Firing steelworks recovery gases in a combined-cycle power station

A new cogeneration power plant producing 500 MW(e) and 140 t h(-1) of process steam is under construction at the ILP iron and steel works in Taranto (Southern Italy). It will be fired with recovery gases by-produced in the integral iron- and steelmaking process. Commissioning is due in 1996. The plant is divided into three equal modules, each comprising a gas-turbine exhausting into a recovery boiler where steam at 100 bar and 540 degrees C is produced for process purposes and for generating electricity. In the following discussion of the basic design, boundary constraints are taken into account. The problems encountered in gas-cleaning and in firing a very lean fuel mixture in the gas-turbine are discussed, with emphasis on the difficulties arising from changes of composition in the recovery gases. Also briefly described is the design solution for the recovery boiler with supplementary gas firing in a specially designed burner.