Reactivated carbon as an alternative to virgin coal-based activated carbon to cut CO₂ footprint and TCO
At DESOTEC, our mission to create a cleaner, greener world is reflected in our circular business model that centres on the reactivation of spent activated carbon. This model not only minimises CO₂ emissions and serves as a pollutant sink, but also reduces the overall Total Cost of Ownership (TCO) for industrial operators. Products and services based on reactivated carbon not only reduce our reliance on imports of virgin activated carbon, potentially incurring tariffs, but also strengthen the supply chain’s resilience and bring down costs for customers.
Calculating our carbon footprint
At DESOTEC, we have calculated the greenhouse gas emission (GHG, carbon footprint) of our products according to the Bilan Carbone methodology, which is based on the United Nations Greenhouse Gas (GHG) Protocol, ISO 14064, and Directive no. 2003/87/CE. We take into account CO2-equivalents as GHG, including not only CO₂ emissions, but also methane (CH₄), nitrous oxide (N₂O) and other compounds. For the complete lifecycle GHG impact of the activated carbon service, see Figure 1.
The cradle-to-gate GHG calculation for virgin activated carbon includes:
- carbon-based raw material provision;
- carbonisation and activation to generate the activated carbon product;
- transport from the production sites to our facilities;
- and filling of mobile filters.
For returned spent carbon it includes:
- reactivation and exhaust after treatment;
- and filling of mobile filters.
The cradle-to-grave GHG calculation further includes:
- transport of the filled filter to and from the customer;
- and potentially end-of-life treatment like valorisation.
Reactivated carbon vs virgin activated carbon
Recycling, reactivating and reusing spent carbon cuts CO₂ by reducing the mining/ harvesting and long-distance transportation of virgin carbon, as well as the end-of-life treatment of spent activated carbon. Reactivating carbon acts as a pollutant sink, with adsorbed compounds being completely destroyed in our furnaces and afterburners and valorised wherever possible. Furthermore, our reactivation process lifts the carbon waste management burden from the customer.
Carbon waste acceptance
We can reactivate most spent activated carbon, managing it in accordance with site-specific operating permits, safety protocols and relevant laws, regulations and standards (such as RCRA, ISO 9001 and ISO 14001). Samples are analysed to determine whether or not the spent activated carbon can be reactivated, detailed in the so-called waste profile.
In the event that our analysis shows concentrations that are above the level we are allowed to reactivate the spent activated carbon, we use our extensive network of industry contacts to help customers find a compliant, safe, cost-effective end-of-life treatment, preferably energy valorisation.
To be reactivated, the spent activated carbon is transported in closed filters away from customers’ sites to our own facilities, where we have the expertise and equipment to handle it safely and sustainably. This process eliminates the need for on-site change-outs at customer facilities.
In addition, reactivated carbon can be reused, creating economies of scale for our customers.
Reactivation process and flue gas treatment
Activated carbon can be reactivated multiple times, effectively creating an infinite resource for our customers. We have some of the most advanced reactivation technology, enabling us to reactivate even heavily contaminated spent carbon at very low losses during the reactivation process.
During the reactivation process, desorbed compounds are completely destroyed through pyrolysis inside the furnace or fully oxidised in an afterburner downstream of the furnace. The resulting exhaust stream of CO₂ and water vapour is safely guided into the atmosphere, while inorganic molecules like acids or heavy metals are neutralised and captured through scrubbing and turned into salts (fly ash).
Our furnaces and flue gas treatment installations are fitted with state-of-the-art emission monitoring to ensure they comply with the most stringent standards in the industry, set by local, regional and national authorities. Naturally, we work closely with the environmental authorities to ensure that any desorbed impurities are effectively destroyed, meeting environmental standards.
Benefits of reactivated carbon
TCO saving
Reactivating carbon improves customers’ financial sustainability by saving on the costs of mining/ harvesting virgin carbon and transporting it internationally (usually from Asia). By reactivating it for reuse, customers also save on the waste disposal costs of spent activated carbon.
Reactivating carbon also boosts business resilience by reducing reliance on imports of virgin coal, thus strengthening the supply chain and avoiding potential unforeseen tariffs.
Our reactivation and flue gas treatment is also designed to be as circular as possible. As an example, in our European facilities, steam produced during flue gas treatment is injected back into the furnace to improve the carbon’s adsorption capacity. We also recuperate heat to warm our installations, boosting the sustainability of our processes.
CO₂ footprint reduction
Another advantage is that reactivating carbon closes the loop, reducing the carbon footprint of industrial activities. It cuts the carbon emissions associated with mining coal, international transport, and waste treatment.
Figure 2: Relative comparison of Greenhouse Gas Footprint of DESOTEC’s activated carbon grades
Taking coal-based activated carbon as the reference, the end-of-life GHG footprint of the reactivated product is 13 times lower.
Future developments in sustainability
With sustainability at the heart of our strategy, we are continuing to expand our portfolio of sustainable products, in particular by pursuing our R&D work.
In Europe, our newest groundbreaking production facility dedicated to the biogas market will support this strategy and reduce our CO₂ footprint even more. This plant has the capacity to reactivate impregnated carbon heavily loaded with H₂S, thereby producing activated carbon of the same quality as virgin carbon – further lowering the CO₂ footprint.
This technology is patented and unique in the world. It revolutionises the treatment of spent activated carbon from the biogas market into a circular model, boosting sustainability, local economies, energy independence, and cost-efficiency. This process even produces gypsum – from the recovered sulfur adsorbed on the spent activated carbon – which is used as a construction material, further improving circularity and sustainability.
-
Our Filtration Solutions
We offer a wide range of filter models and carbon grades to suit your industrial water or air purification requirements. -
Reactivation simply explained
Conserving our planet’s precious natural resources is key to a greener future. Reactivating saturated carbon reduces the amount of virgin raw materials needed for filtration, closing the loop and improving sustainability. -
Industries we help
We partner with companies in a variety of sectors, adapting our modular filtration solutions to your unique needs.