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AquaGreen is a cleantech engineering company.
We develop new and innovative solutions for wastewater sludge treatment and for converting low-grade biomass into thermal energy and biochar or activated carbon.

Our solution integrates superheated Steam Drying and Pyrolysis in an energy efficient process.
The calorific content of the sludge is utilised for drying and converting wastewater sludge into biochar and thermal energy. The thermal energy is recoverable and can be used for district or process heating purposes. The residual biochar is rich in plant-available phosphorus and is suitable as an agricultural fertiliser.

Development of the technology has taken place in a close collaboration with the Danish Technical University. The technology is being commercialized by mid-2021 at 2 danish municipal wastewater treatment plants and is ready for broad commercialization.

Each of these units treat sludge from 50.000 people and deliver the following benefits:

  • No micro-pollutants in soil and ground water
  • No malodor or health risks
  • 10 x less transport

Supports meeting climate targets saving Greenhouse Gas emissions, storing CO2e and producing energy:

  • Total saved emissions:                                               1800 tons CO2e reduction1
  • Carbon storage in biochar:                                          500 tons CO2e storage
  • 2000 MWh renewable energy produced:        1500 tons CO2e reduction2

Safeguard our grandchildren’s food supply by recirculating Phosphorus to the soil.

  • 25 tons life critical Phosphorus re-circulated

The investment has an attractive pay-back time as the current biomass/sludge handling cost will be converted to an income from selling renewable energy and carbon- and carbon removal credits.

In case you are interested – find more information on and please contact Christian Wieth, Chief Commercial Officer at AquaGreen, by e-mail:



  1. Based on LCA by Thomsen, T.P, DTU (2018) “Drying and pyrolysis of sludge ‐in a climate perspective”
  2. Oil-based power production CO2 emission acc. to