98.403—Calculating GHG emissions.
(a)
LDCs and fractionators shall, for each individual product reported under this part, calculate the estimated CO2 emissions that would result from the complete combustion or oxidation of the products supplied using either of Calculation Methodology 1 or 2 of this subpart:
(1) Calculation Methodology 1.
NGL fractionators shall estimate CO2 emissions that would result from the complete combustion or oxidation of the product(s) supplied using Equation NN-1 of this section. LDCs shall estimate CO2 emissions that would result from the complete combustion or oxidation of the product received at the city gate using Equation NN-1. For each product, use the default value for higher heating value and CO2 emission factor in Table NN-1 of this subpart. Alternatively, for each product, a reporter-specific higher heating value and CO2 emission factor may be used, in place of one or both defaults provided they are developed using methods outlined in § 98.404. For each product, you must use the same volume unit throughout the equation.
Code of Federal Regulations
Code of Federal Regulations
733
Where:
CO2i = Annual CO2 mass emissions that would result from the combustion or oxidation of each product “h” for redelivery to all recipients (metric tons).
Fuelh = Total annual volume of product “h” supplied (volume per year, in thousand standard cubic feet (Mscf) for natural gas and bbl for NGLs).
HHVh = Higher heating value of product “h” supplied (MMBtu/Mscf or MMBtu/bbl).
EFh = CO2 emission factor of product “h” (kg CO2/MMBtu).
1 x 10−3 = Conversion factor from kilograms to metric tons (MT/kg).
(2) Calculation Methodology 2.
NGL fractionators shall estimate CO2 emissions that would result from the complete combustion or oxidation of the product(s) supplied using Equation NN-2 of this section. LDCs shall estimate CO2 emissions that would result from the complete combustion or oxidation of the product received at the city gate using Equation NN-2. For each product, use the default CO2 emission factor found in Table NN-2 of this subpart. Alternatively, for each product, a reporter-specific CO2 emission factor may be used in place of the default factor, provided it is developed using methods outlined in § 98.404. For each product, you must use the same volume unit throughout the equation.
Where:
CO2i = Annual CO2 mass emissions that would result from the combustion or oxidation of each product “h” (metric tons)
Fuelh = Total annual volume of product “h” supplied (bbl or Mscf per year)
EFh = CO2 emission factor of product “h” (MT CO2/bbl, or MT CO2/Mscf)
(1)
For natural gas that is received for redelivery to downstream gas transmission pipelines and other local distribution companies, use eEquation NN-3 of this section and the default values for the CO2 emission factors found in Table NN-2 of this subpart. Alternatively, reporter-specific CO2 emission factors may be used, provided they are developed using methods outlined in § 98.404.
Where:
CO2j = Annual CO2 mass emissions that would result from the combustion or oxidation of natural gas for redelivery to transmission pipelines or other LDCs (metric tons).
Fuel = Total annual volume of natural gas supplied (Mscf per year).
EF = Fuel-specific CO2 emission factor (MT CO2/Mscf).
(2)
(i)
For natural gas delivered to each meter registering a supply equal to or greater than 460,000 Mscf per year, use Equation NN-4 of this section and the default values for the CO2 emission factors found in Table NN-2 of this subpart.
(ii)
Alternatively, reporter-specific CO2 emission factors may be used, provided they are developed using methods outlined in § 98.404.
Where:
CO2k = Annual CO2 mass emissions that would result from the combustion or oxidation of natural gas received by end-users that receive a supply equal to or greater than 460,000 Mscf per year (metric tons).
Fuel = Total annual volume of natural gas supplied (Mscf per year).
EF = Fuel-specific CO2 emission factor (MT CO2/Mscf).
(3)
For natural gas received by the LDC at the city gate that is injected into on-system storage, and/or liquefied and stored, use Equation NN-5 of this section and the default value for the CO2 emission factors found in Table NN-2 of this subpart. Alternatively, a reporter-specific CO2 emission factor may be used, provided it is developed using methods outlined in § 98.404.
Where:
CO2l = Annual CO2 mass emissions that would result from the combustion or oxidation of the net natural gas that is liquefied and/or stored and not used for deliveries by the LDC within the reported year (metric tons).
Fuel1 = Total annual volume of natural gas received by the LDC at the city gate and stored on-system or liquefied and stored in the reporting year (Mscf per year).
Fuel2 = Total annual volume of natural gas that is used for deliveries in the reporting year that was not otherwise accounted for in Equation NN-1 or NN-2 of this section (Mscf per year). This primarily includes natural gas previously stored on-system or liquefied and stored that is removed from storage and used for deliveries to customers or other LDCs by the LDC within the reporting year. This also includes natural gas that bypassed the city gate and was delivered directly to LDC systems from producers or natural gas processing plants from local production.
EF = Fuel-specific CO2 emission factor (MT CO2/Mscf).
(4)
Calculate the total CO2 emissions that would result from the complete combustion or oxidation of the annual supply of natural gas to end-users using Equation NN-6 of this section.
Where:
CO2 = Annual CO2 mass emissions that would result from the combustion or oxidation of natural gas delivered to LDC customers not covered in paragraph (b)(2) of this section (metric tons).
CO2i = Annual CO2 mass emissions that would result from the combustion or oxidation of natural gas received at the city gate as calculated in paragraph (a)(1) or (a)(2) of this section (metric tons).
CO2j = Annual CO2 mass emissions that would result from the combustion or oxidation of natural gas delivered to transmission pipelines or other LDCs as calculated in paragraph (b)(1) of this section (metric tons).
CO2k = Annual CO2 mass emissions that would result from the combustion or oxidation of natural gas received by end-users that receive a supply equal to or greater than 460,000 Mscf per year as calculated in paragraph (b)(2) of this section (metric tons).
CO2l = Annual CO2 mass emissions that would result from the combustion or oxidation of natural gas received by the LDC and liquefied and/or stored but not used for deliveries within the reported year as calculated in paragraph (b)(3) of this section (metric tons).
(1)
(i)
For fractionated NGLs received by the reporter from other NGL fractionators, you shall use Equation NN-7 of this section and the default values for the CO2 emission factors found in Table NN-2 of this subpart.
(ii)
Alternatively, reporter-specific CO2 emission factors may be used, provided they are developed using methods outlined in § 98.404.
Where:
CO2m = Annual CO2 mass emissions that would result from the combustion or oxidation of each fractionated NGL product “g” received from other fractionators (metric tons).
Fuelg = Total annual volume of each NGL product “g” received (bbls).
EFg = Fuel-specific CO2 emission factor of NGL product “g” (MT CO2/bbl).
(2)
Calculate the total CO2 equivalent emissions that would result from the combustion or oxidation of fractionated NGLs supplied less the quantity received by other fractionators using Equation NN-8 of this section.
Where:
CO2 = Annual CO2 mass emissions that would result from the combustion or oxidation of fractionated NGLs delivered to customers or on behalf of customers (metric tons).
CO2i = Annual CO2 mass emissions that would result from the combustion or oxidation of fractionated NGLs delivered to all customers or on behalf of customers as calculated in paragraph (a)(1) or (a)(2) of this section (metric tons).
CO2m = Annual CO2 mass emissions that would result from the combustion or oxidation of fractionated NGLs received from other fractionators and calculated in paragraph (c)(1) of this section (metric tons).