Hydro's technology center in Ardal of Norway is installing a unit to remove sulfur dioxide from the flue gas from aluminum production. The unit will reduce annual emissions of SO2 from the technology center by 200 tonnes. It is the first industrial application of this technology.

Mr Are Dyrøy who is responsible for environmental technology in the technology unit in Hydro's Primary Metal business area said that "We have evaluated SO2 capture in Ardal for some time and have now found a new solution that can be implemented and that will remove at least 95% of the sulfur emissions. The installation will also be completed without creating additional emissions or production losses."

The treatment plant for the recovery of fluorine which was built during the expansion of the technology center in 2008 does not remove SO2 as the metal plant in Ardal had dispensation for the increased discharge. A standard solution for the treatment of SO2 would have increased project costs significantly. So studies were initiated instead into how treatment could be added at a later date.

A solution has now been developed in cooperation with the supplier Alstom that can be installed on a full scale. It is the world's first treatment plant of its kind. The new treatment facility enables the Ardal metal plant to meet the stricter requirements for emissions of sulfur dioxide that are expected in the future.

Sulfur dioxide is a by product of aluminum production and the consumption of anodes in the electrochemical process. Anodes contain petroleum coke; the coke contains sulfur, which forms the SO2 when the anode is consumed.

Mr Knut Omholt Austreid director of Technology in Primary Metals said that "This is an interesting project for two reasons. First, the unit will be installed during full operation at the technology center and second we have to learn to run aluminum production with anodes containing more sulfur. If the sulfur content rises in the anodes at least 95% of all sulfur dioxide will be removed in the new facility."

The new facility has an expected cost of NOK 35 million and is scheduled to be in full operation by the autumn of 2012. To implement this initiative the project has received support from the Process Industry Environment Fund in Norway. The fund was established in 2001 by the Federation of Norwegian Industries and the Ministry of the Environment for the purpose of planning and financing reductions in SO2 emissions from the Norwegian processing industry.

The project which led to the decision to invest in new environmental technologies has been a collaboration between the technology areas in Primary Metal, the Ardal metal plant and Hydro's central Health, Safety and Environment department.

Mr Dyrøy said that "This is an excellent example of interdisciplinary collaboration, where the technology and operating environments in close cooperation with the HSE department have succeeded in finding a good technical solution that can be installed while the plant is in operation. In addition, we have succeeded in getting support from the Environmental Fund for a good environmental project."

(Sourced from www.azom.com)