Coke Oven Gas
Reviewed by Afonso Firmo, Co-Founder & Director · Updated 7 July 2026
Coke oven gas has a combined Scope 1 emission factor of 37.08 kg CO₂-e/GJ under NGA Factors 2025. Worked examples, unit conversions and a calculator.
Emission Factor Value
37.08 kg CO₂-e/GJ
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Estimated emissions
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Coke oven gas combustion is reported under Scope 1 at 37.08 kg CO₂-e/GJ (NGA Factors 2025, Table 5). Cubic metres are converted at an energy content of 0.0181 GJ/m³.
Official Source & Citation
This emission factor is sourced from the Australian National Greenhouse Accounts Factors 2025 , Table 5 — Gaseous fuels including liquefied natural gas, published by the Department of Climate Change, Energy, the Environment and Water (DCCEEW).
Citation: DCCEEW (2025). Australian National Greenhouse Accounts Factors 2025. Commonwealth of Australia. Available at: https://www.dcceew.gov.au/climate-change/publications/national-greenhouse-accounts-factors-2025
Notes
Combined Scope 1 factor of 37.08 kg CO₂-e/GJ = CO₂ 37 + CH₄ 0.03 + N₂O 0.05 (NGA Factors 2025, Table 5). Energy content 0.0181 GJ/m³. 1 GJ of coke oven gas combusted = 37.08 kg CO₂-e. Its low factor per GJ reflects the gas's high hydrogen share; a by-product fuel of metallurgical coke production.
Calculation Example
If your steelworks combusted 20,000 GJ of coke oven gas during the year:
| Working | Result |
|---|---|
| 20,000 GJ × 37.08 kg CO₂-e/GJ = 741,600 kg CO₂-e | 741.60 tonnes CO₂-e (Scope 1) |
Steelworks run on their own exhaust. Coke oven gas — the hydrogen-rich by-product driven off when coking coal is carbonised — is captured and piped back into ovens, boilers and power plants across an integrated site, and every gigajoule combusted lands in the operator’s Scope 1 inventory.
It is also, counter-intuitively, the lowest-factor fossil gas in the NGA tables. This entry explains why, and shows how to calculate emissions from energy or volume data.
Quick Verdict
Coke oven gas has a combined Scope 1 emission factor of 37.08 kg CO₂-e per gigajoule under the NGA Factors 2025 (Table 5) — CO₂ 37 plus negligible CH₄ and N₂O — at an energy content of 0.0181 GJ/m³. Because the gas is roughly half hydrogen, it emits about 28% less CO₂ per gigajoule than natural gas (51.53) and a sixth of blast furnace gas (234.05), its CO-rich sibling in steelmaking. The factor applies to organisations combusting the gas, in practice integrated steelworks and coke plants reusing their own by-product. Report combustion under Scope 1 for the 2025–26 year, separately from coke-making process emissions.
How to Calculate Coke Oven Gas Emissions
Emissions (kg CO₂-e) = Energy consumed (GJ) × 37.08 kg CO₂-e/GJ
Convert cubic metres at 0.0181 GJ/m³ and megajoules at 1,000 MJ per GJ.
Worked Example 1: Integrated steelworks reuse
A steelworks combusts 20,000 GJ of coke oven gas across its ovens and power plant.
20,000 GJ × 37.08 = 741,600 kg CO₂-e
741.60 tonnes CO₂-e (Scope 1)
Worked Example 2: Boiler fuel
Site boilers consume 2,500 GJ of coke oven gas.
2,500 GJ × 37.08 = 92,700 kg CO₂-e
92.70 tonnes CO₂-e (Scope 1)
Worked Example 3: Battery offgas metered in cubic metres
A coke battery supplies 1,000,000 m³ of gas to combustion equipment.
1,000,000 m³ × 0.0181 GJ/m³ = 18,100 GJ
18,100 GJ × 37.08 = 671,148 kg CO₂-e
671.15 tonnes CO₂-e (Scope 1)
How coke oven gas compares with other gaseous fuels
| Gaseous fuel | Combined Scope 1 factor (kg CO₂-e/GJ) |
|---|---|
| Hydrogen | 0.05 |
| Landfill biogas | 6.43 |
| Coke oven gas | 37.08 |
| Natural gas (pipeline) | 51.53 |
| Ethane | 56.56 |
| Town gas | 60.27 |
| Blast furnace gas | 234.05 |
NGER and AASB S2 Reporting
Coke oven gas combustion is reported as Scope 1 under the NGER scheme, separate from the industrial process emissions of coke making itself. The same figures roll into your Scope 1 inventory under AASB S2 — for integrated steel sites, keeping by-product gases (coke oven, blast furnace) metered and itemised individually is essential for a reconcilable disclosure.
Related Emission Factors
Frequently Asked Questions
Disclaimer
This page is provided for general information, not professional or compliance advice. The factor shown is reproduced from the official publication cited above, and while we work to keep it current, government factors change — the publication is always the authoritative source.
- Before using this value in any formal reporting — including under the National Greenhouse and Energy Reporting Act 2007 — confirm it against the current official publication and the methods specified by the Clean Energy Regulator.
- NetNada is independent of the Australian Government, DCCEEW, and the Clean Energy Regulator. Government data is Crown copyright, Commonwealth of Australia.