Solving wastewater sludge problems through steam drying and pyrolysis
Published on by Water Network Research, Official research team of The Water Network for AquaGreen
JUL 21, 2023
AquaGreen receives €4m investment for “groundbreaking” biomass treatment technology
AquaGreen's current lead investor, Nordic Alpha Partners, and Swedish FMG Circular Invest have invested 30 million DKK (€4m) in AquaGreen.
AquaGreen's groundbreaking technology eliminates environmentally harmful substances in biomasses and reduces greenhouse gas emissions, and is now ready to be put onto the global market.
"AquaGreen is a technology pioneer within sustainable biomass treatment with their groundbreaking technology solution, which is currently unique in the world. The potential is enormous on a global scale, and since AquaGreen has already proved their factory concept in Denmark and is underway in Sweden, the timing is perfect for us to increase our investment to enable the accelerated internalisation and expansion of the company," said Rasmus Lund, senior partner at Nordic Alpha Partners”.
“The trends related to the circular economy within wastewater treatment are strong and AquaGreen is well-positioned to meet the market’s demand for a better utilisation of valuable nutrition and elimination of PFAS, microplastics and medical residues, in wet biomasses. We look forward to supporting AquaGreen in accelerating the company’s growth by leveraging our network and understanding of the industry,” said Ludovic Huitorel, co-CEO of Feralco Group.
Proven technology ready for the global market
The company said it has developed a groundbreaking technology to address one of the biggest environmental problems - namely, wet biomasses, including sewage sludge, in a CO₂-negative way, where 80% of the energy in the biomasses is recovered, while environmental pollutants are eliminated and the vital nutrients such as phosphorus remains available for plants.
The first HECLA® plants have been installed in Denmark, on Zealand and on Funen, where they have delivered positive results and demonstrated that wastewater sludge can be transformed into a sought-after environmentally friendly resource through a circular process, and AquaGreens plant concept, is now ready for internationalisation.
AquaGreen has therefore entered into an agreement with the current lead investor and FMG Circular Invest AB.
It is expected that there will be significant competence synergies between AquaGreen's growth potential and FMG Circular Invest AB, which is a joint investment initiative between Feralco Group and its owner Mellby Gård.
Feralco Group is a major player in the European wastewater market with representation in most European countries and a broad network and knowledge base that AquaGreen can benefit from implementing aggressive growth plans.
An average citizen discharges around two tons of wet bio-waste per year, which needs to be disposed of, currently by spreading it on farmland, storing it, or burning it. This is expensive, bad for the climate and the environment, and burning it leads to the loss of valuable nutrients.
Just one of AquaGreen's industrial plants can handle the discharge from 50-75,000 people, according to the organisation.
This means that the potential in Denmark and Sweden alone is approximately 250 plants, which will result in a more cost-effective, and environmentally- and climate-efficient handling of this waste stream compared to current alternatives.
If the need for sustainable wastewater sludge management is to be met by AquaGreen's HECLA® plants throughout the EU, it would require the installation of approximately 5,000 plants. This is - in addition to the climate and environmental benefits - the reason for the new capital injection.
"At Nordic Alpha Partners, we strive to spot the technology pioneers within the green transformation, that can scale into highly impactful global market leaders. AquaGreen is a perfect example, and we are thrilled that the company’s unique technology and scalable factory concept is now ready for fast paced global expansion and we are confident that wet biomass recirculation, will be one of the largest CO₂ abatement drivers and critical nutrients recovery technologies already by 2030, due to the pioneering role and market position of AquaGreen," said Laurits Bach Sørensen, senior partner at Nordic Alpha Partners.
“FMG Circular Invest AB’s purpose is to invest in companies with innovative technologies related to sustainable water treatment solutions. AquaGreen and their technique that transforms biomass, like sewage sludge, into valuable resources, such as soil-improving biochar, while eliminating harmful substances is fully aligned with our investment focus. We foresee a significant demand for AquaGreen’s offering going forward and are excited to be part of the continued growth journey,” added Filip Eliasson, director of business development at Mellby Gård.
Climate and environmental benefits
Today, sewage sludge is collected and stored in tanks or warehouses before being spread on farmland. During this process, the sewage sludge emits potent greenhouse gases such as CO₂, methane, and nitrous oxide. Through AquaGreen's HECLA® technology, the sewage sludge can without storage be converted into biochar, which can be used as fertiliser and district heating for heating homes throughout the year.
At the same time, wet bio-waste is becoming an increasing problem for the environment worldwide and for the climate. When sludge is spread on farmland and land field, it introduces environmentally harmful substances into nature's cycle, which affects the environment, food, and groundwater. AquaGreen's solutions remove the environmentally harmful substances and preserve the phosphorus, which is a vital nutrient in agricultural soil and a resource that the world is running out of.
The sewage sludge, that remains after wastewater treatment in municipal wastewater treatment plants, contains greenhouse gases, PFAS, microplastics, pharmaceutical residues, tar substances, and several other environmentally and climate-damaging substances. But now it has been proven that AquaGreen's HECLA® technology can convert the sewage sludge into a sought-after environmentally friendly resource.
AquaGreen is currently focusing on the wastewater treatment industry, but the HECLA® technology is a technological solution that can be applied across many industries.
From sludge to biochar - facts about the technology
AquaGreen's innovative HECLA® technology is based on an integrated steam dryer and a pyrolysis oven. Sewage sludge is steam-dried, causing the water to evaporate, and the remaining biomass is subsequently pyrolysed in the oven at 650°C under oxygen-free conditions. The biomass is converted into biochar, where the amount of unwanted environmentally harmful substances is significantly reduced. In the process, nutrients and minerals such as phosphorus, which are essential for plants, animals, and humans, are preserved. At the same time, the process significantly reduces CO₂ emissions. Firstly, by preventing the sludge from dissolving and releasing climate-damaging greenhouse gases, and secondly, by binding CO₂ in the biochar.
The process is self-sufficient and circular since gases released during pyrolysis, fuels both the pyrolysis- and the steam drying process. Excess steam is condensed into hot water, which can be used, among other things, in district heating grids.
The technology has been developed in collaboration with the Technical University of Denmark (DTU), Odsherred Forsyning, and VandCenter Syd.
Information
- Location: Denmark
Attached link
https://www.youtube.com-nocookie/embed/oUXeyV7ixnATaxonomy
- Nutrients Recovery
- Nutrient Recovery & Reuse
- Biochar