PROCESS FOR REGULATING THE JOULE VALUE OF OFFGASES FROM PLANTS FOR PIG IRON PRODUCTION OR OF SYNTHESIS GAS

In a plant having integrated CO2 removal, for pig iron production or synthesizing gas, at least part of the offgas or synthesis gas is discharged as export gas from the plant, optionally collected in an export gas container and subsequently thermally utilized in a gas turbine. The offgas from the gas turbine is fed to a waste heat boiler for generation of steam. To reduce the addition of high-grade fuel gases, at least part of the tailgas from the CO2 removal plant is mixed into the export gas upstream of the gas turbine as a function of the joule value of the export gas after addition of the tailgas. The proportion of tailgas is increased when the joule value of the export gas goes above a predefined maximum joule value and the proportion of tailgas is reduced when the joule value of the export gas drops below a predefined minimum joule value.