Ragn-Sells, HZI develop process for recycling flue gas residues

Swedish recycling company Ragn-Sells has selected Hitachi Zosen Inova (HZI) to build a flue gas treatment residue processing facility at its Stockholm base. The plant will extract materials including potassium chloride, sodium chloride and calcium chloride salts, along with ammonium sulphate from flue gas residues, which can then be used in industrial and chemical processes. The plant will combine ash leaching technology with brine cleaning and salt recovery, said Stefan Forsberg from HZI. Construction work is set to begin in the autumn.

In Sweden, recycling company Ragn-Sells AB and Swiss cleantech company Hitachi Zosen Inova AG (HZI) are to build a facility for processing flue gas treatment residues at Ragn-Sells Högbytorp facility in northwest Stockholm. The process enables salts to be extracted from the flue gas residues which can then be reused in industrial and chemical processes.

The flue gas treatment residue processing facility is being built at the Högbytorp site of the Swedish recycling company Ragn-Sells and will collect and wash residues from industrial processes, enabling the recovery of various commercial salts. Following a joint project development phase, the client, Ragn-Sells Treatment & Detox AB, has commissioned HZI to supply and integrate the entire process technology.

HZI is a well-known name in plant construction and has many years of process technology experience. These were crucial factors in our choice of partner for this project, said Ulrik Améen, Project Manager at Ragn-Sells.

Realizing a Sustainable Circular Economy

With the objective of creating a sustainable circular solution, once commissioned the installation will extract useful materials such as potassium chloride, sodium chloride, and calcium chloride salts as well as ammonium sulphate from the residue. These materials can then be reused for industrial or chemical purposes.

For HZI this project marks a return to familiar territory: in the past, the company has successfully developed and installed diverse fly ash washing systems at thermal waste treatment plants.

Given the various interpretations of the European legislation on treatment and landfilling fly ash and residues in different countries, the Ragn-Sells facility marks the way forward. We’re proud to be able to contribute our know-how and experience to this prestigious project, said Ruedi Frey, Senior Engineer at HZI.

The solution produced by the washing process will then be vapourised in a distillation process, with the crystallised salts separated out. After that, the cleaned residue will be dewatered and used as feedstock for new production processes.

What makes this project special, is that we combine the proven ash leaching technology with brine cleaning and salt recovery for the first time, said Stefan Forsberg, Service Manager at HZI.

Work to build the relevant section of the building will begin in autumn 2020, and assembly of the process technology will follow in January 2021.