Date: May 2012

Subject: Statistical Evaluation of CEMS Data to Determine the NO

(Updated Memo for Final Standard)

Nitric Acid NSPS Review

EPA Contract No. EP

RTI Project No. 02103199.000.001

From: Melissa Icenhour

To: Nathan Topham

OAQPS/SPPD/M

U. S. Environmental Protection Agency

Research Triangle Park, NC 27711

As a result of the Section 114 Information Collection Request (ICR), EPA received continuous 

emission monitoring system (CEMS) data from multiple nitric acid plants. The CEMS data 

represent NOX emissions from the nitric acid trains during 

summary of the CEMS data received from the nitric acid trains

and Table 3.

Only data from the most recent year was considered in the analyses. Some facilities only

submitted one year of data so we only considered one year of data from

to bias the analysis toward a plant with more data.

As shown in Table 1, Table 2, and Table 3

with Selective Catalytic Reduction (SCR)

Reduction (NSCR), and one nitric acid train with Hydrogen Peroxide Injection (HPI)

(North Bend and Sacramento) supplied 2010 data, El Dorado Nitrogen supplied data from July 

2010 through June 2011, Dyno Nobel Deer Island 

and PCS Geismar supplied 2009 data from Train 5, Train 4, and Train 3.

1

Statistical Evaluation of CEMS Data to Determine the NOX Emission Standard 

(Updated Memo for Final Standard)

Nitric Acid NSPS Review

EPA Contract No. EP-D-11-084; Work Assignment No. 0-01 

02103199.000.001

OAQPS/SPPD/MICG (D243-02)

U. S. Environmental Protection Agency

Research Triangle Park, NC 27711

114 Information Collection Request (ICR), EPA received continuous 

emission monitoring system (CEMS) data from multiple nitric acid plants. The CEMS data 

emissions from the nitric acid trains during day-to-day operating conditions. 

f the CEMS data received from the nitric acid trains are shown in Table 1

Only data from the most recent year was considered in the analyses. Some facilities only

submitted one year of data so we only considered one year of data from all submissions so as not 

to bias the analysis toward a plant with more data.

, and Table 3, we received CEMS data for three nitric acid trains 

with Selective Catalytic Reduction (SCR), three nitric acid trains with Non-Selecti

, and one nitric acid train with Hydrogen Peroxide Injection (HPI)

(North Bend and Sacramento) supplied 2010 data, El Dorado Nitrogen supplied data from July 

Dyno Nobel Deer Island and Agrium Kennewick supplied 2009 data, 

PCS Geismar supplied 2009 data from Train 5, Train 4, and Train 3.

Emission Standard 

114 Information Collection Request (ICR), EPA received continuous 

emission monitoring system (CEMS) data from multiple nitric acid plants. The CEMS data 

day operating conditions. A 

are shown in Table 1, Table 2, 

Only data from the most recent year was considered in the analyses. Some facilities only

all submissions so as not 

, we received CEMS data for three nitric acid trains 

Selective Catalytic 

, and one nitric acid train with Hydrogen Peroxide Injection (HPI). Agrium 

(North Bend and Sacramento) supplied 2010 data, El Dorado Nitrogen supplied data from July 

supplied 2009 data, 
2

The CEMS data from JR Simplot were not in terms of the standard (lb NOX/ton acid) and were 

not supplied as hourly averages. The data were not directly comparable to the data from the other 

two nitric acid trains using NSCR so the nitric acid train at JR Simplot is not included in the 

analyses.

Train 3 and Train 4 at PCS Geismar were not included in the analyses because the trains only

operated during 15% of 2009. The trains did not operate at all during the months of February, 

March, April, May, June, July, August, and December. Sufficient data to evaluate the long term 

performance of controls for this analysis were not available as there are only portions of 4 

months of data, No CEMS data from other years were supplied for Train 4.

The other years of CEMS data were not used for Train 3 because the nitric acid plant is not using 

a best performing SCR. According to a telephone conversation between EPA’s Bill Neuffer and 

Jeremy Richard of PCS Geismar, the SCR is located after the gas expander and is thus an 

atmospheric SCR. According to Mr. Richard, this prevents optimal mixing of gas and ammonia, 

leading to higher NOX emissions. He felt that the unit could be improved to meet a lower 

emissions limit on a consistent basis. The CEMS data include periods of startup and shutdown 

but exclude non-operating periods. Non-operating periods were indicated by the plants as 

“Down” or “Plant Down” for the lb/ton acid value (Agrium and El Dorado) or the flow rate of 

the ammonia feed was zero pounds per hour (PCS Geismar).

Just before the NSPS was proposed, the EPA received CEMS data from Dyno Nobel Deer 

Island. There was insufficient time to include these data in the analyses prior to proposal. During 

the comment period, commenters noted a few mistakes in the analyses for the facilities that the 

EPA did evaluate prior to proposal. Also, the EPA has slightly modified the NOX emissions 

calculation equation for the 30-day rolling emission rate. The new equation assumes that each 

hour that the unit was operating during the 30 day period is weighted the same. The equation

used at proposal equally weighted each day that the unit was operating regardless of how many

hours during each day the unit operated. On partial operating days with startup or shutdown 

events, the methodology could have caused the emissions during those events to be weighted too 

heavily in the 30 day rolling emission rate.

As an update to the earlier memo (Docket ID EPA-HQ-OAR-2010-0750-0082), this memo 

shows the 30 day rolling emission rates used at proposal, shows how the 30 day rolling emission 

rates change after modifying the calculation and includes the updated calculation methodology.

Also, the updated memo includes the analyses of data from Dyno Nobel Deer Island and Agrium 

Kennewick that were not included at proposal.
3

By selecting an emission limit based on the highest average of emissions data from unit with 

BSER (which is SCR), we ensure that this limit reflects BSER but is also achievable during all 

periods by facilities that have BSER equivalent controls. As shown by Table 4, all six units are 

meeting the current Subpart G NOX emission standard of 3.0 lb NOX/ton acid. All SCR units are 

meeting the proposed Subpart Ga NOX emission standard of 0.50 lb NOX/ton acid, and one 

NSCR unit is meeting the proposed Subpart Ga NOX emission standard of 0.50 lb NOX/ton acid. 

The HPI unit is not meeting the proposed Subpart Ga NOX emission standard of 0.50 lb NOX/ton 

acid.

In conjunction with the memo entitled Agrium North Bend Analyses, finalizing a NOX emission 

standard of 0.50 lb/ton NOX/ton acid is recommended.
4

Table 1. NOX CEMS Data from SCR-controlled Nitric Acid Units 

Company

Agrium—

North 

Bend

Coffeyville Resources 

Nitrogen Fertilizers, 

LLC

El Dorado 

Nitrogen

PCS NitrogenGeismar

Train 3

PCS NitrogenGeismar

Train 5

Basis

Hourly 

averages

Requested from plant but 

have not received

Hourly 

averages

15-minute 

readings

15-minute 

readings

Volume of 

data 1 year

Requested from plant but 

have not received 1 year

3 years

(was only 

operational 

15% of 2009) 3 years

Table 2. NOX CEMS Data from NSCR-controlled Nitric Acid Units 

Company

AgriumSacramento

Dyno NobelCheyenne 

(Acid Plant 1)

Dyno NobelCheyenne 

(Acid Plant 2)

Dyno 

Nobel-Deer 

Island

JR 

Simplot

PCS 

NitrogenGeismar

(Train 4)

Basis Hourly ppm NA NA

1 minute 

readings

(lb NOX/ton

acid)

Monthly 

avg ppm

15-minute 

readings (lb

NOX/ton

acid)

Volume of 

data

1 year (only 

operating 

about 50% of 

the year) None None 1 year 3 years

1 year (only 

operating 

15% of the 

year)

Table 3. NOX CEMS Data from HPI-controlled Nitric Acid Units 

Company Agrium—Kennewick

Basis 2 minute readings (lb NOX/ton acid)

Volume of data 3 years
5

Table 4. CEMS Data—Highest Average

Train

30 day rolling emission 

rate--proposal 

(lb NOX/ton acid)

30 operating day rolling 

emission rate

(lb NOX/ton acid)

PCS Geismar-Train 5 (SCR) 0.39 0.35

Agrium North Bend (SCR) 0.50 0.41

El Dorado Nitrogen (SCR) 0.37 0.37

Dyno Nobel Deer Island (NSCR) ------ 0.21

Agrium Sacramento (NSCR) 1.81 0.96

Agrium Kennewick (HPI) ------ 0.72

 
Figure 1. PCS Geismar Train 5 NOX Emission Data

6
7

Figure 2. Agrium North Bend NOX Emission Data

 

0

0.1

0.2

0.3

0.4

0.5

0.6

lb N

OX

/ton acid

Agrium North Bend NOX CEMS Data

proposal-30 day rolling emission rate

final-30 operating day rolling emission rate
8

Figure 3. El Dorado Nitrogen NOX Emission Data

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

6/21/2010 8/10/2010 9/29/2010 11/18/2010 1/7/2011 2/26/2011 4/17/2011 6/6/2011 7/26/2011

lb N

OX

/ton acid

El Dorado Nitrogen NOX CEMS Data

proposal-30 day rolling emission rate

final-30 operating day rolling emission rate
9

Figure 4. Dyno Nobel Deer Island NOX CEMS Data

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

Dec-18-2008 Feb-06-2009 Mar-28-2009 May-17-2009 Jul-06-2009 Aug-25-2009 Oct-14-2009 Dec-03-2009 Jan-22-2010

lb N

OX

/ton acid

Dyno Nobel Deer Island NOX CEMS Data

final-30 operating day rolling emission rate
10

Figure 5. Agrium Sacramento NOX CEMS Data

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

12/18/2008 2/6/2009 3/28/2009 5/17/2009 7/6/2009 8/25/2009 10/14/2009 12/3/2009 1/22/2010

lb N

OX

/ton acid

Agrium Sacramento NOX CEMS Data

proposal-30 day rolling emission rate

final-30 operating day rolling emission rate
11

Figure 6. Agrium Kennewick NOX CEMS Data

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

1/7/2009 2/26/2009 4/17/2009 6/6/2009 7/26/2009 9/14/2009 11/3/2009 12/23/2009

lb N

OX

/ton acid

Agrium Kennewick NOX CEMS Data

final-30 operating day rolling emission rate