Ultra Pure Water for Vattenfall

The area in and around the Eemshaven seaport, on the Wadden Sea coast of Groningen, is buzzing with activity. Numerous businesses have set up there, some quite recently, and with many more on the way. From electrical power plants and chemical firms to data centers and the food industry. What they all have in common is a need for industrial water.

After an extensive feasibility study, North Water found a solution for this water demand: a water plant that produces process water for the various users in the Eemshaven seaport. The first client was the new Vattenfall power plant. Because this new Vattenfall plant already needed high-quality industrial water in 2012 for steam production, North Water built a temporary facility using drinking water as a provisional raw material.

This facility meets the water needs for the first stage of the Nuon Magnum IGCC electrical power plant in the Eemshaven seaport. The pure water it produces will be used to produce steam in the Combined Cycle Units (CCU).

This facility uses drinking water as its feedwater and produces DM water of very high quality, with a conductivity < 0.1 μS/cm, Na+ and K+ < 0.01 mg/l and a silica content < 0.02 mg/l. For supply security, the facility is fully redundant, with a nominal capacity of 25 m3/h and a design capacity of 50 m3/h. This is achieved with two separate lines, each consisting of a double-pass reverse osmosis (RO) system. This is followed by electrodeionization (EDI) as a polishing step. The facility is also fitted with a Clean In Place (CIP) system and extensive controls, and was built to Vattenfall’s stringent requirements.​

Process Description (Raw Material: Drinking Water)

In the modular water treatment facility, the incoming drinking water first passes through a self-cleaning filter, and then a candle filter. Before the candle filter, an antiscalant is added to prevent salt deposits (“scaling”) on the membranes. Next, reverse osmosis filtration is used for initial desalination and Total Organic Compound (TOC) removal. A second RO system provides further desalination and TOC removal. To remove the carbon dioxide from the water, it receives a dose of caustic soda between the two RO systems. Finally, to achieve the required conductivity and TOC content, the product water from the second RO system is treated with EDI.​

When the facility is idle, the Fresh Flush (FF) system pushes the concentrate water out of the first system using product water (pure water). Where necessary, any contamination is removed by cleaning with chemicals. The facility is fitted with an automatic CIP system: a hot water tank to heat pure water or drinking water for optimal CIP efficiency. This tank can also be used to perform an FF.

Depending on the type of contamination, the CIP operation will be acidic or basic. The system continuously measures and analyzes the relevant process parameters. We can control and monitor the facility remotely.​