Biomass treatment

We turn a problem into a resource

Re-think innovation

Fast Re-turn on investment

Re-circulate resources

Re-duce pollutants

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  • Scalable technology and compact design
  • Autonomous operation
  • Innovative energy utilisation
  • Environmentally friendly technology


  • Sludge weight and volume is reduced
  • Foreign environmental pollutants are reduced
  • End product is sanitised, odourless and storage safe
  • Pathogenic bacteria are eliminated


  • Sustainable usage of embedded energy
  • Steam converted to thermal energy
  • Preservation of nutrients in biochar
  • Phosphorus re-circulated
  • Carbon as soil improver, CO2 emission reduced


  • Energy cost saving technology
  • Production of excess thermal energy
  • Reduction of sludge disposal costs
  • End product is marketable biochar

Who we are

Our solutions

Combined steam dryer and pyrolysis unit

The AquaGreen solution for sludge treatment includes our combined steam dryer and pyrolysis unit, which will Re-think your business, Re-duce your costs, Re-circulate valuable resources, and improve the Re-turn on your investment.

Our patent pending technology is divided into three separate process steps.

Sludge of 15-25% dry matter is dried up to >95% in an oxygen-free atmosphere of superheated steam. The surplus steam is condensed into a heat exchanger so that the thermal energy can be recovered and odour- and dust nuisance eliminated.

The dried sludge is heated to temperatures around 650° C in an oxygen-free atmosphere, whereby the organic pollutants of the sludge are degraded by the pyrolysis process.

The pyrolysis gas is combusted and turned into thermal energy. The energy can be utilised in your production facility, or it can be distributed as district heating. The main end product in form of biochar is stable, odourless and rich in re-circulated phosphorus. Thus, combining the steam drying and pyrolysis solution optimises the return on your investment.

Steam dryer unit

AquaGreen's patent pending technology uses superheated steam to dry sludge. We have invented a state of the art solution. The result is a very cost efficient process in which we reduce the sludge volume and weight and hence the disposal costs. The steam dryer unit can be used as a stand-alone solution or in combination with our pyrolysis unit, which will further increase your return on investment.

  • Patented technology

  • Compact design

  • Reduced sludge volume and weight

  • Reduced disposal costs

Pyrolysis unit

Our developers and collaborators from the Danish Technical University (DTU) have more than 25 years of experience in using pyrolysis technology, all of which is transferred into the AquaGreen pyrolysis unit. The pyrolysis gas is combusted to produce thermal energy for the steam drying process, and re-circulated for district or on-site heating. Our pyrolysis solution can be used in combination with our steam dryer or as a stand-alone solution.

  • Further reduction in sludge volume and weight >90%

  • Further reduction in disposal costs

  • The end product biochar is storage safe and odourless

  • Pathogenic bacteria and pollutants are eliminated in the biochar

  • The biochar is a valuable resource and can be used as fertiliser

  • The excess thermal energy that is generated is re-circulated

Applicable Industries

AquaGreen's solutions have a broad and versatile usage and can thus be used in various sludge generating industries. Below are a number of industries in which our solutions are typically applicable. Please contact us if you have any special requests.

Aqua Culture Industries

The trend of growing the smolt bigger before they are moved from land to sea pushes the demand to reduce sludge volumes, to utilise the embedded energy, and to re-circulate valuable resources.

Municipal Wastewater Treatment (MWWT)

Our solution turns a problem into a resource for MWWT’s. Our solution is commercially viable and supports a transition towards circular economy by re-circulating resources, such as phosphorus.

Biochemical Industries

Sludge, which does not require further processing, matches our combined solution perfectly. Disposal costs are reduced and the excess thermal energy can be re-circulated and utilised in production.

Food & Beverage Industries

When utilising the AquaGreen solution, the brewery sludge volumes are reduced and turned into valuable biochar. Furthermore, the produced excess thermal energy can be re-circulated and utilised in production.

Agriculture Industries

Livestock manure and other organic waste can be used for energy production, and the biomass can be turned into biochar with the AquaGreen steam dryer and pyrolysis solution.

Special Requests

Cruise ships, refugee camps, military camps and festivals all generate wastewater sludge, which poses a possible health risk. When implementing our solutions, this risk is eliminated, and the excess thermal energy can be utilised for e.g. heating.

"AquaGreen's solutions will create great value in both Norway and the rest of the world and will have a great customer base"

- Lars Olav Sparboe, Senior adviser, Akvaplan-niva AS

"I see a huge potential in AquaGreen and their sustainable sludge drying technology. No doubt that the timing is right for this type of technology within a large number of different Industries. Not only in Denmark, but also in a Global context"

- Peter Vangsbo, Innovation Lead and Nordic Business Developer, Climate KIC

Grants & Awards

The Danish Eco-Innovation Program (MUDP)

The Eco-Innovation Program help companies to obtain public support for technological research and development projects. MUDP does this by translating projects into thorough applications improving the companies’ chances in competing for support.

2019: AquaGreen has in co-operation with Arhus Vand A/S and the Chemical Engineering Department at DTU been granted financial support for the development of a system for the production of activated carbon out of biochar from pyrolysis of municipal sewage sludge. The purpose of converting biochar into activated carbon is to use it as filter material in the cleaning process of waste water. The prototype is developed at DTU Campus Risø and tested at Aarhus Vand A/S, together with the activated carbon.

The project period is 36 months with a total allocation of 4.9 million DKK.

Promilleafgiftsfonden is a public funded foundation for the agricultural sector, with the purpose of supporting the development of new methods and technologies in the agricultural and food industry.

2018: AquaGreen was granted 105,000 DKK to help finish our comprehensive field-studies with biochar, that is performed by SEGES and The Danish Technological Institute.

Otto Bruuns Fond

Otto Bruuns Fond is a private foundation, that supports industrial research and development of new inventions.

2018: AquaGreen was granted 50,000 DKK to help finish our comprehensive field-studies with biochar, that is performed by SEGES and The Danish Technological Institute.

Miljø- og energifonden

The Environment and Energy Foundation supports new ideas and solutions on current energy or environmental problems.

2018: AquaGreen was granted 50,000 DKK to help finish our comprehensive field-studies with biochar, that is performed by SEGES and The Danish Technological Institute.

Viden der styrker virksomheder i Region Sjælland

ViiRS is a regional govenrnment program that offers local businesses academic support from four universities in the region. The purpose with establishing this co-operation is to help create economic growth and new jobs in the region.

AquaGreen was granted funds to co-operate with researchers from the Chemical Engineering Department at DTU Campus Risø in the first half of 2018. The project was the development of an efficient swirl burner for our pyrolysis system.


The aim of the Market Development Fund is to promote growth, employment and export, particularly for small and medium-sized enterprises in areas where Denmark has particular strengths and potential.

2017: DANVA and the Market Development Fund choose AquaGreen as their supplier in a public tender for Pre-Commercial Procurement.

AquaGreen provides a solution for drying sewage sludge by using superheated steam and subsequent conversion to biochar through pyrolysis. The biochar is analysed and tested as a potential phosphorus-rich fertiliser through chemical and biological laboratory test and analysis, and controlled cultivation tests.

The project runs over 24 months and has been allocated a total of 5.3 million DKK.


Innovation Fund Denmark invests in new knowledge and technology creating growth and employment in Denmark.

2016: AquaGreen has been granted financial support from Innobooster for the development of a second generation 10 kW electrical powered superheated steam dryer prototype for treatment of aquaculture sludge. The prototype development is taking place at DTU Campus Risø, and the test in a live production environment takes place at Smolten AS in Northern Norway.

The project runs over 10 months and has been allocated a total of 1.3 million DKK.


Eurostars is a joint program between EUREKA and the European Commission, which supports international innovative projects led by R&D performing small- and medium-sized entreprises. It is an ideal first step in international cooperation, enabling small businesses to combine and share expertise and benefits from working beyond national borders.

2016: AquaGreen has in a consortium with Melbu Systems AS, Akvaplan-niva AS and the Danish Technical University been granted financial support for the development of a combined solution for drying and pyrolysis of aquaculture sludge, from Eurostars under Horizon 2020. The purpose is to reduce sludge volumes substantially in an efficient process while using the high calorific value of the sludge as an energy source for the process.

The project period is 30 months with a total allocation of 8.9 million DKK.


As business developers, MUDP help companies to obtain public support for technological research and development projects. MUDP does this by translating projects into thorough applications improving the companies’ chances in competing for support.

2016: AquaGreen has in co-operation with VandCenter Syd A/S applied for and been granted financial support from MUDP for the development of 10 kW electrical superheated steam dryer for drying municipal sewage sludge. The prototype is developed and tested at DTU Campus Risø.

The project period is 13 months with a total allocation of 1.2 million DKK.

Danish Tech Challenge

Danish Tech Challenge is for companies, newly established as well as more experienced, who have dedicated their work to developing successful businesses based on newly invented hardware solutions.

2015: AquaGreen is selected as one of 20 participants in the annual Danish Tech Challenge, out of more than 60 applying start-up companies.

Innovation Norge

Innovation Norway is the Norwegian Government's most important instrument for the development of Norwegian entreprises and industries. They support companies in developing their competitive advantage and in enhancing innovation.

2015: Innovation Norway funds a market pre-study which is needed in connection with preparing the application for Eurostars.

Det Grønne Iværksætterhus

The Green Entrepreneurship House has created a leading development and growth environment for green entrepreneurs in Denmark. They have inspired, challenged and strengthened entrepreneurs' products and helped them develop in a sustainable environment.

2015: AquaGreen signs an agreement with the Green Entrepreneurial House at Scion-DTU for support and mentoring for a two-year period, where the Green Entrepreneurial House is to assist AquaGreen through the initial start-up challenges.

"Aquagreen's proposed solution will provide the exact solution that the Waste Water Industry has been asking for during the last many years"

- Per Henrik Nielsen, Vandcenter Syd

About AquaGreen

AquaGreen is an R&D engineering company within the Cleantech industry.

We develop new and innovative solutions for wastewater sludge treatment and for converting low-grade biomaterial resources into thermal energy and fertiliser.

The technology is based on Superheated Steam Drying and Pyrolysis, in an energy efficient process, where the calorific content of the sludge is utilised for drying and converting wastewater sludge into a biochar product.

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.

In addition to being scalable, the technology has a high calorific value, and a well-documented and predictable content of chemical substances, including heavy metals and xenobiotics.

Development of the technology has taken place in a close collaboration with the Danish Technical University.

"I believe that Aquagreen's solution has major potential, also in the Biochemical Industry, because their technology is environmentally friendly and cost reducing"

- Frank Hatzack, Head of Innovation Development, Novozymes


Hi. Please contact us.

AquaGreen ApS

Frederiksborgvej 399, building 763.
DK-4000 Roskilde.
+45 53 660 888

Claus Thulstrup

(+45) 6021 7614

Henning Schmidt-Petersen

(+45) 2928 1848

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