Top gas recycling revisited to reduce blast furnace CO2 emissions
Blast furnace (BF) top gas recycling (O2BF) was tested by the ULCOS program to reduce CO2 emissions using the LKAB experimental blast furnace. During tests, the carbon rate was reduced by about 25%. Hatch and BHP re-visited the O2BF concept to assess if additional technologies could be implemented to further reduce CO2 emissions beyond what was achieved. Using a two-stage heat and mass balance model, viable operating conditions were established for a low-carbon-rate operation, significantly less than what was achieved in the ULCOS trials. Details of the enabling technologies to reach such low CO2 emission rates will be presented.