Steel plant energy recovery
Recovering heat, pressure and gas in steelworks.
Recovery and reuse · Heat to power and cogeneration · No. 130
- Recovery and reuse
- Heat grade: High
Red-hot coke at over 1,000 C used to be cooled with a water spray; now it can make 150 kWh per tonne.
Chart: Illustration: Steel plant energy recovery
Where it comes from
Chart: Map of where it comes from
Integrated steelworks shed unusually rich waste: coke at 1,000-1,200 C, molten slag at about 1,500 C, pressurised top gas and three burnable gases.
Three things to know
- A top-pressure turbine turns blast furnace gas pressure of 1.6 to 3 bar into 15-60 kWh per tonne of hot metal.
- Dry quenching cuts quench dust from 300-400 g to under 3 g per tonne of coke, and uses no water.
- Dry quenching costs about EUR 100 million for a 2 Mt-a-year coke plant, against about EUR 5 million for wet quenching.
The journey
- 1 Hot streamsCoke, sinter, slag, top gas, fuel gases
- 2 CaptureDry quenching, cooler hoods, gas cleaning
- 3 ConvertBoilers and turbines raise steam and power
- 4 Gas networkHolders feed fuel gases to plant users
- 5 Plant powerElectricity and steam used back on site