All subjects
Heat & Power

Söderenergi selects Ragn-Sells for fly ash recycling

Söderenergi AB, Sweden's fourth-largest district heating producer, has signed an agreement with compatriot resource management and environmental company Ragn-Sells Group for the annual recycling of 25 000 tonnes of fly ash. At Ragn-Sell's Salarium Högbytorp, currently under construction in Upplands-Bro, northwest Stockholm, novel Ash2Salt technology will be used to recycle valuable raw materials from the ash while environmental toxins are removed from the cycle.

An error occurred

You are logged in as subsbriber at Bioenergy International, but something is wrong.

On your profile you can see what subscriptions you have access to and more information.

Is some of the information wrong – please contact our customer service.

Please reload the page

We could not ascertain if you are logged in or not. Please reload this page.
Bioenergy International premium

Do you want to read the whole article?

Only logged in payed subscribers can read all contents on
As an subscriber you get:
  • Six editions per year
  • Full access to all digital content
  • The E-magazine Bioenergy international
  • And more ...
Söderenergi, Sweden’s fourth-largest district heating producer, has signed an agreement with compatriot resource management and environmental company Ragn-Sells for the recycling of 25 000 tonnes of fly ash each year. From its facilities in Södertälje, Söderenergi provides district heating for around 300 000 people, offices, and industries in the greater Stockholm region, as well as electricity.

Fly ash is formed when the flue gases from combustion are purified in flue gas treatment systems. In Sweden alone, some 300 000 tonnes of fly ash are produced annually, a residue from the thermal treatment of around seven million tonnes of non-recyclable waste that provides district heating and electricity.

The fly ash can contain elevated levels of substances that are harmful to health and the environment along with large amounts of valuable resources such as potassium, sodium, and calcium.

With Ragn-Sell’s new circular solution, fly ash from combined heat and power companies can be disposed of by extracting valuable resources at the same time as environmental toxins are removed. We are happy and proud that an ambitious player like Söderenergi chooses our new technology to recycle the ash, said Mikael Hedström, CEO of Ragn-Sells Treatment & Detox.

Proprietary Ash2Salt technology

Ragn-Sell’s new Salarium Högbytorp is currently being built in Upplands-Bro northwest of Stockholm. The process is based on the proprietary Ash2Salt technology developed by Ragn-Sells Group subsidiary EasyMining AB, and the new facility will be put into operation during the second half of 2022.

Once fully operational, Salarium Högbytorp will have the capacity to process 150 000 tonnes of fly ash annually. This corresponds to half of all fly ash that Swedish waste-to-energy players produce each year.

Our investment in fly ash recycling is one of the largest investments made in circular material recycling in Sweden. We are delighted with the great interest and look forward to continuing the discussions with more actors, said Mikael Hedström.

Last year, the project was awarded SEK 51 million (≈ EUR 5.2 million) in investment support from the ClimateStep (Klimatklivet) program, the Sweden Government’s investment program for projects that reduce climate emissions.

In addition, the technology can be put to use in twelve countries outside the Nordic region, thanks to a landmark licensing agreement with the global cleantech company Hitachi Zosen Inova AG (HZI). HZI can introduce the Ash2Salt solution as part of its offering when building waste-to-energy plants.

Timely plant

Currently, most of the Swedish fly ash has been sent to a dedicated landfill in Norway. However, as of October 1, 2021, the Swedish Environmental Protection Agency, which is responsible for export permits for fly ash, no longer classifies such handling as recycling, but as removal and disposal.

With the Ash2Salt technology, useful raw materials can be recycled while unwanted substances are removed from the cycle.

Sustainable energy supply is our main task and we must always be at the forefront when choosing technology. Through our collaboration with Ragn-Sells, we took care of 105 tonnes of heavy metals last year. Now, through this new agreement, we can happily ensure that large amounts of useful raw materials in our fly ash return to the cycle, said Karin Medin, CEO of Söderenergi.

The contract also includes the handling of approximately 35 000 tonnes per year of bottom from Söderenergi. Bottom ash and slag from energy plants contain various metals that are removed and recycled at a Ragn-Sells facility in Häradsudden outside Norrköping.

This is done by putting the ash through a special sorting plant where both ferrous and non-ferrous metals are recovered. The remaining material is sorted into different aggregate sizes and can be used as a construction material instead of natural gravel.

Most read on Bioenergy International

Get the latest news about Bioenergy

Subscribe for free to our newsletter
Sending request
I accept that Bioenergy International stores and handles my information.
Read more about our integritypolicy here