Sustainable: electrical energy from process steam

Klein im Vergleich zu „richtigen“ Dampfturbinen mit über 4 m Durchmesser, passt die einige hundert Kilowatt starke Mikro-Dampfturbine leicht in einen 20'-Container. Dennoch erfüllt sie eine wichtige Aufgabe. © Thyssenkrupp Steel

On the roof of thyssenkrupp Steel’s heating center in Duisburg-Hamborn, a turbine will convert process steam into electrical energy in the future. Today, the 5-ton micro steam turbine was lifted to its destination with the help of a truck-mounted crane.

The innovative technology uses the steam that is combined on the roof of the Hamborn heating station: Here, a steam pressure regulator is used to reduce the resulting mains steam pressure of around 13 bar to the required operating pressure of around 2.2 bar. The micro steam turbine uses the potential energy of the steam, which would otherwise not be used in conventional steam pressure reduction, to drive a turbine wheel and thus generate electrical power via a generator.

The micro steam turbine was developed by Turbonik in collaboration with Fraunhofer Umsicht (Environmental, Safety and Energy Technology) and was awarded, among others, the Innovation Prize of the German Steel Industry Association in 2018.

“The new micro steam turbine will generate around 1,800 MWh of electricity per year in the future. This corresponds to the annual consumption of around 420 four-person households,” says Stefan Saalberg, thyssenkrupp Steel. “This makes it another innovative idea that we at thyssenkrupp Steel are using to optimize our processes and thus also save CO2 in as many places as possible in conventional steel production.”

As an integrated steel mill, thyssenkrupp Steel uses various processes to convert metallurgical gases from the coke plant and blast furnace in the power plants and use them to generate heat and electricity. The micro steam turbine for resource-saving and cost-effective power generation is thus a further building block for the efficient use of energy in steel production.