Turning wet sludge
into solid value
We transform wet biowaste into dry, climate-smart HTC biocoal.
“With this technology, we can save both the environment and costs.”
— Mikael Sillfors, Development Manager, Heinola Fluting Mill, Stora Enso, Finland
Highlights
Sludge Trials in the Port of Rotterdam
C-Green's HTC pilot unit was placed to perform tests on different sludge streams. The outgoing product streams — biocoal and HTC filtrate — were sent for external lab analysis and to potential off-takers.
Successful Tests at Forest Nursery
In tests conducted at Stora Enso's tree nursery, 10,000 forest plants had 20% of their peat replaced with C-Green's HTC biocoal. The results showed that the use of artificial fertilizers could be reduced by 50%
1.3 Tons of Pellets Spread in Forest
Together with Karlstad University, a pelletized mix of HTC biocoal and ash is being tested for spreading in growing forests. The purpose is to evaluate the potential of the pellets as a replacement for today's fossil-based forest fertilizers.
HTC Biocoal
HTC biocoal is a solid material produced by dewatering the slurry from the HTC process. It is sterile, odorless, easy to store and friendly to handle – with significantly reduced volume and weight compared to wet sludge.
Visit our Heinola plant
As regulatory requirements are tightened and the cost of sludge handling increases, a C-Green HTC plant provides an environmentally sound, safe, and practical solution.
Watch the film to hear Stora Enso’s perspective on the collaboration with C-Green – and how our HTC technology could play a role in their strategy to become climate-positive.
Why is sludge so hard to handle?
Sludge is dripping wet | With up to 90% water content, sludge is heavy, bulky, and expensive to transport or burn – a major challenge for waste management.
Expensive to dewater | Traditional sludge drying methods consume a lot of energy, making dewatering both expensive and unsustainable.
High pathogen content | Sludge often contains high levels of pathogens, posing a danger to both human health and the surrounding environment.
Foul smell | The ever-present, noxious smell of sludge can be very unpleasant for workers and the surrounding community.
Failure to manage sludge responsibly can result in serious threats to:
Health and the environment | Untreated or poorly managed sludge can release hazardous compounds, contaminating soil and water, and endangering public health and biodiversity.
The climate | Methane and nitrous oxide released from sludge storage and composting have a global warming potential dozens to hundreds of times greater than carbon dioxide.
Don’t waste your waste
- turn your sludge into HTC biocoal
HTC biocoal is useful
HTC biocoal is a solid, carbon-rich material with multiple applications — including use as a carbon sink, biofuel, fertilizer, and for soil improvement.
Climate-smart
Greenhouse gas emissions from sludge are immediately and effectively eliminated, while transport volumes are reduced by up to 80%.
Increases nutrient recovery
Nitrogen is recovered during the HTC process, and when HTC biocoal is incinerated, phosphorus can be extracted from the ash.
Saves money
Compared to conventional sludge handling, the HTC process reduces costs. It is the most energy-efficient method for sludge dewatering available.
Kills pathogens
The HTC process completely destroys viruses, bacteria, and parasites, resulting in a sterile biocoal.
Easy to handle
The HTC biocoal is light, dry and odorless compared to sludge making it much more friendly to handle
