AquaGreen

AquaGreen, founded in 2014, is a Danish engineering company that has developed an innovative technology for treating wet biomass, particularly sewage sludge. The company's patented HECLA technology integrates steam drying and pyrolysis to convert bio-waste into valuable resources. This process dries and pyrolyzes sewage sludge at 650°C without the need for auxiliary fuel, using only the calories from the sludge itself. The technology significantly reduces greenhouse gas emissions by approximately 80% compared to conventional sewage sludge disposal methods.

AquaGreen's HECLA 1,000 plant can process 1,000 metric tons of dry matter annually, reducing greenhouse gas emissions by 1,800 tons of CO2 equivalent, producing 2,000 MWh of sustainable energy, and storing 500 tons of carbon in biochar. The resulting biochar is odorless and contains 5-6% plant-accessible phosphorus, making it valuable for soil improvement and fertilization. The process also eliminates harmful pollutants such as microplastics, medical residues, PFAS, and PAH while preserving essential nutrients like phosphorus.

The company's technology offers a cost-effective and environmentally efficient solution for handling wet bio-waste, presenting a sustainable alternative to traditional sewage sludge management methods. AquaGreen's system is self-sufficient and circular, as the gases produced during pyrolysis fuel both the steam drying and pyrolysis processes. The excess steam, condensed into hot water, can be used for district heating grids and other applications.

Key customers and partnerships

AquaGreen has successfully installed its HECLA plants in Denmark, specifically in Zealand and Funen. The company has also expanded its operations to Sweden and South Africa. In July 2023, AquaGreen secured a tender to supply installations in Malaysia and Borneo. The company was also working on an offer for 11 plants in Saudi Arabia and exploring opportunities in China and Australia.

One of AquaGreen's key customers is Odsherred Forsyning in Denmark, where the world's first integrated steam drying and pyrolysis plant was implemented. This installation has enabled Odsherred Forsyning to transform sewage sludge from 50,000 citizens from an annual expense into a sellable product.

AquaGreen has collaborated with the Technical University of Denmark (DTU) in developing and patenting its technology. The company also partnered with Odsherred Forsyning and VandCenter Syd in the development of its solution. These partnerships have been instrumental in refining and validating AquaGreen's innovative approach to biomass treatment.