1

MEMORANDUM

TO: Jim Eddinger, U.S. Environmental Protection Agency, OAQPS

FROM: Eastern Research Group, Inc.

DATE: August 2012

SUBJECT: Revision (August 2012) of Alternate Equivalent Output-Based Emission Limits for 

Boilers and Process Heaters Located at Major Source Facilities

1.0 INTRODUCTION

The purpose of this memorandum is to discuss the changes in the methodology used to 

calculate alternate output-based emission limits from the analysis conducted for the final

reconsideration of the NESHAP for Major Sources: Industrial, Commercial, and Institutional 

Boilers and Process Heaters (76 FR 80598). The methodology used to calculate alternate 

output-based emission limits for the proposed reconsideration of the rule is discussed in 

another memorandum.1 This memorandum focuses only on the changes in methodology since 

the previous analysis.

This memorandum is organized as follows:

1.0 Introduction

2.0 Changes since the Proposed Reconsideration Analysis

3.0 References

Appendix A: Output-Based Emission Limits for Existing Boilers and Process Heaters

Appendix B: Output-Based Emission Limits for New Boilers and Process Heaters
2

2.0 CHANGES SINCE THE PROPOSED RECONSIDERATION ANALYSIS

This section details the changes in the methodology and results of the alternate outputbased emission limit analysis since the analysis conducted for the proposed reconsideration of 

the rule. The methodology used is identical to the methodology described in the memorandum 

for the December 2011 rule analysis, unless otherwise noted.1 The revised output-based 

emission limits for existing and new sources are provided in Appendices A and B, respectively.

2.1 Revised Conversion Factors for Existing Sources

The boilers and process heaters comprising the top performers for each pollutant and 

subcategory have changed since the proposed reconsideration of the rule. Thus, the sources 

for which boiler output data were used to estimate conversion factors for the proposed rule 

analysis were updated for this analysis. This resulted in the conversion factors changing for a 

few subcategories. There were also two new subcategories added since the proposed rule 

which did not have a previously estimated conversion factor. Table 1 shows the subcategories 

for which the conversion factors have changed since the previous analysis. If a subcategory is 

not shown in the table, then its conversion factor did not change.

Table 1 – Changes in Conversion Factors for Existing Sources since the Previous Analysis

Fuel Category Combustor 

Design

Conversion Factors (Steam Btu 

Out/Fuel Btu In)

Proposed Notes

Reconsideration 

Analysis

Revised 

Analysis

All Coal/Fossil 

Solid N/A N/A 0.96 New subcategory

Coal/Fossil Solid FB-HE N/A 0.96 New subcategory; no output 

data, assumed same as Coal FB

Liquid N/A 0.80 0.83 One unit with output data has 

permanently shut down

Light Liquid N/A 0.77 0.83

Only one unit had output data, 

but has since permanently shut 

down; no remaining output 

data, assumed same as Heavy 

Liquid
3

2.2 Revised Conversion Factors for New Sources

For some pollutants and subcategories, the top performer has changed since the 

previous analysis. Thus, the conversion factor for new sources for these subcategories has also 

changed. Table 2 shows the subcategories for which the conversion factors have changed since 

the previous analysis. If a subcategory is not shown in the table, then its conversion factor did 

not change.

Table 2 – Changes in Conversion Factors for New Sources since the Previous Analysis

Subcategory

Top Performer Conversion Factors (Steam Btu 

Out/Fuel Btu In)

Notes

Facility ID Unit ID

Proposed 

Reconsideration 

Analysis

Revised 

Analysis

TSM Coal ILPolyOne B1 N/A 0.86

Coal PM/TSM no 

longer parsed by 

combustor 

design

TSM Heavy 

Liquid MNGPDuluth EU33 Boiler #3 N/A 0.92 There was no 

TSM alternative 

limit for liquid 

units in the 

proposed rule

TSM Light 

Liquid

No output data, assume same 

as TSM Heavy Liquid N/A 0.92

TSM NC-Liquid No output data, assume same 

as TSM Heavy Liquid N/A 0.92

PM Biomass 

Dutch 

Oven/Pile 

Burner

WAWeyerhaeuser_RaymondHog Fuel 

Boiler EU1 0.66 0.75

PM Biomass 

Fuel Cell

ARWeyerhaeuserDierksMill SN-45 0.37 0.67

PM Coal

IAArchersDanielsMidlandDesMoines

Asea Boiler #1 N/A 1.00

Coal PM/TSM no 

longer parsed by 

combustor 

design

PM Light 

Liquid

No output data, assume same 

as PM Heavy Liquid 0.77 0.92

CO Biomass 

Dutch 

Oven/Pile 

Burner

WAWeyerhaeuser_RaymondHog Fuel 

Boiler EU1 0.67 0.75

CO Biomass 

Fuel Cell

ARWeyerhaeuserDierksMill SN-45 0.57 0.67
4

CO Coal FB IAADMCornProcessingCR EU-530 0.98 1.00

CO Coal FB-HE No output data, assume same 

as CO Coal FB N/A 1.00 New subcategory

CO Coal PC IAUofNorthernIowa Boiler #3 1.02 0.99

CO Light Liquid No output data, assume same 

as CO Heavy Liquid 0.77 0.73
5

3.0 REFERENCES

1. Eddinger, Jim, U.S. EPA OAQPS. Revision of Alternate Equivalent Output-Based Emission 

Limits for Boilers and Process Heaters Located at Major Source Facilities. November 

2011.
6

Appendix A

Output-Based Emission Limits for Existing Boilers and Process Heaters
7

Appendix A – Summary of Calculated Output-based (MACT Floor) Emission Limits for Existing Boilers and Process 

Heaters at Major Sources (Units with Heat Input Capacity of 10 Million Btu per Hour or Greater)

Subcategory Pollutant

MACT (heat inputbased) proposed 

emission limits

Output-based 

emission limits

(lb per MMBtu 

of steam 

output)

Output-based 

emission limits

(lb per Mwh)

1. Units in all 

subcategories designed 

to burn solid fuel

a. Hydrogen 

Chloride

2.2E-02 lb per 

MMBtu of heat 

input.

0.025 0.27

 b. Mercury 5.7E-06 lb per 

MMBtu of heat 

input.

6.4E-06 7.3E-05

2. Units design to burn 

coal/solid fossil fuel

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

4.0E-02 lb per 

MMBtu of heat 

input; or (5.3E-05 lb 

per MMBtu of heat 

input).

0.042; or (5.6E05)0.49; or (6.5E04)

3. Pulverized coal 

boilers designed to burn 

coal/solid fossil fuel

a. CO 130 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen, 3-

run average.

0.11 1.4

4. Stokers designed to 

burn coal/solid fossil 

fuel

a. CO 160 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen, 3-

run average.

0.14 1.7

5. Fluidized bed units 

designed to burn coal/ 

solid fossil fuel

a. CO 130 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen, 3-

run average.

0.12 1.4

6. Fluidized bed units 

with an integrated heat 

exchanger designed to 

burn coal/solid fossil 

fuel

a. CO 140 ppm by volume

on a dry basis 

corrected to 3 

percent oxygen, 3-

run average.

0.13 1.5

7. Stokers/sloped 

grate/others designed 

to burn wet biomass 

fuel

a. CO 1,500 ppm by 

volume on a dry 

basis corrected to 3 

percent oxygen, 3-

run average.

1.4 17
8

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

3.7E-02 lb per 

MMBtu of heat 

input; or (2.4E-04 lb 

per MMBtu of heat 

input).

0.043; or (2.8E04)0.52; or 

(0.0034)

8. Stokers/sloped 

grate/others designed 

to burn kiln-dried 

biomass fuel

a. CO 460 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen.

0.42 5.1

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

3.2E-01 lb per 

MMBtu of heat 

input; or (4.0E-03 lb 

per MMBtu of heat 

input).

0.37; or 

(0.0046) 4.5; or (0.056)

9. Fluidized bed units 

designed to burn 

biomass/bio-based solid

a. CO 470 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen, 3-

run average.

0.46 5.2

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

1.1E-01 lb per 

MMBtu of heat 

input; or (1.2E-03 lb 

per MMBtu of heat 

input). 

0.14; or 

(0.0015) 1.6; or (0.017)

10. Suspension burners 

designed to burn 

biomass/bio-based solid

a. CO 2,400 ppm by 

volume on a dry 

basis corrected to 3 

percent oxygen, 3-

run average.

1.9 27

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

5.1E-02 lb per 

MMBtu of heat 

input; or (6.5E-03 lb 

per MMBtu of heat 

input). 

0.052; or 

(0.0066) 0.71; or (0.091)

11. Dutch Ovens/Pile 

burners designed to 

burn biomass/bio-based

solid

a. CO 770 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen, 3-

run average.

0.84 8.4

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

2.8E-01 lb per 

MMBtu of heat 

input; or (2.0E-03 lb 

per MMBtu of heat 

input).

0.39; or 

(0.0028) 3.9; or (0.028)
9

12. Fuel cell units 

designed to burn 

biomass/ bio-based 

solid

a. CO 1,100 ppm by 

volume on a dry 

basis corrected to 3 

percent oxygen.

2.4 12

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

2.0E-02 lb per 

MMBtu of heat 

input; or (5.8E-03 lb 

per MMBtu of heat 

input). 

0.055; or 

(0.016) 0.28; or (0.081)

13. Hybrid suspension 

grate units designed to 

burn biomass/ biobased solid

a. CO 2,800 ppm by 

volume on a dry 

basis corrected to 3 

percent oxygen, 3-

run average.

2.8 31

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

4.4E-01 lb per 

MMBtu of heat 

input; or (4.5E-04 lb 

per MMBtu of heat 

input). 

0.55; or (5.7E04) 6.2; or (0.0063)

14. Units designed to 

burn liquid fuel

a. Hydrogen 

Chloride

1.1E-03 lb per 

MMBtu of heat 

input.

0.0014 0.016

b. Mercury 2.0E-06 lb per 

MMBtu of heat 

input.

2.5E-06 2.8E-05

15. Units designed to 

burn heavy liquid fuel

a. CO 130 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen, 3-

run average.

0.13 1.4

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

6.2E-02 lb per 

MMBtu of heat 

input; or (2.0E-04 lb 

per MMBtu of heat 

input).

0.075; or (2.5E04)0.86; or 

(0.0028)

16. Units designed to 

burn light liquid fuel

a. CO 130 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen.

0.13 1.4

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

7.9E-03 lb per 

MMBtu of heat 

input; or (6.2E-05 lb 

per MMBtu of heat 

input).

0.0096; or 

(7.5E-05)

0.11; or (8.6E04)
10

17. Units designed to 

burn liquid fuel that is a 

non-continental unit

a. CO 130 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen.

0.13 1.4

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

2.7E-01 lb per 

MMBtu of heat 

input; or (8.6E-04 lb

per MMBtu of heat 

input).

0.33; or 

(0.0011) 3.8; or (0.012)

18. Units designed to 

burn gas 2 (other) gases

a. CO 130 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen.

0.16 1.0

b. Hydrogen 

Chloride

1.7E-03 lb per 

MMBtu of heat 

input.

0.0029 0.018

c. Mercury 7.9E-06 lb per 

MMBtu of heat 

input.

1.4E-05 8.3E-05

d. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals).

6.7E-03 lb per 

MMBtu of heat input 

or (2.1E-04 lb per 

MMBtu of heat 

input). 

0.012; or (3.5E04)0.070; or 

(0.0022)
11

Appendix B

Output-Based Emission Limits for New Boilers and Process Heaters
12

Appendix B – Summary of Calculated Output-based (MACT Floor) Emission Limits for New Boilers and Process Heaters 

at Major Sources (Units with Heat Input Capacity of 10 Million Btu per Hour or Greater)

Subcategory Pollutant MACT Floor Inputbased Emission Limit

Output-based 

Emission Limit

(lb per MMBtu 

of steam 

output)

Output-based 

Emission Limit

(lb per Mwh)

1. Units in all 

subcategories designed 

to burn solid fuel

a. Hydrogen 

Chloride

2.2E-02 lb per 

MMBtu of heat 

input.

0.025A 0.28

 b. Mercury 8.0E-07 lb per 

MMBtu of heat 

input.

8.7E-07 1.1E-05

2. Units design to burn 

coal/solid fossil fuel

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

1.1E-03 lb per 

MMBtu of heat 

input; or (2.3E-05 lb 

per MMBtu of heat 

input). 

0.0011; or 

(2.7E-05)

0.014; or (2.9E04)

3. Pulverized coal 

boilers designed to burn 

coal/solid fossil fuel

a. CO 130 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen, 3-

run average.

0.11 1.4

4. Stokers designed to 

burn coal/solid fossil 

fuel

a. CO 130 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen, 3-

run average.

0.12 1.4

5. Fluidized bed units 

designed to burn coal/ 

solid fossil fuel

a. CO 130 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen, 3-

run average.

0.11 1.4

6. Fluidized bed units 

with an integrated heat 

exchanger designed to 

burn coal/solid fossil 

fuel

a. CO 140 ppm by volume

on a dry basis 

corrected to 3 

percent oxygen, 3-

run average.

0.12 1.5

7. Stokers/sloped 

grate/others designed 

to burn wet biomass 

fuel

a. CO 620 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen, 3-

run average.

0.58 6.8
13

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

3.0E-02 lb per 

MMBtu of heat 

input; or (2.6E-05 lb 

per MMBtu of heat 

input).

0.035; or (2.7E05)0.42; or (3.7E04)

8. Stokers/sloped 

grate/others designed 

to burn kiln-dried 

biomass fuel

a. CO 460 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen.

0.42A 5.1

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

3.0E-02 lb per 

MMBtu of heat 

input; or (4.0E-03 lb 

per MMBtu of heat 

input).

0.035; or 

(0.0042) 0.42; or (0.056)

9. Fluidized bed units 

designed to burn 

biomass/bio-based solid

a. CO 230 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen, 3-

run average.

0.22 2.6

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

9.8E-03 lb per 

MMBtu of heat 

input; or (8.3E-05 lb 

per MMBtu of heat 

input).

0.012; or (1.1E04)0.14; or 

(0.0012)

10. Suspension burners 

designed to burn 

biomass/bio-based solid

a. CO 2,400 ppm by 

volume on a dry 

basis corrected to 3 

percent oxygen, 3-

run average.

1.9 27

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

3.0E-02 lb per 

MMBtu of heat 

input; or (6.5E-03 lb 

per MMBtu of heat 

input).

0.031; or 

(0.0066) 0.42; or (0.091)

11. Dutch Ovens/Pile 

burners designed to 

burn biomass/bio-based 

solid

a. CO 330 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen, 3-

run average.

0.35 3.6

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

3.2E-03 lb per 

MMBtu of heat 

input; or (3.9E-05 lb 

per MMBtu of heat 

input).

0.0043; or 

(5.2E-05)

0.045; or (5.5E04)
14

12. Fuel cell units 

designed to burn 

biomass/ bio-based 

solid

a. CO 910 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen.

1.1 10

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

2.0E-02 lb per 

MMBtu of heat 

input; or (2.9E-05 lb 

per MMBtu of heat 

input).

0.030; or (5.1E05)0.28; or (4.1E04)

13. Hybrid suspension 

grate units designed to 

burn biomass/ biobased solid

a. CO 1,100 ppm by 

volume on a dry 

basis corrected to 3 

percent oxygen, 3-

run average.

1.4 12

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

2.6E-02 lb per 

MMBtu of heat 

input; or (4.4E-04 lb 

per MMBtu of heat 

input).

0.033; or (5.5E04)0.37; or 

(0.0062)

14. Units designed to 

burn liquid fuel

a. Hydrogen 

Chloride

4.4E-04 lb per 

MMBtu of heat 

input.

4.8E-04 0.0061

b. Mercury 4.8E-07 lb per 

MMBtu of heat 

input.

5.3E-07 6.7E-06

15. Units designed to 

burn heavy liquid fuel

a. CO 130 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen, 3-

run average.

0.13A 1.4A

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

1.3E-02 lb per 

MMBtu of heat 

input; or (7.5E-05 lb 

per MMBtu of heat 

input).

0.015; or (8.2E05)0.18; or 

(0.0011)

16. Units designed to 

burn light liquid fuel

a. CO 130 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen.

0.13A 1.4A

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

1.1E-03 lb per 

MMBtu of heat 

input; or (2.9E-05 lb 

per MMBtu of heat 

input).

0.0012; or 

(3.2E-05)

0.016; or (4.0E04)
15

17. Units designed to 

burn liquid fuel that is a 

non-continental unit

a. CO 130 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen, 3-

run average.

0.13A 1.4A

b. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals)

2.3E-02 lb per 

MMBtu of heat 

input; or (8.6E-04 lb 

per MMBtu of heat 

input).

0.025; or (9.4E04) 0.32; or (0.012)

18. Units designed to 

burn gas 2 (other) gases

a. CO 130 ppm by volume 

on a dry basis 

corrected to 3 

percent oxygen.

0.16A 1.0A

b. Hydrogen 

Chloride

1.7E-03 lb per 

MMBtu of heat 

input.

0.0029 0.018

c. Mercury 7.9E-06 lb per 

MMBtu of heat 

input.

1.4E-05 8.3E-05

d. Filterable 

Particulate 

Matter (or Total 

Selected 

Metals).

6.7E-03 lb per 

MMBtu of heat 

input; or (2.1E-04 lb 

per MMBtu of heat 

input).

0.012; or (3.5E04)0.070; or 

(0.0022)

A The calculated output-based limit for new sources was less stringent than the output-based limit for existing 

sources for the same subcategory. The new source output-based limit was defaulted to the existing source limit.