6 pph)
WT<100 CL
RO
GS
BFG
COG
WT1 00-250 CL
RO
GS
BFG
COG
WT>25Q CL
RO
GS
BFG
COG
TOTAL
AT
1.4
3.0
11.3
4.9
2.8
.9
2.0
7.5
3.3
1.9
.7
1.5
5.4
2.4
1.3
50.3
GL
5.4
1.4
4.6
3.6
2.0
5.7
1.4
4.8
3.8
2.2
4.0
1.0
3.4
2.7
1.5
47.5
WS
.1
.2
2.8
1.0
.6
.1
.2
2.2
.8
.4
.1
.2
2.4
.8
.5
12.4
SE
1.6
.2
2.1
1.2
.7
.8
.1
1.1
.7
.4
1.6
.2
2.1.
1.3
.7
14.8
Total
8.5
4.8
20.8
10.7
6.1
7.5
3.7
15.6
8.6
4.9
6.4
2.9
13.3
7.2
4.0
125.0
B-12
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REFERENCES TO APPENDIX B
B-l. The Making, Shaping, and Treating of Steel, 8th Edition, U.S.
Steel Corporation, Pittsburgh, Pa., 1964.
B-2. A Systems Analysis Study of the Integrated Iron and Steel In-
dustry, Battelle Memorial Institute, Columbus, Ohio, 1964.
B-3. Statistical Report, American Iron and Steel Institute, 1970.
B-4. Systematic Study of Air Pollution from Intermediate-Size Fossil-
Fuel Combustion Equipment, Wai den Research Corporation, Cambridge,
Mass., 1971.
B-l3 WALDEN RESEARCH CORPORATION
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APPENDIX C
PROCESS EMISSIONS
INTRODUCTION
Process emissions in the iron and steel industry emanate from two
distinct types of sources. First, emissions are produced during the
handling of raw materials and the subsequent processing of these materials
to produce steel. These emissions fall within the conventional defini-
tion of process emissions. However, in order to meet its energy demands
during the manufacturing steps, the iron and steel industry combusts
significant quantities of fuel. This non-boiler combustion forms the
second source of process emissions.
Estimation of the emission loadings from the two types of sources
will be considered separately. Estimates, both for the base year of
1970 and projections to 1980 will be dealt with together since it is
felt that in that manner the underlying logic will be most easily under-
stood.
Section I of this appendix discusses the conventional process emis-
sions from iron and steel plants in detail by pollutant. For the vari-
ous potential sources of process emissions, uncontrolled emission fac-
tors were determined, a brief look was taken at controls, and finally,
emission estimates were made for 1970, 1975, and 1980. Section II dis-
cusses the emissions from fuels.
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I. CONVENTIONAL PROCESS EMISSIONS
A. PARTICULATES
Each of the following separate processing operations encountered
in the iron and steel industry are potential sources of particulate emis-
sions:
(1) Sinter Plants
(2) Pellet Plants
(3) Coke Manufacture
(4) Blast Furnaces
(5) Steel Furnaces
Open Hearth
Basic Oxygen Furnace (EOF)
Electric Arc Furnace
(6) Scarfing
(7) Materials Handling
In estimating emissions from the above operations, only a very
brief description of the actual process will be given (sufficient for
understanding any subsequent comments). For a more detailed description
of the operations, the reader is directed to "The Making, Shaping and
Treating of Steel" [C-l], and Battelle's Systems Study of the Integrated
Iron and Steel Industry [C-2].
1. Sinter Plants
Sintering plants produce from iron ore fines and blast fur-
nace dust larger sized materials that can be easily charged to the blast
furnace. The technique used is to slowly burn on a slow moving grate
a mixture of fines plus fuel (coal dust or coke) so that a sticky mass
is formed. This material is then cooled producing sinter.
Emissions from sinter plant operation are produced mainly
during the combustion and firing and the cooling and screening stages,
although minor amounts of dusts result from handling of raw materials.
C-2 WALDEN RESEARCH CORPORATION
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a. Uncontrolled Emission Factors
Nationwide Emission Factor Compilation (NEFC) IC-3] quote
the following emission factors:
Windbox (i.e., combustion gases 20 Ib part/ton of sinter
from ignition and firing)
Discharge end (cooling and 22 Ib part/ton of sinter
screening)
These figures are in substantial agreement with average values quoted by
Schueneman, et al. [C-4] although there have been reports of large vari-
ations in dust emissions (windbox and discharge each 5-100 Ib/ton of
sinter) [C-5].
b. Controls
Cyclones and electrostatic precipitators are the gen-
erally used techniques for control of particulate emissions from sinter
plants. NEFC [C-3] report the following collection efficiencies for sinter
plant control techniques.
Windbox:
Dry cyclone collection eff. = 90%
Electrostatic precipitator eff, = 95%
(in series with dry cyclone collection)
Discharge:
Dry cyclone collection eff. = 93%
Private conversations with steel industry representatives [C-6]
indicate that all current sinter plants are controlled. This is confirmed
by the Midwest Research Institute report on particulate emissions £C-7].
c. Estimation of Emissions
(1) Base Year - 1970. American Iron and Steel (AISI)
Statistical Report for 1970 £C-8] indicate that sinter production in 1970
C-3 WALDEN RESEARCH CORPORATION
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(Table 47 in Reference 8) was 45.6 x 10 tons/yr. Thus, assuming con-
servatively that collection efficiencies in sinter plants were 90%, the
following emissions (after controls) are produced:
45.6 x 106
(2) Projections to 1975 and 1980. Estimation of emis-
sions for 1975 and 1980 requires estimates of sinter production for
these years.
Battell e [C-2] reports, as shown in Table C-l below,
the physical form of iron ore consumed in the U.S. and estimates to 1980.
These data can be used to project sinter production to 1975 and 1980 pro-
vided a procedure for estimating the total sinter production (as opposed
to the sinter produced only from iron ore as quoted in Table C-l) can be
determined.
Of course, by far the largest fraction of agglom-
erated products (sinter and pellets) is produced from ore fines and this
is shown below in Table C-2 taken from the AISI Statistical Reports [C-8],
Using the data of Table C-2, the following fraction
was determined:
E other materials (i.e., flue dust and sludge and scale)
_ _^^^___^ _
s ore fines and concentrates
F is plotted against time in Figure C-l, from which
it appears that F has been fairly constant over the past few years. It
will be assumed that this value of 0.075 will hold constant to 1975 and
1980.
It should be noted that F is based on AISI figures
for the total amount of material used to produce both sinter and pellets.
(However, it is assumed that since pellet plants are generally away from
the steel mills, that all the additional material goes to producing
C-4
WALDEN RESEARCH CORPORATION
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o
en
0
a
m
m
c/)
o
:r
o
o
?}
-o
o
X)
TABLE C-1
PHYSICAL FORM OF IRON ORE CONSUMED IN THE U.S. AND ESTIMATES TO 1980
Lump Ore
Year TO6 tons %
1960
1967
1975
1980
alncludes
62.0
46.7
31.7
34.9
only
54.1
35.3
20.0
19.5
iron ore used
Sinter3
106 tons %
41.5
42.2
46.0
48.3
for making
36.3
31.9
29.0
27.0
sinter
Pellets
TO6 tons %
11.0 9.6
43.4 32.8
80.8 51.0
95.8 53.5
Total
106 tons %
114.5
132.3
158.5
179.0
100.0
100.0
100.0
100.0
-------
TABLE C-2
MATERIALS USED IN PRODUCING AGGLOMERATED PRODUCTS (SINTER AND PELLETS)
(Net tons)
0
1
5
r~
O
m
70
m
in
rn
>
3J
o
CORPORA"
Materials Used:
Ore fines and
concentrates
Flue dust and sludge
Scale
Coke breeze
Coal
Cinder and slag
Limestone and
dolomite
Other
Total Materials Used
1970
92,734,970
3,228,350
3,695,427
2,266,675
464,359
625,231
8,430,560
1,645,015
113,090,587
1969
94,349,152
3,452,802
3,720,456
2,290,189
622,660
768,477
8,799,262
1,755,295
115,758,293
1968
92,396,601
3,455,426
3,544,342
2,247,994
747,819
466,682
8,512,911
1,979,162
113,350,937
1967
88,560,907
4,131,686
3,431,559
2,309,236
819,052
329,502
7,929,735
1,976,898
109,488,575
1966
89,542,769
4,661,915
3,287,503
2,486,341
896,969
332,889
7,903,032
1 ,591 ,862
110,703,280
1965
79,289,827
4,965,958
2,938,674
2,439,288
966,014
406,995
6,661,494
1,274,071
98,942,321
1964
79,928,246
5,136,601
2,510,242
2,709,256
1,014,343
445,453
6,623,558
933,560
99,301,259
o
z
-------
0-1
0-09-
Fs
0.08-
0.07-
O.Gb-
»
1
f
i
I
I
1
i
i
S
1
1
'
1964 1965 1966 1967 1968 1969 1970
YEAR
FIGURE C-l. PLOT OF F$ VERSUS YEAR
C-7
-------
sinter.) Thus, using the figures of Table C-l , the total sinter production
for 1975 and 1980 is:
1975
[46.0 + (46.0 + 80.8) x 0.075] x 106 T/yr = 55.5 x 106 T/yr
1980
[48.3 + (48.3 + 95.8) x 0.075] x 106 T/yr = 59.1 x 106 T/yr
Controlled emissions are, therefore:
1975
55.5 x 106 x 2^0" * 0 - 0.9) T/yr = 1.17 x 105 T/yr
1980
59.1 x 106 x x 0 - 0.9) T/yr = 1 .24 x 105 T/yr
2. Pellet Manufacture
In contrast to sintering plants that are usually located near
the blast furnace plant (because sinter does not withstand shipment with-
out degrading), pellet plants are usually located near the ore mine (or
within several hundred miles of the mine). The pellets which are strong,
are often shipped hundreds or thousands of miles to blast furnace plants.
Battelle [C-2] indicates that only very low emissions result
from pellet production and that these emissions are effectively knocked
out by simple cyclones.
3. Coke Manufacture
Metallurgical coke is the major fuel and reducing agent used
in the production of pig iron. Coke is produced from coal by distillation
of the volatile matter. Two types of coke ovens are employed for pro-
ducing coke: (1) the beehive oven and (2) the by-product oven. By far
the largest amount of coke is produced via the by-product oven process.
WALDEN RESEARCH CORPORATION
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In the by-product oven process, coal is heated in the absence
of air. The gaseous products that are evolved are removed from the oven
and stripped of any condensible or absorbable product (tar, ammonia liquor,
light oil) in a by-product plant. The remaining gas is then utilized in
the plant as a high heating value fuel. The process is batch, and neces-
sitates coal charging to the ovens and subsequent quenching of the hot
coke after a 16 to 20 hr carbonizing period.
The coke plants emit both particulate materials and offensive
gases in the normal course of operation. The particulates are mainly coal
and coke dust that become airborne during handling, discharging and quench-
ing of the coke. The gases are mainly mixtures of ammonia and aromatic
vapors that escape from the ovens and the by-product system.
a. Uncontrolled Emission Factors
Table C-3 below is reproduced from NEFC [C-5] and sum-
marizes the uncontrolled emission factors for metallurgical coke manufacture.
b. Control
Control of coke plant emissions generated in a coke plant
is difficult because of the nature of the process and the great amount of
material handling that is required.
At present, no effective controls are utilized in coke
plants [C-7], although new installations are utilizing techniques such as
underground reclaiming to reduce handling emissions. Furthermore, some
success has been demonstrated with the use of baffles to reduce quench
emissions to one quarter of their original value [C-2].
Many of the above types of improvements, however, can
only be installed in new plants and, as such, will be slow in being
implemented.
c. Estimation of Emissions
(1) Base Year - 1970. AISI [C-8] statistics indicate the
following tons of coal used in production of coke = 87.2 x 10
WALDEN RESEARCH CORPORATION
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TABLE C-3
UNCONTROLLED EMISSION FACTORS FOR METALLURGICAL COKE MANUFACTURE0
o
I
By-Product Coking
Unloading
Charging
Coking Cycle
Discharging
Quenching
Particulates
0.4
1.5
0.1
0.6
0.9
Sulfur3 Carbon
Dioxide Monoxide
___
0.02 0.6
0.6
0.07
Hydrocarbons
2.5
1.5
0.2
Nitrogen0
Oxides Ammonia
0.03 0.02
0.01 0.06
0.1
Underfiring
Beehive Ovens
10
200
o
m
z
70
m
in
73
O
8
XI
-o
o
73
5
o
z
so2
^Expressed as methane
:N09
J
Reference 3
-------
.'. Particulate emissions = 87.2 x 106 x IfJL T/yr
= 1.52 x 105 T/yr
(2) Estimation of Emissions to 1975 and 1980. Coke
oven participate emissions are determined by the coke production rate,
which, in turn, is controlled by pig iron requirements and changes in
blast furnace technology. Consequently, several factors must be con-
sidered in estimating future coke oven emissions.
The average coke rate, defined as pounds of coke/
ton of pig iron, has been continually decreasing as is shown in Figure C-2
(calculated from AISI [C-8.C-9] data). Indeed, Ramm [C-10] and Nakatani,
et al. [C-11] have shown that it should be possible to reduce the coke rate
to about 840 Ib (ideally) per net ton of hot metal by the use of improved
burden materials, injection of auxiliary fuels (such as oil and natural
gas) and the use of very high blast temperatures.
Based on extrapolations of the average coke rate
(Figure C-2), the following coke rates were obtained:
1975
Coke rate: 1175 Ib coke/T pig iron
1980
Coke rate: 1100 Ib coke/T pig iron
However, the actual data in Figure C-2 only covers
the years 1958 to 1970 during which time little auxiliary fuel injection
was employed. It will be shown in Section II of this appendix that by
1975 about 30 Ib of fuel oil and natural gas/T pig iron and by 1980 about
80 Ib of fuel and natural/T pig iron will be used in the blast furnace.
Since, to a first approximation (see Figure A-5 in Ref. C-2], a Ib of
oil injected will result in a Ib reduction in the coke rate, this means
that the actual coke rates should be adjusted to:
WALDEN RESEARCH CORPORATION
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1600
1500
1400
1300
UJ
O
o
-q 1200
o
or
a.
o
ui
H
<*
LJ
*:
o
o
a:
w
noo
1000
900
800
I
1956 I960
1965
T rx r 14 n'
YEAR
1970
1975
I960
FIGURE C-2
r a A T r i j
r\ r- n i i c r ten r >r i j o 7 f-i f" 7" --.
-------
1975
1145 1b coke/T pig iron
1980
1020 Ib coke/T pig iron
Finally, before estimating emissions, it is neces-
sary to determine the tons of coal used per ton of coke produced. (Emis
sion factors in Table C-3 are based on tons of coal charged.) Table C-4
summarizes data extracted from the AISI statistical report [C-8,C-9].
No obvious trend is discernable and, consequently,
an average of 1.45 tons coal /ton coke will be utilized in any further
calculations.
Table C-5 presents projected pig iron requirements
for the U.S. to 1980 [C-2].
.'. Uncontrolled emissions are:
1975
106.8 x 106 x - x 1 .45 x = 155,000 T/yr
1980
122.4 x 106 x x 1.45 x - = 159,000 T/yr
As indicated earlier, it is difficult to estimate the
amount of controls likely to be installed by 1980 and, as such, any esti-
mates of the controlled emissions would at present be speculative.
4. Blast Furnaces
Pig iron is produced by reducing iron ores in a blast fur-
nace. Iron ore, fluxes and coke are charged into the top of the furnace
through two or three seals that serve to limit leakage of gas at this
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TABLE C-4
CALCULATION OF TONS OF COAL REQUIRED PER TON OF COKE
Pig Iron
106 T
1970
1
1
1
1
1
1
1
1
1
969
968
967
966
965
964
963
962
961
Year
1
1
1
1
960
967
975
980
91
95
88
86
91
88
85
71
65
64
PIG
Raw
.43
.02
.78
.98
.50
.18
.60
.84
.64
.63
IRON
Steel
(TO6
Coke Rate Coal Used For Tons Coal
T/T Pig Iron Coke Production Ton Coke
.63
.626
.624
.631
.641
.656
.655
.669
.690
.708
TABLE C-5
REQUIREMENTS FOR THE U.S.
AND PROJECTIONS TO 1
87.
84.
81.
82.
85.
83.
78.
67.
66.
65.
IN
980
Production Apparent
tons)
99.3
127.2
1
1
57.0
80.0
21
06
24
70
52
93
70
93
00
03
1960
Pig
(106
66
87
106
122
1
1
1
1
1
1
1
1
1
1
AND 1967
.52
.42
.47
.50
.46
.45
.40
.42
.46
.43
Iron Consumption
tons)
.5
.0
.8
.4
C-14
WALDEN RESEARCH CORPORATION
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point; preheated air (sometimes with oil, gas, oxygen or steam) is forced
through ports near the bottom of the furnace. The incoming air reacts
with the hot coke to produce a reducing gas mixture rich in FL and CO
which reacts with the iron ore producing pig iron.
a. Uncontrolled Emission Factors
Emissions from the blast furnace occur during charging of
the reactants and removal of the products and blast furnace gas.
Estimates of the emissions resulting from raw material
handling and fume and kish particles evolved during product removal are
not known. Similarly, the emissions produced during the occasional
"slips" have not been reported. However, it is generally conceded that
these emissions are relatively minor compared to the dust evolved with
the blast furnace gas.
The particulate loadings in blast furnace gas is depen-
dent on the type of charge used in the blast furnace. NEFC tC-3] quote
the following uncontrolled emission factors:
Ore charge: 110 Ib dust/ton of pig iron
Agglomerates charge: 40 Ib dust/ton of pig iron
These numbers are in substantial agreement with those quoted by
Battelle [C-2].
b. Control
Blast furnace gas is cleaned so that it can be used as a
fuel in the blast furnace stoves and elsewhere. Since the blast furnace
stoves are of the regenerative checker type, dust loadings of about 0.01
grains/SCF are presently required [C-12] for efficient thermal utilization,
and future high temperature blast furnace operations will require dust
loadings of not greater than 0.001 grains/SCF. Consequently, the major-
ity of blast furnaces have preliminary, primary and secondary cleaning
equipment with the following typical collection efficiencies (from NEFC [C-3]):
-l5 WALDEN RESEARCH CORPORATION
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Type Efficiency
1. Preliminary cleaning - 60%
settling chambers or dry
cyclones
2. Primary cleaning - gas 90%
washers and wet scrubbing
3. Secondary cleaning - 90%
electrostatic precipitator
or high energy washers
Because the blast furnace gas produced, even after clean-
ing, is not emitted directly to the atmosphere (but is burnt), there is,
except for losses of the gas, little actual particulate emissions from
the blast furnace "process". However, since upon combustion, blast fur-
nace gas emits the particulates it obtained during the blast furnace
operation, these particulate loadings will be estimated here.
c. Estimation of "Emissions"
(1) Base Year - 1970. Both ore and agglomerates are
presently charged to blast furnaces. In order to estimate emissions fac-
tors for mixed charges, the following linear relationship will be used:
F = a X + b
where F = emission factor Ib dust/ton pig iron
X = fraction of charge that is ore ore
ore + agglomerates
Based on earlier quoted emission factors then
b = 40, a = 70
.'. F = 70X + 40
It should be pointed out that this assumption of linearity is verified
approximately by data quoted by Battelle (Figure C-25 in Ref. C-2).
From the AISI Statistical Report IC-8J, the following
materials were used by blast furnaces in the manufacture of pig iron in 1970:
C-16 WALDEN RESEARCH CORPORATION
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Iron ore; 38.19 x 106 tons
Agglomerates: 109.00 x 106 tons
Y = 38.19
109.00 + 38.19 >
. . F = 70 x 0.26 + 40 = 68.2 Ib dust/ton pig iron
Uncontrolled dust loadings in blast furnace gas:
x 91 .43 x 106 = 3.14 x 105 T/yr
pig iron production 1970 [C-8]
. . Controlled dust loadings in blast furnace gas:
3.14 x 106 x (1 - 0.6) (1 - 0.9) (1 - 0.9)
Preliminary Primary Secondary
= 1.26 x 104 T/yr
(2) Estimation of "Emissions" for 1975 and 1980. The
following sinter productions for 1975 and 1980 were estimated earlier
on page C-3).
1975
1980
55.5 x 106 T/yr
59.1 x 106 T/yr
Then using the data from Table C-l:
1975
J I . /_ r, -1
" UlI
A 31.7 + 55.5 + 80.8
. . F = 53.2 Ib dust/ton pig iron
C-17
VVALDEN RESEARCH CORPORATION
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1980
34,9
- fi 1
34.9 + 59.1 + 95.8 ~ u>l
. . F = 52.9 Ib dust/ton pig iron
Thus, using the pig iron estimates quoted in Table C-5,
the following uncontrolled and controlled dust loadings in the blast fur-
nace g s can be calculated:
1975
Uncontrolled: fggg-x 106.8 x 106 T/yr
= 2.85 x 106 T/yr
Controlled: 2.85 x 106 x (1-0.6)(1-0.9)(1-0.9)
= 1.14 x 104 T/yr
1980
Uncontrolled: f§g§-x 122.4 x 106 T/yr
= 3.24 x 106 T/yr
Controlled: 3.24 x 106 x (1-0.6)0-0.9)0-0.9)
= 1.3 x 104 T/yr
5. Steel making
a. Open Hearth Furnaces
Open hearth steel is made usually from a mixture of scrap
and pig iron. The objective of the operation is to lower the impurities
present in the scrap and pig iron, which consist of carbon, manganese,
silicon, sulfur, and phosphorous. The refining operation is carried out
by means of slag that forms a continuous layer on the surface of the
C-18 WALDEN RESEARCH CORPORATION
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liquid metal. The operation is a batch one and is comprised of several
phases, namely, charging, melt down, hot metal addition, ore and lime
boil, refining and tapping. The entire process takes about 100 hours
from start to finish.
Particulate and gaseous emissions from the open hearth
process originates from (1) the physical action of the flame on charged
materials and the resulting pickup of fines, (2) the chemical reactions
in the bath, (3) the agitation of the bath, and (4) the combustion of
fuel. The emissions include SOp, COp, CO, fly ash from fuels and iron
oxide and other metallurgical fumes. The amount of emissions vary ac-
cording to the stage of the process and according to practice. Recent
use of oxygen lancing in open hearth furnaces has resulted in more par-
ticulate emissions than previous practice without lancing.
(1) Uncontrolled Emissions Factors. NEFC [C-3] quote
the following particulate emission factors:
Open hearth furnace with
oxygen lancing 22 Ib dust/ton pig iron
Open hearth furnace with
no_ oxygen lancing 12 Ib dust/ton pig iron
(2) Controls. The open hearth furnace is one of the
more significant polluters in the iron and steel industry. This is the
result of lack of effective controls on many installations and the ad-
vent of oxygen lancing. The open hearth furnaces operated without the
use of oxygen lances are themselves fairly efficient dust collectors be-
cause of the auxiliary units needed to achieve efficient operation. But
even so, significant emissions result.
Electrostatic precipitators have been the principle
choice for emission control although venturi scrubbers and bag houses
have also been used. The NEFC [C-3] quote the following collection effi-
ciencies for the above control techniques when applied to open hearth
furnaces:
C-19
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Type
Electrostatic precipitator
Venturi scrubber
Bag house
Efficiency
98%
85-98%
99%
However, the fraction of open hearths under control
is a major unanswered question in estimating emissions. Schueneman [C-4]
indicated that in March 1961 only 7.8% of the annual open hearth steel
producing capacity of 9.9 x 10 tons/yr which were controlled (98% of this
capacity used electrostatic precipitators; the rest, venturi scrubbing).
However, control equipment for a further 9.1 x 10 tons/yr of open hearth
steel capacity was under construction or to be installed, as of March
1961 (all using electrostatic precipitators).
Table C-6 extracted from Battelle £C-2] shows pro-
duction of raw steel in the U.S. by type of furnace and projections of
production to 1980.
Based on the figures presented in Table C-6, it is
possible to estimate limits on the fraction of open hearth furnaces that
have emission controls.
TABLE C-6
PRODUCTION OF RAW STEEL IN THE U.S. BY TYPE OF FURNACE
AND PROJECTIONS TO 1980
Year
1960
1967
1975
1980
Open Hearth
(103 tons)
86,368
70,690
44,000
36,000
Basic Oxygen
Bessimer Furnace
(103 tons) (103 tons)
1,189 3,346
41 ,434
80,000
99,000
Electric
Furnace
(103 tons)
8,379
15,089
33,000
45,000
Total
OO3 tons)
99,282
127,213
157,000
180,000
C-20
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In making these estimates, it will be assumed that by
1980 all open hearth furnaces operating will have emission controls.
Thus, assuming that at least controls will be operating
on 19 x 10 T/yr of open hearth capacity [9.1 x 106 + 9.9 x 10 T/yr from
Ref. C-4] by 1967, the following limits can be calculated:
1967
I y _ ri nr
Minimum fraction controlled = jr '
Maximum fraction controlled = yr = 0-51
1975
1 9
Minimum fraction controlled = -^ = 0.43
Maximum fraction controlled = |l- = 0.82
1980
Fraction controlled = f| = 1.00
Jo
Conversations with iron and steel industry representa-
tives [C-14] indicates that at present (1971), probably about 50% of the
open hearths have emission control equipment. Furthermore, the data of
the Midwest Research Institute [C-7] indicate that in 1970, 41% of the
open hearth furnaces were controlled. Both of these data verify the
limit calculations presented earlier.
Thus, in estimation of emissions, the following aver-
ages of the previously calculated limits will be used:
1967
Fraction controlled: 0.38
1970
Fraction controlled: 0.41 (from Ref. C-7)
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1975
Fraction controlled: 0.62
1980
Fraction controlled: 1.00
(3) Estimation of Emissions
(a) Base Year - 1970. From AISI Statistical
Report f.C-8], the open hearth raw steel production for 1970 was 48.0 x 106
tons/yr.
Estimation of emissions necessitates knowledge
of the fraction of the open hearth furnaces using oxygen lancing. Since
no data on this number could be found, two emission limits will be cal-
culated: the first will consider all the furnaces have no oxygen lancing
and the second will be calculated for the case where all the furnaces have
oxygen lancing.
In all cases, it will be assumed that furnaces
with control use electrostatic precipitators with collection efficiencies
of 98%.
Minimum Emissions
48.0 x 106 x £°-41 x (1-0-98)] + (1-0.41)
= 1.70 x 10 tons/yr
Maximum Emissions
1.70 x 105 x tons/yr
= 3.12 x 105 tons/yr
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(b) Estimation of Emissions for 1975 and 1980
1975
Minimum Emissions
44.0 x 106 x 2^10.62 x (1-0.98) + (1-0.62)]
= 1.03 x 105 tons/yr
Maximum Emissions
= 1.03 x 105 x tons/yr
= 1.89 x 10 tons/yr
1980
Minimum Emissions
36.0 x 106 x 2Q-QQ- x (1-0.98)
= 4.32 x 103 tons/yr
Maximum Emissions
4.32 x 103 x || tons/yr
= 7.9 x 103 tons/yr
b. Basic Oxygen Furnace (EOF)
More and more open hearth furnaces are being replaced by
basic oxygen furnaces. These furnaces have the considerable advantage in
that they require much less time to refine the steel and no external heat
has to be supplied as in the open hearth furnace. The EOF is pear shaped
and a water cooled lance is used to supply high purity oxygen at high
velocity to the surface of the metal bath. The high velocity oxygen im-
pinging on the metal surface produces violent agitation and results in
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rapid oxidation of the dissolved carbon silicon and manganese thus pro-
ducing steel. The rapid oxidation reactions supply a considerable quan-
tity of the heat required for refining.
The predominant particulate emission is brown iron oxide
and the only gas of concern is CO. A predominance of submicron sizes in
the oxide dust makes it especially difficult to trap and collect.
(1) Uncontrolled Emission Factors. The NEFC [C-3J quote
uncontrolled emission factors for the BOF as 46 Ib dust/ton steel pro-
duced. These figures are in substantial agreement with data of Massobrio
and Santini [C-16] in Europe (19.6 to 46.6 Ib dust/ton steel) and the
data of Battelle [C-2] for emissions from U.S. furnaces (40 Ib dust/ton
steel).
(2) Controls. Since the BOF has only been in use in the
iron and steel industry since 1952, most of the furnaces are controlled
by either venturi scrubbers or electrostatic precipitators (of collection
efficiency ^98%). The data of the Midwest Research Institute [C-7] con-
firm that all BOF's have controls.
(3) Estimation of Emissions
(a) Base Year - 1970. From the AISI Statistical
Report £C-8] 63.3 x 10 tons/year of steel were produced via basic oxygen
furnaces.
Controlled Emissions
= 63.3 x 105 x Tj x (1-0.98) tons/yr
= 2.82 x 104 tons/yr
(b) Estimation of Emissions for 1975 and 1980. From
Table C-6, the steel produced in the BOF for 1975 and 1980 are:
1975
80.0 x 106 tons/yr
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1980
99.0 x TO6 tons/yr
. . Emissions are:
1975
80.0 x 106 x X (1-0.98)
1980
= 3.56 x 10 tons/yr
4.60 x 104 tons/yr
c. Electric Arc Furnaces
Electric furnaces utilize electrical energy for heating.
Thus, they are extremely versatile and can produce steel from charges
consisting of only cold metal. Oxygen lancing is also frequently used
in electric furnaces.
Emissions generated during electric furnace steel making
originate from the type of scrap used, the nature of the melting opera-
tion and oxygen lancing.
(1) Uncontrolled Emission Factors. Figure C-3 below,
reproduced from Battelle (Figure C-62 in Ref. C-2), shows reported dust
emissions for 22 operations using various combinations of normal scrap
(scrap with little to moderate rust), dirty scrap (scrap with heavy rust),
and oxygen lancing. The effect of type of scrap, nature of the melting
operation and oxygen lancing are clearly evident.
The emission factors quoted in NEFC [C-3] for
electric furnaces are:
Electric furnaces with
oxygen lancing 11 Ib dust/ton of steel
Electric furnaces with
no oxygen lancing 7 Ib dust/ton of steel
C-25
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FURNACE CAPACITY, net tons-
10 40 50 ' 75
CO
20
UJ
UJ
t-
o
:z
O
h-
(-
LU
K.
LJ
Q.
Q
O 15
a
O
- 10
UJ
Z)
Q
0
\\^ i I r
9 NORMAL SCRAP -V/ITH OXYGEN LANCING
O 'NORMAL SCRAP -NO OXYGEN LANCING
Q DIRTY SCRAP"-NO OXYGEN LANCING
o/
O
a
I
I
0
5 10 15 20 25
MELTING RATE^ net tons per hour
30
FIGURE C-3 DUST EMISSIONS DURING ELECTR 1C , FURNACE
MELTING OF'STEEL
C-26
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Comparison with Figure C-3 indicates that these emis-
sion factors are for furnaces of about 50 to 75 tons capacity. Since the
trend in new electric furnaces is towards larger and larger furnaces (the
largest installations to date are a 200 ton direct arc electric at Laclede
Steel Co., Alton, 111.; four 200 ton furnaces at the Republic Steel Corp.,
Canton, Ohio, and a 250 ton furnace at Northwestern Steel and Wire Co.
which was placed in operation in early 1969), the quoted emission factors
in NEFC £C-3] may be in error for estimating emissions from future instal-
lations.
(2) Control. Control of emissions from electric steel -
making furnaces are affected by whether the furnace is a movable roof top
charging furnace or a fixed roof door charging furnace.
Emissions from the electric furnaces are controlled
and collected by three main types of systems: (1) collection of emissions
by the use of hoods over and around the furnace at points of emission,
(2) direct extraction from the furnace interior, and (3) shop roof ex-
traction and collection.
The particulates are removed by the use of high ef-
ficiency scrubbers, electrostatic precipitators and bag houses. NEFC [C-3]
quote the following collection efficiencies when these systems are used
on electric furnaces:
Type Efficiency
High efficiency scrubber up to 98%
Electrostatic precipitators 92-97%
Bag houses 98-99%
Midwest Research Institute IC-7] indicates that at
present 79% of all electric arc furnaces have controls.
However, no data could be found on the fraction of elec-
tric arc furnaces that use oxygen lancing.
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(3) Estimation of Emissions
(a) Base Year - 1970. 20.16 x 106 tons of steel were
produced via the electric arc process in 1970 [C-8].
In calculating emissions it will be assumed that
all the furnaces were oxygen lanced (i.e., a conservative answer will be
obtained); and that the average collection efficiency of the control method
is 95%.
.'. Emissions = 20.16 x 106 x - [0.79 (1-0.95) + (1-0.79)]
= 2.76 x 104 tons/yr
(b) Estimation of Emissions in 1975 and 1980. From
Table C-6, the steel produced in the electric arc furnace in 1975 and 1980
is:
1975
1980
33.0 x 106 tons
45.0 x 106 tons
Assuming that all furnaces are controlled by 1975
and that the average furnace capacity has increased to about 100 tons by
1975 (so that the emission factor is 18 Ib dust/ton product), the following
emissions can be determined:
1975
Emissions: 33.0 x 106 x - (1-0.95)
1980
n
= 1.49 x 10 tons/yr
Emissions: 45.0 x 106 x - (1-0.95)
2.04 x 104 tons/yr
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6. Scarfing
Scarfing is the term applied to the process of removing blem-
ishes from the solid shapes (billets, blooms, slabs) into which molten
steel is formed.
Fairly extensive participate emissions result during the
processing although a significant fraction of this emission is now con-
trolled.
a. Uncontrolled Emission Factors
Little data are available on scarfing particulate emis-
sion factors. However, both Schueneman, et al . [C-4J and NEFC £C-3] in-
dicate that about 3 Ib of dust is produced per ton of steel processed.
b. Control
Only the data of the Midwest Research Institute [C-7]
could be found on controls used for the prevention of particulate emis-
sions from scarfing operations. They indicate that presently 75% of
all scarfing machines are controlled with precipitators of about 90%
average collection efficiency.
c. Estimation of Emissions
It will be assumed for estimating emissions that all
steel produced is scarfed.
(1) Base Year 1970 - From AISI Statistical Report [C-8]
the total steel production for 1970 was 131.0 x 10 tons.
.'. Controlled emissions
= 131.0 x 106 x X [0-0.9) x 0.75 - (1-0.75)]
= 63,000 tons
(2) Estimation of Emissions for 1975 and 1980. Table
C-5 indicates projected raw steel production for 1975 and 1980. Using
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these figures and assuming that the fraction of scarfing machines controlled
remains the same as in 1970, the following emissions can be calculated:
1975
||y- x 63,000 = 73,600 tons
1980
x 63,000 = 86,500 tons
B. SULFUR OXIDE EMISSIONS
Fuels required to carry out the various processes in the making
of iron and steel constitute the major source of sulfur. By far, most
cf this sulfur originates in the coal used to make the coke that is a
vital requirement for operation of the blast furnace. However, fuel oil
and iron ore also contain sulfur and, as such, contribute to sulfur oxide
emissions.
Fortunately, however, most of present day steel technology calls
for operations under basic conditions (these result from the addition of
lime and limestone, etc., as fluxes). Consequently, a significant frac-
tion of the sulfur which enters a steel mill via the raw materials is
removed with the slag and thus does not form an air pollutant. Battelle [C-2]
has produced a comprehensive and thorough description of the fate of sulfur
during the iron and steel plant processing, and it from their calculations
that a significant fraction of the following material is taken.
At this point, only air pollution sulfur emissions that are pro-
duced as a result of the actual process operation (as opposed to sulfur
emissions that result from fuel combustion associated with the particular
process under consideration) will be considered. Thus, in many cases
processes which result in no process sulfur air pollution emissions will
be glossed over lightly.
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1. Process Sulfur Air Pollution Emission Factors
a. Sinter Plants
Sulfur enters sinter plants via the iron bearing materials,
coke, oil, and limestone and leaves in the sinter fines and combustion
gases.
Table C-7 shows a sulfur balance for sintering machine
operation [C-2].
It should be pointed out, however, that Schueneman [C-4]
indicates that 71% of the sulfur in the raw materials is carried up the
stack in sintering operations (as opposed to the 36% shown above from
Ref. C-2).
Thus, process sulfur air pollution emission factor = 0.71
Ib sulfur/ton sinter.
b. Coke Manufacture
Sulfur enters coke ovens via the coal and leaves with the
coke breeze, by-products and coke oven gas. Thus, effectively, no air
pollution sulfur emissions are produced during the coke manufacture.
c. Blast Furnaces
Sulfur enters the blast furnace from practically all of
the raw materials used for making iron; the major source being the sulfur
in the coke. Because of the reducing and basic conditions in the blast
furnace no sulfur leaves the furnace as sulfur dioxide, instead it is
carried out as reduced compounds in the slag.
d. Steelmaking
(1) Open Hearth Furnaces. Sulfur enters the open hearth
furnace with most of the added raw materials and leaves in the steel and
scrap, slag and combustion gases. About 47% of the sulfur entering the
open hearth system leaves in the metal and slag; the remainder leaves as
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TABLE C-7
SULFUR BALANCE FOR SINTERING MACHINE OPERATION
(Based on production of one net ton of sinter)
Item
Iron bearing material
Coke
Oil
Limestone
Sinter
Sinter fines
Sulfur in combustion
gases
Amount
Pounds
2,200
100
50
200
2,000
289
Sulfur
Content
Input
0.041
0.70
0.55
0.049
Output
0.055
0.055
Amount of
% Sulfur Pounds
0.90
0.70
0.27
0.10
TOTAL 1.97
1.10
0.16
0.71
TOTAL 1.97
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S02- A sulfur balance for an open hearth furnace using 60% hot metal and
40% steel scrap is given in Table C-8.
. . Process sulfur air pollution emission factor = 0.70 Ib sulfur/ton of
steel.
(2) Basic Oxygen Furnaces. A sulfur balance for a EOF
practice using 70% hot metal and 30% steel scrap is given in Table C-9.
Almost all the sulfur leaves the system in the metal and slag with only
about 4% of the sulfur leaving as SOp in the off gas. Battelle [C-2]
indicates that there is no detailed information available in the litera-
ture on the sulfur content of BOF off gases.
(3) Electric Furnace. Like the BOF process, the electric
furnace steelmaking process does not depend on a sulfur bearing fuel as
the major source of energy. However, sulfur enters the system via the
steelmaking raw materials but a considerable fraction of this sulfur is
removed in the slag. A sulfur balance for an electric furnace is given
in Table C-10.
e. Controls
At present, no controls exist for sulfur air pollution
emissions.
2. Estimation of S0? Emissions
In all cases (i.e., both for the base year and the pro-
jections to 1975 and 1980) only the uncontrolled SOp emissions will be
estimated. Whereas this is correct for the present, it may be in error
in the calculations for future years.
(1) Base Year - 1970. From the AISI Statistical Report [C-8]
the following 1970 productions can be obtained:
Sinter production 45.61 x 10 tons
Open hearth production 48.02 x 10 tons
BOF production 63.33 x 10 tons
Electric furnace production 20.16 x 10 tons
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TABLE C-8
SULFUR BALANCE FOR OPEN HEARTH FURNACE WITH 60% HOT METAL
AND 40% STEEL SCRAP WITH OXYGEN LANCING
(Based on production of one ton of raw steel)
Item
Hot metal
Steel scrap
Iron ore
Flux
Fuel oil
Ferro alloys
Steel and scrap
Slag
Combustion gases
Amount
Pounds
,361
907
70
150
111
14
2,060
200
Sulfur
Content %
Input
0.030
0.020
0.040
0.049
0.55
0.07
Output
0.02
0.10
Amount of
Sulfur Pounds
0.41
0.18
0.03
0.07
0.61
0.01
TOTAL 1.31
0.41
0.20
0.70
TOTAL 1.31
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TABLE C-9
SULFUR BALANCE FOR EOF STEELMAKING WITH
70% HOT METAL AND 30% SCRAP
(Based on the production of one net ton of steel)
Item
Hot metal
Steel scrap
Burnt lime
Ferro alloys
Steel and scrap
Slag
Sulfur in off
gases
Amount
Pounds
1,581
678
142
14
2,077
263
Sulfur
Content %
Input
0.030
0.020
0.060
0.070
Output
0.020
0.100
Amount of
Sulfur Pounds
0.47
0.14
0.08
0.01
TOTAL 0.70
0.41
0.26
0.03
TOTAL 0.70
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TABLE C-10
SULFUR BALANCE FOR AN ELECTRIC FURNACE USING A CHARGE OF COLD
STEEL SCRAP AND OXYGEN LANCING
(Based on the production of one ton of steel)
Item
Steel scrap
Coke breeze
Burnt lime
Ferro alloys
Amount
Pounds
2,136
6
99
14
Sulfur
Content %
Input
0.020
0.700
0.060
0.070
Amount of
Sulfur Pounds
0.43
0.04
0.06
TOTAL 0.54
Steel and scrap
Slag
Off gas
2,060
140
Output
0.020
0.080
TOTAL
0.42
0.11
0.01
0.54
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. . S0? emissions are:
TO3 [45.61 x 0.71 + 48.02 x 0.70 + 63.33 x 0.03 + 20.16 x 0.01] tons/yr
= 68.1 x 103 tons/yr
(2) Projected SO., Process Emissions for 1975 and 1980.
From previous calculations on sinter plant (Section A.I) and Table C-6,
the following data are obtained:
1975
Sinter production 55.5 x 10 tons
Open hearth production 44.0 x 10 tons
BOF production 80.0 x 106 tons
Electric furnace production 33.0 x 10 tons
1980
Sinter production 59.1 x 10 tons
Open hearth production 36.0 x 10 tons
BOF production 99.0 x 10 tons
Electric furnace production 45.0 x 10 tons
.'. 1975 S02 emissions:
103 [55.5 x 0.71 + 44.0 x 0.70 + 80.0 x 0.03 + 33.0 x 0.01]
= 73.0 x 103 tons/yr
1980 S02 emissions:
103 [59.1 x 0.71 + 36.0 x 0.7 + 99 x 0.03 + 45.0 x 0.01]
= 80.0 x 10 tons/yr
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C. NITROGEN OXIDE EMISSIONS
Once again, as was done in estimating sulfur oxide emissions, only
nitrogen oxide emissions that result from the actual process under con-
sideration will be considered in this section. Thus, for example, the
NO produced from combustion of blast furnace gas in the blast furnace
A
stoves is a fuel combustion source (even though it is associated with
the blast furnace) and, as such, will not be considered here.
The literature is sparse in NO emission data taken on processes
X
in the iron and steel industry. Most of the data quoted in this section
have been extracted from Esso's System Study on NO emissions IC-16]
A
(Section 3.1.3.4 - Metallurgical Processes). Perusal of NO emission data
A
indicate that only the open hearth furnace and sintering plants produce
"process" NO air pollution emissions.
A
1. Uncontrolled Emission Factors
a. Open Hearth Furnace
1970 fuel figures indicate that 3.x 10 Btu of fuel are
required/T of steel produced in an open hearth. This agrees with Esso's
estimate [C-16J. Furthermore, the average open hearth furnace steel
batch is 200 tons in size and the batch is heated over a period averaging
10 hours £C- 2]. It will be assumed these averages apply also in the
years 1975 and 1980.
.'. Average combustion rate = 3.2 x 10 x 200 Btu/hr
= 64 x 106 Btu/hr
Using emissions of oxides of nitrogen from stationary sources in Los
Angeles County [C-17], the following Ibs NO are emitted in the production
A
of a 200 ton batch of steel:
Fuel Ibs NO/200 Tons Steel
A
Fuel oil and tar 250
Natural gas and
coke oven gas 150
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b. Sinter Plants
1.04 Ib N0x/ton sinter [C-16]
2. Controls
No controls are currently employed to reduce NO emissions.
X
It will further be assumed that no controls are available even in 1980.
3. Estimation of NO Emissions
A - - ------- -
a. Base Year - 1970
Open hearth production [C-8]: 48 x 10 tons
Sinter production [C-8]: 45.6 x 10 tons
Fractional fuel consumption in open hearths:
Fuel oil and tar and pitch: 0.57
Natural gas and coke oven gas: 0.43
.'. Open hearth emissions:
24 x 104 [0.125 x 0.57 + 0.075 x .43] = 24,800 tons N0>
No. of 200 ton batches
Sinter emissions:
45.6 x x ]° tons = 23,700 tons NOY
L. X
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b. Estimation of Emissions for 1975 and 1980
From previous calculations on sinter plants (Section A.I of
this Appendix) and Table C-6, the following data are obtained:
1975
Open hearth production: 44.0 x 10 tons
Sinter production: 55.5 x 10 tons
Fractional fuel consumption in open hearths:
Fuel oil and tar and pitch 0.55
Natural gas and coke oven gas 0.45
1980
Open hearth production: 36.0 x 10 tons
Sinter production: 59.1 x 10 tons
Fractional fuel consumption in open hearths:
Fuel oil and tar and pitch 0.55
Natural gas and coke oven gas 0.45
.'. 1975 NO emissions are:
Open hearths: 22,500 tons NO
Sinter production: 28,600 tons NO
A
1980 NO emissions are:
A
Open hearths: 18,400 tons NOV
A
Sinter production: 31,000 tons NO
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II. EMISSIONS FROM FUELS
Five fuels are extensively used in the Iron and Steel Industry to
supply process energy. These are fuel oil, natural gas, tar and pitch,
coke oven gas and blast furnace gas. The latter three fuels are pro-
duced within the steel mill as by-products and their production is de-
pendent on the coke rate and ultimately on pig iron requirements. Fuel
oil and natural gas, on the other hand, are purchased fuels whose usage
is tied into the process in a fairly complex fashion as will be discussed
later.
In estimating emissions from fuels used in process areas, it is neces-
sary first to determine fuel consumption and then to apply emission fac-
tors. Fuel consumptions for 1970 are available F.C-8] but extrapolation
to 1975 and 1980 will have to be made based on understanding of how fuel
usage is connected to process requirements.
The AISI Statistical Reports [C-8,C-9] break down fuel consumption
into the following use categories:
(1) Blast Furnace Area Furnaces
(2) Steel Melting Furnaces
(3) Heating and Annealing Furnaces
(4) Heating Ovens for Mire Rods
(5) Other
In addition, included under other uses in the blast furnace area,
are reported the quantity of fuel used for coke oven underfiring.
Discussions with AISI officials [C-15] indicate that:
(1) The category of "other" (i.e., 5) could be considered to refer
mainly to the use of the particular fuel in steam raising boilers, and
(2) Steel melting furnaces refers to fuel usage in open hearth
furnaces.
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A. FUEL CONSUMPTIONS
1. Base Year - 1970
Table C-11 summarizes the fuel consumption data for 1970 ex-
tracted from the AISI Statistical Report [C-8].
2. Estimation of Fuel Consumptions for 1975 and 1980
Estimation of fuel consumption for future years must be
based on an understanding of how the particular fuels are utilized in the
overall process. Fuel oil and natural gas will be considered first:
a. Fuel Oil and Natural Gas
The following underlying logic will be used to estimate
future fuel usage.
(1) Fuel oil and natural gas used in the blast furnace
are injected through the tuyeres [C-2]. As such these fuels reduce the
blast furnace coke burden and lead to more efficient performance of the
furnace [C-2]. Since these fuels ultimately produce blast furnace gas,
estimation of their consumption for future years is necessary in order
to determine blast furnace gas production.
The fuels used in the blast furnace area are
dependent on pig iron production and thus their consumption will be cor-
related with pig iron production.
(2) As indicated earlier, steel melting furnaces refer
to open hearth furnaces. Thus fuel oil and natural gas consumption used
in steel melting furnaces will be correlated with open hearth production.
(3) Heating and annealing furnaces are mainly utilized
in steel production and therefore fuel oil and natural gas consumption
in these areas will be correlated with raw steel production.
(4) Finally it will be assumed that fuel consumption used
for steam raising will correlated with raw steel production.
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TABLE C-11
1970 FUEL CONSUMPTION IN THE IRON AND STEEL INDUSTRY
Fuel
Blast Furnace Area
Other3 Coke Oven
Furnaces Uses Underfiring
Fuel Oil 146,031 19,801 5,000
103 gals
Tar & Pitch 42,500
103 gals
o
£ Natural Gas 44,474 10,262 4,000
106 scf
Coke Oven 9,177 319,628 274,603
Gas
106 scf
Blast Fur- 1,592,038 1,246,894 286,402
nace Gas
0 106 scf
z Liquid Pet.
% Gas
en o
5 10J gals
O
-r -. ,..-. ...I .-.. - . . . i -
Purpose
Steel Heating & Heating .
Melting Annealing Ovens for Steam
Furnaces Furnaces Wire Rods Other Raising Total
416,822 377,593 1,648 273,558 288,359 1,235,453
176,902 -- 41,503 41,503 260,905
57,797 306,097 4,403 170,483 176,745 593,516
22,056 363,899 4,217 208,959 253,984 927,936
164,693 -- 1,519,250 2,479,742 4,522,875
6,555 -- 12,220 12,220 18,775
8 alncludes coke oven underfiring
33 U
o Steam raising = E other - coke oven underfiring
o
z
-------
Table C-12 shows time series data extracted from the AISI
Statistical Reports [C-8,C-9] that were used in the above correlations.
Based on extrapolations of the data, ratios of fuel oil and natural gas
consumptions relative to production were obtained for 1975 and 1980.
These ratios are listed below:
Fuel Oil:
1. Blast furnace area:
2. Steel melting furnaces:
(open hearth)
3. Heating and annealing
furnaces:
4. Steam raising
Natural Gas:
1. Blast furnace area:
2. Steel melting furnaces:
(open hearth)
no obvious trend
use avg. of 1969-1964
3. Heating and annealing
furnaces:
4. Steam raising
1975: 3.7 gal/ton pig iron
1980: 10 gal/ton pig iron
1975: 8.3 gal/ton open hearth steel
1980: 8.3 gal/ton open hearth steel
1975: 2.2 gal/ton raw steel
1980: 2.2 gal/ton raw steel
1975: 2.1 gal/ton raw steel
1980: 2.1 gal/ton raw steel
1975:
1980:
1975:
1980:
1975:
1980:
1975:
1980:
0.5 x 103 ft3/T pig iron
0.5 x 103 ft3/T pig iron
1.1 x 103 ft3/T open hearth
1.1 x 103 ft3/T open hearth
2.7 x 103 ft3/T raw steel
3.05 x 103 ft3/T raw steel
1.34 x 103 ft3/T raw steel
1.55 x 103 ft3/T raw steel
BatteHe [C-2] quote the following projected production rates:
C-44
WALDEN RESEARCH CORPORATION
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O
m
z
m
CO
33
O
X
O
O
2)
TJ
O
z
TABLE C-12
TIME SERIES OF FUEL OIL AND NATURAL GAS CONSUMPTION IN THE IRON AND STEEL INDUSTRY
Year
1970
1969
1968
1967
1966
1965
1964
aOpen
Pig Iron
Production
103 tons
91,435
95,017
88,780
86,984
91,500
88,185
85,601
Raw
Steel
Production
103 tons
131 ,514
141,262
131,462
127,213
134,101
131,462
127,076
Open
Hearth
Production
103 tons
48,000
61,000
66,000
71 ,000
85,000
94,000
98,000
hearth production obtained from data
Fuel Oil
in Blast
Furnaces
103 gal
146,031
116,770
80,778
67,223
53,247
53,131
46,189 1
of Battel
Fuel Oil
in Steel
Melting
Furnaces
103 gal
416,822
504,673
549,585
567,663
721,661
889,580
,008,296
le [C-2J,
Fuel Oil
In Heating
& Anneal ing
103 gal
377,593
314,064
368,253
403,426
461,939
448,649
392,300
as shown in
Fuel Oil
In Steam
Raising
103 gal
287,558
298,541
282,097
215,663
206,071
219,144
228,344
Figure C-7
Nat. Gas
In Blast
Furnaces
106 scf
44,474
44,355
46,507
44,255
51,510
46,636
38,796
Nat. Gas
In Steel
Melting
106 scf
57,797
92,446
102,159
85,932
96,002
105,571
108,540
Nat. Gas
In Heating
& Annealing
106 scf
310,500
342,112
303,982
283,004
264,228
277,317
256,250
-------
TABLE C-12 (Cont.)
o
Year
1970
1969
1968
1967
1966
1965
1964
Nat. Gas
in Steam
Raising
106 scf
180,747
155,607
134,212
121,270
105,385
117,552
109,513
Fuel Oil
in Blast
Furnace
Pig Iron
gal/ton
1.597
1.229
0.910
0.773
0.582
0.602
0.540
Fuel Oil
in Heating
& Annealing
Raw Steel
gal/ton
2.87
2.22
2.80
3.17
3.44
3.41
3.09
Fuel Oil
in Steel
Melting
Open Hearth
gal /ton
8.7
8.3
8.3
8.0
8.5
9.4
10.2
Fuel Oil
in Steam
Raising
Raw Steel
gal /ton
2.19
2.11
2.15
1.69
1.54
1.67
1.80
Nat. Gas
in Blast
Furnace
Pig Iron
103 scf/ton
0.486
0.467
0.524
0.510
0.563
0.530
0.453
Nat. Gas
in Heating
& Annealing
Raw Steel
103 scf/ton
2.36
2.42
2.31
2.22
1.97
2.11
2.01
Nat. Gas
in Steel
Melting
Open Hearth
103 scf/ton
1.2
1.5
1.54
1.21
1.13
1.12
1.10
Nat. Gas
in Steam
Raising
Raw Steel
103 scf/tor
1.374
1.101
1.02
0.953
0.786
0.894
0.862
a
m
33
m
en
o
o
o
7)
-0
O
70
-------
1975
Pig i>on: 106.8 x TO6 tons
Open hearth production: 44.0 x 106 tons
Raw steel production: 157.0 x 106 tons
1980
Pig iron: 122.4 x 106 tons
Open hearth production: 36.0 x 10 tons
Raw steel production: 180.0 x 10 tons
Using the above production figures, together with the extrapolated ratios,
fuel oil and natural gas consumption can be calculated and the results
are shown in Table C-13.
TABLE C-13
PROJECTED FUEL OIL AND NATURAL GAS CONSUMPTIONS
FOR 1975 AND 1980
Fuel
Fuel Oil
103 gals
Fuel Oil
103 gals
Nat. Gas
106 scf
Nat. Gas
106 scf
Year
Blast
Furnace
1975 396,000
1980 1,224,000
1975 53,400
1980 61,400
Purpose
Steel
Melting
366,000
300,000
49,500
39,400
Heating
& Annealing
395,000
396,000
424,000
549,000
Steam
Raising
377,000
377,000
210,000
278,000
C-47 WALDEN RESEARCH CORPORATION
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b. Coke Based Fuels, i.e., Coke Oven Gas, Blast Furnace Gas
and Tar and Pitch
Production rates of coke oven gas, tar and pitch and
blast furnace gas are closely correlated with the coke rate and ultimately
the projected pig iron requirements. The coke rate has been discussed in
Section I of this appendix, where it was shown, based on extrapolations,
that the coke rate for 1975 and 1980 would be 1175 and 1110 Ib/coke/f pig
iron. However, previous estimates based on extrapolation of historical
data indicated that the following quantities of fuel oil and natural gas
would be injected into the tuyeres of the blast furnace.
Fuel Oil: 1975: 3.5 gal/T pig iron
1980: 10.0 gal/T pig iron
Natural Gas: 1975: 500 ft3/T pig iron
1980: 500 ft3/T pig iron
These fuel quantities translate to about 30 and 80 Ib/T pig iron respectively,
for 1975 and 1980. Thus assuming approximately that one pound of fuel will
result in an equivalent pound reduction in the coke rate. The actual coke
rates of 1975 and 1980 were projected to be 1145 and 1020 Ib coke/T pig
iron. However, before total production rates can be calculated, it is
necessary to determine how the production rates are related to the coke
rate.
(1) Total Production Rates - Coke Oven Gas. Volumetric
production rates of coke oven gas/T coke are not easily predicted and as
such the historical data presented in Table C-14 and taken from AISI [C-8,
C-9] will be used.
There is no obvious trend in the data and as such
a mean of 15,000 scf/T coke will be used in subsequent computations.
Thus total coke oven gas production rates for 1975
and 1980 are readily computed:
C-48 WALDEN RESEARCH CORPORATION
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TABLE C-14
COKE OVEN GAS PRODUCTION/T COKE
Year
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
SCF/T Coke
14,200
15,200
17,200
15,000
14,800
12,400
17,300
17,640
15,300
15,700
15,600
15,100
15,900
C-49
WALDEN RESEARCH CORPORATION
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1975
15,000 x X 106-8 X 1C)6 SCF
= 9.2 x 1011 SCF
1980
15,000 x x 122.4 x 106 SCF
= 9.35 x 1011 SCF
(2) Blast Furnace Gas. A similar procedure based on
historical data, can be used to estimate blast furnace gas production
rates. Table C-15 presents such data extracted from AISI statistics [C-8,
C-9].
TABLE C-15
BLAST FURNACE GAS PRODUCTION/T COKE USED IN BLAST FURNACE
1966
1967
1968
1969
1970
106 SCF Blast
Furnace Gas
Production
4,076,149
4,131,003
4,453,712
4,757,049
4,522,875
Coke Used in
Blast Furnace
Ctons)
59.6 x 106
56.2 x 106
56.2 x 105
60.2 x 106
59.4 x 106
Pig Iron
Production
(tons)
91.5 x 106
87.0 x 106
88.8 x 106
95.0 x 106
91.4 x 106
SCF/T Coke
68,500
73,400
79,100
79,100
76,000
Esso IC-16] reports that four to five tons of
blast furnace gas are generated/ton of pig iron produced, i.e., approxi-
mately 96,000 SCF to 120,000 SCF of blast furnace gas is produced/T of
pig iron. It would be expected that the blast furnace gas production
C-50 WALDEN RESEARCH CORPORATION
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rate should depend on the coke rate and this is bourne out by the data
presented in Figure C-12 below [C-18]. However, it is readily seen from
Figure C-12 that at a coke rate of 1260-1300 Ib coke/T pig iron (i.e.,
the data from Table C-15), total blast furnace production rate is about
118,000 SCF/T coke.
Both the results of Esso IC-16] and Heynert [C-18]
indicate considerably higher production rates than are shown by the data
in Table C-15 (even if a fraction of the blast furnace gas is lost as
shown in Figure C-12. Discussion with personnel at AISI concerning this
problem, revealed that measurements of the volumetric blast furnace gas
production rates as reported in the AISI statistics may be in error due to
the difficulties in determining such large volumetric rates.
If it is assumed that 20% of the blast furnace gas
produced is lost through leaks etc., then the data of Heynert £C-18] would
only be 20% above the measured data shown in Table C-15. It is clear
that without further information this disparity cannot be resolved, al-
though after considering a reasonable loss rate, the data are not that
far apart. Thus in estimating blast furnace gas production rates for
1975 and 1980, it will be assumed that the production rate is a function
of the coke rate as predicted by Figure C- 4, but that this value of the
rate obtained at a given coke rate will be reduced by 40%.
An equivalent coke rate of the actual coke rate
plus fuel oil and natural gas injection rate into the tuyeres was used
to calculate the SCF blast furnace gas/T pig iron from Figure C-4.
.'. For 1975
Ib coke
Effective coke rate =1175
T pig iron
Blast furnace gas production rate
= 79,000 x 0.6 x 106.8 x 105 SCF
= 5.07 x 1012 SCF
C-51 WALDEN RESEARCH CORPORATION
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en
ro
a
m
en
m
3D
a
o
o
XI
140
120
O)
100
1/1
rd <+-
CD O
o o
(O -M
c:
i- s-
3 Ol
Ll_ CX
tO O>
(O O>
I
-------
and for 1980
Effective coke rate = 1100 1b.coke
T pig iron
. . Blast furnace gas production rate
= 62,000 x 0.6 x 122.4 x 106 SCF
= 4.56 x 1012 SCF
(3) Tar and Pitch. Production rate of tar and pitch/T
coke are presented in Figure C-5. Extrapolations to 1975 and 1980 indi-
cate productions of 3.5 and 2.6 gals/T coke.
. . Tar and pitch production rates for 1975 and 1980 are respectively:
1975
3'5 x ' x 106'8 x 1C|6 ga1s
= 2.14 x 108 gals
2.6 x x 122.4 x 106 gals
1980
= 1.62 x 108 gals
3. Fractional Usage of Fuels
Calculation of emissions necessitates an estimation of
fractional usage of the total fuel production amongst the different
process units. This fractional allocation of the coke based fuels is a
complex economic problem which will be circumvented by assuming that
the fractional allocations for 1975 and 1980 can be estimated from extrapo-
lation of historical data.
Tables C-16 and C-17 present historical data taken from
AISI statistics together with fractional fuel consumption in the dif-
ferent process areas,
WALDEN RESEARCH CORPORATION
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I
en
s
I
o
m
c/i
o
I
8
64 65 66 67 68 69
70 71 72 73 74
Year
75 76 77 78 79 80
Figure C-5. Relative Production Rate of Tar and Pitch.
O
33
-------
o
en
c_n
TABLE C-16
BLAST FURNACE GAS HISTORICAL DATA
Year
1970
1969
1968
1967
1966
Blast
Furnaces
1,592,038
1,733,763
1,542,082
1,400,147
1,329,672
Fraction
B.F.G.
Used in
Blast
Furnaces
.352
.364
.346
.339
.326
Coke Oven
Underfiring
286,402
345,270
340,771
334,068
358,288
Fraction
B.F.G.
Used in
Coke Oven
Underfiring
.063
.072
.076
.081
.088
Fraction
B.F.G.
Used in
Steel Steel
Melting Melting
Furnaces Furnaces
11,571 .002
Heating &
Annealing
Furnaces
164,693
185,223
165,451
162,898
156,010
Fraction
B.F.G.
Used in
Heating
Furnaces
.036
.039
.037
.039
.038
I
33
m
33
O
X
o
o
33
T3
O
33
-------
TABLE C-16 (Cont.)
o
en
cn
Year
1970
1969
1968
1967
1966
Steam
Raising
2,479,742
2,492,793
2,405,408
2,233,890
2,220,608
Fraction
B.F.G.
Used in
Steam
Raising
.548
.524
.540
.540
.544
Total
4,522,875
4,757,049
4,453,712
4,731,003
4,076,149
o
m
in
m
>
X)
o
o
o
30
-o
o
-------
m
in
o
o
o
-o
O
33
TABLE C-17
COKE OVEN GAS HISTORICAL DATA
Blast
Year Furnaces
1970
1969 1
fp 1968 1
pi
^ 1967 1
1966
1965 1
1964
Average
1966-1970
5
m -
9,177
1,021
2,118
3,433
7,529
1,233
8,458
Fraction
C.O.G.
Used in
Blast Coke Oven
Furnaces Underfiring
.01 274,603
.01 254,991
.013 231,922
.014 237,541
.01 225,119
.01 n.a.
.01 n.a.
.01
Fraction
C.O.G.
Used in Steel
Coke Oven Melting
Underfiring Furnaces
.295 22,056
.277 29,946
.262 32,800
.267 32,762
.245 55,042
71,864
76,335
.269
Fraction
C.O.G.
Used in
Steel
Melting
Furnaces
.02
.03
.04
.04
.06
.09
.10
.03
Heating &
Annealing
Furnaces
363,899
378,028
359,368
352,236
359,949
350,029
334,310
Fraction
C.O.G.
Used in
Heating
Furnaces
.392
.413
.407
.397
.393
.444
.466
.400
-------
TABLE C-17 (Cont.)
o
1
en
00
Year
1970
1969
1968
1967
1966
1965
1964
Aver.
Heating
Ovens
For Wire
Rods
4,217
12,606
12,705
9,681
5,378
4,471
5,257
1966-1970
1
Fraction
C.O.G.
Used in
Heating
Ovens
For Wire
Rods
.004
.013
.014
.010
.006
.005
.007
.01
Steam
Raising
253,984
229,049
232,161
240,575
261 ,874
350,495
291 ,874
.273
.250
.263
.270
.285
.444
.406
.268
Total
927,436
915,641
881 ,074
886,228
914,891
788,095
716,234
33
m
O
X
o
o
33
T)
O
3D
-------
Perusal of the fractional usage of coke oven gas and blast
furnace gas indicate little variation of time since 1966 and as such the
average values presented in the tables will be used in subsequent compu-
tations where necessary.
4. Estimation of Emissions
a. Emission Factors
The following emission factors v/ere used in estimation
of emissions:
Sulfur Oxides
Fuel Oil (see Appendix D, Table D-l):
4 1b S0x
0.68 xlO4* (% sulfur) 10QO barre*$ Ql1
Natural Gas (see Appendix D, Table D-l): 0.0
Blast Furnace Gas (see Appendix D, Section 2): 0.0
Coke Oven Gas (see Appendix D, Section 2):
0.77 Ib SO,.
1000 SCF C.O.G.
Parti culates
Fuel Oil (see Appendix D, Table D-l):
3 1b particulates
barrels Oll
Natural Gas (see Appendix D, Table D-l):
0.15 xlO2 T> Particulates
10° SCF
ro WALOEN RESEARCH CORPORATION
-------
Blast Furnace Gas Csee Appendix D, Section 2):
2.4 1b particulates
TO6 SCF
Coke Oven Gas (see Appendix D, Section 2):
0.15 x TO2 1b particulates
106 SCF
Nitrogen Oxides
Whereas the emission factors for sulfur oxides and
particulates are essentially independent of the process unit size and
firing rate, emissions of NO are strongly dependent on the firing rate
X
and fuel. As such emission factors for the different process units have
to be discussed separately. Some of the following information was ob-
tained from NO Systems Study {C-16J.
A
(1) Blast Furnace. Fuel is used to heat the three
blast furnace stoves which are usually associated with each blast fur-
nace. Two are generally on heat while the third is on blast.
The Battelle Systems Study £C-2] indicated the
following average pig iron productions per day.
TABLE C-18
AVERAGE PRODUCTION OF PIG IRON PER U.S. BLAST FURNACE PER DAY
Year Net Tons/Day
1960 1181
1967 1570
1975 1920
1980 2200
C-60 WALDEN RESEARCH CORPORATION
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Fuel oil and natural gas used in the blast furnace
area are injected into the blast furnace, so that effectively the only
major fuel used for heating is blast furnace gas. Thus the following
estimates can be computed of the average Btu/hr firing rate of blast
furnace gas in an averaged size blast furnace.
TABLE C-19
DETERMINATION OF THE AVERAGE FIRING RATE OF BLAST FURNACE
GAS IN AN AVERAGE SIZED BLAST FURNACE
Total Usage in
Blast Furnace Area
Year
1970
1975
1980
Btu/Yr
1.51X1014
1.66xl014
14
1.50x10^
How Obtained
Table C-ll
Use of Total
Production &
Fract. B.F.G.
Used in Blast
Furnaces
Pig Iron
Production
91. 4x1 O6
106. 8x1 O6
c
122.4x10°
Fuel Usage
Per Ton
Pig Iron
Btu/T
1.67X106
1.56xl06
F.
1.22x10°
Average Fuel
Usage Per
Blast Furnace
Btu/Hr
1.19xl08
1.24xl08
o
1.12x10
NO emission rates from combustion of blast furnace
A
gas is not well established. However, it is suggested in Appendix D, Sec-
tion 2, that emission rates be estimated as if the blast furnace gas was
natural gas and then more realistically adjusted by multiplying by 0.022.
Table C-20 summarizes these NO emission factors.
J\
(2) Coking Ovens. The estimations of Esso [C-16] in-
dicate that 2.7 Ibs NO is produced in the carbonization of 20 tons of coal
J\
.'. Emission factor = 0.135 Ibs NO/T coal fed
X
(3) Heating and Annealing Furnaces. Esso [C-16] indi-
cates that NO emissions from heating and annealing furnaces are best
X
estimated on the basis of steel production. It is estimated that
0.086 Ib NO produced/ton steel.
C-61
WALDEN RESEARCH CORPORATION
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TABLE C-20
NO EMISSION FACTORS FOR BLAST FURNACE GAS COMBUSTION
A
Year
1970
1975
1980
Production
Rate T/Hr
70.7
80
91.6
5. Estimation of Fuel
Average Fuel
Usage/Blast
Furnace Stove
Btu/Hr
5.9 x 107
6.2 x 107
5.6 x 107
Based Process
Conservative
NOX Emissions
Ib/hr
11.4
11.5
11.0
Emissions
Tables C-21, C-22 and C-23 summarize the fuel based process
emissions calculated from the previously estimated fuel consumption data
and emission factors for 1970, 1975 and 1980, respectively.
Based on the data of Battelle [C-2], the following average
sulfur contents were used in the above calculations.
Fuel Oil: 1.8% sulfur
Tar and Pitch: 0.6% sulfur
6. Summary
Tables C-24, C-25 and C-26 summarize the results of Sections
I and II of this Appendix.
C-62 WALDEN RESEARCH CORPORATION
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TABLE C-21
1970 EMISSIONS IN PROCESS FROM FUEL COMBUSTION
(tons)
o
c
en
CO
|
0
Blast Furnace Area
Fuel SO Particulate NOV
X X
Fuel
Oil
Tar &
Pitch
Natural
Gas
Coke Oven
Gas
Blast - 2,220
Furnace
Gas
TOTAL 2,220 160
Coke Oven Underfiring
SO Particulate NO
X X
tons
725 25
-
30
106,000 2,060
400
106,725 2,515 5,900
Heating
Heating
S0x
54,000
-
-
140,000
-
194,000
& Annealing
Ovens for
Particul
1,890
-
2,330
2,720
230
7,170
Furnaces &
Wire Rods
ate NOV
/\
5,600
33
m
CO
33
O
X
o
o
33
t)
O
33
-------
TABLE C-22
1975 EMISSIONS IN PROCESS FROM FUEL COMBUSTION
(tons)
o
cr>
1
o
m
a
m
in
m
aj
o
8
1
33
Blast Furnace Area
Fuel SOV Particulate NO
X X
Fuel
Oil
Tar &
Pitch
Natural
Gas
Coke Oven
Gas
Blast 2,400
Furnace
Gas
TOTAL 2,400 170
Coke Oven Underfiring Heating & Annealing Furnaces &
Heating Ovens for Wire Rods
SO Particulate NOV SOV Particulate NO
X XX X
57,500 2,000
3,000
95,000 1,800 145,000 3,000
500 - 300
95,000 2,300 6,000 196,500 8,300 6,700
o
-------
TABLE C-23
1980 EMISSIONS IN PROCESS FROM FUEL COMBUSTION
(tons)
o
I
01
en
z
3J
m
en
m
>
33
O
I
O
O
33
s
3J
Blast Furnace Area
Fuel SOV Particulate NOV
X X
Fuel
Oil
Tar &
Pitch
Natural
Gas
Coke Oven
Gas
Blast - 2,200
Furnace
Gas
TOTAL 2,200 170
Coke Oven Underfiring Heating & Annealing Furances &
Heating Ovens for Wire Rods
SO Particulate NO SO Particulate NOV
/\ J\ J\ /\
57,500 2,000
4,000
97,000 2,000 148,000 3,000
500 300
97,000 2,500 6,000 205,500 9,300 7,700
O
z
-------
TABLE C-24
SUMMARY OF 1970 PROCESS EMISSIONS
*
(tons)
o
en
en
WALDEN RESEARCH CORPOR
Sinter Plants
Coke Manufacture
Blast Furnaces
Steel Furnaces
(Open Hearth)
B.O.F.
Electric Arc
Heating &
Annealing
Furnaces
Scarfing
Material
Handling
TOTAL
*
Tons rounded to
Process Fuel Combusted in
SOV Part. NOV SOV Part.
X XX
32,000 96,000 24,000
152,000 107,000 3,000
2,000
35,000 312,000 25,000
2,000 28,000
negl. 28,000
194,000 7,000
63,000
446,000
69,0001,125,000 49,000 301,000 12,000
the nearest thousand
Process Total
NOV SOV Part.
*\ J\
32,000 96,000
6,000 107,000 155,000
negl. 2,000
35,000 312,000
2,000 28,000
negl. 28,000
6,000 194,000 7,000
63,000
446,000
12,000 370,000 1,137,000
NOX
24,000
6,000
negl .
25,000
6,000
61 ,000
-------
TABLE C-25
SUMMARY OF 1975 PROCESS EMISSIONS
(tons)
o
I
CTi
O
m
35
m
to
33
O
I
O
o
;0
-o
o
33
Sinter Plants
Coke Manufacture
Blast Furnaces
Steel Furnaces
(Open Hearth)
B.O.F.
Electric Arc
Heating &
Anneal ing
Furnaces
Scarfing
Material
Hand! ing
TOTAL
*
Tons rounded to
Process Process - From Fuel
SQ Part. H0y SOV Part.
X XX
39,000 117,000 29,000
155,000 95,000 2,000
2,000
31,000 189,000 22,000
2,000 36,000
negl. 15,000
196,000 8,000
73,000
533,000
72,000 1,118,000 51,000 291,000 12,000
the nearest thousand
Combustion
N0x S0x
39,000
6,000 95,000
negl .
31,000
2,000
negl.
7,000 196,000
13,000 363,000
Total
Part.
117,000
157,000
2,000
189,000
36,000
15,000
8,000
73,000
533,000
1,130,000
NOX
29,000
6,000
negl .
22,000
7,000
64,000
-------
TABLE C-26
SUMMARY OF 1980 PROCESS EMISSIONS
*
(tons)
o
1
00
f
'ALDEN RESEARCH
CORPOR,
Sinter Plants
Coke Manufacture
Blast Furnaces
Steel Furnaces
(Open Hearth)
B.O.F.
Electric Arc
Heating &
Annealing
Furnaces
Scarfing
Material
Handling
TOTAL
*
Tons rounded to
Process Emissions Process - From Fuel Combustion
SOY Part. NOY SOV Part. NOV SOV
A A A XX
42,000 124,000 31,000 42,000
159,000 97,000 2,000 6,000 97,000
2,000 negl.
25,000 8,000 18,000 25,000
3,000 46,000 3,000
negl. 20,000 negl.
205,000 9,000 8,000 205,000
86,000
612,000
70,000 955,000 49,000 302,000 13,000 14,000 372,000
the nearest thousand
Total
Part.
124,000
161,000
2,000
8,000
4,600
20,000
9,000
86,000
612,000
968,000
X
31,000
6,000
negl .
18,000
8,000
63,000
o
2
-------
REFERENCES TO APPENDIX C
C-l The Making, Shaping, and Treating of Steel, 8th Edition, U.S. Steel
Corporation, Pittsburgh, Pa. (1964).
C-2. A Systems Analysis Study of the Integrated Iron and Steel Industry
Battelle Memorial Institute, Columbus, Ohio (1964).
C-3. McGraw, M.J. and R.L. Duprey, Compilation of Air Pollution Emis-
sion Factors, Preliminary Document E.P.A., Research'TriangTe Park,
N.C. (April 1971).
C-4. Schueneman, J.J., et al., Air Pollution Aspects of the Iron and
Steel Industry, Public Health Service, Cincinnati, Ohio.
C-5. O'Mara, R.F., Dust and Fume Problems in the Steel Industry, Air
Pollution Symposium, Iron Steel Engr., 30, 100 (1953).
C-6. Private communication with R. Devorek, U.S. Steel Corp., U.S.
Steel Bldg., Pittsburgh, Pa.
C-7, Systems Study on Particulate Emissions, Midwest Research Institute,
Information obtained from R.C. Lorentz, E.P.A. , 411 W. Chapel Hill
Street Annex, Durham, N.C. 27701.
C-8. Statistical Report American Iron and Steel Institute (1970).
C-9. Statistical Report American Iron and Steel Institute (1968).
C-10. Ramm, A.N., Minimum Theoretical Possible Coke Oven Consumption for
Pig Iron Production underModern Conditions, Stal No. 10, 860 (1964)
C-ll. Nakatani, F., et al., Theoretical Considerations on Blast Furnace
Coke Rate, Trans, of the Iron and Steel Dist. Japan 6, 263 (1966).
C-12. Weise, W.H., Blast Furnace Dust Treatment Facilities, Sewage and
Industrial Wastes 28. 1398 (1956).
C-13. Hipp, N.E. and J.R. Westerholm, Developments in Gas Cleaning -
Great Lakes Steel Corp., Iron and Steel Engineer 44 (8), 101 (1967).
C-14. Private communication with Dr. Smith, Jones & Laughlin Steel Corp.,
3 Gateway Center, Pittsburgh, Pa.
C-15. Private communication with Mr. Eckel, American Iron and Steel
Institute, 150 E. 42nd Street, New York, N.Y. 10017.
C-16. Bartok, W., et al., Systems Study of Nitrogen Oxide Control Methods
for Stationary Sources, Esso Research and Engineering Co., Govern-
ment Research Laboratory.
C-69
WALDEN RESEARCH CORPORATION
-------
REFERENCES TO APPENDIX C (Cont.)
C-17. Massobrio, G. and F. Santini, Some Starting and Operating Experi-
ences with the 300 Ton Oxygen Furnaces at the Toronto Works, AIME
Open Hearth Proceedings 48., 115 (1965).
C-18. Heynert, Von 6., et al, Charge Preparation and Its Effect on Op-
erating Results of the Blast Furnace, Stahl und Eisle 81. 1 (1961),
C_7Q WALDEN RESEARCH CORPORATION
-------
APPENDIX D
EMISSION FACTORS AND BOILER EMISSIONS
1. DISCUSSION OF EMISSION FACTORS FOR COAL, RESIDUAL OIL, AND
NATURAL GAS
The emissions resulting from combustion of coal, residual oil,
and natural gas under boilers were based on the emission factors and
sulfur and ash contents used for industrial intermediate-size boilers
in the Systems Study of Air Pollution from Intermediate-Size Fossil-
Fuel Combustion Equipment, and are shown below in Tables D-l and D-2 [D-l],
D-l
WALDEN RESEARCH CORPORATION
-------
TABLE D-l
EMISSION FACTORS
Pollutant Size
S02 all
S02 all
S00 all
2
N0v WT,
x 1
WT0
2
NOX WT'
WT0
2
WT,
3
NO all
x
Particulates WT,
1
WT0
2
WT,
3
WT,
I
WT,
3
all
Particulates all
*
Emission factors: GS -
RO -
CL -
Fuel
GS
RO
CL
GS
GS
GS
RO
RO
RO
CL
GS
GS
GS
RO
RO
RO
CL
CL
pounds
pounds
pounds
Firing Type
all
PV
CY
OF
SS
UF
PV
CY
OF
SS
UF
pollutants per million
pollutants per thousand
pollutants per thousand
*
Factor
0
.6804 x 104
.3800 x 105
3
.1676 x 10J
.2280 x 103
.2489 x 103
.2218 x 104
4
.3072 x 1(T
.3372 x 104
.2000 x 105
.6000 x 105
.1500 x 105
.1000 x 105
.1000 x 105
.1800 x 102
.1500 x 102
.1500 x 102
.9660 x 103
.4200 x 103
.4200 x 103
.1600 x 105
.2000 x 104
.1300 x 105
.5000 x 104
.5000 x 104
cubic feet
barrels
tons
D-2
WALDEN RESEARCH CORPORATION
-------
TABLE D-2
SULFUR AND ASH CONTENTS
% Sulfur % Ash
AT
AT
GL
GL
WS
WS
SE
SE
RO
CL
RO
CL
RO
CL
RO
CL
1.34
1.83
1.52
2.38
1.44
2.06
1.81
1.67
0
8.07
0
8.57
0
7.89
0
7.72
D-3 WALDEN RESEARCH CORPORATION
-------
2. EMISSION FACTORS FOR BLAST FURNACE GAS AND COKE OVEN GAS
A. PARTICIPATE EMISSIONS
(1) Blast Furnace Gas
The particulate emissions resulting from the combustion of
B.F.G. come primarily from particles entering with the gas, i.e., the
particulate emissions are determined by the efficiency with which the
B.F.G. gas is cleaned upon leaving the blast furnace.
The incentive for cleaning the gas is high, since if B.F.G.
were not cleaned the particulate matter would clog the holes in the regen-
erative brickwork of the blast furnace stoves, slagging reactions would be
accelerated and might lead to catastrophic failure of the large amount of
brickwork in the stoves.
Weise [D-4] reported in 1956 that cleaned gas had dust
contents of order 0.01 grains/SCF while Hipp and Westerholm [D-5] indi-
cate that future use of higher blast temperatures (which result in im-
provements in furnace efficiency) will create the need for gas cleanli-
ness in the 0.001 grains/SCF range. 0.01 grains/SCF translates to
1.4 lb/10 SCF. However, based on emission factors from the blast fur-
nace and quoted cleaning efficiencies estimates show that the blast
furnace gas contains about 3.4 lb/10 SCF. Thus as a compromise a mean
of 2.4 lb/10 SCF were used for the particulate emission factor for
blast furnace gas.
(2) Coke Oven Gas
No information on particulate loadings of coke oven gas could
be found. However, since almost all C.O.G. is produced via the "by-
product" coking process which involves a significant number of scrubbers
and condensers, it will be assumed that C.O.G. is as clean as natural gas
when it is finally used.
D-4
WALDEN RESEARCH CORPORATION
-------
B. NITROGEN OXIDE EMISSIONS
(1) Blast Furnace Gas
The only reported data that could be found on NO production
X
from B.F.G. combustion are in the Esso Study [D-6]. They state that un-
published data on stack gas samples from the blast furnace stoves had NO
/\
concentrations varying from 1.7 to 6.6 ppm. No mention of the stove size
is indicated but if it is assumed that it is an average sized blast furnace
stove (67 x 10 Btu/hr) then it can be shown that
(NO) observed with burning of B.F.G. _
(NO) from natural gas Burning
Although this ratio is dependent on the firing rate it will be assumed that
it holds constant for all sizes.
(2) Coke Oven Gas
NO emissions from coke oven gas combustion will be calculated
J\
as if the fuel was natural gas. This conclusion was based on good com-
parisons obtained between measured NO concentrations from coke oven gas
/\
combustion (from Esso) and values predicted from natural gas combustion
at similar burning rates.
C. SULFUR OXIDE EMISSIONS
(1) Blast Furnace Gas
BatteHe [D-7] indicates that because of the reducing con-
ditions in the blast furnace, it is not possible for any of the sulfur
present in the charge material to be oxidized and leave the blast fur-
nace as S0?. This is confirmed by Bureau of Mines tests [D-3].
(2) Coke Oven Gas
The sulfur in C.O.G. is determined by the sulfur content of
the coal used to produce the coke. The sulfur content of bituminous coals
shipped to American coke plants varied between 0.5 and 2.1% [D-2] with
D-5
WALDEN RESEARCH CORPORATION
-------
an average of 0.8% S. Battelle indicates a linear relationship between
sulfur in C.O.G. and % S in coal.
From Battelle [D-7], for 0.8% S coal, ^ 4.25 Ib S in C.O.G.
results from the coking of 1 ton of coal. Now, 1.4 T coal required/T coke
and 15,500 ft C.O.G. produced/T coke (see AISI statistics).
.'. Ib S02/1000 ft3 C.O.G.
- 4.25 x 1.4 x 2
15.5
= 0.77 Ib S02/1000 ft3 C.O.G.
Of course, if the iron and steel industry is forced to use higher S coal
in the future, this will affect the S02 content of C.O.G.
Table D-3 shows a summary of the emission factors for
blast furnace gas and coke oven gas.
D-6 WALDEN RESEARCH CORPORATION
-------
TABLE D-3
SUMMARY OF EMISSION FACTORS FOR BLAST FURNACE
GAS AND COKE OVEN GAS
Pollutant Size
S02 al 1
S02 all
NO WT,
X I
WT3
NO WT,
x 1
WT2
VIT3
Particulates all
WTi
WT2
WT3
Fuel
BFG
COG
BFG
BFG
BFG
COG
COG
COG
BFG
COG
COG
COG
Factor
(Ib/million cu ft)
0
.77 x TO3
3.69 (.022 x .1676 x
5.02 (.022 x .2280 x
5.48 (.022 x .2489 x
T
.1676 x 10J
.2280 x 103
.2489 x 103
2.4
18
15
15
103)
103)
103)
D-7
WALDEN RESEARCH CORPORATION
-------
3. EMISSIONS
The calculated emissions are shown in detail in Tables D-4 through
D-12.
Uncontrolled boiler emissions were calculated according to the equa-
tions shown below:
S02 (tons) -
fuel consumption x emission factor x % sulfur
Mn i^. ~r.\ fuel consumption x emission factor
N0x (tons) = * 2000
Particulates (tons) = fue1 ^sumption * lesion factor x % ash
zooo
**
Only in the case of coal- or oil-fired boilers
Ir
Only in the case of coal-fired boilers
D-8
WALDEN RESEARCH CORPORATION
-------
TABLE D-4
S02 EMISSIONS FROM BOILERS IN THE IRON AND STEEL INDUSTRY - 1970
(TO3 tons)
Size Fuel
WT<100 CL
RO
GS
BFG
COG
WT1 00-250 CL
RO
GS
BFG
COG
WT>250 CL
RO
GS
BFG
COG
TOTAL
Firing
PV
CY
OF
SS
UF
PV
CY
OF
SS
UF
PV
CY
OF
SS
UF
AT
4.2
0
9.8
4.2
2.8
15.1
0
0
16.8
8.8
.3
4.3
1.2
.3
10.8
0
0
11.9
10.3
.5
0
.3
.1
8.2
0
0
9.0
118.9
GL
12.4
0
29.2
12.4
8.0
8.7
0
0
9.7
40.5
1.4
20.0
5.6
1.4
9'. 8
0
0
10.9
46.5
2.4
0
1.0
.5
7.1
0
0
7.9
235.4
WS
.3
0
.5
.2
.2
1.3
0
0
6.9
.3
0
.2
.2
0
,7
0
0
3.7
.9
0
0
0
0
1.2
0
0
6.2
22.8
SE
3.2
0
7.4
3.2
5.2
1.8
0
0
3.5
5.2
.1
2.6
.7
.2
.7
0
0
1.9
16.0
.9
0
.4
.1
1.3
0
0
3.8
58.2
Total
20.1
0
46.9
20.0
16.2
26.9
0
0
36.9
54.8
1.8
27.1
7.7
1.9
22.0
0
0
28.4
73.7
3.8
0
1.7
.7
17.8
0
0
26.9
435.3
D-9 WALDEN RESEARCH CORPORATION
-------
TABLE D-5
PARTICULATES EMISSIONS FROM BOILERS IN THE IRON AND STEEL INDUSTRY - 1970
(TO3 tons)
Size Fuel
w^ioo CL
RO
GS
BFG
COG
WT1 00-250 CL
RO
GS
BFG
COG
WT>250 CL
RO
GS
BFG
COG
TOTAL
Firing
PV
CY
OF
SS
UF
PV
CY
OF
SS
UF
PV
CY
OF
SS
UF
AT
7.7
0
14.7
2.4
1.6
1.6
.4
.7
.4
16.4
.1
6.5
.7
.2
.5
.2
.5
.2
19.2
.1
0
.2
.1
.4
.2
.4
.2
75.6
GL
18.7
0
36.0
5.9
3.8
.8
.2
.4
.2
61.4
.3
24.6
2.6
.7
.4
.2
.5
.2
70.4
.5
0
.5
.2
.3
.1
.4
.2
229.5
WS
.5
0
.6
.1
.1
.1
.1
.1
.2
.5
0
.2
.1
0
0
0
.1
.1
1.5
0
0
0
0
.1
.1
.1
.1
4.7
SE
6.2
0
11.8
1.9
1.3
.1
.1
.1
.1
10.2
0
4.1
.4
.1
0
0
.1
0
31.1
.2
0
.2
.1
0
.1
.2
.1
68.5
Total
33.1
0
63.1
10.3
6.8
2.6
.8
1.3
.9
88.5
.4
35.4
3.8
1.0
.9
.4
1.2
.5
122.2
.8
0
.9
.4
.8
.5
1.1
.6
378.3
D-10
WALDEN RESEARCH CORPORATION
-------
TABLE D-6
NOX EMISSIONS FROM BOILERS IN THE IRON AND STEEL INDUSTRY - 1970
(TO3 tons)
Size Fuel
WT<100 CL
RO
GS
BFG
COG
WT1 00-250 CL
RO
GS
BFG
COG
WT>25Q CL
RO
GS
BFG
COG
TOTAL
Firing
PV
CY
OF
SS
UF
PV
CY
OF
SS
UF
PV
CY
OF
SS
UF
AT
1.2
0
2.1
.6
.4
3.7
3.8
1.0
3.7
2.5
.2
.9
.2
0
3.6
3.7
1.0
3.5
3.0
.5
0
0
0
3.0
3.0
.8
2.9
45.3
GL
2.7
0
4.8
1.4
.9
1.9
1.8
.7
2.1
9.0
.9
3.3
.6
.2
2.9
2.8
1.0
3.2
10.3
1.6
0
.1
.1
2.3
2.2
.8
2.6
60.2
WS
.1
0
.1
0
0
.3
1.0
.2
1.5
.1
0
0
0
0
.2
.7
.1
1.1
.2
0
0
0
0
.4
1.3
.3
2.0
9.6
SE
1.0
0
1.8
.5
.3
.2
.9
.1
.8
1.7
.1
.6
.1
0
.2
.7
.2
.6
5.0
.8
0
.1
0
.4
1.4
.4
1.2
19.1
Total
5.0
0
8.8
2.5
1.6
6.1
7.5
2.0
8.1
13.3
1.2
4.8
.9
.2
6.9
7.9
2.3
8.4
18.5
2.9
0
.2
.1
6.1
7.9
2.3
8.7
134.2
WALDEN RESEARCH CORPORATION
-------
TABLE D-7
S02 EMISSIONS FROM BOILERS IN THE IRON AND STEEL INDUSTRY - 1975
(103 tons)
Size Fuel
WT250 CL
RO
GS
BFG
COG
TOTAL
Firing
PV
CY
OF
SS
UF
PV
CY
OF
SS
UF
PV
CY
OF
SS
UF
AT
3.1
0
7.4
3.1
2.1
16.8
0
0
17.3
6.0
.3
2.9
.8
.1
10.7
0
0
11.0
5.8
.3
0
.1
.1
8.2
0
0
8.5
104.6
GL
14.8
0
34.5
14.8
9.6
10.7
0
0
13.2
43.3
1.6
21.2
5.9
1.4
10.7
0
0
13.0
47.7
2.6
0
1.0
.5
8.0
0
0
9.0
263.5
US
.3
0
.6
.3
.2
1.4
0
0
4.2
.8
0
.3
.2
0
.6
0
0
1.9
1.1
.2
0
0
0
1.3
0
0
3.0
16.4
SE
3.1
0
7.2
3.1
2.0
1.8
0
0
4.9
4.9
.1
2.3
.6
.2
.8
0
0
1.9
14.0
.7
0
.4
.1
1.6
0
0
4.2
53.9
Total
21.3
0
49.7
21.3
13.9
30.7
0
0
39.6
55.0
2.0
26.7
7.5
1.7
22.8
0
0
27.8
68.6
3.8
0
1.5
.7
19.1
0
0
24.7
438.4
D-12 WALDEN RESEARCH CORPORATION
-------
TABLE D-8
PARTICULATES EMISSIONS FROM BOILERS IN THE IRON AND STEEL INDUSTRY - 1975
^ tons)
Size Fuel
WT CL
RO
GS
BFG
COG
UT n
w '100-250 tL
RO
GS
BFG
COG
WT>250 CL
RO
GS
BFG
COG
TOTAL
Firing
PV
CY
OF
SS
UF
PV
CY
OF
SS
UF
PV
CY
OF
SS
UF
AT
5.7
0
11.1
1.8
1.2
1.8
.7
.6
.4
11.2
.1
4.4
.5
.1
.5
.4
.4
.2
10.7
.1
0
.1
.1
.4
.3
.3
.2
53.3
GL
22.4
0
42.4
7.0
4.5
1.0
.3
.5
.3
65.7
.3
26.1
2.8
.7
.4
.2
.5
.3
72.3
.5
0
.5
.2
.3
.2
.3
.2
249.9
WS
.5
0
.8
.2
.1
.1
.1
.1
.1
1.2
0
.4
.1
0
0
.1
.1
0
1.7
0
0
0
0
.1
.1
.1
.1
6.0
SE
5.9
0
11.4
1.9
1.2
.1
.1
.2
.1
9.5
0
3.7
.4
.1
0
.1
.1
0
27.3
.2
0
.2
.1
.1
.1
.2
.1
63.1
Total
34.5
0
65.7
10.9
7.0
3.0
1.2
1.4
.9
87.6
.4
34.6
3.8
.9
.9
.8
1.1
.5
112.0
.8
0
.8
.4
.9
.7
.9
.6
372.3
D-13 WALDEN RESEARCH CORPORATION
-------
TABLE D-9
N0x EMISSIONS FROM BOILERS IN THE IRON AND STEEL INDUSTRY - 1975
(TO3 tons)
Size Fuel
WT<100 CL
RO
GS
BFG
COG
WT1 00-250 CL
RO
GS
BFG
COG
WT>25Q CL
RO
GS
BFG
COG
TOTAL
Firing
PV
CY
OF
SS
UF
PV
CY
OF
SS
UF
PV
CY
OF
SS
UF
AT
.9
0
1.6
.4
.3
4.1
6.9
1.0
3.8
1.7
.2
.6
.1
0
3.6
6.0
.9
3.3
1.7
.2
0
0
0
3.0
4.8
.7
2.7
48.5
GL
3.3
0
5.7
1.6
1.1
2.3
2.6
.7
2.9
9.6
1.0
3.5
.7
.2
3.2
3.5
1.0
3.9
10.5
1.7
0
.1
.1
2.6
2.7
.8
2.9
68.2
WS
.1
0
.1
0
0
.3
1.8
.2
.9
.2
0
.1
0
0
.2
1.2
.1
.6
.3
.1
0
0
0
.4
2.0
.2
1.0
9.8
SE
1.0
0
1.7
.5
.3
.3
1.3
.3
1.1
1.5
.1
.5
.1
0
.2
.9
.2
.6
4.4
.7
0
.1
0
.4
1.9
.4
1.4
19.9
Total
5.3
0
9.1
2.5
1.7
7.0
12.6
2.2
8.7
13.0
1.3
4.7
.9
.2
7.2
11.6
2.2
8.4
16.9
2.7
0
.2
.1
6.4
11.4
2.1
8.0
146.4
D-14 WALDEN RESEARCH CORPORATION
-------
TABLE D-10
S02 EMISSIONS FROM BOILERS IN THE IRON AND STEEL INDUSTRY - 1980
(TO3 tons)
Size Fuel
WT<100 CL
RO
GS
BFG
COG
WT1 00-250 CL
RO
GS
BFG
COG
WT>250 CL
RO
GS
BFG
COG
TOTAL
Firing
PV
CY
OF
SS
UF
PV
CY
OF
SS
UF
PV
CY
OF
SS
UF
AT
3.4
0
7.9
3.4
2.3
20.2
0
0
19.4
6.0
.3
2.9
.8
.1
12.7
0
0
12.3
6.8
.4
0
.1
0
8.8
0
0
7.9
115.7
GL
16.9
0
39.7
16.9
11.1
10.7
0
0
13.9
49.4
1.7
24.2
6.6
1.7
10.0
0
0
14.2
50.1
2.8
0
1.0
.5
6.6
0
0
9.0
287.0
WS
.3
0
.6
.3
.2
1.4
0
0
4.1
.8
0
.3
.2
0
1.4
0
0
2.6
1.1
.2
0
0
0
1.3
0
0
3.0
17.8
SE
3.5
0
8.3
3.5
2.2
1.8
0
0
4.9
4.9
.1
2.3
.6
.2
.8
0
0
2.6
14.0
.7
0
.4
.1
1.6
0
0
4.2
56.7
Total
24.1
0
56.5
24.1
15.8
34.1
0
0
42.3
61.1
2.1
29.7
8.2
2.0
24.9
0
0
31.7
72.0
4.1
0
1.5
.6
18.3
0
0
24.1
477.2
WALDEN RESEARCH CORPORATION
-------
TABLE D-11
PARTICULATES EMISSIONS FROM BOILERS IN THE IRON AND STEEL INDUSTRY - 1980
(TO3 tons)
Size Fuel
WT<100 CL
RO
GS
BFG
COG
^100-250 CL
RO
GS
BFG
COG
WT>250 CL
RO
GS
BFG
COG
TOTAL
Firing
PV
CY
OF
SS
UF
PV
CY
OF
SS
UF
PV
CY
OF
SS
UF
AT
6.2
0
11.9
1.9
1.3
2.1
.9
.6
.5
11.2
.1
4.4
.5
.1
.6
.5
.4
.2
12.7
.1
0
.1
0
.4
.3
.2
.2
57.4
GL
25.6
0
48.9
8.0
5.3
1.0
.4
.4
.3
74.9
.3
29.8
3.1
.8
.4
.3
.4
.3
75.9
.5
0
.5
.2
.3
.2
.3
.2
278.3
HS
.5
0
.8
.2
.1
.1
.2
.1
.1
1.2
.4
.4
.1
0
.1
.1
.1
.1
1.7
0
0
0
0
.1
.1
.1
.1
6.7
SE
6.9
0
13.1
2.2
1.3
.1
.2
.1
.1
9.5
0
3.7
.4
.1
0
.1
.1
.1
27.3
.2
0
.2
.1
.1
.1
.1
.1
66.2
Total
39.2
0
74.7
12.3
8.0
3.3
1.7
1.2
1.0
96.8
.8
38.3
4.1
1.0
1.1
1.0
1.0
.7
117.6
.8
0
.8
.3
.9
.7
.7
.6
408.6
D-16
WALDEN RESEARCH CORPORATION
-------
TABLE D-12
N0x EMISSIONS FROM BOILERS IN THE IRON AMD STEEL INDUSTRY - 1980
(TO3 tons)
Size Fuel
WT<100 CL
RO
GS
BFG
COG
WT1 00-250 CL
RO
GS
BFG
COG
WT>250 CL
RO
GS
BFG
COG
TOTAL
Firing
PV
CY
OF
SS
UF
PV
CY
OF
SS
UF
PV
CY
OF
SS
UF
AT
1.0
0
1.7
.5
.3
4.9
8.5
.9
4.2
1.7
.2
.6
.1
0
4.3
7.2
.7
3.6
2.0
.3
0
0
0
3.2
5.3
.5
2.5
54.2
GL
3.7
0
6.6
1.9
1.2
2.3
3.5
.6
3.0
10.9
1.2
4.0
.7
.2
3.0
4.6
.8
4.2
11.1
1.8
0
.1
.1
2.2
3.3
.6
2.9
74.5
WS
.1
0
.1
0
0
.3
2.1
.2
.9
.2
0
.1
0
0
.4
2.1
.2
.8
.3
.1
0
0
0
.4
2.3
.2
1.0
11.8
SE
1.1
0
2.0
.6
.3
.3
1.6
.2
1.1
1.5
.1
.5
.1
0
.2
1.1
.2
.8
4.4
.7
0
.1
0
.4
2.0
.3
1.4
21.0
Total
5.9
0
10.4
3.0
1.8
7.8
15.7
1.9
9.2
14.3
1.5
5.2
.9
.2
7.9
15.0
1.9
9.4
17.8
2.9
0
.2
.1
6.2
12.9
1.6
7.8
161.5
£}_17 WALDEN RESEARCH CORPORATION
-------
REFERENCES TO APPENDIX D
D-l. Systematic Study of Air Pollution from Intermediate-Size Fossil-
Fuel Combustion Equipment, Wai den Research Corporation, Cambridge,
Mass., 1971.
D-2. DeCarlo, et al., Sulfur Content in U.S. Coals, Bureau of Nines
Information Circular 8312, p. 40. 1966.
D-3. Woolf, P.L. and Mahan, W.M., Fuel Oil Injection in an Experimental
Blast Furnace, Bureau of Mines Report of Investigations 6150, p. 13,
1963.
D-4. Vleise, W.H., Blast Furnace Flue Dust Treatment Facilities, Sewage
and Industrial Vlastes. 28, 1398, 1956.
D-5. Hipp, N.E. and Westerholm, J.R., Development in Gas Cleaning -
Great Lakes Steel Corp., Iron and Steel Engineer 44, (8), 101,
1967.
D-6. Bartok, W., et al., Systems Study of Nitrogen Oxide Content Methods
for Stationary Sources, Esso Research and Engineering Co., Govern-
ment Research Laboratory.
D-7. A Systems Analysis Study of the Integrated Iron and Steel Industry,
Battelle Memorial Institute, Columbus, Ohio, 1964.
D-l 8 WALDEN RESEARCH CORPORATION
-------
BIBLIOGRAPHIC DATA
SHEET
1. Report No.
EPA-R2-73-192
3. Recipient's Accession No.
4. Title and Subtitle
Systems Study of Conventional Combustion Sources in the
Iron and Steel Industry
5- Report Date
April 1973
6.
7. Author(s)
J. Goldish, G.Margolis, J. Ehrenfeld, R. Bernstein
8. Performing Organization Kept.
No.
9. Performing Organization Name and Address
Walden Research Corporation
359 Alls ton Street
Cambridge, Massachusetts 02139
10. Project/Task/Work Unit No.
11. Contract/Grant No.
EHSD 71-21
12. Sponsoring Organization Name and Address
EPA, Office of Research and Monitoring
NERC/RTP, Control Systems Laboratory
Research Triangle Park, North Carolina 27711
13. Type of Report & Period
Covered
Final
14.
15. Supplementary Notes
stracts ,j,he rep0rt provides an estimated inventory of: conventional boiler
capacity; and the pollutant emissions attributable to these boilers. Boiler capacity
and emissions are projected to 1980. The report supplements a separate iron and
steel industry process systems study report. Significant findings are that the
boilers are often fired with process waste gases supplementing conventional fuels,
and that the boiler pollutant emissions are significant, compared to process emission:
17. Key U'ords and Document Analysis. 17a. Descriptors
*Iron and Steel Industry
Air Pollution
Boilers
Capacity
Emission
Inventories
Forecasting
17b. Identifiers/Open-Ended Terms
Stationary Sources
17c. COSAT1 Field/Group
18. Availability Statement
Unlimited
19. Security Class (This
Report)
UNCLASSIFIED
20. Security Class (This
Page
UNCLASSIFIED
21. No. of Pages
22. Price
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USCOMM-OC H952-P72
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