---
kind: "section"
citation: "40 C.F.R. § 98.493"
title: "40"
number: "98.493"
heading: "Calculating GHG emissions."
url: "https://uscodex.org/cfr/40/98.493"
---

# §98.493. Calculating GHG emissions.

- (a) Calculate GHG emissions required to be reported in [§ 98.492(a)](/cfr/40/98.492.md?p=a) using the applicable methods in [paragraph (b)](#b) of this section.
- (b) For each coke calcining unit, calculate GHG emissions according to the applicable provisions in [paragraphs (b)(1) through (4)](#b-1..b-4) of this section.
  - (1) If you operate and maintain a CEMS that measures CO2 emissions according to [subpart C](/cfr/40/subpartC.md) of this part, you must calculate and report CO2 emissions under this subpart by following the Tier 4 Calculation Methodology specified in [§ 98.33(a)(4)](/cfr/40/98.33.md?p=a-4) and all associated requirements for Tier 4 in [subpart C](/cfr/40/subpartC.md) of this part. Auxiliary fuel use CO2 emissions should be calculated in accordance with [subpart C](/cfr/40/subpartC.md) of this part and subtracted from the CO2 CEMS emissions to determine process CO2 emissions. Other coke calcining units must either install a CEMS that complies with the Tier 4 Calculation Methodology in [subpart C](/cfr/40/subpartC.md) of this part or follow the requirements of [paragraph (b)(2)](#b-2) of this section.
  - (2) Calculate the CO2 emissions from the coke calcining unit using monthly measurements and equation 1 to this [paragraph (b)(2)](#b-2).
  - (3) **Calculate CH4 emissions using equation 2 to this paragraph (b)(3).**
  - (4) **Calculate N<I>2</I>O emissions using equation 3 to this paragraph (b)(4).**

## Notes

### Source

Source: 89 FR 31948, Apr. 25, 2024, unless otherwise noted.

### Authority

Authority: 42 U.S.C. 7401-7671q.

### Source

Source: 74 FR 56374, Oct. 30, 2009, unless otherwise noted.