May 5, 2020

Adven is implementing a biogas plant in Hanko

Adven has successfully developed a solution for producing biogas from nitrogen-rich biomass. The planned biogas production will significantly reinforce circular economy in the Hanko area.

Adven is planning to build a biogas plant in Hanko, Finland. The feed for the plant is planned to consist of the side streams of the DuPont Nutrition & Biosciences plant in Hanko as well as of the industrial wastewater treatment plant, Hangon Puhdistamo Oy, and it will contribute to the circular economy in the area in many ways. Biogas is not only used as a fuel for gas-powered cars, it is also a source of heat and electricity. In Hanko, the thermal energy from the biogas will be fed into Hanko’s district heating network, which is owned by Adven, and will cover roughly 20 per cent of the network’s heating needs. The green electricity generated will be used locally at the site.

In addition to biogas, the plant will produce solid soil-improvement materials and liquid nitrogen fertilizer for agriculture. A closed water cycle solution is also being implemented at the biogas plant. Feed for the biogas plant contains a high volume of water, which can be extracted and purified into clean water for reuse in Hangon Puhdistamo Oy’s process, thereby also reducing the water consumption of the wastewater treatment plant.

“Our main raw materials in the fermentation process are from agriculture. The nutrients we use in our process are similar to the ones used in fertilizers in agriculture. One can envision a big picture where we receive raw materials from agriculture, use our process to produce enzymes and then supply the organic side streams into Adven’s biogas plant to be turned into energy – and nutrient rich soil. It’s an appealing concept to produce enzymes that e.g. enable us to wash our clothes at 20˚C, thus saving energy, and at the same time be able to locally convert the side streams to energy and soil – which can then be used again in agriculture where our main raw materials come from”, says Stefan Ekbom, Plant Manager at the DuPont Nutrition & Biosciences plant in Hanko.

“We succeeded in producing biogas from nitrogen-rich sludge thanks to a long piloting stage – after many trials, we found a combination of methods that finally led to this solution,” says Adven’s Sales Manager Hanna Litendahl.

Biogas plant will not affect day-to-day life in Hanko

The compact biogas plant will not cause any odour problems in the area as the biogas production process will also take place in an entirely enclosed space. Odorous gases will be collected and directed to a dedicated processing unit. Even the feed will be transported to the biogas plant in a closed pipeline.

“Previously, biogas plants were able to process the nitrogen-rich feed only by mixing it with other streams, thereby reducing the overall nitrogen content in the feedstock. This meant transporting the biomass sometimes even for long distances. Now we can process the biomass where it is available and transportation is not needed,” says Litendahl.

Adven has received EUR 2.5 million in renewable energy support from the Ministry of Economic Affairs and Employment for its investment in the biogas construction project. The biogas plant is planned to start up operations in 2023. An environmental impact assessment (EIA) on the plant began in March 2020. Once completed, the biogas plant will be operated and controlled remotely by Adven.

How will biogas production work in Hanko?

1. Adven will receive the raw materials, organic side streams from enzyme production and wastewater treatment plant, via a pipeline.

2. Adven will produce approx. 15,000 megawatt hours’ worth of biogas from the nitrogen-rich feedstock.

3. Electricity and heat will be generated from the biogas using gas engine.

4. The electricity will be used by, e.g., Adven’s energy plant. In the future, it will also bepossible to use the biogas in vehicles.

5. Thermal energy will be fed into Hanko’s district heating network and will cover roughly 20 per cent of the network’s heating needs.

6. After the production of biogas, the digestates will be used to produce solid soil-improvement materials and liquid nitrogen fertilizer for agriculture.

7. Along with the feed, high volumes of water will be directed to the biogas plant, and most of it will be cleaned using the same technology as is used for producing potable water. The purified water is planned to be reused at Hangon Puhdistamo Oy, and the closed solution will reduce the clean water consumption of the wastewater treatment plant.

Additional information:

Adven: Sales Manager Hanna Litendahl,, tel. +358 50 464 4629

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