Stockholm-based climate tech company C-Green has raised SEK 40 million (~€3.7M / $4.3M) in a funding round completed in June 2026, backed by both existing and new investors.
The capital will support the industrial scaling and commercialization of its hydrothermal carbonization (HTC) technology, alongside upgrades to its flagship facility in Heinola, Finland.
What C-Green does
C-Green develops technology that converts wet biowaste into solid hydrochar, a carbon-rich material that can be used as:
- biofuel
- soil improvement product
- fertilizer input
Its process is based on hydrothermal carbonization (HTC), which transforms sludge and organic waste under heat and pressure into stable, energy-rich material while also enabling nutrient recovery and biogas production.
This makes the technology particularly relevant for:
- wastewater treatment plants
- pulp and paper mills
- food industry waste streams
Funding details
- Round: Other / growth financing
- Amount: SEK 40M
- Date: June 2026
- Sector: CleanTech / ClimateTech / Energy
- HQ: Stockholm, Sweden
- Previous name: —
The financing is tied closely to the upgrade of C-Green’s full-scale HTC plant at Stora Enso Heinola fluting mill in Finland, where the company is advancing its system to Design 3.0.
Strategic development: HTC Design 3.0
The new investment supports the rollout of next-generation HTC Design 3.0, which aims to:
- increase operational reliability
- improve energy efficiency
- reduce CAPEX and OPEX
- bring the technology to TRL 9 (commercial readiness)
This marks a key step from pilot/industrial demonstration toward full-scale commercialization across Europe and international markets.
Market context
C-Green operates in a growing segment of industrial waste valorization and circular bioeconomy infrastructure. As wastewater treatment and industrial waste regulations tighten across Europe, demand is increasing for technologies that:
- reduce landfill dependency
- recover nutrients (phosphorus, nitrogen)
- convert waste into energy and usable carbon products
HTC-based systems are gaining attention as a scalable alternative to traditional sludge disposal methods.
Company link
Official website: C-Green
Bottom line
C-Green is moving from technology validation into industrial-scale deployment, using fresh capital to push its hydrochar platform toward full commercial maturity. The Heinola upgrade and TRL9 milestone position the company as a serious infrastructure player in Europe’s emerging circular waste-to-energy ecosystem.
