**Subpart G —**  **Ammonia Manufacturing** § 98.70 Definition of source category. The ammonia manufacturing source category comprises the process units listed in paragraphs (a) and (b) of this section. (a) Ammonia manufacturing processes in which ammonia is manufactured from a fossil - based feedstock produced via steam reforming of a hydrocarbon. (b) Ammonia manufacturing processes in which ammonia is manufactured through the gasification of solid and liquid raw material. § 98.71 Reporting threshold. You mus t report GHG emissions under this subpart if your facility contains an ammonia manufacturing process and the facility meets the requirements of either §98.2(a)(1) or (2). § 98.72 GHGs to report. You must report: (a) CO 2 process emissions from steam reform ing of a hydrocarbon or the gasification of solid and liquid raw material, reported for each ammonia manufacturing process unitfollowing the requirements of this subpart (CO 2 process emissions

reported under this subpart may include CO 2 that is later consumed on site for urea production, and therefore is not released to the ambient air from the ammonia manufacturing process unit). (b) CO 2 , CH 4 , and N 2 O emissions from each stationary fuel combustion unit. You must report these emissions under subpart C of thi s part (General Stationary Fuel Combustion Sources), by following the requirements of subpart C, except that for ammonia manufacturing processes subpart C does not apply to any CO 2 resulting from combustion of the waste recycle stream (commonly referred to as the purge gas stream). (c) CO 2 emissions collected and transferred off site under subpart PP of this part (Suppliers of CO 2 ), following the requirements of subpart PP. § 98.73 Calculating GHG emissions. You must calculate and report the annual process CO 2 emissions from each ammonia manufacturing process unit using the procedures in either paragraph (a) or (b) of this section. (a) Calculate and report under this subpart the process CO 2 emissions by operating and maintaining CEMS according to the Tier 4 Calculation Methodology specified in §98.33(a)(4) and allassociated requirements for Tier 4 in subpart C of this part

(General Stationary Fuel Combustion Sources). (b) Calculate and report under this subpart process CO 2 emissions using the procedures in pa ragraphs (b)(1) through (b)(5) of this section for gaseous feedstock, liquid feedstock, or solid feedstock, as applicable. (1) Gaseous feedstock . You must calculate, from each ammonia manufacturing unit, the CO 2process emissions from gaseous feedstock according to Equation G

– 1 of this section:

Where: CO 2,G,k= Annual CO 2 emissions arising from gaseous feedstock consumption (metric tons). Fdstk n= Volume of the gaseous feedstock used in month n (scf of feedstock). CC n= Carbon content of the gaseous feedst ock, for month n (kg C per kg of feedstock), determined according to 98.74(c). MW = Molecular weight of the gaseous feedstock (kg/kg - mole).MVC = Molar volume conversion factor (849.5 scf per kg - mole at

standard conditions). 44/12 = Ratio of molecular weights, CO 2 to carbon. 0.001 = Conversion factor from kg to metric tons. k = Processing unit. n = Number of month. (2) Liquid feedstock . You must calculate, from each ammonia manufacturing unit, the CO 2process emissions from liquid feedstock according to E quation G

– 2 of this section:

Where: CO 2,L,k= Annual CO 2 emissions arising from liquid feedstock consumption (metric tons). Fdstk n= Volume of the liquid feedstock used in month n (gallons of feedstock). CC n= Carbon content of the liquid feedstock, for mont h n (kg C per gallon of feedstock) determined according to 98.74(c).44/12 = Ratio of molecular weights, CO 2 to carbon.

0.001 = Conversion factor from kg to metric tons. k = Processing unit. n = Number of month. (3) Solid feedstock . You must calculate, from each ammonia manufacturing unit, the CO 2process emissions from solid feedstock according to Equation G

– 3 of this section:

Where: CO 2,S,k= Annual CO 2 emissions arising from solid feedstock consumption (metric tons). Fdstk n= Mass of the solid feedstock us ed in month n (kg of feedstock). CC n= Carbon content of the solid feedstock, for month n (kg C per kg of feedstock), determined according to 98.74(c). 44/12 = Ratio of molecular weights, CO 2 to carbon. 0.001 = Conversion factor from kg to metric tons.k = Processing unit.

n = Number of month. (4) You must calculate the annual process CO 2 emissions from each ammonia processing unit k at your facility according to Equation G - 4 of this section:

k S k L k G k CO CO

CO CO E , , 2 , , 2 , , 2 , 2 

  (Eq. G - 4) Where: E CO2 k = Annual CO 2 emissions from each ammonia processing unit k (metric tons). k = Processing unit. (5) You must determine the combined CO 2 emissions from all ammonia processing units at your facility using Equation G

– 5 of this section. 

## 

  j k k CO E CO 1 ,

2 2 (Eq. G - 5)
Where: CO 2 = Annual combined CO 2 emissions from all ammonia processing units (metric tons) (CO 2 process emissions reported under this subpart may include CO 2 that is later consumed on site for ureaproduction, and therefore is not released to the ambient air

from the ammonia manufacturing process unit(s)). E CO2 k = Annual CO 2 emissions from each ammonia processing unit k (metric tons). k = Processing unit. j = Total number of ammonia processing units. (c) If GHG emissions from an ammonia manufacturing unit are vented through the same stack as any combustion unit or process equipment that reports CO 2 emissions using a CEMS that complies with the Tier 4 Calculat ion Methodology in subpart C of this part (General Stationary Fuel Combustion Sources), then the calculation methodology in paragraph (b) of this section shall not be used to calculate process emissions. The owner or operator shall report under this subpar t the combined stack emissions according to the Tier 4 Calculation Methodology in §98.33(a)(4) and all associated requirements for Tier 4 in subpart C of this part. § 98.74 Monitoring and QA/QC requirements. (a) You must continuously measure the quantity of gaseous or liquid feedstock consumed using a flow meter. The quantity ofsolid feedstock consumed can be obtained from company records

and aggregated on a monthly basis. (b) You must document the procedures used to ensure the accuracy of the estimates of feedstock consumption. (c) You must determine monthly carbon contents and the average molecular weight of each feedstock consumed from reports from your supplier. As an alternative to using supplier information on carbon contents, you can also collect a sample of each feedstock on a monthly basis and analyze the carbon content and molecular weight of the fuel using any of the following methods listed in paragraphs (c)(1) through (c)(8) of this section, as applicable. (1) ASTM D1945

– 03 Standard Test Metho d for Analysis of Natural Gas by Gas Chromatography (incorporated by reference, see §98.7). (2) ASTM D1946

– 90 (Reapproved 2006) Standard Practice for Analysis of Reformed Gas by Gas Chromatography (incorporated by reference, see §98.7). (3) ASTM D2502

– 04 ( Reapproved 2002) Standard Test Method for Estimation of Mean Relative Molecular Mass of Petroleum Oilsfrom Viscosity Measurements (incorporated by reference, see

§98.7). (4) ASTM D2503

– 92 (Reapproved 2007) Standard Test Method for Relative Molecular Mass (Molecular Weight) of Hydrocarbons by Thermoelectric Measurement of Vapor Pressure (incorporated by reference, see §98.7). (5) ASTM D3238

– 95 (Reapproved 2005) Standard Tes t Method for Calculation of Carbon Distribution and Structural Group Analysis of Petroleum Oils by the n - d - M Method (incorporated by reference, see §98.7). (6) ASTM D5291

– 02 (Reapproved 2007) Standard Test Methods for Instrumental Determination of Carbon, Hydrogen, and Nitrogen in Petroleum Products and Lubricants (incorporated by reference, see §98.7). (7) ASTM D3176

– 89 (Reapproved 2002) Standard Practice for Ultimate Analysis of Coal and Coke (incorporated by reference, see §98.7). (8) ASTM D5373

– 08 Standard Methods for Instrumental Determination of Carbon, Hydrogen, and Nitrogen in Laboratory Samples of Coal (incorporated by reference, see §98.7).(d) Calibrate all oil and gas flow meters that are used to

measure liquid and gaseous feedstock volumes and flow rates (except for gas billing meters) according to the monitoring and QA/QC requirements for the Tier 3 methodology in §98.34(b)(1). Perform oil tank drop measurements (if used to quantify feedstock volumes) according to §98.34(b )(2). (e) For quality assurance and quality control of the supplier data, on an annual basis, you must measure the carbon contents of a representative sample of the feedstocks consumed using the appropriate ASTM Method as listed in paragraphs (c)(1) through (c)(8) of this section. (f)[Reserved] (g) If CO 2 from ammonia production is used to produce urea at the same facility, you must determine the quantity of urea produced using methods or plant instruments used for accounting purposes (such as sales records ). You must document the procedures used to ensure the accuracy of the estimates of urea produced. § 98.75 Procedures for estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations is required. Therefore, whenever themonitoring and quality assurance procedures in §98.74 cannot be

followed (e.g., if a meter malfunctions during unit operation), a substitute data value for the missing parameter shall be used in the calculations following paragraphs (a) and ( b) of this section. You must document and keep records of the procedures used for all such estimates. (a) For missing data on monthly carbon contents of feedstock, the substitute data value shall be the arithmetic average of the quality - assured values of t hat carbon content in the month preceding and the month immediately following the missing data incident. If no quality - assured data are available prior to the missing data incident, the substitute data value shall be the first quality - assured value for carbon content obtained in the month after the missing data period. (b) For missing feedstock supply rates used to determine monthly feedstock consumption , you must determine the best available estimate(s) of the parameter(s), based on all available process data. § 98.76 Data reporting requirements. In addition to the information required by §98.3(c), each annual report must contain the information specified inparagraphs (a) and (b) of this se ction, as applicable for each

ammonia manufacturing process unit. (a) If a CEMS is used to measure CO 2 emissions, then you must report the relevant information required under §98.36 for the Tier 4 Calculation Methodology and the information in paragraph s (a) (1) and (a)(2) of this section : (1) Annual quantity of each type of feedstock consumed for ammonia manufacturing (scf of feedstock or gallons of feedstock or kg of feedstock). (2) Method used for determining quantity of feedstock used. ( b) If a CEMS is not used to measure emissions, then you must report all of the following information in this paragraph (b) : (1) Annual CO 2process emissions (metric tons) for each ammonia manufacturing process unit. (2) Monthly quantity of each type of feed stock consumed for ammonia manufacturing for each ammonia processing unit (scf of feedstock or gallons of feedstock or kg of feedstock). (3) Method used for determining quantity of monthly feedstock used.(4) Whether carbon content for each feedstock for month n

is based on reports from the supplier or analysis of carbon content. (5) If carbon content of feedstock for month n is based on analysis, the test method used. (6) Sampling analysis results of carbon content of feedstock as determined for QA/QC of s upplier data under §98.74(e). (7) If a facility uses gaseous feedstock, the carbon content of the gaseous feedstock, for month n, (kg C per kg of feedstock). (8) If a facility uses gaseous feedstock, the molecular weight of the gaseous feedstock (kg/kg - mole). (9) If a facility uses gaseous feedstock, the molar volume conversion factor of the gaseous feedstock (scf per kg - mole). (10) If a facility uses liquid feedstock, the carbon content of the liquid feedstock, for month n, (kg C per gallon of fe edstock). (11) If a facility uses solid feedstock, the carbon content of the solid feedstock, for month n, (kg C per kg of feedstock).(12) Annual urea production (metric tons) and method used

to determine urea production. (13) Annual CO 2 emissions (metric tons) from the steam reforming of a hydrocarbon or the gasification of solid and liquid raw material at the ammonia manufacturing process unit used to produce urea and the method used to determine the CO 2 consumed in urea production. § 98.77 Records tha t must be retained. In addition to the records required by §98.3(g), you must retain the following records specified in paragraphs (a) and (b) of this section for each ammonia manufacturing unit. (a) If a CEMS is used to measure emissions, retain records o f all feedstock purchases in addition to the requirements in §98.37 for the Tier 4 Calculation Methodology. (b) If a CEMS is not used to measure process CO 2 emissions, you must also retain the records specified in paragraphs (b)(1) through (b)(2) of this se ction: (1) Records of all analyses and calculations conducted for reported data as listed in §98.76(b).(2) Monthly records of carbon content of feedstock from

supplier and/or all analyses conducted of carbon content. § 98.78 Definitions. All terms used in this subpart have the same meaning given in the Clean Air Act and subpart A of this part.