Reliable corrosion protection and longer service life of district heating systems

Catalytic de-oxidation - 100 % chemical-free and environmentally friendly
An innovative technology, catalytic de-oxidation (DeOx), removes all oxygen in the district heating water and protects piping against corrosion.

The transmission company VEKS, supplying 20 local district heating utilities, had in 2013 high expectations when they put the newly acquired catalytic de-oxidation plant from BWT into operation. “And the expectations have already been met,” says VEKS’ responsible for boiler and distribution systems, Mike Jarvig. The DeOx plant at VEKS was the first of its kind on a large scale, and the transmission company advocates that catalytic de-oxidation is a future-proof, environmentally friendly and even inexpensive method for removing oxygen from district heating water.

Top quality water ensures longer service life
There are currently three 150 m³/hour catalytic de-oxidation systems in the Copenhagen district heating area. “Even though the district heating water had an increase in oxygen content during repairs, replacement of valves, expansion of the district heating system, etc., the three de-oxidation plants have worked flawlessly, and a high water quality has been maintained in the district heating system..,” continues Mike Jarvig from VEKS.

With the BWT DeOx plants, VEKS has managed to reduce operating costs by more than half - and with a payback period of only five years! Mike Jarvig is enthusiastic: “Any service life extension is a benefit! Furthermore, it has even provided us additional earnings by enabling us to sell make-up water of the highest quality to the local district heating utilities.”

Stanford University avoids chemicals with the Danish technology
The solution from BWT has also created a stir outside of Denmark. Via the consulting engineers COWI, BWT was contacted by Stanford University, where the old steam heating was to be replaced by a new district heating system inspired by Danish models. The university had decided on a green profile with zero emissions through long-lasting, environmentally friendly solutions.

In the past it was estimated that service-life of piping was about 10 years, and a high consumption of chemicals was calculated in for controlling water quality and prevent corrosion of the pipes.

Therefore, it was a mystery to Stanford University how VEKS could maintain more than 25-year-old piping in the best condition and now without chemicals. After sparring and an exchange of experiences between all parties, it all ended with the university having a de-oxidation system from BWT integrated into the new district heating system.

The BWT DeOx plant has proved its worth
In the meantime, the success story has also reached other district heating companies in Denmark. BWT has installed serveral DeOx plants into Danish district heating systems. The plants protect against corrosion and contribute to a long service-life of the piping.

A DeOx plant is installed directly into the loop of the district heating piping and when needed, it automatically removes oxygen from the district heating water. A DeOx plant is dimensioned according to the customers’ needs.