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Subpart U—Miscellaneous Uses of Carbonate

§98.210 Definition of the source category.

(a) This source category includes any equipment that uses carbonates listed in Table U-1 

in manufacturing processes that emit carbon dioxide. Table U-1 includes the following 

carbonates: limestone, dolomite, ankerite, magnesite, siderite, rhodochrosite, or sodium 

carbonate. Facilities are considered to emit CO2 if they consume at least 2,000 tons per year of 

carbonates heated to a temperature sufficient to allow the calcination reaction to occur.

(b) This source category does not include equipment that uses carbonates or carbonate 

containing minerals that are consumed in the production of cement, glass, ferroalloys, iron and 

steel, lead, lime, phosphoric acid, pulp and paper, soda ash, sodium bicarbonate, sodium 

hydroxide, or zinc.

(c) This source category does not include carbonates used in sorbent technology used to 

control emissions from stationary fuel combustion equipment. Emissions from carbonates used 

in sorbent technology are reported under 40 CFR 98, subpart C (Stationary Fuel Combustion 

Sources).

§98.211 Reporting threshold.

You must report GHG emissions from miscellaneous uses of carbonate if your facility 

uses carbonates as defined in §98.210 of this subpart and the facility meets the requirements of 

either §98.2(a)(1) or (a)(2).

§98.212 GHGs to report.

You must report CO2 process emissions from all miscellaneous carbonate use at your 

facility as specified in this subpart.

§98.213 Calculating GHG emissions.
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You must determine CO2 process emissions from carbonate use in accordance with the 

procedures specified in either paragraphs (a) or (b) of this section.

(a) Calculate the process emissions of CO2 using calcination fractions with Equation U-1 

of this section.

Where:

ECO2 = Annual CO2 mass emissions from consumption of carbonates (metric tons).

Mi = Annual mass of carbonate type i consumed (tons).

EFi = Emission factor for the carbonate type i, as specified in Table U-1 to this subpart, 

metric tons CO2/metric ton carbonate consumed.

Fi = Fraction calcination achieved for each particular carbonate type i (decimal fraction). 

As an alternative to measuring the calcination fraction, a value of 1.0 can be used.

n = Number of carbonate types.

2000/2205 = Conversion factor to convert tons to metric tons.

(b) Calculate the process emissions of CO2 using actual mass of output carbonates with 

Equation U-2 of this section.

Where:

ECO2 = Annual CO2 mass emissions from consumption of carbonates (metric tons).

Mk = Annual mass of input carbonate type k (tons).

EFk = Emission factor for the carbonate type k, as specified in Table U-1 of this subpart 

(metric tons CO2/metric ton carbonate input).
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Mj = Annual mass of output carbonate type j (tons).

EFj = Emission factor for the output carbonate type j, as specified in Table U-1 of this 

subpart (metric tons CO2/metric ton carbonate input).

m = Number of input carbonate types.

n = Number of output carbonate types.

§98.214 Monitoring and QA/QC requirements.

(a) The annual mass of carbonate consumed (for Equation U-1 of this subpart) or 

carbonate inputs (for Equation U-2 of this subpart) must be determined annually from monthly

measurements using the same plant instruments used for accounting purposes including purchase 

records or direct measurement, such as weigh hoppers or weigh belt feeders.

(b) The annual mass of carbonate outputs (for Equation U-2 of this subpart) must be 

determined annually from monthly measurements using the same plant instruments used for 

accounting purposes including purchase records or direct measurement, such as weigh hoppers 

or belt weigh feeders.

(c) If you follow the procedures of §98.213(a), as an alternative to assuming a calcination 

fraction of 1.0, you can determine on an annual basis the calcination fraction for each carbonate 

consumed based on sampling and chemical analysis using a suitable method such as using an xray fluorescence standard method or other enhanced industry consensus standard method 

published by an industry consensus standard organization (e.g., ASTM, ASME, etc.).

§98.215 Procedures for estimating missing data.

(a) A complete record of all measured parameters used in the GHG emissions 

calculations 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 
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specified in paragraph (b) of this section. You must document and keep records of the procedures 

used for all such estimates.

(b) For each missing value of monthly carbonate consumed, monthly carbonate output, or 

monthly carbonate input, the substitute data value must be the best available estimate based on 

the all available process data or data used for accounting purposes.

§ 98.216 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 (g) of this section at the facility level, as 

applicable.

(a) Annual CO2 emissions from miscellaneous carbonate use (metric tons).

(b) Reserved.

(c) Measurement method used to determine the mass of carbonate.

(d) Method used to calculate emissions.

(e) If you followed the calculation method of § 98.213(a), you must report the 

information in paragraphs (e)(1) through (e)(3) of this section.

(1) Reserved.

(2) Reserved.

(3) If you determined the calcination fraction, indicate which standard method was used.

(f) Reserved.

(g) Number of times in the reporting year that missing data procedures were followed to 

measure carbonate consumption, carbonate input or carbonate output (months).

§ 98.217 Records that must be retained.
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In addition to the records required by § 98.3(g), you must retain the records specified in 

paragraphs (a) through (e) of this section:

(a) Monthly carbonate consumption (by carbonate type in tons).

(b) You must document the procedures used to ensure the accuracy of the monthly

measurements of carbonate consumption, carbonate input or carbonate output including, but not 

limited to, calibration of weighing equipment and other measurement devices.

(c) Records of all analyses conducted to meet the requirements of this rule.

(d) Records of all calculations conducted.

(e) Verification software records. You must keep a record of the file generated by the 

verification software specified in § 98.5(b) for the applicable data specified in paragraphs (e)(1) 

through (4) of this section. Retention of this file satisfies the recordkeeping requirement for the 

data in paragraphs (e)(1) through (4) of this section.

(1) Fraction calcination achieved for each particular carbonate type. As an alternative to 

measuring the calcination fraction, a value of 1.0 can be used (decimal fraction) (Equation U-1

of § 98.213).

(2) Annual mass of each carbonate type consumed (tons) (Equation U-1).

(3) Annual mass of each input carbonate type (tons) (Equation U-2 of § 98.213).

(4) Annual mass of each output carbonate type (tons) (Equation U-2).

§98.218 Definitions.

All terms used in this subpart have the same meaning given in the Clean Air Act and 

subpart A of this part.

Table U-1 to Subpart U of Part 98—CO2 Emission Factors for Common Carbonates

Mineral name—carbonate

CO2 emission factor

(tons CO2/ton carbonate)
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Limestone—CaCO3 0.43971

Magnesite—MgCO3 0.52197

Dolomite—CaMg(CO3)2 0.47732

Siderite—FeCO3 0.37987

Ankerite—Ca(Fe, Mg, Mn)(CO3)2 0.47572

Rhodochrosite—MnCO3 0.38286

Sodium Carbonate/Soda Ash—Na2CO3 0.41492