Attachment 1

October 2, 2014 Follow-Up Letter
Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

October 2, 2014 

Colleen McKaughan 

Associate Director 

Air Division (AIR-2) 

EPA Region 9 

75 Hawthorne Street 

San Francisco, CA 94105 

Re: Summary of LNA Comments Following LNA/EPA Meeting at Region 9 Headquarters on September 

4, 2014, Regarding Publication of “Promulgation of Air Quality Implementation Plans; Arizona; Regional

Haze and Interstate Visibility Transport Federal Implementation Plan; Final Rule” (Federal. Register, 

Vol. 79, No. 170, September 3, 2014). 

Dear Ms. McKaughan; 

Lhoist North America of Arizona, Inc. (LNA) would like to thank you for giving us the opportunity to 

meet with you and your staff at EPA Region 9 Headquarters this past September 4th to voice our 

concerns regarding the final Regional Haze rules referenced above. As promised in the meeting, this 

letter provides a summary of LNA’s comments and concerns as expressed during the meeting along 

with EPA’s responses, as interpreted by LNA. Our comments are organized into two sections. The 

first section provides a summary of our position on the various aspects of the final rule as discussed in 

the meeting, along with some of our questions which did not get addressed during the meeting due to 

time constraints. The second section provides some technical corrections regarding the actual text of

the final rule. 

Summary of LNA’s Comments and Concerns 

1. Specific Emission Limits Listed in Final Rule 

LNA is in agreement with the emission limits listed in the final rule published September 3, 2014 

which are as follows: 

a. NOX limits: 

 3.80 lb/ton lime for Kiln 1 - 12-month rolling average 

 2.61 lb/ton lime for Kiln 2 -12-month rolling average 

 Short term limit for both kilns combined of 3.27 tons NOx per day based on a 30-kilnoperating-day rolling average 

b. SO2 limits: 

 9.32 lb/ton lime for Kiln 1 - 12-month rolling average 

 9.73 lb/ton lime for Kiln 2 - 12-month rolling average 

 Short term limit for both kilns combined of 10.10 tons SO2 per day based on a 30-kilnoperating-day rolling average 

2. Specific Compliance Deadlines 

As specified in the final rule, LNA must comply with the SO2 limits, including installation of 

Continuous Emission Monitoring Systems (CEMS), no later than March 3, 2016 and must comply 

with the NOX limits no later than September 4, 2017. 
Colleen McKaughan, October 2, 2014 Page 2 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

a. As stated by EPA in the meeting, the above compliance dates mark the beginning of the 

data collection period such that after 30 days and 12 months, respectively, compliance with 

the 30-day and 12-month rolling average limits will be demonstrated. 

b. This is a critical determination as the collection of compliance data over the first 30 days 

and 12 months after the compliance dates affects other stated reporting requirements as 

discussed further below. 

3. Design Report 

As specified in the final rule, a Design Report must be submitted to EPA for review at least 6 

months prior to commencing construction of an ammonia injection system used to comply with the 

limits. 

a. During the meeting LNA asked if there was any specific deadline for submittal of the 

Design Report other than the requirement that it be submitted at least 6-months in advance 

of construction of the Selective Non-Catalytic Reduction (SNCR) for NOX control. EPA 

responded “No”. 

b. LNA then asked EPA what its time commitment was for providing approval/disapproval of 

the Design Report. 

i. EPA responded that they did not intend to approve or disapprove the Design 

Report (or any of the other required documents such as the Optimization Protocol 

and Report) and that they didn’t expect LNA to delay in moving forward with 

installation of the SNCR system because they were waiting for an EPA response. 

ii. LNA then pointed out that Item 13 in Appendix B of the final rule (FR Vol. 79, No. 

170, Page 52497, Column 2) that outlines Optimization Targets specifically states: 

“... with its maximum design stoichiometric rate identified in the Design Report 

approved pursuant to Item 3 of this appendix”. 

iii. EPA acknowledged that the rule would need to be revised to resolve this conflict 

between the rule language and EPA’s intent. 

c. LNA pointed out that the SNCR system will be designed by the contracted vendor with a 

great deal of input from LNA. LNA then asked what level of detail EPA was expecting in 

the Design Report. 

i. EPA responded that they did not have a specific level of detail in mind but that 

they were interested in having general design information such as the injection 

locations. 

ii. LNA then asked how EPA proposed to resolve disagreements between LNA and 

the Agency regarding the Design Report. EPA responded that there was no 

resolution process in place and that EPA did not intend to offer comments on the 

Design Report. This matter may need to be addressed by a change in the 

published rules. 

iii. EPA then stated that their intent was to gather as much information as possible 

regarding the use of SNCR on lime kilns because of the lack of information 

available. 

1). This led to further discussion with LNA pointing out that SNCR has been 

installed on two LNA kilns in Alabama and on another lime kiln in Alabama 

at one of LNA competitor’s plant. LNA also pointed out that LNA’s Five-
Colleen McKaughan, October 2, 2014 Page 3 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

Factor BART analysis contained information documenting that a NOX

control efficiency of 50% is possible on preheater lime kilns. Furthermore, 

the estimated SNCR costs contained in the Five-Factor BART analysis 

were based on information derived from the SNCR systems installed at 

LNA’s facilities

2). EPA stated that they misinterpreted that information and thought the 

information was based on SNCR systems installed at Lhoist plants outside 

of the USA. EPA reiterated that they were under the assumption that no 

lime kilns in the USA currently utilize SNCR for NOX control. 

3). EPA then asked LNA to provide additional details regarding the installation 

of the SNCR systems at the Alabama plants and to explain under what 

permitting circumstances the systems were installed. LNA explained that 

the SNCR system was installed on the new and existing lime kilns as part 

of a capacity expansion project in what was at the time an ozone 

nonattainment area (Jefferson/Shelby County, Alabama). The SNCR 

systems on the two kilns allowed LNA to more than double our existing 

capacity without a significant increase in NOx emissions. 

d. LNA reiterated that the anticipated approach to NOX control at the Nelson Plant may 

incorporate several equipment and operational changes as was the case at LNA’s O’Neal 

Plant in Alabama. These may include changes to the solid fuel milling system, burner pipe 

modifications, installation of an SNCR system, and other operational changes. The SNCR 

system and other changes may incorporate proprietary technology and equipment and will 

need to be treated by both LNA and EPA as confidential business information. EPA 

acknowledged the possible need to designate certain information that may be provided by 

LNA as confidential business information. 

4. Baseline Data Collection 

As stated in the final rule, prior to commencement of continuous operation of the ammonia injection 

system, LNA shall either: (a) collect new baseline emissions and operational data for a 180-day 

period; or (b) submit for EPA review existing baseline emissions and operational data collected 

from a period of time prior to the initiation of a baseline collection period. Such baseline emissions

and operational data shall include the data required by Item 8 below for periods of time 

representing the full range of normal kiln operations. 

a. During the meeting, LNA asked EPA to identify the purpose for collecting 6 months of new 

baseline data. 

 

i. EPA responded that they had received comments that the baseline data used in 

LNA’s BART Analysis was not adequate in length to be considered representative 

data and therefore, EPA wanted to collect new baseline data over a 6-month 

period to compare with the data used in the original analysis. 

ii. LNA responded that even if there were some differences in the baseline averages, 

there would be no other use for the new baseline data. In other words, the BART 

analysis would not be redone in any event. 

iii. More importantly, LNA pointed out that collecting new baseline data would shorten 

by more than 6 months the 18-month and 3-year compliance windows for SO2 and 

NOx compliance. During the 6-month baseline period, LNA would be prohibited 

from initiating any fuel switching, kiln operation control testing, or other emission 

reduction activities that will be required to meet the new emission limits. 
Colleen McKaughan, October 2, 2014 Page 4 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

b. LNA re-emphasized that we do not object to collecting the emissions data once the CEMS 

are in place but the requirement to operate for 6 months without testing and implementing 

emission reduction activities is unacceptable unless EPA revises the rules to allow a 6-

month extension of the compliance dates. As proposed, the 6-month baseline data 

collection period is unacceptable simply because it does not leave LNA enough time to 

implement and test all of the control equipment and operational changes that will be 

required to comply with the new emission limits. LNA also discussed the fact that lime kiln 

emissions vary seasonally (due to changes in ambient temperature, humidity, and moisture 

content of fuels) and that emissions during any 6-month period may differ from those 

observed during any subsequent 6-month period. 

5. Optimization Protocol and Optimization Period 

The final rule states that prior to commencement of the Optimization Period, LNA must submit for 

EPA review an Optimization Protocol for optimizing the ammonia injection system, including 

optimization of the operational parameters resulting in the minimization of emissions of NOX to the 

greatest extent practicable without violating any limits. 

LNA and EPA discussed both the specific language of the final rule and EPA’s expectations with 

respect to the Optimization Protocol and Optimization Period. Major points included in this 

discussion are outlined below: 

a. LNA asked EPA to identify the Agency’s authority to require the Optimization “Study”. EPA 

responded that the definition of BART in the Regional Haze Rule and Section 114 of the 

Clean Air Act gives EPA broad authority to issue such requirements and that they would 

provide LNA with a written justification of their authority to require that LNA prepare and 

submit the Optimization Protocol and conduct the Optimization and Demonstration studies. 

b. LNA explained that the company’s vision of “optimization” was fundamentally different than 

EPA’s definition. 

i. EPA’s definition of optimization essentially requires the NOx control system, 

(SNCR), to be operated so as to minimize emissions of NOx. EPA’s approach 

would require that LNA inject the SNCR reagent (likely urea) at whatever amounts 

necessary to achieve the maximum NOx emission reductions. 

ii. LNA explained that their approach to reducing NOX emissions to meet the 

compliance limits will likely be a combination of SNCR, equipment modifications 

and operational controls so as to meet the numeric NOx emission limitation 

specified in the final rule. LNA believes “optimization” means implementation of 

equipment and operational controls that minimize NOx emissions while also 

minimizing other possibly adverse environmental impacts. LNA’s vision of 

optimization includes minimizing the use of urea and energy consumption 

(including associated GHG emissions). LNA’s objectives include minimizing water 

consumption, avoiding waste production as well as consideration of costs, 

production losses and impacts on product quality. 

iii. LNA emphasized that the fundamental differences in how LNA and EPA perceive 

the concept of optimizing the NOX controls presents a serious problem for LNA 

with respect to complying with the specific optimization requirements listed in the 

final rule. 

c. The final rule also requires that the Optimization Protocol describe procedures to be used 

during the Optimization Period to optimize facility processes to minimize emissions from 

the kiln and to adjust the ammonia injection system operating parameters. Item 10 in 
Colleen McKaughan, October 2, 2014 Page 5 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

Appendix B of the final rule (FR Vol. 79, No. 170, Page 52497, Column 1) states that the 

protocol shall specify: 

 The range of reagent injection rates (as a molar ratio of the average pollutant 

concentration); 

 Sampling and testing programs that will be undertaken during the initial reagent 

injection rate period; 

 A plan to increase the reagent injection rate to identify the injection rates with the 

maximum emission reduction effectiveness and associated sampling and testing 

programs for each increase in the reagent rate. The owner/operator shall test, at a 

minimum, the ammonia injection system at three molar ratios of 0.75, 1.0, and 1.20; 

 The factors that will determine the optimum reagent injection rates and pollutant 

emission reductions (including maintenance of Kiln, productivity, and product 

quality); 

 Evaluation of any observed synergistic effects on Kiln emissions, Kiln operation, 

reagent slippage, or product quality from the ammonia injection system; and 

 Any additional facility processes that the owner/operator determines may reduce 

NOX emissions in conjunction with the ammonia injection system. 

i. Again, LNA pointed out how the above requirements are in conflict with how LNA 

anticipates it will achieve compliance with the NOX emission limits. 

ii. LNA also pointed out that kiln operating parameters are not easily “optimized” as 

defined by EPA. As explained by LNA, kiln operating parameters are dynamic, 

constantly changing depending on various related parameters such as ambient 

temperatures, stone characteristics, fuel characteristics, and normal operational 

changes that occur between major kiln outages. Furthermore, as each operating 

parameter changes, other parameters are in-turn affected and may need to be 

adjusted accordingly. Thus, most kiln operating parameters don’t lend themselves 

to being “optimized” to a given operating value or range of values. The system is 

simply too dynamic and interdependent. 

iii. LNA explained how they have substantial reservations about “optimizing kiln 

operations” for the purposes of operating the SNCR system. LNA went on to 

explain further that kiln operations are “optimized” to meet production, fuel 

efficiency and quality demands and that BART applies retrofit controls to the 

existing equipment and operations and conforms to those operations; it does not 

require the process operations to conform to BART except to the extent necessary 

to meet the applicable emission limitations. 

d. LNA stated that they assumed that the 180-day Optimization Period would occur after the 

compliance date. EPA stated they anticipated that it would occur prior to the compliance 

date. 

i. LNA did not have a chance during the meeting to fully comment on this issue. 

LNA’s position is that the very prescriptive nature of the optimization requirements 

being imposed by EPA is in direct conflict with how LNA anticipates they will 

achieve compliance with the BART emission limits. LNA believes emission control 

and kiln operating parameters will be always changing in response to changes in 

related equipment conditions and ambient conditions. Thus, LNA anticipates it will 

fully utilize all of the time in the compliance window to study and adjust parameters 

in order to develop a compliance strategy by the compliance date. If LNA is forced 

to conduct the Optimization Period prior to compliance date, their opportunity to 

develop a successful compliance strategy will be shortened by 6 months, much 

like what will happen if LNA is forced to collect new baseline data for 6 months as 

discussed above. Also, an optimization period of 6 months does not capture an 
Colleen McKaughan, October 2, 2014 Page 6 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

annual weather cycle and therefore, the information most likely will not represent 

the normal and anticipated range of weather conditions. 

ii. This difference in interpretation regarding the conduct and scheduling of the 

Optimization Period was not resolved in the meeting. 

e. LNA believes the issues surrounding the Optimization Protocol and Optimization Period 

must be formally resolved before moving forward. LNA suggested in the meeting that EPA 

remove the specific requirements of the Optimization and Demonstration Programs from 

the final rule and transfer them into a separate written agreement that can be negotiated 

outside the boundaries of the rule making process. 

6. Optimization Report 

As stated in the final rule, within 60 days following the termination of the Optimization Period, LNA 

shall submit to EPA for review an Optimization Report demonstrating conformance with the 

Optimization Protocol for the ammonia injection system and establishing the optimized operating 

parameters for the facility processes and the ammonia injection system determined under the 

Optimization Protocol, including optimized injection rates for all reagents. 

 Optimization Targets: Except as otherwise provided in this Item and in the next item below, the 

ammonia injection system shall be deemed to be optimized if the Optimization Report 

demonstrates that the ammonia injection system during periods of normal operation has 

achieved emission reductions consistent with its maximum design stoichiometric rate identified 

in the Design Report approved pursuant to the conditions listed above. 

 Notwithstanding the provisions listed above, the ammonia injection system may be deemed to 

be optimized at a lower rate of emission reductions than that identified above if the 

Optimization Report demonstrates that, during periods of normal operation, a lower rate of 

emission reductions cannot be sustained after all parameters and injection rates are optimized 

during the Optimization Period without creating a meaningful risk of impairing product quality, 

impairing Kiln system reliability, impairing compliance with a maximum ammonia slip emissions 

limit of 10 ppm or other permitted levels, or forming a detached plume. 

a. LNA explained that a 180-day Optimization Period provides no guarantee that optimized 

operating parameters can be established for the facility processes and the ammonia 

injection system. LNA reiterated the fact that environmental factors and operating 

conditions change throughout the year. Winter conditions, such as below zero 

temperatures, snow, and frozen fuel, present much different operating challenges than 

summer conditions consisting of temperatures above 100°F, monsoon rains and frequent 

power bumps. Thus, the optimization of parameters “optimized” during one part of the year 

may not be sustainable during another part of the year because of constantly changing 

environmental and operational conditions, not to mention forced changes due to such 

things as inventory control and customer demands. 

b. LNA noted that that continuous ammonia slip measurement systems are not readily 

available. Usually, compliance with ammonia slip limits is demonstrated through an initial 

stack test and then annual stack tests thereafter. LNA asked that EPA define the 

requirements for demonstrating compliance with the ammonia slip limit of 10 ppm. LNA 

also asked how EPA expected LNA to collect ammonia slip data throughout the 

optimization period. These issues were not resolved in the meeting. 

c. Due to time constraints, several questions regarding the Optimization Program that LNA 

presented to EPA before the meeting did not get discussed. One question concerned the 

mechanism for LNA and EPA to resolve disagreements concerning any proposed 

optimization parameter values, particularly if based on LNA’s knowledge and experience 
Colleen McKaughan, October 2, 2014 Page 7 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

such conditions are considered unachievable or non-sustainable by LNA or LNA's 

equipment design and supply firms? This question was not resolved. 

7. Demonstration Period: 

The Demonstration Period shall commence within 7 days after the owner/operator’s receipt of the 

final comments from EPA on the Optimization Report. During the Demonstration Period, the 

owner/operator shall operate the ammonia injection system for a period of 360 Operating Days 

consistent with the optimized operations of the Facility and the ammonia injection system as 

contained in the Optimization Report. 

a. LNA’s position is that whether or not the Optimization Period is before or after the NOX

compliance date, the requirement to begin the Demonstration Period within 7 days after 

receipt of final comments from EPA on the Optimization Report is unreasonable. First, 

EPA has no stated time commitment to provide comments on the Optimization Report. 

Consequently, LNA could be waiting for weeks with no idea when comments might be 

received and then will have to act within 7 days after receiving the comments. Additionally, 

the rules as written, provide no mechanism for LNA and EPA to discuss any conclusions 

from the Optimization Period. Likewise, the rules as finalized do not provide a mechanism 

for rebutting or resolving disagreements between EPA and LNA. At a minimum, LNA 

requests this requirement be revised to a more reasonable time period in the order of 45 to 

60 days and that EPA revise the rules to provide a dispute resolution mechanism related to 

technical and regulatory matters. 

b. If EPA determines that the rules as promulgated require that the Optimization Period must 

be completed before the NOX compliance date and even if LNA receives timely comments 

from EPA on the Optimization Report, LNA will be forced to begin the Demonstration 

Period before the compliance date. Again, like the collection of new baseline data, this will 

take away valuable time from LNA’s compliance window, time needed to develop a 

sustainable compliance strategy. 

c. LNA requests that if a Demonstration Period is ultimately required, it be explicitly required 

to begin after the NOX compliance date. 

8. Demonstration Report 

Within 60 days following completion of the Demonstration Period for the ammonia injection system, 

shall submit a Demonstration Report to EPA, based upon and including all of the data collected 

during the Demonstration Period including data from Startup, Shutdown and Malfunction events 

that identifies a proposed rolling 12-month emission limit for NOX. The rolling 12-month emission 

limit for NOX shall be based upon an analysis of CEMS data and lime production data collected 

during the Demonstration Period, while the process and ammonia injection system parameters 

were optimized in determining the proposed Emission Limit(s) achievable for the Facility. 

 The owner/operator shall propose a rolling 12-month emission limit for NOx in the 

Demonstration Report(s) as provided in the preceding Paragraph. This rolling 12-month limit 

shall be calculated in accordance with the following formula: 

X= μ + 1.65σ 

Where: 

X = Rolling 12-month Average Emission Limit (lb/ton of lime product) 

μ = arithmetic mean of all of the Rolling 12-month averages 

σ = standard deviation of all of the rolling 12-month averages 
Colleen McKaughan, October 2, 2014 Page 8 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

a. LNA demonstrated during the meeting that the equation as presented in the final rule is in 

error as there will be only one (1) 12-month rolling average upon which to calculate the 

value of “μ”. This fact is explained in the next section of this letter. 

b. LNA then pointed out that an emission limit based upon an average plus 1.65 standard 

deviations statistically captures 90% of the normal distribution, with 5% of the values being 

on the low end of the normal bell-shaped distribution and 5% of the values being on the 

high end of the distribution. Statistically, this means that 5% of the values would be above 

the calculated emission limit and thus, excess emissions would be expected to be 

exceeded 5% of the time. 

c. LNA reiterated that they must be in compliance 100% of the time and that proposing a limit 

based on the equation in the final rule, which predicts non-compliance 5% of the time, was 

simply unacceptable. 

d. LNA requests that EPA revise the rule regarding submittal of a Demonstration Report to 

specify that the report shall contain the data collected but without the proposed 

methodology for calculating a revised limit. LNA does not believe that this requirement 

conforms to BART and that LNA cannot be required to propose a limit that statistically 

predicts the source will be out of compliance 5% of the time. 

9. Data Collection 

The data to be collected during the Baseline Data Collection Period and the Optimization Period 

will include the following information either derived from available direct monitoring or as estimated

from monitored or measured data: 

 

 Kiln flue gas temperature at the inlet to the fabric filter or at the Kiln stack (daily 

average); 

 Kiln production rate in tons of lime product (daily total) by type; 

 NOx and CO concentrations (dry basis) and mass rates for the Kiln (daily average for 

concentrations and daily totals for mass rates) as measured at the Kiln stack gas 

analyzer location; 

 Flue gas volumetric flow rate (daily average in dry acfm); 

 Sulfate in feed (calculated to a daily average percentage); 

 Feed burnability (C3S) (at least daily). In the event that more than one type of lime 

product is produced, the feed burnability for each type of lime product will be included; 

 Temperatures in or near the burning zone (by infrared or optical pyrometer); 

 Kiln system fuel feed rate and type of fuel by weight or heat input rate (calculated to a 

daily average); 

 Fuel distribution, an estimate of how much is injected at each location (daily average); 

 Kiln amps (daily average); 

 Kiln system draft fan settings and primary air blower flow rates; 

 Documentation of any Startup, Shutdown, or Malfunction events; 

 An explanation of any gaps in the data or missing data; and 

 Amount of oxygen generated and introduced into the Kiln (lb/day). 

 

a. LNA explained that the parameters "Sulfate in feed", "Feed burnability" and "Fuel 

distribution" are common cement industry operating parameters and are not applicable to 

the lime industry. Consequently, LNA will not be able to provide data on these parameters. 

Additionally, the "Amount of oxygen generated and introduced into the kiln" is a cement 

industry practice not used at the Nelson Plant. Consequently, LNA will not be able to 

provide data on this parameter as well. EPA acknowledged that some of the parameters 
Colleen McKaughan, October 2, 2014 Page 9 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

were drawn from a cement industry consent order and that EPA understood that data for 

some of the parameters listed could not be collected. 

b. LNA contends that it is inappropriate and unnecessary for EPA to extrapolate from a 

cement industry enforcement action to LNA’s BART emission limitations and that the 

requirements for the Optimization Protocol, Optimization Period, Demonstration Period and 

Demonstration Report should be removed from the rules applicable to the Nelson Plant. 

10. Installation of CEMS 

The final rule states that at all times after the compliance dates, LNA shall maintain, calibrate, and

operate a CEMS, in full compliance with the requirements found at 40 CFR 60.13 and 40 CFR Part 

60, Appendices B and F, to accurately measure diluent, stack gas volumetric flow rate, and 

concentration by volume of NOX and SO2 emissions into the atmosphere from kilns 1 and 2. The 

CEMS shall be used to determine compliance with the emission limitations, in combination with 

data on actual lime production. LNA must operate the monitoring system and collect data at all 

required intervals at all times that an affected kiln is operating, except for periods of monitoring 

system malfunctions, repairs associated with monitoring system malfunctions, and required 

monitoring system quality assurance or quality control activities (including, as applicable, 

calibration checks and required zero and span adjustments). 

a. LNA requested that EPA clarify whether the above condition means that the CEMS must 

be operated during periods when the units are down. It should not, but the language 

literally says they must. The obligation to operate CEMS should be limited to when the 

units themselves are operating. This is implied by the third sentence, but there is a 

conflict. EPA confirmed LNA’s interpretation is correct. 

11. Compliance Determination for ton per day NOX and SO2 limits 

As stated in the final rule, compliance with the NOX and SO2 emission limits shall be determined 

based on a rolling 30-kiln-operating-day basis. The rolling 30-kiln operating day emission rate for 

the kilns shall be calculated for each kiln operating day in accordance with the following procedure. 

The rule then goes on to explain the procedure. 

a. Unlike the provisions for the lb/ton limits, EPA does not state when LNA needs to have 

these values calculated. LNA suggested three business days or within a calendar week to 

complete the 30-day calculation. There was some discussion about these data being 

automatically derived by the CEMS data acquisition system but since the limit is a 

combined kiln limit, this possibility could not be confirmed. Thus, this issue was not fully 

resolved in the meeting. 

12. Recordkeeping 

The owner/operator shall maintain operating conditions at the time of measurement or monitoring 

equipment maintenance activity. 

a. Although not discussed in the meeting, LNA requests that the specific “operating 

conditions” to be measured and monitored be specified. 

13. Reporting: 

The final rule states that all reports required under this section shall be submitted by the 

owner/operator to the Director, Enforcement Division (Mail Code ENF-2-1), U.S. Environmental 

Protection Agency, Region 9, 75 Hawthorne Street, San Francisco, California 94105-3901. All 

reports required under this section shall be submitted within 30 days after the applicable 
Colleen McKaughan, October 2, 2014 Page 10 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

compliance date(s) in paragraph (i)(4) of this section and at least semiannually thereafter, within 30

days after the end of a semiannual period. The final rule states that the following reports need to be

submitted. 

 The owner/operator shall submit a report that lists the daily rolling 30-kiln operating day 

emission rates for NOX and SO2, calculated in accordance with paragraphs (i)(6)(iii) and (iv) of 

this section. 

 The owner/operator shall submit a report that lists the monthly rolling 12-month emission rates 

for NOX and SO2, calculated in accordance with paragraphs (i)(6)(v) and (vi) of this section. 

a. As explained in the discussion above, LNA and EPA both agreed that collecting the first 

30-day and 12-month compliance data will begin after the compliance dates. 

Consequently, the above reporting requirements need to be revised. With the first report 

due within 30 days, a full set of 30-day and 12-month rolling average data will not have 

been collected yet. Likewise, the first two semi-annual reports will not include a full set of 

12-month rolling data as that data will not have been collected yet. 

14. Startup, Shutdown and Malfunction Emissions 

LNA notes that EPA has deleted the startup, shutdown and malfunction provisions from the 

proposed rule. LNA notes that the development of the limits in this matter only reflected routine 

startup and shutdown and short-term malfunctions (e.g., those resolvable in a 5 hour or shorter 

period). It is not clear what regulatory basis exists for extending the proposed limits to long-term 

malfunctions. Because LNA cannot foresee such issues, LNA reserves its rights to contest the 

attempt by any party, including EPA, to apply these BART limits against LNA in the event of a longterm malfunction situation. 

General Editorial and Technical Corrections 

1. The table in the first column on page 52480 of the Federal Register, Vol. 79, No. 170, under 

§ 52.145(i)(3)(i) has incorrect column headings. 

The table should be corrected from: 

Kiln ID Pollutant 

NOx SO emission limit 2

Kiln 1 ........... 3.80 .......... 9.32 

Kiln 2 ........... 2.61 .......... 9.73 

To: 

 Pollutant Emission Limits 

Kiln ID NOx SO2

Kiln 1 ........... 3.80 .......... 9.32 .......... 

Kiln 2 ........... 2.61 .......... 9.73 .......... 
Colleen McKaughan, October 2, 2014 Page 11 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

2. Consistent with the discussion above, the introductory language of paragraph (i)(5) in the 

center column on page 52480 of the Federal Register, Vol. 79, No. 170, needs to be revised 

because it suggests that the process should be optimized to the SNCR system rather than the 

SNCR system optimized to the process. LNA suggests the following change: 

(5) Control technology demonstration requirements. If the owner/operator of a kiln 

installs an ammonia injection system to comply with the limits specified in paragraph 

(i)(3) of this section, the owner/operator must comply with the following requirements 

for implementing combustion and process optimization measures: 

In subparagraph (ii), “for the purpose of adjusting ammonia injection operating 

parameters and minimizing emissions. 

In subparagraph (iv), strike “as well as other facility processes.” 

In subparagraph (v), strike “with the optimized operations of the facility and.” LNA also 

notes that this requirement is extremely vague. 

In subparagraph (vi), as discussed above, LNA has significant problems with the 

proposed calculation methodology and the requirement that it “propose” an approach 

with which it disagrees. LNA believes that this disagreement can be minimized by 

striking everything after “shall submit a Demonstration Report” or, if EPA wishes for 

LNA to propose a limit, striking everything starting with the following sentence: “In a 

subsequent regulatory action...” EPA may, obviously, start a regulatory action at any 

time so the language is not needed. 

3. The equation in the third column on page 52480 of the Federal Register, Vol. 79, No. 170, 

under §52.145(i)(5)(vi) is incorrect based on the BART requirements of the Clean Air Act. See 

discussion above. It is also incorrect as a statistical matter based on the requirement to solve 

this equation following the Demonstration Period which is 360 days. The equation is stated as 

follows: 

X = μ + 1.65σ

Where: 

X = Rolling 12-month emission limit, in pounds of NOX per ton of lime product; 

μ = Arithmetic mean of all of the rolling 12-month emission rates; 

σ = Standard deviation of all of the rolling 12-month emission rates, as calculated in 

the following manner: 

Where: 

N = The total number of rolling 12-month emission rates; 

xi = Each rolling 12-month emission rate; 

̅ = The mean value of all of the rolling 12-month emission rates. 
Colleen McKaughan, October 2, 2014 Page 12 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

After 360 days, there will be only one (1) 12-month average (short by 5 days) making the value 

of N equal to 1. With only one average, the values of xi and ̅ will be the same making the 

value of (xi – ̅)

2

 zero. This in turn will make the value of σ zero, rendering the value of X 

simply equal to the single 12-month average with no added standard deviation value to 

account for variability. 

The above equation becomes meaningful as written only after 12 months or so of data is 

collected after the 360-day Demonstration Period, making the value of N equal to 12. 

4. On page 52481 of the Federal Register, Vol. 79, No. 170, column 3, in subparagraph 

(i)(7)(v)(C), the “operating conditions at the time of measurement or monitoring equipment 

maintenance activity” is vague. It should be reworded as “whether the equipment controlled or 

monitored is operating” or something similar. 

Again, LNA appreciates the opportunity to submit these comments. If you have any questions or need 

any additional information please do not hesitate to contact me. I can be reached at (928) 769-2271 

extension 645104 or by email at Herbert.Verville@Lhoist.com. 

Sincerely, 

Herbert J. Verville 

Environmental Manager 
Attachment 2

October 2, 2014 O’Neal Plant Data
 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

October 2, 2014 

Colleen McKaughan 

Associate Director 

Air Division (AIR-2) 

EPA Region 9 

75 Hawthorne Street 

San Francisco, CA 94105 

Re: LNA Response to EPA Request for Information Regarding SNCR Control Efficiencies at the O’Neal 

Lime Plant. 

Dear Ms. McKaughan; 

This letter provides the NOx emissions data from Lhoist North America’s (LNA) O’Neal Alabama Lime 

Plant. These data demonstrate a range of Selective Non-Catalytic Reduction (SNCR) performance 

values as requested in your email to LNA dated September 5, 2014. Also included is the additional 

information you requested regarding a description of similarities between the Alabama kilns and the 

Nelson kilns. The purpose of these data is to support the use of the O’Neal kiln SNCR data as being 

sufficiently representative of the expected performance of SNCR and other NOx emission reduction 

techniques to be implemented on the Nelson kilns to achieve the emission limitations contained in EPA’s 

September 3, 2014 rulemaking. From LNA’s industrial experience, we feel that O’Neal Kiln 1 is more 

similar to the two Nelson Plant kilns. Consequently, the data regarding SNCR control efficiencies are

from Kiln 1 at the O’Neal Plant. 

Kiln Comparison Data 

Nelson Kiln 1 

a) Fuel Mill Type: 9 foot x 12 foot (diameter x length) roller mill operating at 22 revolutions per 

minute 

b) Fuel Blend: approximately 72% coke / approximately 28% coal 

c) Burner Pipe: single channel burner pipe 

d) Kiln: KVS 15 foot x 155 foot (diameter x length) rotary kiln 

e) Preheater: 14 plunger polygon preheater 

f) Production: Design = nominal 850 tons per day lime production; Permitted = No enforceable limit; 

Actual = approximately 850 tons per day 

g) Fuel Efficiency: Range = 4.7 to 5.2 MMBtu/ton of lime; Average = 4.97 MMBtu/ton of lime 

(2014 year-to-date) 

Nelson Kiln 2 

a) Fuel Mill Type: 10 foot x 10 foot (diameter x length) roller mill operating at 21 revolutions per 

minute 

b) Fuel Blend: approximately 72% coke / approximately 28% coal 

c) Burner Pipe: single channel burner pipe 

d) Kiln: KVS 17 foot x 178 foot (diameter x length) rotary kiln 

e) Preheater: 18 plunger polygon preheater 

f) Production: Design = nominal 1100 tons per day lime production; Permitted = No enforceable 

limit; Actual = approximately 1100 tons per day 

g) Fuel Efficiency: Range = 4.3 to 5.0 MMBtu/ton of lime; Average = 4.58 MMBtu/ton of lime 

(2014 year-to-date) 
Colleen McKaughan, October 2, 2014 Page 2 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

O’Neal Kiln 1 

a) Fuel Mill Type: AB Raymond Model 633 roller mill with a nominal capacity of 10 tons per hour 

b) Fuel Blend: 99.9% Coal / 0.1% Natural Gas 

c) Burner Pipe: Multi-channel 

d) Kiln: 16 foot x 210 foot (diameter x length) rotary kiln 

e) Preheater: 20 plunger 

f) Production: Design = Nominal 1500 tons per day; Permitted = 1500 tons per day; Actual = 

approximately 1000 tons per day based on current production demand. Higher production rates 

have previously been demonstrated 

g) Fuel Efficiency: Range = 5.0 to 6.0 MMBtu/ton of lime; Average = 5.2 MMBtu/ton of lime 

O’Neal Kiln 2 

a) Fuel Mill Type: AB Raymond Model 623RS roller mill with a nominal capacity of 15 tons per hour 

b) Fuel Blend: 98% Coal / 2% Natural Gas 

c) Burner Pipe: Multi-channel 

d) Kiln: 16 foot x 241 foot (diameter x length) rotary kiln 

e) Preheater: 16 plunger 

f) Production: Design = 1500 tons per day; Permitted = 1500 tons per day; Actual = approximately 

1000 tons per day based on current production demand. Higher production rates have previously 

been demonstrated 

g) Fuel Efficiency: Range = 5.0 to 6.0 MMBtu/ton of lime; Average = 5.9 MMBtu/ton of lime 

SNCR Control Efficiencies 

As shown in the kiln comparison data presented above, Kiln 1 at the O’Neal Plant is more similar to the 

two Nelson Plant kilns when considering the kiln dimensions and solid fuel use. The preheater on Kiln #2 

at O’Neal is a modular or canister design. The preheater on Kiln #1 at O’Neal is more similar in design to 

the preheaters used at the Nelson Plant. Kiln 1 is also the kiln that LNA used to establish baseline 

emissions as part of the permitting process for Kiln 2. Consequently, the data regarding SNCR control 

efficiencies presented below are from Kiln 1 at the O’Neal Plant. 

LNA installed the SNCR system on Kiln 1 at O’Neal to reduce NOx to the extent necessary to allow 

construction of Kiln 2 without triggering major new source review. For that purpose, the total reduction in 

tonnage of NOx, rather than the specific control efficiency, was most important and engineering was 

focused on achieving the needed reduction. Operation of the plant has provided, however, some short 

term opportunities to assess the relative performance of the kiln due to interruptions in the SNCR system 

while the CEMS was still operating. LNA has based its assessment of the likely control efficiencies 

achievable by an SNCR system on the Nelson kilns based upon these periods, together with an 

understanding of additional steps that could be taken to further improve efficiency based on lessons 

learned at O'Neal. The data are presented below, as is LNA's analysis of why a slightly higher value 

should be achievable at Nelson. 

Background 

The SNCR system at the O’Neal Plant is operated on a continuous basis. However, there are times 

when the system malfunctions. The majority of these malfunctions have occurred at night during the 

winter when ambient temperatures fall to the point where the 50/50 water/urea mixture freezes in the 

distribution pipes. This freezing prevents the SNCR system from working. It often takes several hours 

before the pipes are thawed and SNCR operations resume. NOX CEMS data associated with these 

freeze up periods can be evaluated to establish a range of SNCR performance values, at least under the

conditions then present. 
Colleen McKaughan, October 2, 2014 Page 3 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

SNCR Control Efficiencies 

Graphic presentations of six separate SNCR malfunctions are presented in Figures 1 through 6. These 

figures show the NOx emissions data in pounds of NOx per hour (lb/hr). The raw CEMS data (in parts 

per million (ppm)) for these six time periods were extracted from the O’Neal data acquisition system and 

are summarized into hourly averages. These summaries are presented in Tables 1 through 6. 

Figure 1. Graphic presentation of NOx emissions (lb/hr) for August 28, 2011 (see associated 

hourly averages in Table 1). 

 
Colleen McKaughan, October 2, 2014 Page 4 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

Table 1. Hourly NOx Averages for August 28, 2011 

Date and Time NOx Hourly Avg (ppm) SNCR Status 

8/28/11 1:00:00 AM 147.42 SNCR On 

8/28/11 2:00:00 AM 124.21 SNCR On 

8/28/11 3:00:00 AM 65.87 SNCR On 

8/28/11 4:00:00 AM 98.05 SNCR On 

8/28/11 5:00:00 AM 88.74 SNCR On 

8/28/11 6:00:00 AM 110.44 SNCR On 

8/28/11 7:00:00 AM 123.36 SNCR On 

8/28/11 8:00:00 AM 115.02 SNCR On 

8/28/11 9:00:00 AM 155.64 SNCR On 

8/28/11 10:00:00 AM 108.10 SNCR On 

8/28/11 11:00:00 AM 139.64 SNCR On 

8/28/11 12:00:00 PM 114.27 SNCR On 

8/28/11 1:00:00 PM 125.74 SNCR On 

8/28/11 2:00:00 PM 146.04 SNCR On 

8/28/11 3:00:00 PM 155.72 SNCR On 

8/28/11 4:00:00 PM 64.95 SNCR On 

8/28/11 5:00:00 PM 219.88 SNCR Malfunction 

8/28/11 6:00:00 PM 248.71 SNCR Malfunction 

8/28/11 7:00:00 PM 266.95 SNCR Malfunction 

8/28/11 8:00:00 PM 261.90 SNCR Malfunction 

8/28/11 9:00:00 PM 236.30 SNCR Malfunction 

8/28/11 10:00:00 PM 249.38 SNCR Malfunction 

8/28/11 11:00:00 PM 238.58 SNCR Malfunction 

8/29/11 12:00:00 AM 226.32 SNCR Malfunction 
Colleen McKaughan, October 2, 2014 Page 5 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

Figure 2. Graphic presentation of NOx emissions (lb/hr) for August 30, 2011 (see associated 

hourly averages in Table 2). 

 
Colleen McKaughan, October 2, 2014 Page 6 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

Table 2. Hourly NOx Averages for August 30, 2011 

Date and Time NOx Hourly Avg (ppm) SNCR Status 

8/30/11 1:00:00 AM 145.38 SNCR On 

8/30/11 2:00:00 AM 128.05 SNCR On 

8/30/11 3:00:00 AM 177.31 SNCR On 

8/30/11 4:00:00 AM 207.63 SNCR Malfunction 

8/30/11 5:00:00 AM 305.12 SNCR Malfunction 

8/30/11 6:00:00 AM 341.27 SNCR Malfunction 

8/30/11 7:00:00 AM 247.11 SNCR Malfunction 

8/30/11 8:00:00 AM 266.96 SNCR Malfunction 

8/30/11 9:00:00 AM 226.23 SNCR Malfunction 

8/30/11 10:00:00 AM 295.71 SNCR Malfunction 

8/30/11 11:00:00 AM 312.34 SNCR Malfunction 

8/30/11 12:00:00 PM 236.44 SNCR Malfunction 

8/30/11 1:00:00 PM 174.49 SNCR On 

8/30/11 2:00:00 PM 188.99 SNCR On 

8/30/11 3:00:00 PM 147.29 SNCR On 

8/30/11 4:00:00 PM 161.18 SNCR On 

8/30/11 5:00:00 PM 151.17 SNCR On 

8/30/11 6:00:00 PM 148.31 SNCR On 

8/30/11 7:00:00 PM 153.88 SNCR On 

8/30/11 8:00:00 PM 148.61 SNCR On 

8/30/11 9:00:00 PM 154.33 SNCR On 

8/30/11 10:00:00 PM 151.53 SNCR On 

8/30/11 11:00:00 PM 151.31 SNCR On 

8/31/11 12:00:00 AM 153.71 SNCR On 
Colleen McKaughan, October 2, 2014 Page 7 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

Figure 3. Graphic presentation of NOx emissions (lb/hr) for December 2, 2011 (see associated 

hourly averages in Table 3). 

 
Colleen McKaughan, October 2, 2014 Page 8 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

Table 3. Hourly NOx Averages for December 2, 2011 

Date and Time NOx Hourly Avg (ppm) SNCR Status 

12/1/11 11:00:00 AM 196.44 SNCR On 

12/1/11 12:00:00 PM 85.40 SNCR On 

12/1/11 1:00:00 PM 121.78 SNCR On 

12/1/11 2:00:00 PM 94.26 SNCR On 

12/1/11 3:00:00 PM 206.19 SNCR On 

12/1/11 4:00:00 PM 142.46 SNCR On 

12/1/11 5:00:00 PM 190.69 SNCR On 

12/1/11 6:00:00 PM 160.62 SNCR On 

12/1/11 7:00:00 PM 383.51 SNCR Malfunction 

12/1/11 8:00:00 PM 400.21 SNCR Malfunction 

12/1/11 9:00:00 PM 410.49 SNCR Malfunction 

12/1/11 10:00:00 PM 393.59 SNCR Malfunction 

12/1/11 11:00:00 PM 364.03 SNCR Malfunction 

12/2/11 12:00:00 AM 369.14 SNCR Malfunction 
Colleen McKaughan, October 2, 2014 Page 9 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

Figure 4. Graphic presentation of NOx emissions (lb/hr) for December 5, 2011 (see associated 

hourly averages in Table 4). 

 
Colleen McKaughan, October 2, 2014 Page 10 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

Table 4. Hourly NOx Averages for December 5, 2011 

Date and Time NOx Hourly Avg (ppm) SNCR Status 

12/5/11 1:00:00 AM 317.16 SNCR Malfunction 

12/5/11 2:00:00 AM 248.86 SNCR Malfunction 

12/5/11 3:00:00 AM 270.39 SNCR Malfunction 

12/5/11 4:00:00 AM 289.12 SNCR Malfunction 

12/5/11 5:00:00 AM 363.57 SNCR Malfunction 

12/5/11 6:00:00 AM 359.70 SNCR Malfunction 

12/5/11 7:00:00 AM 350.14 SNCR Malfunction 

12/5/11 8:00:00 AM 293.90 SNCR Malfunction 

12/5/11 9:00:00 AM 274.23 SNCR Malfunction 

12/5/11 10:00:00 AM 187.52 SNCR On 

12/5/11 11:00:00 AM 184.18 SNCR On 

12/5/11 12:00:00 PM 207.46 SNCR On 

12/5/11 1:00:00 PM 185.17 SNCR On 

12/5/11 2:00:00 PM 183.99 SNCR On 

12/5/11 3:00:00 PM 187.29 SNCR On 

12/5/11 4:00:00 PM 133.09 SNCR On 

12/5/11 5:00:00 PM 156.10 SNCR On 

12/5/11 6:00:00 PM 132.43 SNCR On 

12/5/11 7:00:00 PM 162.11 SNCR On 

12/5/11 8:00:00 PM 162.85 SNCR On 

12/5/11 9:00:00 PM 171.22 SNCR On 

12/5/11 10:00:00 PM 150.76 SNCR On 

12/5/11 11:00:00 PM 144.79 SNCR On 

12/6/11 12:00:00 AM 149.78 SNCR On 
Colleen McKaughan, October 2, 2014 Page 11 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

Figure 5. Graphic presentation of NOx emissions (lb/hr) for January 23-24, 2012 (see associated 

hourly averages in Table 5). 
Colleen McKaughan, October 2, 2014 Page 12 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

Table 5. Hourly NOx Averages for January 23-24, 2012 

Date and Time NOx Hourly Avg (ppm) SNCR Status 

1/23/12 7:00:00 PM 163.67 SNCR On 

1/23/12 8:00:00 PM 161.47 SNCR On 

1/23/12 9:00:00 PM 201.69 SNCR On 

1/23/12 10:00:00 PM 184.17 SNCR On 

1/23/12 11:00:00 PM 190.43 SNCR On 

1/24/12 12:00:00 AM 175.74 SNCR On 

1/24/12 1:00:00 AM 313.46 SNCR Malfunction 

1/24/12 2:00:00 AM 374.28 SNCR Malfunction 

1/24/12 3:00:00 AM 349.30 SNCR Malfunction 

1/24/12 4:00:00 AM 189.10 SNCR On 

1/24/12 5:00:00 AM 196.08 SNCR On 

1/24/12 6:00:00 AM 188.13 SNCR On 

1/24/12 7:00:00 AM 167.47 SNCR On 

1/24/12 8:00:00 AM 163.69 SNCR On 

1/24/12 9:00:00 AM 204.70 SNCR On 

1/24/12 10:00:00 AM 184.15 SNCR On 

1/24/12 11:00:00 AM 134.22 SNCR On 

1/24/12 12:00:00 PM 175.09 SNCR On 

1/24/12 1:00:00 PM 179.87 SNCR On 

1/24/12 2:00:00 PM 166.96 SNCR On 

1/24/12 3:00:00 PM 155.04 SNCR On 

1/24/12 4:00:00 PM 173.76 SNCR On 

1/24/12 5:00:00 PM 169.36 SNCR On 

1/24/12 6:00:00 PM 157.05 SNCR On 

1/24/12 7:00:00 PM 177.28 SNCR On 

1/24/12 8:00:00 PM 172.28 SNCR On 

1/24/12 9:00:00 PM 158.79 SNCR On 

1/24/12 10:00:00 PM 196.19 SNCR On 

1/24/12 11:00:00 PM 161.20 SNCR On 

1/25/12 12:00:00 AM 251.66 SNCR On 
Colleen McKaughan, October 2, 2014 Page 13 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

Figure 6. Graphic presentation of NOx emissions (lb/hr) for January 3, 2014 (see associated 

hourly averages in Table 6). 
Colleen McKaughan, October 2, 2014 Page 14 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

Table 6. Hourly NOx Averages for January 3, 2014 

Date and Time NOx Hourly Avg (ppm) SNCR Status 

1/3/14 1:00:00 AM 153.44 SNCR On 

1/3/14 2:00:00 AM 150.14 SNCR On 

1/3/14 3:00:00 AM 151.69 SNCR On 

1/3/14 4:00:00 AM 151.10 SNCR On 

1/3/14 5:00:00 AM 289.42 SNCR Malfunction 

1/3/14 6:00:00 AM 304.72 SNCR Malfunction 

1/3/14 7:00:00 AM 306.40 SNCR Malfunction 

1/3/14 8:00:00 AM 261.90 SNCR Malfunction 

1/3/14 9:00:00 AM 351.54 SNCR Malfunction 

1/3/14 10:00:00 AM 400.68 SNCR Malfunction 

1/3/14 11:00:00 AM 245.07 SNCR Malfunction 

1/3/14 12:00:00 PM 312.04 SNCR Malfunction 

1/3/14 1:00:00 PM 195.85 SNCR On 

1/3/14 2:00:00 PM 190.27 SNCR On 

1/3/14 3:00:00 PM 171.01 SNCR On 

1/3/14 4:00:00 PM 185.01 SNCR On 

1/3/14 5:00:00 PM 150.27 SNCR On 

1/3/14 6:00:00 PM 142.76 SNCR On 

1/3/14 7:00:00 PM 149.07 SNCR On 

1/3/14 8:00:00 PM 151.02 SNCR On 

1/3/14 9:00:00 PM 151.05 SNCR On 

1/3/14 10:00:00 PM 149.20 SNCR On 

1/3/14 11:00:00 PM 149.29 SNCR On 

1/4/14 12:00:00 AM 152.66 SNCR On 
Colleen McKaughan, October 2, 2014 Page 15 

Lhoist North America – Nelson Plant 

P.O. Box 370 

Peach Springs, Arizona 86434 

Phone: (928) 769-2271 Fax: (928) 769-2305

SNCR control efficiencies were evaluated based on the hourly average NOx summaries presented in 

Tables 1 through 6 above. These hourly averages were calculated separately for the time periods when 

the SNCR system was malfunctioning and when the system was on. The average NOx value for the time 

period when the SNCR system was malfunctioning was then considered as the baseline for the SNCR 

control efficiency calculations. The final calculated efficiencies are summarized in Table 7. 

Table 7. Calculated SNCR Control Efficiencies 

Date Average NOx - 

SNCR Off (ppm) 

Average NOx - 

SNCR On (ppm) 

SNCR Control 

Efficiency (%) 

08/28/2011 243.50 117.70 51.66 

08/30/2011 270.98 155.70 42.54 

12/02/2011 386.83 149.73 61.29 

12/05/2011 307.45 166.58 45.82 

01/23-24/2012 345.68 177.75 48.58 

01/03/2014 308.97 158.99 48.54 

Averages 310.57 154.41 49.74 

The six time periods evaluated above show SNCR efficiencies between 42% and 61% with an average of 

49.74%. These efficiencies are comparable to the 50% control efficiency used by LNA in the Five-Factor 

Bart Analysis presented to EPA. LNA selected the 50% value in the BART Analysis based on information 

provided by LNA’s corporate engineers familiar with the SNCR system at O’Neal and by LNA engineers in 

Europe who have experimented with NOx controls on lime kilns there. LNA believes a 50% NOx control 

efficiency is reasonable and achievable at the Nelson Plant based on LNA’s experience with 

implementing SNCR systems for NOx control on lime kilns at its facilities. 

If you have any questions or need any additional information please do not hesitate to contact me. I can 

be reached at (928) 769-2271, extension 645104 or by email at Herbert.Verville@Lhoist.com. 

Sincerely, 

Herbert J. Verville 

Environmental Manager 
Attachment 3

UNIMIN presentation
Mick Britton, Unimin Lime Corp.

NLA Environmental Committee Meeting

November 3, 2011

1
 Preheater rotary kiln Title V limit: 

◦ 3.2 lb NOx/ton lime

 NOx trending up

 Combustion modifications explored

◦ New KFS burner installed in 2006

 Calera Plant Goals:

1. Ensure continued compliance with current limit

2. Facilitate compliance with possibly more 

restrictive future limit

3. Avoid NOx CEMS

 Decision: Evaluate post-combustion controls

 

2
 Mid Kiln Air Injection

 Selective Non-Catalytic Reduction

3
 Ambient air (typically 10% of theoretical 

combustion air) blown into kiln through 

injection pipes, typically located 2/3 down 

the kiln from the burner

◦ Allows area between flame & air injection point to 

run with reducing atmosphere, which destroys NOx 

or prevents its formation

4
5
 Mechanically vulnerable

◦ Motor & fan fastened to kiln

◦ Electricity fed through slip rings

 Repair of motor, impeller, injector nozzles or 

slip rings requires kiln shutdown

 NOx reduction rates variable

◦ Requires all elements to be in good working order

6
 Reagent injected into kiln exhaust gases

 For systems using urea solution primary 

reaction is:

CO (NH2)2 + 2NOx + 1⁄2O2 = 2N2 + CO2 + 2H2O

 Reductions up to 50%

 Mechanical & control elements located away 

from kiln

 Injection lances can be repaired on-line

7
 Ammonia Slip

◦ Unreacted ammonia reacts with SO3to form sticky 

ammonium bisulfite – could coat bags

 Urea crystallization

◦ 32.5% urea solution must be kept above 30°F

◦ 50% solution must be above 70°F

8
MKAI SNCR

Capital Cost Moderate Moderate

Operating Costs Low Moderate

NOx Reduction Effectiveness <30% <50%

NOx Reduction Reliability Medium High

NOx Reduction Controllability Low High

Repairs Costly –

Involve Downtime

Low Cost –

No Downtime

9
 Vendor: Combustion Components Associates 

(CCA)

 Seven stainless steel pipes installed in 

expansion joint of transfer chute during 

annual kiln maintenance, February 2010

◦ Kiln exhaust gases around 2100° F

◦ Residence time about 2/3 second

 Testing lasted two days

10
11
1. Establish baseline NOx emissions using CCA 

portable monitor

2. Increase urea concentrations to identify 

level at which ammonia slip occurs

3. Identify NOx reduction rates associated with 

varying urea dilution & injection rates

12
 32.5% urea solution used because at this 

concentration it:

◦ will not crystallize out until 12°F

◦ is readily available as it is used by over-the-road 

diesel trucks

 NOx reduction up to 50% achieved with no 

ammonia slip

13
Two Urea Injection Lances 

14
Control Rack for Five of the Lances 

15
Water and Urea Pump Unit with 

Urea Tote Behind 

16
17
 October 2010 Commissioning

 Trial lance location in expansion joint worked 

so well that permanent system also located 

there

 Same 3 objectives as with 2-day trial

 Following commissioning Southern Lime 

adjusted urea addition rates to achieve 

desired 10% NOx reduction:

◦ 14 gal/hr of 32.5% urea solution

◦ 40 psi dilution water pressure

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Urea Storage Tank 

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Urea and Water Pump Skid 

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Air Compressor 

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Flowmeter Rack 

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Urea Solution Injection Lances 

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Control Screen 
 Week one:

◦ Buildup in injector rotometer tubes

 Two days later: 

◦ Rotometer floats jammed

◦ No flow in some nozzles

 Had been anticipated; not expected to 

manifest for several months

 Limescale removed with industrial grade 

vinegar

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 NOxOUT A = 50% urea solution with acidic 

additive

 50% urea not used initially because salt-out 

temperature is 62°F, requiring storage 

temperatures above 70° F

 Permanent installation has heater pads in doublewalled storage tank and heater in recirculation line 

from urea pump, so ambient temperature below 

70° F not a problem

◦ One minor incident: Power failure caused urea pump to go 

down for 15 minutes when ambient temp 17 °F; return line 

plugged with urea crystals. When heated, line cleared.

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 Costs less per unit product than 32.5% 

solution

 More readily available (truckers allocated 

almost all 32.5% solution)

 One caveat: substantial price fluctuation for 

all grades of urea solution.

 Price for NOxOUT A

◦ Oct. 2010: $1.09/gal

◦ Mar. 2011: $1.95/gal 

◦ Oct. 2011: $2.20/gal

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 8 gal/hr required to assure compliance 

(about 10% reduction)

 Reduced injection rate & lower unit cost of 

50% urea resulted in operating costs 25% of 

projected

 Bottom line:

◦ Capital costs: approx. $500K

(Substantial amount of Capital cost was licensing fee. 

Patent has expired, so fee no longer payable)

◦ Operating costs: less than 0.5% per ton lime 

produced 

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Clean Air Technology

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