BFI VDEh-Betriebsforschungsinstitut GmbH

Initial situation:

The legal limits for cooling and wastewater discharge are continually being tightened. Water withdrawal is increasingly limited and there is a temporary water shortage. This results in a potential negative impact on production (corrosion, water/plant availability) in steel and iron production, particularly in cooling and casting processes. Easy-to-use desalination processes (e.g. capacitive deionization) are available, but are not yet adapted to the requirements of the iron and steel industry. The handling of saline concentrates is still unclear. There is an increased need for biocides in cooling circuits to comply with legal requirements while at the same time reducing available biocides.

Project objectives:

• Development of a reliable and energy-efficient process technology for cooling water desalination,
• Production of mono-concentrates from the desalination concentrate as a prerequisite for material recycling using suitable processes,
• Realization of an almost zero-liquid discharge with regard to wastewater discharge and reuse of the concentrate in the event of temporary water stress.

Innovative approaches:

• Ion-selective desalination processes for the production of monosalt-concentrates
• Electrochemical biocide production from chloride-containing concentrates and suitable processes for removing impurities
• Realization of “near” zero liquid discharge

Benefits for the industry:

• Closing the water-cycle by reusing the desalinated cooling water and recycling the concentrate produced for biocide production
• Decoupling of production and freshwater requirements
• Reduction in operating costs through reduced use of fresh water and use of internally produced biocide

About the project:

Project duration: 03/2021 – 12/2023

Funding provider: Federal Ministry for Economic Affairs and Climate Protection