Major reduction in greenhouse gas emissions from Norwegian aluminium plants

In 1997, Hydro entered into a voluntary agreement with Norwegian environmental authorities to reduce specific greenhouse gas emissions from our aluminium works by 55 per cent. Now, together with other Norwegian aluminium producers, we have actually reduced emissions by 62 per cent per tonne produced — making the Norwegian aluminium industry among the cleanest in the world.

September 3, 2007

Emissions of greenhouse gases from our aluminium works in Norway have fallen dramatically after we carried out major improvements to our smelter technology. In fact, by reducing emissions by 62 percent per tonne produced we have surpassed the targets agreed with the Norwegian Ministry of Environment – helping to making the Norwegian aluminium industry the cleanest in the world.

The goal was to reduce emissions of greenhouse gases by 50 per cent per tonne of aluminium produced by the year 2000 and 55 percent by 2005. Figures obtained by the Norwegian Pollution Control Authority (SFT) show that the specific emissions in 2005 were no less than 62 percent lower than 1990 levels per tonne of aluminium produced.

 

How we did it

These reductions have been achieved phasing out old Søderberg technology as well as investments and improvements in the production process. These initiatives have led to the decrease in emissions of perfluorocarbon (PFC) gases CF4 and C2F6. These gases are particularly strong greenhouse gases with a global warming potential several thousand times stronger than C02.

Specifically, the improvements have been achieved through major investments in point feeder technology, better process management and pot supervision.  Emissions of PFCs are a function of the frequency and duration of anode effects. Earlier, anode effects occurred almost daily. Today, Hydro’s best pre-bake series have reduced the anode effects frequency to less than once a month.

A pro-active approach to climate protection

In Hydro, we recognize that the risk of long-term climate change means that initiatives must be taken to reduce global greenhouse emissions. In 1988, when we became aware of the challenges presented by PFCs, our response was to investigate problem. The results were then published internationally. When in 1997 the Norwegian authorities proposed various policy measures regulating the greenhouse gas emissions from the industry, we entered into a dialogue which culminated in the voluntary greenhouse gas agreement.

These improvements mean that Norway's aluminium production is environmentally in the forefront globally.

Aluminium – part of the solution

With the production increase that has taken place since 1990, emissions of CO2 equivalents from the aluminium industry would have been 4.7 million tonnes higher than present levels if the discharges per produced kilo of aluminium had remained unchanged. That is the equivalent of nearly four gas power stations of the kind currently being built in Norway, or half of all emissions from Norway’s road traffic.

“The agreement that the industry entered into with the minister of the Environment in Norway, Thorbjørn Berntsen (Ap) in 1997 was a major step forward, and the results are beyond all our expectations,” commented Managing Director of the Federation of Norwegian Industries, Stein Lier-Hansen.

But reductions in emissions during production aren’t the only positive aspects. It’s important to remember that aluminium’s properties as a metal also enables important technology contributions, for instance in the transport sector, packaging and building industries, by saving weight, increasing safety, reducing fuel consumption and thus reducing greenhouse gas emissions.


Updated: October 11, 2016