Pilot CDI in BFI technical centre (max. flow rate: 840 l/h)

SPOTVIEW – Sustainable Processes and Optimized Technologies for Industrially Efficient Water Usage in steel, dairy or pulp and paper industry

Initial situation

  • Water use in steel industry: 1980 million m³ for production of 169 million tons crude steel divided in 75% cooling applications, 13% gas washing and 12% material conditioning
  • Inhibition of water reuse because of salts and hardness (corrosion, scaling), abrasive solids or organic compounds (oil, grease) and cooling water treatment chemicals
  • Effect of water components: decreasing salt/hardness removal efficiency of available technologies to an insufficient economic or technical level

Project objectives of the steel case

  • Decoupling of production processes from water consumption and reduction of fresh water demand about 20 – 40% or waste waters up to 90%
  • 20% energy saving by recovery from cooling water with chemical heat pump

Innovative approaches

  • Desalination and softening of waters by capacitive deionization (CDI)
  • Use of chemical heat pump for energy recovery
  • Direct internal reuse of low or loaded process waters after treatment in different applications (cascade)

Current results (as of 11/2017)

  • Determination of suitable streams for applying chemical heat pump and internal multiple use after treatment based on prepared process and waste water overview
  • Fulfillment of operational specifications for water composition after treatment of backwash water and river water by means of CDI – chloride and hardness removal: up to 89%, pure water yields: 68 – 79%
  • Generation of pure water with conductivities as demineralized water (0 – 50 μS / cm)

Outlook

  • Optimization of CDI operating parameters to increase pure water yields and reduce energy demand

Identification of potential disturbing contaminants in the CDI treatment

Gallery

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