The heat recovered by inert gas is used to produce steam, which may be used on-site or to generate electricity. Hot coke from the coke oven is cooled in specially designed refractory lined steel cooling chambers by counter-currently circulating an inert gas media in a closed circuit consisting of 1) cooling chamber, 2) dust collecting bunker, 3) waste heat boiler, 4) dust cyclones, 5) mill fan, 6) blowing device (to introduce the cold air from the bottom), 7) circulating ducts.
- Fuel savings: 1.9GJ/t-coke
- Electricity savings: 150kWh /t-coke
- 74.9 kg-CO2/t-coke (as electricity), 135 kg-CO2/t-coke (as coke)
- Improvement strength of coke by 4%
- Dust: less than 3 g/t-coke (20 mg/Nm3)
- SO2: 200 mg/Nm3
- Water saving
Waste heat of hot cokes is recovered from temperature of approx. 1000 C to approx. 200 C.
- New plant costs: $50/t-coke
- Payback time: 4.7years
The Japan Iron and Steel Federation