Home News Combating PFAS and utilizing phosphorus with pyrolysis

Combating PFAS and utilizing phosphorus with pyrolysis

by Linda Bertelsen

PRESS RELEASE | 05.03.2024 |

Excess sludge from wastewater treatment and digestate from biogas production is utilized as fertilizer in farming due to its high phosphorus content. However, this type of sludge may contain harmful PFAS.

For this reason, the Danish district heating company DIN Forsyning recently decided to combat this issue by establishing a large-scale pyrolysis plant with a local partner, Dall Energy. With this solution, they aspire to achieve 16,500 tons in CO2 reductions and produce 8,000 tons of biofertilizer annually.

Any biofertilizer produced from the pyrolysis plant will be CO2-negative and contribute to the neutrality of CO2 emissions. Phosphorus and potassium, valuable nutrients for crops on farmland, are preserved in the biofertilizer and will be available for the crops. The pyrolysis plant is highly flexible and able to regulate between output heat and the desired carbon content in the biofertilizer.

Project Manager and Business Developer Kim Stenholdt Madsen from DIN Forsyning explains:
“Pyrolysis, sludge is heated to 650°C, followed by combustion of the pyrolysis gases at over 1,000°C. Studies have shown that compounds such as PFAS break down under intense heating. Furthermore, we preserve the sludge’s important phosphorus content. The residue after sludge pyrolysis is biofertilizer. The biofertilizer binds carbon from the sludge instead of emitting it as CO2. So, we also expect that CO2 emissions from our wastewater sludge could be reduced by up to 16,500 tons a year, which is quite significant”.

Dall Energy MD, Jens Dall Bentzen adds:
“We have developed a technology that converts waste streams into energy and other useful products. This solution for the DIN Forsyning plant is an excellent example of how we can turn waste-water sludge into an environmentally friendly and efficient solution for agriculture. Credit to DIN Forsyning for being forward-looking and for embracing the value of pyrolysis technology. A technology with enormous potential – not only in terms of wastewater sludge but also for CCS and the utilization of excess fibers from biogas production”.

Jens Bentzen and the Project Manager from DIN Forsyning, Kim Madsen, are both available for interview and further comment.