Conserving our planet’s precious natural resources is key to a greener future. Reactivating saturated carbon reduces the amount of fresh raw materials needed for filtration, closing the loop and improving sustainability. We also neutralise the adsorbed components and recover them where possible. Reactivation cuts customers’ costs, protecting businesses too. Desotec already reactivates most spent carbon, and we are developing technology to move towards 100% circularity.
A step by step process
1. Filters are taken back
Once the carbon is saturated, the filter is sealed off. No waste carbon is handled at customers’ sites, and the filter exchange process is dust-free, so operators are not exposed to the spent carbon. Desotec technicians transport the closed filter safely to our own facilities. We handle all waste transport administration.
2. Samples are analysed
At our facilities, we have the equipment and trained staff to handle waste carbon safely. We test samples to see which components have been adsorbed, and in what concentrations. This determines how we manage this waste, and whether we can reactivate the carbon. In the rare cases where we cannot manage certain types of hazardous waste ourselves, we arrange for its safe valorisation.
3. Activated carbon is reactivated
We empty the filters safely at our facilities, where we have state-of-the-art industrial reactivation set-ups. Each of our furnaces uses pyrolysis, heating the waste carbon without oxygen to avoid burning. The carbon is passed through different temperature zones to desorb the components and reactivate it.
4. Components are neutralised and recovered
Desorbed components undergo state-of-the-art flue gas treatment to neutralise them. The process is continuously monitored online to ensure only harmless water vapour and CO₂ exit the chimney. Solid wastes like salts are recycled or valorised by specialist companies. Energy is recovered for reuse in the reactivation process, and to heat our premises and those of a neighbouring company.
5. Carbon is reused
Reactivated carbon is cooled and sieved into granular or extruded products. These are stored in big bags in our distribution centres, ready to refill filters. By-products from the reactivation process are also recovered, for reuse as powdered activated carbon for example. Repeat customers are supplied with filters containing reactivated carbon, enhancing sustainability and cutting costs.