William C. Herz 

 Vice President, 

Scientific Programs 

Capitol View 202.962.0490 

425 Third Street, S.W., Suite 950 202.962.0577 fax 

Washington, DC 20024 www.tfi.org 

July 15, 2011 

VIA ELECTRONIC SUBMISSION 

U.S. Environmental Protection Agency 

Office of Air Quality Planning and Standards 

Research Triangle Park 

North Carolina, 27711 

Mr. Brian Shrager 

Shrager.brian@epa.gov 

Docket ID No. EPA-HQ-OAR-2002-0058 

RE: TFI Comments on EPA’s Industrial, Commercial, and Institutional 

Boilers and Process Heaters Final Rule; Delay of Effective Dates 

Dear Sir or Madam: 

The Fertilizer Institute (TFI), on behalf of its member companies, submits these comments in 

response to the U.S. Environmental Protection Agency’s (EPA) May 18 Federal Register notice 

entitled Industrial, Commercial, and Institutional Boilers and Process Heaters and Commercial 

and Industrial Solid Waste Incineration Units; Final Rules, Delay of Effective Dates (the 

“Notice”) (76 Fed. Reg. 28662). This Notice delays the effective date of two EPA final rules: (1) 

National Emission Standards for Hazardous Air Pollutants for Major Sources: Industrial, 

Commercial, and Institutional Boilers and Process Heaters (“Boiler MACT”); and (2) Standards 

of Performance for New Sources and Emission Guidelines for Existing Sources; Commercial and 

Industrial Solid Waste Incineration Units. 1 Further, the Notice, as part of EPA’s reconsideration 

of these two final rules, seeks “any additional data and information” to “inform the EPA’s 

proposed reconsideration.” 76 Fed. Reg. at 28663. To that end, TFI submits these comments in 

response to the Notice.

Statement of Interest 

TFI represents the nation’s fertilizer industry including producers, importers, retailers, 

wholesalers and companies that provide services to the fertilizer industry. Its membership is 

 

1

 While the Notice pertains to two EPA final rules, TFI’s comments only address the final Boiler MACT rule. 
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Docket ID No. EPA-HQ-OAR-2002-0058 

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Page 2 

served by a full-time Washington, D.C., staff in various legislative, educational and technical 

areas as well as with information and public relations programs. 

Many TFI members own and/or operate industrial boilers and process heaters subject to the final 

Boiler MACT rule. Further, TFI submitted comments on EPA’s proposal Boiler MACT rule (75 

Fed. Reg. 32006 (June 4, 2010)). As such, TFI has an interest in the Notice and EPA’s 

reconsideration of the final Boiler MACT rule. 

TFI Comments 

TFI offers the following comments on four elements of the final Boiler MACT rule for EPA’s 

reconsideration. 

A. EPA Fails to Explain Why it Modified the Definition of 

“Units Designed to Burn Gas 1 Subcategory” to Delete the 

“At Least 90 Percent Natural Gas and/or Refinery Gas on a 

Heat Input Basis on an Annual Average” Language as Proposed 

In the proposed Boiler MACT rule, EPA recognized that the designation of subcategories for 

boilers and process heaters should be based on the “primary fuel” that the boiler or process 

heater is designed to burn. 75 Fed. Reg. at 32017. To this end, the Agency recognized when 

defining a number of the subcategories that a boiler or process heater may burn fuels other than 

the primary fuel, so long as the other-than-primary fuels are burned at no more than 10 percent of 

the heat input to the unit. 

As examples: 

 Blast furnace gas fuel-fired boiler or process heater means an 

industrial/commercial/institutional boiler or process heater that receives 90 

percent or more of its total heat input (based on an annual average) from blast 

furnace gas. 

 Liquid fuel subcategory includes any boiler or process heater of any design that 

burns more than 10 percent liquid fuel and less than 10 percent solid fuel, on an 

annual heat input basis. 

 Unit designed to burn biomass subcategory includes any boiler or process heater 

that burns at least 10 percent biomass, but less than 10 percent coal, on a heat 

input basis on an annual average, either alone or in combination with liquid fuels 

or gaseous fuels. 
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 Unit designed to burn coal subcategory includes any boiler or process heater that 

burns coal alone or at least 10 percent coal on a heat input basis on an annual 

average in combination with biomass, liquid fuels, or gaseous fuels. 

- and relevant to TFI members - 

 Unit designed to burn gas 1 (NG/RG) subcategory includes any boiler or process 

heater that burns at least 90 percent natural gas and/or refinery gas on a heat input 

basis on an annual average. 

75 Fed. Reg. at 32063 – 32065 (proposed for codification at 40 C.F.R. § 63.7575) (emphasis 

added). 

In the final Boiler MACT rule, EPA retains the flexibility for units to remain within a 

subcategory while also burning other fuels, so long as the other-than-primary fuels are burned at 

no more than 10 percent of the heat input to the unit. 

As examples: 

 Blast furnace gas fuel-fired boiler or process heater means an 

industrial/commercial/institutional boiler or process heater that receives 90 

percent or more of its total annual gas volume from blast furnace gas. 

 Liquid fuel subcategory includes any boiler or process heater of any design that 

burns more than 10 percent liquid fuel and less than 10 percent solid fuel, based 

on an total annual heat input to the unit. 

 Unit designed to burn biomass/bio-based solid subcategory includes any boiler or 

process heater that burns at least 10 percent biomass or bio-based solids on an 

annual heat input basis in combination with solid fossil fuels, liquid fuels, or 

gaseous fuels. 

 Unit designed to burn coal/solid fossil subcategory includes any boiler or process 

heater that burns coal or other solid fossil fuel alone or at least 10 percent coal or 

other solid fossil fuel on an annual heat input basis in combination with liquid 

fuels, gaseous fuels, or less than 10 percent biomass and bio-based solids on an 

annual heat input basis. 

76 Fed. Reg. at 15682 – 15686 (codified at 40 C.F.R. § 63.7575) (emphasis added). 

However, relevant to TFI members, in the final Boiler MACT rule EPA deletes the no more than 

10 percent other-than-primary fuels flexibility for units to remain within the “Unit designed to 

burn gas 1 subcategory”: 
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 Unit designed to burn gas 1 subcategory includes any boiler or process heater that 

burns only natural gas, refinery gas, and/or other gas 1 fuels; with the exception of 

liquid fuels burned for periodic testing not to exceed a combined total of 48 hours 

during any calendar year, or during periods of gas curtailment and gas supply 

emergencies. 

Id. at 15686 (codified at 40 C.F.R. § 63.7575) (emphasis added). Notably, in the preamble to the 

final Boiler MACT rule discussing changes to the definitions section of the rule, EPA does not 

discuss why it removed the flexibility for gas 1 subcategory units to burn no more than 10 

percent of fuels other than natural gas or refinery gas and still remain in this subcategory. See Id.

at 15620. 

The change in the definition of a “Unit designed to burn gas 1 subcategory” unfairly prejudices 

TFI’s members because instead of relying on the “at least 90 percent natural gas and/or refinery 

gas” threshold to remain in the “Unit designed to burn gas 1 subcategory,” owners and operators 

must now prepare and submit to EPA a site-specific fuel analysis plan and demonstrate that the 

mercury and hydrogen sulfide concentrations meet the “other gas 1 fuel” limits. Further, based 

on conversations with laboratories, TFI members are having difficulties locating laboratories to 

run the designated mercury analysis and hydrogen sulfide analyses specified in Table 6. 

Because this change was made without discussion in the final Boiler MACT rule, or providing 

the public with the ability to comment on it, TFI requests that EPA revert to its proposed 

definition of this subcategory, namely: 

 Unit designed to burn gas 1 (NG/RG) subcategory includes any boiler or process 

heater that burns at least 90 percent natural gas and/or refinery gas on a heat input 

basis on an annual average. 

B. EPA Fails to Recognize Industry-Specific Turn-Around 

Periods and ASME Standards For Inspections of Boilers 

(Including Reformers) in the Ammonia Industry 

Both the proposed and final Boiler MACT rules contain an annual inspection program for units in 

the Gas 1 subcategory. 75 Fed. Reg. at 32059 (proposed for codification at 40 C.F.R. 

§ 63.7540); 76 Fed. Reg. at 15677-78 (codified at 40 C.F.R. § 63.7540). Unlike the proposal 

rule, the final Boiler MACT rule allows the annual burner inspection to be delayed until the next 

scheduled shutdown of the unit, provided the inspection occurs at least once every 36 months. 

Cf proposed 40 C.F.R. § 63.7540(a)(10)(i) with final 40 C.F.R. § 63.7540(a)(10)(i). 

In its comments on the proposed Boiler MACT, TFI urged EPA to recognize limitations 

associated with inspecting the burners in a reformer on an annual basis. Letter from Bill Herz to 

EPA Docket Center (Aug. 23, 2010). As noted by TFI, burner adjustments or pulling burners 

while units or associated process equipment are operating may present worker and/or safety 
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hazards. Further, not all boilers and a few process heaters cannot be readily shut-down, which is 

required for reformers, and the reformer cannot be spared or shut-down without shutting down 

the entire ammonia manufacturing process. 

As such, TFI requested that EPA specify tune-up frequencies based upon standard industry 

practice regarding scheduled turn-arounds or on a frequency consistent with state-specific boiler 

inspection requirements. For example, ASME Section 1 boilers are required to be inspected 

within five years from the date of the last inspection. This boiler inspection interval is consistent 

with preventative maintenance inspections of other equipment and catalyst life in a process unit. 

In its response to TFI’s comments on this issue, EPA stated “[a]s long as owners/operators 

complete the parts of the tune-up that can be completed, they can postpone impractical 

requirements until the next scheduled outage.” EPA, Responses to Comments, Comment EPAHQ-OAR-2002-0058-1910.1, Excerpt 6. This suggests that the time period between outages is 

determined by the owner/operator of the unit, or based on industry-recognized standards such as 

ASME Section 1. However, the regulatory language in 40 C.F.R. § 63.7540(a)(10)(i) provides 

that the shutdown must occur at least every 36 months. 

TFI suggests that EPA adopt the ASME Section 1 standard of a shut-down and inspection of the 

boiler (including the reformer) burners every five years. As an alternative, TFI suggests that the 

Agency define the burner inspection requirement in such a way that does not require the shutdown of the unit, if the “at least every 36 months” language is retained. To that end, TFI 

suggests that the burner inspection requirement be defined to require only inspection of the flame 

and, as necessary, adjustment of the air. 

C. TFI Supports the Ability to Classify Certain Gases, Such as 

Purge Gas Associated with Ammonia Production, as “Other 

Gas 1 Fuel”; however, EPA’s Required Demonstration Does 

Not Make Sense for the Purge Gas Stream 

In the final Boiler MACT rule, EPA allows entities to demonstrate that process gases are 

comparable to natural gas and refinery gas and, therefore, that units combusting these gases are 

subject to the standards for Gas 1 units (referred to as “other gas 1 fuel”). 76 Fed. Reg. at 15669 

(codified at 40 C.F.R. § 63.7521(f) – (i)), 15685 (codified at 40 C.F.R. § 63.7575). TFI supports 

this flexibility. 

As EPA may be aware, a typical ammonia plant uses desulfurized natural gas as both a process 

gas and a fuel gas (see enclosure). Some of the process gas containing unreacted methane is 

purged from the ammonia loop section and routed back to the primary reformer where it is 

burned with incoming desulfurized natural gas as fuel. This purge gas does not contain sulfur 

because the feed to the reformer is desulfurized natural gas, therefore, there is no need to perform 

testing to determine the hydrogen sulfide concentration. Further, the purge gas should not 
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require testing to determine the mercury concentration and a comparison to the 40 

micrograms/cubic meters limit in the regulations since the purge gas stream is merely unreacted 

natural gas purges from the ammonia loop section. 

As such, TFI suggests that EPA revise the Boiler MACT rule to explicitly recognize purge gas 

from an ammonia plant as an “other gas 1 fuel” in EPA’s regulations without the need for the 

preparation and submission to EPA of a site-specific fuel analysis plan and sampling and 

analysis of the purge gas stream to demonstrate that the mercury and hydrogen sulfide 

concentrations meet the “other gas 1 fuel” limits. There is no benefit to developing and 

implementing a sampling plan for this purge gas stream when it is just unreacted natural gas in 

the first instance. 

D. EPA Should Exempt Ammonia Plant Start Up Fired Heaters 

from the Limited-Use Process Heater Definition 

Most ammonia plants have a < 50 mmBtu/hr fired heater which is only used during the initial 

cold start up of an ammonia converter. These heaters are rarely used, and usually have federally 

enforceable permit limits of less than 100 hrs/year. The heaters are usually only required to be 

fired every turnaround, which could be only once in five years. It is not uncommon for these 

heaters to run three years or more before being fired. 

As defined in the final rule, they would meet the definition of a “limited-use process heater” 

since they are over 10 mmBtu/hr and are limited in hours of operation below the threshold of 876 

hours of operation. The regulation would subject these heaters to a one time energy assessment, 

and a tune up every two years. The tune up required would include all of the elements of 40 

CFR 63.7540(a)(10)(i) through 40 CFR 63.7540(a)(10)(vi). 

TFI requests that EPA provide a categorical exemption from the regulation for any boiler or 

process heater that operates less than 100 hrs/yr and that has a federally enforceable limit for 

hours of operation. This could be done either within the definition of limited-use boiler or 

process heater (section 63.7575) or this could be added to the exemptions listed in 63.7491, 

which is titled "Are there any boilers or process heaters that are not subject to this subpart?" 
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Conclusion

TFI is pleased to submit these comments in response to EPA’s Notice regarding reconsideration 

of the final Boiler MACT rule. Should you have any questions regarding our comments, please 

call me at (202) 515-2706, or email me at wcherz@tfi.org. 

Sincerely yours, 

William C. Herz 

Vice President, Scientific Programs 

Enclosure