High-performance complete desalination

With 2,160 megawatts, RWE npower’s power plant near Pembroke in South Wales, which was built by Alstom Power Systems, is one of the largest and most efficient gas and steam power plants in Europe. It can supply close to three million households with electricity. An important component of the plant is the generation of ultrapure water from surface water, which is fed into the water/steam cycle. This requires, among other things, a demineralisation system. Alstom Power Systems awarded this contract directly to H+E. The removal of organic impurities from the water played a key role in the process selection, since they need to be kept away from the water/steam circuit for corrosion-chemical reasons.

With the various treatment stages, the water quality improves continuously along the entire process. The deionised water conductivity must be less than 0.10 μS, and the TOC less than 200 μg/l. In order to ensure compliance with the TOC, the H+E team opted for a membrane plant combination with redundant design. This enables parallel operation and allows the power plant operator to fill the water/steam cycle with double-installed plant capacity and to quickly put it back into operation.

Six steps to demineralised water

For complete desalination of the surface water, H+E connected the following process stages in succession: first a prefiltration, followed by inline flocculation, which destabilises colloidally dissolved substances. Ultrafiltration removes solids and lowers the fouling potential before the water flows through an antiscalant dosing system. The permeate-stepped reverse osmosis unit with NaOH dosing serves as the penultimate process step for the main desalination and for the removal of TOC and carbonic acid. Fine desalination is carried out by the final mixed-bed ion exchanger system.

Facts & figures:

  • Full desalination for one of the largest gas and steam power plants in Europe
  • A reliable, redundant system concept
  • Ultrapure water quality even with large fluctuations in the raw water composition
  • A low number of CIP cleanings per year

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High-performance complete desalination

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Customised service for reliable operation

24-hour hotline

  • Expert answers from the right contact person
  • Over the phone or on site

Maintenance service

  • Regular maintenance for a constant water quality
  • Support of third-party plants

Modernisation and optimisation

  • Of control systems and automation systems
  • Adjustment of chemical dosing during operation

Qualified advice

  • Audits for status checks
  • Consulting for process and plant optimisation

Service for anaerobic reactors

  • Functional testing and maintenance prior to official approvals
  • Review and recommendations for performance improvement

Servo – bundled expertise

  • For all process technologies and steps
  • Chemicals and working materials

Contact our experts

We are expanding our production, which means that our process and wastewater amounts will increase and their qualities will change.