ULCOS top gas recycling blast furnace process (ULCOS TGRBF) : final report$nElektronische Ressource

The current blast furnaces are efficient and highly optimised and the scope for further lowering the carbon usage (and thus CO2 emissions) in these furnaces is approaching its limits. A possible breakthrough solution is to recycle the remaining CO and H2 in blast furnace top gas back into the process, effectively lowering the coke requirements. The CO and H2 can be recovered with a CO2 separation step. However, to avoid N2 build-up, the blast furnace needs to operate on pure O2 instead of hot blast. The objective of this project was to determine and optimise the best configuration for a Top Gas Recycling Blast Furnace. The project has shown that it is possible to operate a blast furnace in a closed loop with a CO2 separation unit in an effective way. The obtained C-savings are consistent with the model predictions. The tests also proved that conventional burden material sinter, pellet and coke can be used. The VPSA plant was able to remove the CO2 efficiently from the blast furnace top gas and up to 90% of the top gas could be treated and recycled. It was possible to operate the blast furnace process and the VPSA gas separation plant in a closed loop. The optimum configuration for an industrial scale furnace was found to be the injection of hot decarbonated top gas in both the hearth tuyeres and the tuyeres in the shaft. These three EBF campaigns in the ULCOS BF mode can be considered as a great success.