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Subpart AA—Pulp and Paper Manufacturing

§98.270 Definition of source category.

(a) The pulp and paper manufacturing source category consists of facilities that produce 

market pulp (i.e., stand-alone pulp facilities), manufacture pulp and paper (i.e., integrated 

facilities), produce paper products from purchased pulp, produce secondary fiber from recycled 

paper, convert paper into paperboard products (e.g., containers), or operate coating and 

laminating processes.

(b) The emission units for which GHG emissions must be reported are listed in 

paragraphs (b)(1) through (b)(5) of this section:

(1) Chemical recovery furnaces at kraft and soda mills (including recovery furnaces that 

burn spent pulping liquor produced by both the kraft and semichemical process).

(2) Chemical recovery combustion units at sulfite facilities.

(3) Chemical recovery combustion units at stand-alone semichemical facilities.

(4) Pulp mill lime kilns at kraft and soda facilities.

(5) Systems for adding makeup chemicals (CaCO3, Na2CO3) in the chemical recovery

areas of chemical pulp mills.

§98.271 Reporting threshold.

You must report GHG emissions under this subpart if your facility contains a pulp and 

paper manufacturing process and the facility meets the requirements of either §98.2(a)(1) or 

(a)(2).

§98.272 GHGs to report.

You must report the emissions listed in paragraphs (a) through (f) of this section:

(a) CO2, biogenic CO2, CH4, and N2O emissions from each kraft or soda chemical 

recovery furnace.
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(b) CO2, biogenic CO2, CH4, and N2O emissions from each sulfite chemical recovery

combustion unit.

(c) CO2, biogenic CO2, CH4, and N2O emissions from each stand-alone semichemical 

chemical recovery combustion unit.

(d) CO2, biogenic CO2, CH4, and N2O emissions from each kraft or soda pulp mill lime 

kiln.

(e) CO2 emissions from addition of makeup chemicals (CaCO3, Na2CO3) in the chemical 

recovery areas of chemical pulp mills.

(f) CO2, CH4, and N2O combustion emissions from each stationary combustion unit. You 

must calculate and report these emissions under subpart C of this part (General Stationary Fuel 

Combustion Sources) by following the requirements of subpart C.

§98.273 Calculating GHG emissions.

(a) For each chemical recovery furnace located at a kraft or soda facility, you must 

determine CO2, biogenic CO2, CH4, and N2O emissions using the procedures in paragraphs (a)(1) 

through (a)(3) of this section. CH4 and N2O emissions must be calculated as the sum of 

emissions from combustion of fossil fuels and combustion of biomass in spent liquor solids.

(1) Calculate fossil fuel-based CO2 emissions from direct measurement of fossil fuels 

consumed and default emissions factors according to the Tier 1 methodology for stationary

combustion sources in §98.33(a)(1). Tiers 2 or 3 from § 98.33(a)(2) or (3) may be used to 

calculate fossil fuel-based CO2 emissions if the respective monitoring and QA/QC requirements 

described in §98.34 are met.

(2) Calculate fossil fuel-based CH4 and N2O emissions from direct measurement of fossil 

fuels consumed, default or site-specific HHV, and default emissions factors and convert to 
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metric tons of CO2 equivalent according to the methodology for stationary combustion sources in 

§98.33(c).

(3) Calculate biogenic CO2 emissions and emissions of CH4 and N2O from biomass using 

measured quantities of spent liquor solids fired, site-specific HHV, and default emissions factors, 

according to Equation AA-1 of this section:

View or download PDF

Where:

CO2, CH4, or N2O, from Biomass = Biogenic CO2 emissions or emissions of CH4 or N2O 

from spent liquor solids combustion (metric tons per year).

Solids = Mass of spent liquor solids combusted (short tons per year) determined 

according to §98.274(b).

HHV = Annual high heat value of the spent liquor solids (mmBtu per kilogram) 

determined according to §98.274(b).

(EF) = Default emission factor for CO2, CH4, or N2O, from Table AA-1 of this subpart 

(kg CO2, CH4, or N2O per mmBtu).

0.90718 = Conversion factor from short tons to metric tons.

(b) For each chemical recovery combustion unit located at a sulfite or stand-alone 

semichemical facility, you must determine CO2, CH4, and N2O emissions using the procedures in 

paragraphs (b)(1) through (b)(4) of this section:

(1) Calculate fossil CO2 emissions from fossil fuels from direct measurement of fossil 

fuels consumed and default emissions factors according to the Tier 1 Calculation Methodology

for stationary combustion sources in §98.33(a)(1). Tiers 2 or 3 from § 98.33(a)(2) or (3) may be 
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used to calculate fossil fuel-based CO2 emissions if the respective monitoring and QA/QC 

requirements described in § 98.34 are met.

(2) Calculate CH4 and N2O emissions from fossil fuels from direct measurement of fossil 

fuels consumed, default or site-specific HHV, and default emissions factors and convert to 

metric tons of CO2 equivalent according to the methodology for stationary combustion sources in 

§98.33(c).

(3) Calculate biogenic CO2 emissions using measured quantities of spent liquor solids 

fired and the carbon content of the spent liquor solids, according to Equation AA-2 of this 

section:

Where:

Biogenic CO2 = Annual CO2 mass emissions for spent liquor solids combustion (metric 

tons per year).

Solids = Mass of the spent liquor solids combusted (short tons per year) determined 

according to §98.274(b).

CC = Annual carbon content of the spent liquor solids, determined according to 

§98.274(b) (percent by weight, expressed as a decimal fraction, e.g., 95% = 0.95).

44/12 = Ratio of molecular weights, CO2 to carbon.

0.90718 = Conversion from short tons to metric tons.

(4) Calculate CH4 and N2O emissions from biomass using Equation AA-1 of this section 

and the default CH4 and N2O emissions factors for kraft facilities in Table AA-1 of this subpart 

and convert the CH4 or N2O emissions to metric tons of CO2 equivalent by multiplying each 
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annual CH4 and N2O emissions total by the appropriate global warming potential (GWP) factor 

from Table A-1 of subpart A of this part.

(c) For each pulp mill lime kiln located at a kraft or soda facility, you must determine 

CO2, CH4, and N2O emissions using the procedures in paragraphs (c)(1) through (c)(3) of this 

section:

(1) Calculate CO2 emissions from fossil fuel from direct measurement of fossil fuels 

consumed and default HHV and default emissions factors, according to the Tier 1 Calculation 

Methodology for stationary combustion sources in §98.33(a)(1). Tiers 2 or 3 from §98.33(a)(2)

or (3) may be used to calculate fossil fuel-based CO2 emissions if the respective monitoring and 

QA/QC requirements described in § 98.34 are met.

(2) Calculate CH4 and N2O emissions from fossil fuel from direct measurement of fossil 

fuels consumed, default or site-specific HHV, and default emissions factors and convert to 

metric tons of CO2 equivalent according to the methodology for stationary combustion sources in 

§98.33(c); use the default HHV listed in Table C-1 of subpart C and the default CH4 and N2O 

emissions factors listed in Table AA-2 of this subpart.

(3) Biogenic CO2 emissions from conversion of CaCO3 to CaO are included in the 

biogenic CO2 estimates calculated for the chemical recovery furnace in paragraph (a)(3) of this 

section.

(d) For makeup chemical use, you must calculate CO2 emissions by using direct or 

indirect measurement of the quantity of chemicals added and ratios of the molecular weights of 

CO2 and the makeup chemicals, according to Equation AA-3 of this section:

Where:
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CO2 = CO2 mass emissions from makeup chemicals (kilograms/yr).

M (CaCO3) = Make-up quantity of CaCO3 used for the reporting year (metric tons per 

year).

M (NaCO3) = Make-up quantity of Na2CO3 used for the reporting year (metric tons per 

year).

44 = Molecular weight of CO2.

100 = Molecular weight of CaCO3.

105.99 = Molecular weight of Na2CO3.

§98.274 Monitoring and QA/QC requirements.

(a) Each facility subject to this subpart must quality assure the GHG emissions data 

according to the applicable requirements in §98.34. All QA/QC data must be available for 

inspection upon request.

(b) Fuel properties needed to perform the calculations in Equations AA-1 and AA-2 of 

this subpart must be determined according to paragraphs (b)(1) through (b)(3) of this section.

(1) High heat values of black liquor must be determined no less than annually using T684 

om-06 Gross Heating Value of Black Liquor, TAPPI (incorporated by reference, see §98.7). If 

measurements are performed more frequently than annually, then the high heat value used in 

Equation AA-1 of this subpart must be based on the average of the representative measurements 

made during the year.

(2) The annual mass of spent liquor solids must be determined using either of the 

methods specified in paragraph (b)(2)(i) or (b)(2)(ii) of this section.

(i) Measure the mass of spent liquor solids annually (or more frequently) using T-650 

om-05 Solids Content of Black Liquor, TAPPI (incorporated by reference in §98.7). If 
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measurements are performed more frequently than annually, then the mass of spent liquor solids 

used in Equation AA-1 of this subpart must be based on the average of the representative 

measurements made during the year.

(ii) Determine the annual mass of spent liquor solids based on records of measurements 

made with an online measurement system that determines the mass of spent liquor solids fired in 

a chemical recovery furnace or chemical recovery combustion unit.

(3) Carbon analyses for spent pulping liquor must be determined no less than annually

using ASTM D5373-08 Standard Test Methods for Instrumental Determination of Carbon, 

Hydrogen, and Nitrogen in Laboratory Samples of Coal (incorporated by reference, see §98.7). If 

measurements using ASTM D5373-08 are performed more frequently than annually, then the 

spent pulping liquor carbon content used in Equation AA-2 of this subpart must be based on the 

average of the representative measurements made during the year.

(c) Each facility must keep records that include a detailed explanation of how company 

records of measurements are used to estimate GHG emissions. The owner or operator must also 

document the procedures used to ensure the accuracy of the measurements of fuel, spent liquor 

solids, and makeup chemical usage, including, but not limited to calibration of weighing 

equipment, fuel flow meters, and other measurement devices. The estimated accuracy of 

measurements made with these devices must be recorded and the technical basis for these 

estimates must be provided. The procedures used to convert spent pulping liquor flow rates to 

units of mass (i.e., spent liquor solids firing rates) also must be documented.

(d) Records must be made available upon request for verification of the calculations and 

measurements.
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§98.275 Procedures for estimating missing data.

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 

(e.g., if a meter malfunctions during unit operation or if a required sample is not taken), a 

substitute data value for the missing parameter shall be used in the calculations, according to the 

requirements of paragraphs (a) through (c) of this section:

(a) There are no missing data procedures for measurements of heat content and carbon 

content of spent pulping liquor. A re-test must be performed if the data from any annual 

measurements are determined to be invalid.

(b) For missing measurements of the mass of spent liquor solids or spent pulping liquor 

flow rates, use the lesser value of either the maximum mass or fuel flow rate for the combustion 

unit, or the maximum mass or flow rate that the fuel meter can measure. Alternatively, records of 

the daily spent liquor solids firing rate obtained to comply with § 63.866(c)(1) may be used, 

adjusting for the duration of the missing measurements, as appropriate.

(c) For the use of makeup chemicals (carbonates), the substitute data value shall be the 

best available estimate of makeup chemical consumption, based on available data (e.g., past 

accounting records, production rates). The owner or operator shall document and keep records of 

the procedures used for all such estimates

§ 98.276 Data reporting requirements.

In addition to the information required by § 98.3(c) and the applicable information 

required by § 98.36, each annual report must contain the information in paragraphs (a) through 

(l) of this section as applicable:
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(a) Annual emissions of CO2, biogenic CO2, CH4, biogenic CH4 N2O, and biogenic N2O 

(metric tons per year).

(b) Reserved.

(c) Basis for determining the annual mass of the spent liquor solids combusted (whether 

based on T650 om-05 Solids Content of Black Liquor, TAPPI (incorporated by reference, see § 

98.7) or an online measurement system).

(d) Reserved.

(e) The default emission factor for CO2, CH4, or N2O, used in Equation AA-1 of this 

subpart (kg CO2, CH4, or N2O per mmBtu).

(f) Reserved.

(g) Reserved.

(h) Reserved.

(i) Reserved.

(j) Annual steam purchases (pounds of steam per year).

(k) Total annual production of unbleached virgin chemical pulp produced onsite during 

the reporting year in air-dried metric tons per year. This total annual production value is the sum 

of all kraft, semichemical, soda, and sulfite pulp produced onsite, prior to bleaching, through all 

virgin pulping lines. Do not include mechanical pulp or secondary fiber repulped for paper 

production in the virgin pulp production total.

(l) For each pulp mill lime kiln, report the information specified in paragraphs (l)(1) and 

(2) of this section.

(1) The quantity of calcium oxide (CaO) produced (metric tons).

(2) The percent of annual heat input, individually for each fossil fuel type.
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§ 98.277 Records that must be retained.

In addition to the information required by § 98.3(g), you must retain the records in 

paragraphs (a) through (g) of this section.

(a) GHG emission estimates (including separate estimates of biogenic CO2) for each 

emissions source listed under § 98.270(b).

(b) Annual analyses of spent pulping liquor HHV for each chemical recovery furnace at 

kraft and soda facilities.

(c) Annual analyses of spent pulping liquor carbon content for each chemical recovery

combustion unit at a sulfite or semichemical pulp facility.

(d) Annual quantity of spent liquor solids combusted in each chemical recovery furnace 

and chemical recovery combustion unit, and the basis for detemining the annual quantity of the 

spent liquor solids combusted (whether based on T650 om-05 Solids Content of Black Liquor, 

TAPPI (incorporated by reference, see § 98.7) or an online measurement system). If an online 

measurement system is used, you must retain records of the calculations used to determine the 

annual quantity of spent liquor solids combusted from the continuous measurements.

(e) Annual steam purchases.

(f) Annual quantities of makeup chemicals used.

(g) 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 (g)(1) 

through (27) of this section. Retention of this file satisfies the recordkeeping requirement for the 

data in paragraphs (g)(1) through (27) of this section.

(1) Mass of the solid fuel combusted (tons/year) (Equation C-1 of § 98.33).

(2) Volume of the liquid fuel combusted (gallons/year) (Equation C-1).
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(3) Volume of the gaseous fuel combusted (scf/year) (Equation C-1).

(4) Annual natural gas usage (therms/year) (Equation C-1a of § 98.33).

(5) Annual natural gas usage (mmBtu/year) (Equation C-1b of § 98.33).

(6) Mass of the solid fuel combusted (tons/year) (Equation C-2a of § 98.33).

(7) Volume of the liquid fuel combusted (gallons/year) (Equation C-2a).

(8) Volume of the gaseous fuel combusted (scf/year) (Equation C-2a).

(9) Annual mass of the solid fuel combusted (short tons/year) (Equation C-3 of § 98.33).

(10) Annual average carbon content of the solid fuel (percent by weight, expressed as a 

decimal fraction) (Equation C-3).

(11) Annual volume of the liquid fuel combusted (gallons/year) (Equation C-4 of § 

98.33).

(12) Annual average carbon content of the liquid fuel (kg C per gallon of fuel) (Equation 

C-4).

(13) Annual volume of the gaseous fuel combusted (scf/year) (Equation C-5 of § 98.33).

(14) Annual average carbon content of the gaseous fuel (kg C per kg of fuel) (Equation 

C-5).

(15) Annual average molecular weight of the gaseous fuel (kg/kg-mole) (Equation C-5).

(16) Molar volume conversion factor at standard conditions, as defined in § 98.6 (scf per 

kg-mole) (Equation C-5).

(17) Identify if you will use the default high heat value from Table C-1, or actual HHV 

data (Equation C-8 of § 98.33).

(18) High heat value of the fuel (mmBTU/tons) (Equation C-8).

(19) High heat value of the fuel (mmBTU/gallons) (Equation C-8).
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(20) High heat value of the fuel (mmBTU/scf) (Equation C-8).

(21) Mass of spent liquor solids combusted from each chemical recovery furnace located 

at a kraft or soda facility, in short tons in year, determined according to § 98.274(b) (tons/year) 

(Equation AA-1 of § 98.273).

(22) Annual high heat value of the spent liquor solids from each chemical recovery

furnace located at a kraft or soda facility determined according to § 98.274(b) (mmBtu per 

kilogram) (Equation AA-1).

(23) Annual high heat value of the spent liquor solids from each chemical recovery

combustion unit located at a sulfite or stand-alone semichemical facility, determined according 

to § 98.274(b) (mmBtu per kilogram) (Equation AA-1).

(24) Mass of the spent liquor solids combusted in short tons per year determined 

according to § 98.274(b) (tons/year) (Equation AA-2 of § 98.273).

(25) Annual carbon content of the spent liquor solids, determined according to § 

98.274(b) (percent by weight, expressed as a decimal fraction (e.g., 95% = 0.95)) (Equation AA2).

(26) Make-up quantity of CaCO3 used for the reporting year (metric tons/year) (Equation 

AA-3 of § 98.273).

(27) Make-up quantity of Na2CO3 used for the reporting year metric tons/year) (Equation 

AA-3).

§98.278 Definitions.

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

subpart A of this part.
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Table AA-1 to Subpart AA of Part 98—Kraft Pulping Liquor Emissions Factors for 

Biomass-Based CO2, CH4, and N2O

Wood furnish

Biomass-based emissions factors

(kg/mmBtu HHV)

aCO2 CH4 N2O

North American Softwood 94.4 0.0019 0.00042

North American Hardwood 93.7 0.0019 0.00042

Bagasse 95.5 0.0019 0.00042

Bamboo 93.7 0.0019 0.00042

Straw 95.1 0.0019 0.00042

a

Includes emissions from both the recovery furnace and pulp mill lime kiln.

Table AA-2 to Subpart AA of Part 98—Kraft Lime Kiln and Calciner Emissions Factors 

for CH4 and N2O

Fuel

Fossil fuel-based emissions factors (kg/mmBtu HHV)

Kraft rotary lime kilns Kraft calcinersa

CH4 N2O CH4 N2O

Residual Oil (any type) 0.0027 00.0027 0.0003

Distillate Oil (any type) 0.0027 00.0027 0.0004

Natural Gas 0.0027 00.0027 0.0001

Biogas 0.0027 00.0027 0.0001

Petroleum coke 0.0027 0

bNA bNA

Other Fuels See Table C-2 0See Table C-2 See Table C-2

a

Includes, for example, fluidized bed calciners at kraft mills.

b

Emission factors for kraft calciners are not available.