Regulations last checked for updates: Jun 02, 2024

Title 40 - Protection of Environment last revised: May 30, 2024
§ 98.80 - Definition of the source category.

The cement production source category consists of each kiln and each in-line kiln/raw mill at any portland cement manufacturing facility including alkali bypasses, and includes kilns and in-line kiln/raw mills that burn hazardous waste.

§ 98.81 - Reporting threshold.

You must report GHG emissions under this subpart if your facility contains a cement production process and the facility meets the requirements of either § 98.2(a)(1) or (2).

§ 98.82 - GHGs to report.

You must report:

(a) CO2 process emissions from calcination in each kiln.

(b) CO2 combustion emissions from each kiln.

(c) CH4 and N2O combustion emissions from each kiln. 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.

(d) CO2, CH4, and N2O emissions from each stationary combustion unit other than kilns. You must report these emissions under subpart C of this part (General Stationary Fuel Combustion Sources) by following the requirements of subpart C.

§ 98.83 - Calculating GHG emissions.
Link to an amendment published at 89 FR 31905, Apr. 25, 2024.

You must calculate and report the annual process CO2 emissions from each kiln using the procedure in paragraphs (a) and (b) of this section.

(a) For each cement kiln that meets 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 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) For each kiln that is not subject to the requirements in paragraph (a) of this section, calculate and report the process and combustion CO2 emissions from the kiln by using the procedure in either paragraph (c) or (d) of this section.

(c) Calculate and report under this subpart the combined process and combustion CO2 emissions 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).

(d) Calculate and report process and combustion CO2 emissions separately using the procedures specified in paragraphs (d)(1) through (d)(4) of this section.

(1) Calculate CO2 process emissions from all kilns at the facility using Equation H-1 of this section:

Where: CO2 CMF = Annual process emissions of CO2 from cement manufacturing, metric tons. CO2 Cli,m = Total annual emissions of CO2 from clinker production from kiln m, metric tons. CO2 rm = Total annual emissions of CO2 from raw materials, metric tons. k = Total number of kilns at a cement manufacturing facility.

(2) CO2 emissions from clinker production. Calculate CO2 emissions from each kiln using Equations H-2 through H-5 of this section.

Where: Cli,j = Quantity of clinker produced in month j from kiln m, tons. EFCli,j = Kiln specific clinker emission factor for month j for kiln m, metric tons CO2/metric ton clinker computed as specified in Equation H-3 of this section. CKD,i = Cement kiln dust (CKD) not recycled to the kiln in quarter i from kiln m, tons. EFCKD,i = Kiln specific CKD emission factor for quarter i from kiln m, metric tons CO2/metric ton CKD computed as specified in Equation H-4 of this section. p = Number of months for clinker calculation, 12. r = Number of quarters for CKD calculation, 4. 2000/2205 = Conversion factor to convert tons to metric tons.

(i) Kiln-Specific Clinker Emission Factor. (A) Calculate the kiln-specific clinker emission factor using Equation H-3 of this section.

Where: CliCaO = Monthly total CaO content of Clinker, wt-fraction. ClincCaO = Monthly non-calcined CaO content of Clinker, wt-fraction. MRCaO = Molecular-weight Ratio of CO2/CaO = 0.785. CliMgO = Monthly total MgO content of Clinker, wt-fraction. ClincMgO = Monthly non-calcined MgO content of Clinker, wt-fraction. MRMgO = Molecular-weight Ratio of CO2/MgO = 1.092.

(B) Non-calcined CaO is CaO that remains in the clinker in the form of CaCO3 and CaO in the clinker that entered the kiln as a non-carbonate species. Non-calcined MgO is MgO that remains in the clinker in the form of MgCO3 and MgO in the clinker that entered the kiln as a non-carbonate species.

(ii) Kiln-Specific CKD Emission Factor. (A) Calculate the kiln-specific CKD emission factor for CKD not recycled to the kiln using Equation H-4 of this section.

Where: CKDCaO = Quarterly total CaO content of CKD not recycled to the kiln, wt-fraction. CKDCaO = Quarterly non-calcined CaO content of CKD not recycled to the kiln, wt-fraction. MRCaO = Molecular-weight Ratio of CO2/CaO = 0.785. CKDMgO = Quarterly total MgO content of CKD not recycled to the kiln, wt-fraction. CKDMgO = Quarterly non-calcined MgO content of CKD not recycled to the kiln, wt-fraction. MRMgO = Molecular-weight Ratio of CO2/MgO = 1.092.

(B) Non-calcined CaO is CaO that remains in the CKD in the form of CaCO3 and CaO in the CKD that entered the kiln as a non-carbonate species. Non-calcined MgO is MgO that remains in the CKD in the form of MgCO3 and MgO in the CKD that entered the kiln as a non-carbonate species.

(3) CO2 emissions from raw materials. Calculate CO2 emissions from raw materials using Equation H-5 of this section:

Where: rm = The amount of raw material i consumed annually, tons/yr (dry basis) or the amount of raw kiln feed consumed annually, tons/yr (dry basis). CO2,rm = Annual CO2 emissions from raw materials. TOCrm = Organic carbon content of raw material i or organic carbon content of combined raw kiln feed (dry basis), as determined in § 98.84(c) or using a default factor of 0.2 percent of total raw material weight. M = Number of raw materials or 1 if calculating emissions based on combined raw kiln feed. 44/12 = Ratio of molecular weights, CO2 to carbon. 2000/2205 = Conversion factor to convert tons to metric tons.

(4) Calculate and report under subpart C of this part (General Stationary Fuel Combustion Sources) the combustion CO2 emissions from the kiln according to the applicable requirements in subpart C.

[74 FR 56374, Oct. 30, 2009, as amended at 75 FR 66461, Oct. 28, 2010]
§ 98.84 - Monitoring and QA/QC requirements.

(a) You must determine the weight fraction of total CaO and total MgO in CKD not recycled to the kiln from each kiln using ASTM C114-09, Standard Test Methods for Chemical Analysis of Hydraulic Cement (incoporated by reference, see § 98.7). The monitoring must be conducted quarterly for each kiln from a CKD sample drawn either as CKD is exiting the kiln or from bulk CKD storage.

(b) You must determine the weight fraction of total CaO and total MgO in clinker from each kiln using ASTM C114-09 Standard Test Methods for Chemical Analysis of Hydraulic Cement (incorporated by reference, see § 98.7). The monitoring must be conducted monthly for each kiln from a monthly clinker sample drawn from bulk clinker storage if storage is dedicated to the specific kiln, or from a monthly arithmetic average of daily clinker samples drawn from the clinker conveying systems exiting each kiln.

(c) The total organic carbon content (dry basis) of raw materials must be determined annually using ASTM C114-09 Standard Test Methods for Chemical Analysis of Hydraulic Cement (incorporated by reference, see § 98.7) or a similar industry standard practice or method approved for total organic carbon determination in raw mineral materials. The analysis must be conducted either on sample material drawn from bulk raw kiln feed storage or on sample material drawn from bulk raw material storage for each category of raw material (i.e., limestone, sand, shale, iron oxide, and alumina). Facilities that opt to use the default total organic carbon factor provided in § 98.83(d)(3), are not required to monitor for TOC.

(d) The quantity of clinker produced monthly by each kiln must be determined by direct weight measurement of clinker using the same plant techniques used for accounting purposes, such as reconciling weigh hopper or belt weigh feeder measurements against inventory measurements. As an alternative, facilities may also determine clinker production by direct measurement of raw kiln feed and application of a kiln-specific feed-to-clinker factor. Facilities that opt to use a feed-to-clinker factor must verify the accuracy of this factor on a monthly basis.

(e) The quantity of CKD not recycled to the kiln generated by each kiln must be determined quarterly using the same plant techniques used for accounting purposes, such as direct weight measurement using weigh hoppers, truck weigh scales, or belt weigh feeders.

(f) The annual quantity of raw kiln feed or annual quantity of each category of raw materials consumed by the facility (e.g., limestone, sand, shale, iron oxide, and alumina) must be determined monthly by direct weight measurement using the same plant instruments used for accounting purposes, such as weigh hoppers, truck weigh scales, or belt weigh feeders.

(g) The monthly non-calcined CaO and MgO that remains in the clinker in the form of CaCO3 or that enters the kiln as a non-carbonate species may be assumed to be a default value of 0.0 or may be determined monthly by careful chemical analysis of feed material and clinker material from each kiln using well documented analytical and calculational methods or the appropriate industry standard practice.

(h) The quarterly non-calcined CaO and MgO that remains in the CKD in the form of CaCO3 or that enters the kiln as a non-carbonate species may be assumed to be a default value of 0.0 or may be determined quarterly by careful chemical analysis of feed material and CKD material from each kiln using well documented analytical and calculational methods or the appropriate industry standard practice.

[74 FR 56374, Oct. 30, 2009, as amended at 75 FR 66461, Oct. 28, 2010]
§ 98.85 - Procedures for estimating missing data.

A complete record of all measured parameters used in the GHG emissions calculations in § 98.83 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. The owner or operator must document and keep records of the procedures used for all such estimates.

(a) If the CEMS approach is used to determine combined process and combustion CO2 emissions, the missing data procedures in § 98.35 apply.

(b) For CO2 process emissions from cement manufacturing facilities calculated according to § 98.83(d), if data on the carbonate content (of clinker or CKD), noncalcined content (of clinker or CKD) or the annual organic carbon content of raw materials are missing, facilities must undertake a new analysis.

(c) For each missing value of monthly clinker production the substitute data value must be the best available estimate of the monthly clinker production based on information used for accounting purposes, or use the maximum tons per day capacity of the system and the number of days per month.

(d) For each missing value of monthly raw material consumption the substitute data value must be the best available estimate of the monthly raw material consumption based on information used for accounting purposes (such as purchase records), or use the maximum tons per day raw material throughput of the kiln and the number of days per month.

§ 98.86 - Data reporting requirements.
Link to an amendment published at 89 FR 31905, Apr. 25, 2024.

In addition to the information required by § 98.3(c), each annual report must contain the information specified in paragraphs (a) and (b) of this section, as appropriate.

(a) If a CEMS is used to measure CO2 emissions, then you must report under this subpart the relevant information required by § 98.36(e)(2)(vi) and the information listed in this paragraph(a):

(1) Monthly clinker production from each kiln at the facility.

(2) Annual facility cement production.

(3) Number of kilns and number of operating kilns.

(b) If a CEMS is not used to measure CO2 emissions, then you must report the information listed in this paragraph (b) for each kiln:

(1) Kiln identification number.

(2) [Reserved]

(3) Annual cement production at the facility.

(4) Number of kilns and number of operating kilns.

(5)-(6) [Reserved]

(7) Method used to determine non-calcined CaO and non-calcined MgO in clinker.

(8) [Reserved]

(9) Method used to determine non-calcined CaO and non-calcined MgO in CKD.

(10) [Reserved]

(11) Quarterly kiln-specific CKD CO2 emission factors for each kiln (metric tons CO2/metric ton CKD produced).

(12) [Reserved]

(13) Name of raw kiln feed or raw material.

(14) Number of times missing data procedures were used to determine the following information:

(i) Clinker production (number of months).

(ii) Carbonate contents of clinker (number of months).

(iii) Non-calcined content of clinker (number of months).

(iv) CKD not recycled to kiln (number of quarters).

(v) Non-calcined content of CKD (number of quarters)

(vi) Organic carbon contents of raw materials (number of times).

(vii) Raw material consumption (number of months).

(15) Method used to determine the monthly clinker production from each kiln.

(16) Annual clinker production (metric tons).

(17) Annual average clinker CO2 emission factor for the facility, averaged across all kilns (metric tons CO2/metric ton clinker produced).

(18) Annual average CKD CO2 emission factor for the facility, averaged across all kilns (metric tons CO2/metric ton CKD produced).

[74 FR 56374, Oct. 30, 2009, as amended at 75 FR 66461, Oct. 28, 2010; 78 FR 71953, Nov. 29, 2013; 79 FR 63785, Oct. 24, 2014]
§ 98.87 - Records that must be retained.

(a) If a CEMS is used to measure CO2 emissions, then in addition to the records required by § 98.3(g), you must retain under this subpart the records required for the Tier 4 Calculation Methodology in § 98.37.

(b) If a CEMS is not used to measure CO2 emissions, then in addition to the records required by § 98.3(g), you must retain the records specified in this paragraph (b) for each portland cement manufacturing facility.

(1) Documentation of monthly calculated kiln-specific clinker CO2 emission factor.

(2) Documentation of quarterly calculated kiln-specific CKD CO2 emission factor.

(3) Measurements, records and calculations used to determine reported parameters.

(c) 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 (c)(1) through (17) of this section. Retention of this file satisfies the recordkeeping requirement for the data in paragraphs (c)(1) through (17) of this section.

(1) Identify per kiln per month if clinker is measured directly, or is calculated from raw feed (Equation H-2 of § 98.83 and the method in § 98.84(d)).

(2) Quantity of raw kiln feed in month from kiln (tons) (Equation H-2 and the method in § 98.84(d)).

(3) Kiln-specific factor per kiln per month (ton clinker per ton raw feed) (Equation H-2 and the method in § 98.84(d)).

(4) Quantity of clinker produced in month from kiln (tons) (Equation H-2 and the method in § 98.84(d)).

(5) Cement kiln dust (CKD) not recycled to the kiln in quarter from kiln (tons) (Equation H-2 and the method in § 98.84(d)).

(6) Monthly total CaO content of clinker per kiln (weight fraction) (Equation H-3 of § 98.83).

(7) Monthly non-calcined CaO content of clinker per kiln (weight fraction) (Equation H-3).

(8) Monthly total MgO content of clinker per kiln (weight fraction) (Equation H-3).

(9) Monthly non-calcined MgO content of clinker per kiln (weight fraction) (Equation H-3).

(10) Quarterly total CaO content of cement kiln dust not recycled to each kiln (weight fraction) (Equation H-4 of § 98.83).

(11) Quarterly non-calcined CaO content of cement kiln dust not recycled to each kiln (weight fraction) (Equation H-4).

(12) Quarterly total MgO content of cement kiln dust not recycled to each kiln (weight fraction) (Equation H-4).

(13) Quarterly non-calcined MgO content of cement kiln dust not recycled to each kiln (weight fraction) (Equation H-4).

(14) The amount of each raw material consumed annually per kiln (tons/yr (dry basis)) (Equation H-5 of § 98.83).

(15) The amount of each raw kiln feed consumed annually per kiln (tons/yr (dry basis)) (Equation H-5).

(16) Organic carbon content of each raw material per kiln, as determined in § 98.84(c). Default value is 0.002 weight fraction (Equation H-5).

(17) Organic carbon content of combined raw kiln feed per kiln, as determined in § 98.84(c). Default value is 0.002 weight fraction (Equation H-5).

[75 FR 66461, Oct. 28, 2010, as amended at 79 FR 63785, Oct. 24, 2014]
§ 98.88 - Definitions.

All terms used in this subpart have the same meaning given in the Clean Air Act and subpart A of this part.

source: 74 FR 56374, Oct. 30, 2009, unless otherwise noted.
cite as: 40 CFR 98.87