Page 1 of 16

**Subpart V**

**— Nitric Acid Production**  § 98.220 Definition of source category. A nitric acid production facility uses one or more trains to produce weak nitric acid (30 to 70 percent in strength). A nitric acid train produces weak nitric acid through the catalytic oxidation of ammonia. § 98.221 Reporting threshold. You must report GHG emissions under this subpart if your facility contains a nitric acid train and the facility meets the requirements of either §98.2(a)(1) or (a)(2). § 98.222 GHGs to report. (a) You must report N 2 O process emissions from each nitric acid train as required by this subpart. (b) You must report under subpart C of this part (General Stationary Fuel Combustion Sources) the emissions of CO 2 , CH 4 , and N 2 O from each stationary combustion unit by following the requirements of subpart C. § 98.223 Calculating GHG emissions. (a) You must determine annual N 2 O process emissions from each nitric acid train according to paragraphs (a)(1) or (a)(2) of this section. (1) Use a site
- specific emission factor and production data according to paragraphs (b) through (i) of this section.Page 2 of 16

(2) Request Administrator approval for an alternative method of determining N 2 O emissions according to paragraphs (a)(2)(i) and (a)(2)(ii) of this section. (i) You must submit the request within 45 days following promulgation of this subpart or within the first 30 days of each subsequent reporting year. (ii) If the Administrator does not approve your requested alternative method within 150 days of the end of the reporting year, you must determine the N 2 O emissions for the current reporting period using the procedures specified in paragraph (a)(1) of this section. (b) You must conduct an annual performance test for each nitric acid train according to paragraphs (b)(1) through ( b) ( 3) of this section. (1) You must conduct the performance test at the absorber tail gas vent, referred to as the test point, for each nitric acid train according to §98.2 24(b) through (f). If multiple nitric acid trains exhaust to a common abatement technology and/or emission point, you must sample each process in the ducts before the emissions are combined, sample each process when only one process is oper ating, or sample the combined emissions when multiple processes are operating and base the site
- specific emission factor on the combined production rate of the multiple nitric acid trains .Page 3 of 16

(2) You must conduct the performance test under nor mal process operating conditions. (3) You must measure the production rate during the performance test and calculate the production rate for the test period in tons (100 percent acid basis) per hour. (c) Using the results of the performance test in paragraph (b) of this section, you must calculate an average site
- specific emission factor for each nitric acid train “t” according to Equation V

– 1 of this section:

Where:
EFN2 Ot = Average site
- specific N 2 O emissions factor for nitric acid train “t” (lb N 2 O/ton nitric acid produced, 100 percent acid basis). CN2O = N 2 O concentration for each test run during the performance test (ppm N 2 O). 1.14 × 10 −7 = Conversion factor (lb/dscf

-ppm N 2 O). Q = Volumetric flow rate of effluent gas for each test run during th e performance test (dscf/hr). P = Production rate for each test run during the performance test (tons nitric acid produced per hour, 100 percent acid basis).
n = Number of test runs. (d) If nitric acid train “t” exhausts to any N 2 O abatement technology “N ”, you must determine the destruction efficiencyPage 4 of 16

for each N 2 O abatement technology “N” according to paragraphs (d)(1), (d)(2), or (d)(3) of this section. (1) Use the manufacturer's specified destruction efficiency. (2) Estimate the de struction efficiency through process knowledge. Examples of information that could constitute process knowledge include calculations based on material balances, process stoichiometry, or previous test results provided the results are still relevant to the current vent stream conditions. You must document how process knowledge (if applicable) was used to determine the destruction efficiency. (3) Calculate the destruction efficiency by conducting an additional performance test on the emissions stream followin g the N 2 O abatement technology. (e) If nitric acid train “t” exhausts to any N 2 O abatement technology “N ”, you must determine the annual amount of nitric acid produced on nitric acid train “t” while N 2 O abatement technology “N” is op erating according to §98.224(f). Then you must calculate the abatement utilization factor for each N 2 O abatement technology “N” for each nitric acid train “t” according to Equation V

– 2 of this section.

Where:Page 5 of 16

AF t,N = Abatement utilization factor of N 2 O abatement technology “N” at nitric acid train “t” (fraction of annual production that abatement technology is operating). P t = Total annual nitric acid production from nitric acid train “t” (ton acid produced, 100 percent acid basis). P t ,N = Annual nitri c acid production from nitric acid train “t” during which N 2 O abatement technology “N” was operational (ton acid produced, 100 percent acid basis). (f) [Reserved] (g) You must calculate N 2 O emissions for each nitric acid train “t” according to paragraph (g )(1), (g)(2), (g)(3), or (g)(4) of this section. (1) If nitric acid train “t” exhausts to one N 2 O abatement technology “N” after the test point, you must use the emissions factor (determined in Equation V

– 1 of this section), the destruction efficiency (det ermined in paragraph (d) of this section), the annual nitric acid production (determined in paragraph (i) of this section), and the abatement utilization factor (determined in paragraph (e) of this section) according to Equation V

– 3a of this section:

Where:
E N2 Ot = Annual N 2 O mass emissions from nitric acid train “t” according to this Equation V

– 3a (metric tons).Page 6 of 16

EFN2 Ot = Average site
- specific N 2 O emissions factor for nitric acid train ”t” (lb N 2 O/ton acid produced, 100 percent acid basis). P t = Annual nitric acid production from nitric acid train “t” (ton acid produced, 100 percent acid basis). DF = Destruction efficiency of N 2 O abatement technology N that is used on nitric acid train “t” ( decimal fraction of N 2 O removed fr om vent stream). AF = Abatement utilization factor of N 2 O abatement technology “N” for nitric acid train “t” ( decimal fraction of annual production during which abatement technology is operating). 2205 = Conversion factor (lb/metric ton ). (2) If multiple N 2 O abatement technologies are located in series after your test point, you must use the emissions factor (determined in Equation V

– 1 of this section), the destruction efficiency (determined in paragraph (d) of this section), the annual nitric acid production (determined in paragraph ( i ) of this section), and the abatement utilization factor (determined in paragraph (e) of this section), according to Equation V

– 3b of this section:

Where:
E N2 Ot = Annual N 2 O mass emissions from nitric ac id train “t” according to this Equation V

– 3b (metric tons). EFN2 O,t = N 2 O emissions factor for nitric acid train “t” (lb N 2 O/ton nitric acid produced).Page 7 of 16

P t = Annual nitric acid produced from nitric acid train “t” (ton acid produced, 100 percent acid basis). DF 1 = Destruction efficiency of N 2 O abatement technology 1 ( decimal fraction of N 2 O removed from vent stream). AF 1 = Abatement utilization factor of N 2 O abatement technology 1 ( decimal fractio n of time that abatement technology 1 is operating). DF 2 = Destruction efficiency of N 2 O abatement technology 2 ( decimal fraction of N 2 O removed from vent stream). AF 2 = Abatement utilization factor of N 2 O abatement technology 2 ( decimal frac tion of time that abatement technology 2 is operating). DFN = Destruction efficiency of N 2 O abatement technology N ( decimal fraction of N 2 O removed from vent stream). AFN = Abatement utilization factor of N 2 O abatement technology N ( decimal f raction of time that abatement technology N is operating). 2205 = Conversion factor (lb/metric ton). N = Number of different N 2 O abatement technologies. (3) If multiple N 2 O abatement technologies are located in parallel after your test point, you must use the emissions factor (determined in Equation V

– 1 of this section), the destruction efficiency (determined in paragraph (d) of this section), the annual nitric acid production (determined in paragraph ( i ) of this section), and the abatement utilization fac tor (determined in paragraph (e) of this section), according to Equation V

– 3c of this section:Page 8 of 16

Where:

E N2 Ot = Annual N 2 O mass emissions from nitric acid train “t” according to this Equation V

– 3c (metric tons). EFN2 O,t = N 2 O emissions factor for nitric acid train “t” (lb N 2 O/ton nitric acid produced). P t = Annual nitric acid produced from nitric acid train “t” (ton acid produced, 100 percent acid basis). DFN = Destruction efficiency of N 2 O abatement technology “N” ( decimal fraction of N 2 O removed from vent stream). AFN = Abatement utilization factor of N 2 O abatement technology “N” ( decimal fraction of time that abatement technology “N” is operating). FCN = Fraction control factor of N 2 O abatement technology “N” ( decimal fraction of total emissions from nitric acid train “t” that are sent to abatement technology “N”). 2205 = Conversion factor (lb/metric ton). N = Number of different N 2 O abatement technologies with a fraction control facto r. (4) If nitric acid train “t” does not exhaust to any N 2 O abatement technology after the test point, you must use the emissions factor (determined in Equation V

– 1 of this section), and the annual nitric acid production (determined in paragraph (i) of thi s section) according to Equation V

– 3b of this section:

Where:
E N2 Ot = Annual N 2 O mass emissions from nitric acid train “t” according to this Equation V

– 3d (metric tons).Page 9 of 16

EFN2 Ot = Average site
- specific N 2 O emissions factor for nitric acid t rain ”t” (lb N 2 O/ton acid produced, 100 percent acid basis). P t = Annual nitric acid production from nitric acid train “t” (ton acid produced, 100 percent acid basis). 2205 = Conversion factor (lb/metric ton). (h) You must determine the annual nitric acid production emissions combined from all nitric acid trains at your facility using Equation V

– 4 of this section:

Where:
N 2 O = Annual process N 2 O emissions from nitric acid production facility (metric tons). E N2Ot = N 2 O mass emissions per year for nitric acid train “t” (metric tons).
m = Number of nitric acid trains. (i) You must determine the total annual amount of nitric acid produced on each nitric acid train “t” (tons acid produced, 100 percent acid basis), according to §98.22 4(f). § 98.224 Monitoring and QA/QC requirements. (a) You must conduct a new performance test according to a test plan as specified in paragraphs (a)(1) through (3) of this section. (1) Conduct the performance test annually. The test should be conducted at a point during the campaign which is representative of the average emissions rate from the nitricPage 10 of 16

acid campaigns. Facilities must document the methods used to determine the represen tative point of the campaign when the performance test is conducted. (2) Conduct the performance test when your nitric acid production process is changed, specifically when abatement equipment is installed. (3) If you requested Administrator approval for an alternative method of determining N 2 O emissions under §98.223(a)(2), you must conduct the performance test if your request has not been approved by the Administrator within 150 days of the end of the reporting year in which it was submitted. (b) You must measure the N 2 O concentration during the performance test using one of the methods in paragraphs (b)(1) through (b)(3) of this section. (1) EPA Method 320 at 40 CFR part 63, appendix A, Measurement of Vapor Phase Organic and Inorganic Emissions by Extract ive Fourier Transform Infrared (FTIR) Spectroscopy. (2) ASTM D6348

– 03 Standard Test Method for Determination of Gaseous Compounds by Extractive Direct Interface Fourier Transform Infrared (FTIR) Spectroscopy (incorporated by reference in §98.7). (3) An equ ivalent method, with Administrator approval.Page 11 of 16

(c) You must determine the production rate(s) (100 percent acid basis) from each nitric acid train during the performance test according to paragraphs (c)(1) or (c)(2) of this section. (1) Direct measurement of production and concentration (such as using flow meters, weigh scales, for production and concentration measurements). (2) Existing plant procedures used for accounting purposes (i.e. dedicated tank
- level and acid concentration measurements). (d) You must determine the volumetric flow rate during the performance test in conjunction with the applicable EPA methods in 40 CFR part 60, appendices A

– 1 through A

– 4. Conduct three emissions test runs of 1 hour each. All QA/QC procedures specified in the reference t est methods and any associated performance specifications apply. For each test, the facility must prepare an emission factor determination report that must include the items in paragraphs (d)(1) through (d)(3) of this section. (1) Analysis of samples, dete rmination of emissions, and raw data. (2) All information and data used to derive the emissions factor(s). (3) The production rate during each test and how it was determined.Page 12 of 16

(e) You must determine the total monthly amount of nitric acid produced. You must also determine the monthly amount of nitric acid produced while N 2 O abatement technology is operating from each nitric acid train. These monthly amounts are determined according to the methods in paragraphs (c)(1) or (2) of this section. (f) You must determine the annual amount of nitric acid produced. You must also determine the annual amount of nitric acid produced while N 2 O abatement technology is operating for each nitric acid train. These annual amounts are determined by summing the respective monthly nitric acid quantities determined in paragraph (e) of this section. § 98.225 Procedures for estimating missing data. A complete record of all measured parameters used in the GHG emissions calcu lations is required. Therefore, whenever a quality
- assured value of a required parameter is unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified in paragraphs (a) and (b) of this section. (a) For each missing value of nitric acid production, the substitute data shall be the best available estimate based on all available process data or data used for accounting purposes (such as sales records).Page 13 of 16

(b) For missing values related to the performance test, in cluding emission factors, production rate, and N 2 O concentration, you must conduct a new performance test according to the procedures in §98.224 (a) through (d). § 98.226 Data reporting requirements. In addition to the information required by §98.3(c), each annual report must contain the information specified in paragraphs (a) through (p) of this section. (a) Nitric Acid t rain identification number. (b) Annual process N 2 O emissions from each nitric acid train (metric tons). (c) [Reserved] (d) Annual ni tr i c acid production from each nitric acid train during which N 2 O abatement technology is operating (ton acid produced, 100 percent acid basis). (e) Annual nitric acid production from the nitric acid facility (tons, 100 percent acid basis). (f) Number of nitric acid trains. (g) Number of different N 2 O abatement technologies per nitric acid train “t”. (h) Abatement technologies used (if applicable). (i) Abatement technology destruction efficiency for each abatement technology (percent destruction).Page 14 of 16

(j) Abat ement utilization factor for each abatement technology (fraction of annual production that abatement technology is operating). (k) Type of nitric acid process used for each nitric acid train (low, medium, high, or dual pressure). (l) Number of times in the reporting year that missing data procedures were followed to measure nitric acid production (months). (m) If you conducted a performance test and calculated a site
- specific emissions factor according to §98.223(a)(1), each annual report must also contain the information specified in paragraphs (m)(1) through (7) of this section. (1) Emission factor calculated for each nitric acid train (lb N 2 O/ton nitric acid, 100 percent acid basis). (2) Test method used for performance test. (3) Production rate per test run during performance test (tons nitric acid produced/hr, 100 percent acid basis). (4) N 2 O concentration per test run during performance test (ppm N 2 O). (5) Volumetric flow rate per test run during performance test (dscf/hr). (6) Number of test runs during performance test. (7) Number of times in the reporting year that a performance test had to be repeated (number).Page 15 of 16

(n) If you requested Administrator approval for an alternative method of determining N 2 O emissions under §98.223(a)(2), each annual report mu st also contain the information specified in paragraphs (n)(1) through (n)(4) of this section. (1) Name of alternative method. (2) Description of alternative method. (3) Request date. (4) Approval date. (o) [Reserved] (p) Fraction control factor for each abatement technology (percent of total emissions from the nitric acid train that are sent to the abatement technology) if equation V

– 3c is used. § 98.227 Records that must be retained. In addition to the information required by §98.3(g), you must retain the records specified in paragraphs (a) through (g) of this section for each nitric acid production facility: (a) Records of significant changes to process. (b) Documentation of how process knowledge was used to estimate abatement technology de struction efficiency (if applicable). (c) Performance test reports. (d) Number of operating hours in the calendar year for each nitric acid train (hours).Page 16 of 16

(e) Annual nitric acid permitted production capacity (tons). (f) Measurements, records, and calculations used to determine reported parameters. (g) Documentation of the procedures used to ensure the accuracy of the measurements of all reported parameters, including but not limited to, calibration of weighing equipment, flow meters, and other meas urement devices. The estimated accuracy of measurements made with these devices must also be recorded, and the technical basis for these estimates must be provided. § 98.228 Definitions. All terms used in this subpart have the same meaning given in the Cle an Air Act and subpart A of this part.