New innovation makes trash incineration more sustainable
FIRST PLANT WILL BE BUILT IN COPENHAGEN
When waste is incinerated to produce heat and electricity, ash is also produced. Only in the Nordic countries several hundred thousand tons of incineration ash need to be dealt with every year. Rather than being transported long distances to special landfills, ash can now be treated and deposited at standard local landfills. All thanks to a technique developed by Stena Metall Group's Research & Development Department.
The patented technique is called HaloSep. It makes it possible to solve several problems arising from waste incineration. The technique uses two problematic remnants to neutralize each other in a joint process: alkaline smoke ash and hydrochloric acid. What remains is treated and washed ash, a saline solution that can be discharged into the sea or used as road salt and a metal concentrate that can be recycled in a smelter.
“It’s win-win in many ways. The facilities do not have to buy large quantities of chemicals for purification. HaloSep tech-nology also makes it possible to save a lot on transportation every year, as it’s no longer necessary to transport ashes long distances to special landfills. The treated ash is cleansed of heavy metals like lead and zinc, and clears the EU’s requirements for being deposited at the local landfill”, says Christer Forsgren, Head of Research & Development, the Stena Metall Group.
The technology was developed in the Research & Development department at Stena Metall Group, and now a demonstration plant is being built in Vestforbrænding in Copenhagen, with support from the EU program LIFE.
“This will be the first full-scale plant. Our aim is also to find applications for the treated ash, such as construction materials. Then we can remove the ash completely from the landfill”, says Christer Forsgren.
