Hyphae

Coke Oven Gas

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Generated from the Hyphae knowledge graph. Drafted by claude-sonnet-4-6

A hydrogen-rich fuel gas recovered as a byproduct of high-temperature carbonization of coal in by-product coke oven batteries. Raw coke oven gas (COG) exits the ovens at ~700–800°C and is cooled, scrubbed, and purified to remove tar, ammonia, benzene, naphthalene, and hydrogen sulfide. Purified COG is approximately 50–55 vol% hydrogen, 25–30 vol% methane, 5–7 vol% CO, with minor N₂, CO₂, and higher hydrocarbons. Its calorific value is approximately 17–19 MJ/m³ (net). Used primarily as fuel to heat the coke ovens themselves; surplus is distributed through integrated steel plant fuel networks.

Common forms

  • Raw COG (high-temperature gas exiting oven tops; contains tar, ammonia, benzene — sent to byproduct recovery plant)
  • Purified/clean COG (after byproduct recovery — fuel gas distributed to ovens and plant fuel network)

Composition

Typical purified COG (vol%): H₂ ~50–55%; CH₄ ~25–30%; CO ~5–7%; N₂ ~3–5%; CO₂ ~2–3%; C₂H₄ and higher hydrocarbons ~2–3%.

Hazards

  • Explosion — high hydrogen content; COG/air mixtures are flammable over a wide range and ignite easily.
  • CO poisoning — CO content makes COG acutely toxic at low concentrations.
  • Asphyxiation — displaces oxygen in enclosed spaces.

Properties

  • toxicity: CO component (5–7 vol%) is highly toxic; COG is an asphyxiation and CO poisoning hazard in enclosed spaces.
  • flammability: Highly flammable; H₂ component makes it lighter than air and creates significant explosion risk if leaked in enclosed spaces. Lower explosive limit (LEL) ~5 vol% H₂ in air; upper explosive limit (UEL) ~75 vol% H₂.
  • calorific_value: Net calorific value approximately 17–19 MJ/m³ (at standard conditions); varies with coal type and carbonization conditions.

Connections

Outgoing

  • Has hazard → Coke Oven Gas Explosion — COG is ~50-55 vol% hydrogen; extremely flammable over wide range (LEL ~4 vol% H2 in air). CO component (~5-7 vol%) creates acute toxicity hazard.
  • Manufactured by → Cokemaking — Coke oven gas is recovered from by-product slot oven batteries during coal carbonization.

Incoming

  • Produces ← Cokemaking — By-product of carbonization; recovered from by-product ovens. ~50-55 vol% H2, ~25-30 vol% CH4, 5-7 vol% CO. Used as fuel to heat ovens and for plant energy. Net CV ~17-19 MJ/m3.

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