How ArcelorMittal is helping keep Dunkirk warm this winter
Posted on 18.01.16 by
Waste gas is an unavoidable waste product in the steelmaking process, but ArcelorMittal has been putting it to good use over the years. That’s why many of our plants are industry leaders when it comes to power recovery.
Take the company’s plant in Dunkirk, France, for example, which is almost 100% self-sustaining in terms of energy use. Across the past thirty years, the site has been redirecting waste heat to Dunkirk’s urban heating network – warming the equivalent of 15,000 city homes.
With help from ArcelorMittal, Dunkirk’s heating network – 90% reliant on energy recovery – is now close to zero emissions and has significantly reduced its use of fossil fuels.
So how does it work?
The first step in the steelmaking process is the transformation of iron ore into sinter – a process that generates more heat than any other stage.
The ore is heated to a temperature of 1,200°C, before being cooled down again using industrial blowers. Once the temperature reaches 400°C, the air is captured via a giant extractor hood, after which it makes its way to a heat exchanger to heat up the water in the pipes.
This hot water is then used to fuel Dunkirk’s heating network.
In total, more than 40km of pipes currently run under the city of Dunkirk, keeping the hospital, housing blocks, the town hall, schools and sports facilities warm.
The network is currently being extended, and within the next five years, the equivalent of 28,000 homes will be connected to the network. By 2020, an additional 30km of pipes will be installed to supply other communes in the Nord department in northern France.
Providing more affordable energy
Residents linked up to the heating network are seeing the benefits of this sustainable re-use of waste energy. One has claimed that her energy bill is almost half what she was paying in a previous home that was not connected to the network, which provides energy that’s 15-20% cheaper than alternative energy sources.
But of course Dunkirk is just one example of how our sites are reusing waste energy – a process that now represents a major lever for improving energy efficiency worldwide.
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Image credit: Alain Sauvan