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Recycling Services

How does our recycling offer work?

A patented technology, unique in the market

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Through our SOLVAir® Residual Sodium Chemicals (RSC) recycling solution, we offer our customers the possibility to handle the recycling of the residue generated by their flue gas treatment systems.

To do this, SOLVAir® has developed and patented an original technology that allows the production of purified sodium brine from flue gas treatment residue in order to replace the natural brine used in soda ash production plants. Our operations Solval® in Italy and Resolest® in France have successfully industrialized this technology since 1998.

None of our competitors can offer this service at the moment.

A service adapted to all our customers

This offer could work for all our customers in search of solutions to decrease their environmental footprint and increase their regulatory compliance, from waste-to-energy operators to industrial clients as well as the marine industry.

Whatever the industry, recycling replaces the extraction of virgin raw materials with chemical processes and reduces the amount of residue to be landfilled by a factor of 10 or more.

The brine recycling process

The SOLVAir® RSC Recycling process yields a brine whose contents can be recycled. The residue is dissolved in water at a controlled PH, with additives, and filtered in order to eliminate residual organic matter and any remaining traces of heavy metals.

The purified brine is then re-used in the sodium carbonate manufacturing process. The recycling operations are conducted at specialized facilities located close to sodium carbonate production centers.

What are the key benefits of our recycling process?

Promoting the circular economy

Thanks to this process, natural resources are saved and landfilling following the incineration of flue gas residues is avoided. What’s more, recycling sodium chemicals residue is in line with circular economy policies.

A unique, environmentally sound service

SOLVAir® is the only player offering the recycling of flue gas treatment residue. We combine the transport of sodium sorbent with that of the residue by using the same trucks, thereby reducing pollution and traffic congestion. Lastly, the recycling process doesn’t generate any emissions in the air or effluents, making it an environmentally sound process.


SOLVAir® recycling - Key figures

  • Nearly 2 million tons of brine recycled so far
  • Successful operation for over 20 years

Our operations 

These are the operations to offer our Residual Sodium Chemicals (RSC) recycling solution services:

Since 1998 flue gas treatment in Rosignano, Italy works by NEUTREC process

Solval® , Italy

Solval®  operates the first recycling plant for RSCs from waste-to-energy facilities. The facility is in Rosignano, close to Pisa and near Solvay’s legacy soda ash plant in Italy, which uses the purified brine produced by Solval as raw material to produce soda ash.
At Ecomondo, the international green economy exhibition, the Solval plant received a ‘special mention’ among the best Italian projects for adopting best practices in the circular economy. 

Resolest® , France


Located in the north of France, Resolest®  handles the recycling of RSCs from the flue gas treatment systems of waste-to-energy plants.
The facility was inaugurated in 2003, through a joint venture between Solvay and Suez. The purified brine it produces is used as raw material at the nearby Solvay soda works at Dombasle to produce soda ash. 



The Resogypse®  process is a SOLVAir® Solution applied by Resolest for the recycling of RSCs from desulfurization facilities. It offers the significant advantage of transforming the residuals into two valuable products: calcium sulfate, known as gypsum and widely used in cement production, and sodium chloride, used as a raw material in soda ash production.


How is our recycling offer evolving?

Full presence in Europe

We have currently extended our residue recycling offer beyond France and Italy. Our French-based operator Resolest is also present in neighboring countries such as The Netherlands, Belgium and Switzerland.

Extending beyond Europe

Though our offer remains currently only available in Europe, we are looking at several opportunities to extend it to other continents in the near future.

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