
522 Oxygen-Enhanced Combustion
In some variations, the top gas injected at the tuyeres
is also preheated. Removing the CO
2
from the top gas
improves furnace efciency, and with the CO
2
removed
the top gas preheating can be done by burning a side
stream of top gas with air. CO
2
removal from the top
gas can signicantly lower the carbon footprint of the
blast furnace if the CO
2
is subsequently sequestered.
A major program is underway in Europe to demon-
strate an oxygen blast furnace with sequestration on a
commercial scale.
21,22
Projected oxygen consumption is
225 Nm
3
/thm.
21.3 Direct Reduction andAlternate
Ironmaking
Direct reduction processes ...