Page 1 of 12

Subpart S—Lime Manufacturing

§ 98.190 Definition of the source category.

(a) Lime manufacturing plants (LMPs) engage in the 

manufacture of a lime product by calcination of limestone, 

dolomite, shells or other calcareous substances as defined in 40 

CFR 63.7081(a)(1).

(b) This source category includes all LMPs unless the LMP 

is located at a kraft pulp mill, soda pulp mill, sulfite pulp 

mill, or only processes sludge containing calcium carbonate from 

water softening processes. The lime manufacturing source 

category consists of marketed and non-marketed lime 

manufacturing facilities.

(c) Lime kilns at pulp and paper manufacturing facilities 

must report emissions under subpart AA of this part (Pulp and 

Paper Manufacturing).

§ 98.191 Reporting threshold.

You must report GHG emissions under this subpart if your 

facility is a lime manufacturing plant as defined in §98.190 and 

the facility meets the requirements of either §98.2(a)(1) or 

(a)(2).

§ 98.192 GHGs to report.

You must report:

(a) CO2 process emissions from lime kilns.

(b) CO2 emissions from fuel combustion at lime kilns.
Page 2 of 12

(c) N2O and CH4 emissions from fuel combustion at each lime 

kiln. You must report these emissions under 40 CFR part 98, 

subpart C (General Stationary Fuel Combustion Sources).

(d) CO2, N2O, and CH4 emissions from each stationary fuel 

combustion unit other than lime kilns. You must report these 

emissions under 40 CFR part 98, subpart C (General Stationary 

Fuel Combustion Sources).

(e) CO2 collected and transferred off site under 40 CFR part 

98, following the requirements of subpart PP of this part 

(Suppliers of Carbon Dioxide (CO2)).

§ 98.193 Calculating GHG emissions.

You must calculate and report the annual process CO2

emissions from all lime kilns combined using the procedure in 

paragraphs (a) and (b) of this section.

(a) If all lime kilns meet the conditions specified in 

§98.33(b)(4)(ii) or (b)(4)(iii), you must calculate and report 

under this subpart the combined process and combustion CO2

emissions from all lime kilns by operating and maintaining a 

CEMS to measure CO2 emissions according to the Tier 4 Calculation 

Methodology specified in §98.33(a)(4) and all associated 

requirements for Tier 4 in subpart C of this part (General 

Stationary Fuel Combustion Sources).

(b) If CEMS are not required to be used to determine CO2

emissions from all lime kilns under paragraph (a) of this 
Page 3 of 12

section, then you must calculate and report the process and 

combustion CO2 emissions from the lime kilns by using the 

procedures in either paragraph (b)(1) or (b)(2) of this section.

(1) Calculate and report under this subpart the combined 

process and combustion CO2 emissions from all lime kilns by 

operating and maintaining a CEMS to measure CO2 emissions from 

all lime kilns according to the Tier 4 Calculation Methodology 

specified in §98.33(a)(4) and all associated requirements for 

Tier 4 in subpart C of this part (General Stationary Fuel 

Combustion Sources).

(2) Calculate and report process and combustion CO2

emissions from all lime kilns separately using the procedures 

specified in paragraphs (b)(2)(i) through (b)(2)(v) of this 

section.

(i) You must calculate a monthly emission factor for each 

type of lime produced using Equation S–1 of this section. 

Calcium oxide and magnesium oxide content must be analyzed 

monthly for each lime product type that is produced:

Where:

EFLIME,i,n = Emission factor for lime type i, for month n 

(metric tons CO2/ton lime).

SRCaO = Stoichiometric ratio of CO2 and CaO for calcium 

carbonate [see Table S–1 of this subpart] 

(metric tons CO2/metric tons CaO).
Page 4 of 12

SRMgO = Stoichiometric ratio of CO2 and MgO for 

magnesium carbonate (See Table S–1 of this 

subpart) (metric tons CO2/metric tons MgO).

CaOi,n = Calcium oxide content for lime type i, for 

month n, determined according to §98.194(c) 

(metric tons CaO/metric ton lime).

MgOi,n = Magnesium oxide content for lime type i, for 

month n, determined according to §98.194(c) 

(metric tons MgO/metric ton lime).

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

(ii) You must calculate a monthly emission factor for each 

type of calcined byproduct or waste sold (including lime kiln 

dust) using Equation S–2 of this section:

Where:

EFLKD,i,n = Emission factor for calcined lime byproduct or 

waste type i sold, for month n (metric tons 

CO2/ton lime byproduct).

SRCaO = Stoichiometric ratio of CO2 and CaO for calcium 

carbonate (see Table S–1 of this 

subpart((metric tons CO2/metric tons CaO).

SRMgO = Stoichiometric ratio of CO2 and MgO for 

magnesium carbonate (See Table S–1 of this 

subpart) (metric tons CO2/metric tons MgO).

CaOLKD,i,n = Calcium oxide content for calcined lime 

byproduct or waste type i sold, for month n 

(metric tons CaO/metric ton lime).

MgOLKD,i,n = Magnesium oxide content for calcined lime 

byproduct or waste type i sold, for month n 

(metric tons MgO/metric ton lime).

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

(iii) You must calculate the annual CO2 emissions from each 

type of calcined byproduct or waste that is not sold (including 
Page 5 of 12

lime kiln dust and scrubber sludge) using Equation S–3 of this 

section:

Where:

Ewaste,i = Annual CO2 emissions for calcined lime 

byproduct or waste type i that is not sold 

(metric tons CO2).

SRCaO = Stoichiometric ratio of CO2 and CaO for calcium 

carbonate (see Table S–1 of this subpart) 

(metric tons CO2/metric tons CaO).

SRMgO = Stoichiometric ratio of CO2 and MgO for 

magnesium carbonate (See Table S–1 of this 

subpart) (metric tons CO2/metric tons MgO).

CaOwaste,i = Calcium oxide content for calcined lime 

byproduct or waste type i that is not sold 

(metric tons CaO/metric ton lime).

MgOwaste,i = Magnesium oxide content for calcined lime 

byproduct or waste type i that is not sold 

(metric tons MgO/metric ton lime).

Mwaste,i = Annual weight or mass of calcined byproducts

or wastes for lime type i that is not sold 

(tons).

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

(iv) You must calculate annual CO2 process emissions for all 

lime kilns using Equation S–4 of this section:

Where:

ECO2 = Annual CO2 process emissions from lime 

production from all lime kilns (metric 

tons/year).
Page 6 of 12

EFLIME,i,n = Emission factor for lime type i produced, in 

calendar month n (metric tons CO2/ton lime) 

from Equation S–1 of this section.

MLIME,i,n = Weight or mass of lime type i produced in 

calendar month n (tons).

EFLKD,i,n = Emission factor of calcined byproducts or 

wastes sold for lime type i in calendar month 

n, (metric tons CO2/ton byproduct or waste) 

from Equation S–2 of this section.

MLKD,i,n = Monthly weight or mass of calcined byproducts

or waste sold (such as lime kiln dust, LKD) 

for lime type i in calendar month n (tons).

Ewaste,i = Annual CO2 emissions for calcined lime 

byproduct or waste type i that is not sold 

(metric tons CO2) from Equation S–3 of this 

section.

t = Number of lime types produced.

b = Number of calcined byproducts or wastes that 

are sold.

z = Number of calcined byproducts or wastes that 

are not sold.

(v) Calculate and report under subpart C of this part

(General Stationary Fuel Combustion Sources) the combustion CO2

emissions from each lime kiln according to the applicable 

requirements in subpart C.

§ 98.194 Monitoring and QA/QC requirements.

(a) You must determine the total quantity of each type of 

lime product that is produced and each calcined byproduct or 

waste (such as lime kiln dust) that is sold. The quantities of 

each should be directly measured monthly with the same plant 

instruments used for accounting purposes, including but not 

limited to, calibrated weigh feeders, rail or truck scales, and 
Page 7 of 12

barge measurements. The direct measurements of each lime product 

shall be reconciled annually with the difference in the 

beginning of and end of year inventories for these products, 

when measurements represent lime sold.

(b) You must determine the annual quantity of each calcined 

byproduct or waste generated that is not sold by either direct 

measurement using the same instruments identified in paragraph 

(a) of this section or by using a calcined byproduct or waste

generation rate.

(c) You must determine the chemical composition (percent 

total CaO and percent total MgO) of each type of lime product 

that is produced and each type of calcined byproduct or waste 

sold according to paragraph (c)(1) or (2) of this section. You 

must determine the chemical composition of each type of lime 

product that is produced and each type of calcined byproduct or 

waste sold on a monthly basis. You must determine the chemical 

composition for each type of calcined byproduct or waste that is 

not sold on an annual basis.

(1) ASTM C25–06 Standard Test Methods for Chemical Analysis 

of Limestone, Quicklime, and Hydrated Lime (incorporated by 

reference— see §98.7).

(2) The National Lime Association's CO2 emissions 

Calculation Protocol for the Lime Industry English Units 
Page 8 of 12

Version, February 5, 2008 Revision-National Lime Association 

(incorporated by reference—see §98.7).

(d) You must use the analysis of calcium oxide and 

magnesium oxide content of each lime product that is produced 

and that is collected during the same month as the production 

data in monthly calculations.

(e) You must follow the quality assurance/quality control 

procedures (including documentation) in National Lime 

Association's CO2 emissions Calculation Protocol for the Lime 

Industry English Units Version, February 5, 2008 Revision—

National Lime Association (incorporated by reference— see

§98.7).

§ 98.195 Procedures for estimating missing data.

For the procedure in §98.193(b)(1), a complete record of 

all measured parameters used in the GHG emissions calculations 

is required (e.g., oxide content, quantity of lime products, 

etc.). 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) or (b) of this section. You must document and 

keep records of the procedures used for all such estimates.

(a) For each missing value of the quantity of lime produced 

(by lime type), and quantity of calcined byproduct or waste

produced and sold, the substitute data value shall be the best 
Page 9 of 12

available estimate based on all available process data or data 

used for accounting purposes.

(b) For missing values related to the CaO and MgO content, 

you must conduct a new composition test according to the 

standard methods in §98.194 (c)(1) or (c)(2).

§ 98.196 Data reporting requirements.

In addition to the information required by §98.3(c), each 

annual report must contain the information specified in 

paragraphs (a) or (b) of this section, as applicable.

(a) If a CEMS is used to measure CO2 emissions, then you 

must report under this subpart the relevant information required 

by §98.36 and the information listed in paragraphs (a)(1) 

through (8) of this section.

(1) Method used to determine the quantity of lime that is 

produced and quantity of lime that is sold.

(2) Method used to determine the quantity of calcined lime 

byproduct or waste sold.

(3) Beginning and end of year inventories for each lime 

product that is produced, by type.

(4) Beginning and end of year inventories for calcined lime 

byproducts or wastes sold, by type.

(5) Annual amount of calcined lime byproduct or waste sold, 

by type (tons).

(6) Annual amount of lime product sold, by type (tons).
Page 10 of 12

(7) Annual amount of calcined lime byproduct or waste that 

is not sold, by type (tons).

(8) Annual amount of lime product not sold, by type (tons).

(b) If a CEMS is not used to measure CO2 emissions, then you 

must report the information listed in paragraphs (b)(1) through

(17) of this section.

(1) Annual CO2 process emissions from all lime kilns 

combined (metric tons).

(2) Monthly emission factors (metric ton CO2/ton lime 

product) for each lime product type produced.

(3) Monthly emission factors for each calcined byproduct or 

waste by lime type that is sold.

(4) Standard method used (ASTM or NLA testing method) to 

determine chemical compositions of each lime type produced and 

each calcined lime byproduct or waste type.

(5) Monthly results of chemical composition analysis of 

each type of lime product produced and calcined byproduct or 

waste sold.

(6) Annual results of chemical composition analysis of each 

type of lime byproduct or waste that is not sold.

(7) Method used to determine the quantity of lime produced 

and/or lime sold.

(8) Monthly amount of lime product sold, by type (tons).
Page 11 of 12

(9) Method used to determine the quantity of calcined lime 

byproduct or waste sold.

(10) Monthly amount of calcined lime byproduct or waste 

sold, by type (tons).

(11) Annual amount of calcined lime byproduct or waste that 

is not sold, by type (tons).

(12) Monthly weight or mass of each lime type produced 

(tons).

(13) Beginning and end of year inventories for each lime 

product that is produced.

(14) Beginning and end of year inventories for calcined 

lime byproducts or wastes sold.

(15) Annual lime production capacity (tons) per facility.

(16) Number of times in the reporting year that missing 

data procedures were followed to measure lime production 

(months) or the chemical composition of lime products sold 

(months).

(17) Indicate whether CO2 was used on-site (i.e., for use in 

a purification process). If CO2 was used on-site, provide the 

information in paragraphs (b)(17)(i) and (ii) of this section.

(i) The annual amount of CO2 captured for use in the on-site 

process.

(ii) The method used to determine the amount of CO2

captured.
Page 12 of 12

§ 98.197 Records that must be retained.

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

retain the records specified in paragraphs (a) and (b) of this 

section.

(a) Annual operating hours in calendar year.

(b) Records of all analyses (e.g. chemical composition of 

lime products, by type) and calculations conducted.

§ 98.198 Definitions.

All terms used in this subpart have the same meaning given 

in the Clean Air Act and subpart A of this part.

Table S–1 to Subpart S of Part 98—Basic Parameters for the 

Calculation of Emission Factors for Lime Production

Variable Stoichiometric ratio

SRCaO 0.7848

SRMgO 1.0918