News

The biogas plant in Estonia designed by AAT is on its final construction stage and will start producing energy in the summer of 2026. Location: Tahula village, Saaremaa municipality, Estonia. The biogas plant is the biggest biogas plant in the Baltics so far, it has two lines with 1 Mix tank, 3 Digesters and 1 Post Digester on each line. The plant is designed to process almost 800 tons per day of locally collected liquid and solid agricultural waste, namely cow and pig manure, feed rests, grass, flotation sludge, whey, etc. The produced biogas will be upgraded to biomethane. Technical data of the plant: - 6 digesters with 3,880 m³ volume each (Ø 26m x 8 m) - Biogas production: 1460 Nm³/h (or 880 Nm³/h biomethane equivalent) - Fertilizer production: 756 t/d

Construction of the biogas plant Olsztyn is proceeding and can be seen in the following photos. After finishing of the all tender procedures Olsztyn municipality together with nominated technology provider AAT started to build a biogas plant in November 2024. In this biogas plant 115 t/d of organic waste (mainly the separately collected food/kitchen) waste will arrive to the site and further will be prepared and digested. From the produced biogas the electricity will be generated with a power of up to 1MW. To provide more flexibility to the future biogas plant was decided to design and build 2 independent lines with digester, post digester and final storage on each line. The biogas plant will be equipped with a most innovative and efficient equipment for the waste treatment and fermentation from the well-known European manufactures. Technical data of the plant: - 2 digesters with 4,000 m³ volume each (Ø 22m x 6 m) - Biogas production: 408 Nm³/h - Capacity generation electrical energy: 1MW - Energy generated: 8760 MWh/a - Capacity generation thermal energy: 1MW - Thermal energy generated: 8760 MWh/a - Fertilizer production: 105t/d

The Al Warsan waste water treatment plant has been upgraded by AAT with two modern double membrane gas storages and a specially designed control cabinet in a container so that the system can operate with different input pressures and works in extreme weather conditions. Project data: 2x gas storages with 4000m³ volume each Gas flow 2545 m³/h Operating pressure 13/20 mbar AAT scope of supply: Implementation planning Double membrane (Type V) gas storages with all needed connections Control room in protection container Support air and ventilation blowers (ATEX Zone I) Gas sensors, gas analysis Gas valves and axial compensators

The Zapresic wastewater treatment plant was reconstructed and upgraded. AAT delivered design, supply of equipment, start-up and operation support. Project data: 2x digesters with 1.600m³ volume each 1x gas storage 940m³ AAT scope of supply: vertical agitators digester equipment gas storage gravel filter, activated carbon filters, condensate trap gas sensors, gas analysis gas blower, emergency flare

New digestate storage tanks will be built for the biogas plant Recycling Energie AG in Nesselnbach, Switzerland. Four tanks with each 6200 m³ are needed for the storage of digestate during the winter. Digestate as high quality fertilizer is spread on nearby fields during the rest of the year. AAT is responsible for engineering, equipment and start-up of the plant. Technical data of the plant: - 90,000 t/a digestate - 4 CSTR final storage tanks with each 6,200 m³ volume - Biogas upgrading with CNG-filling station and combined CO 2 -liquefaction - Start-up scheduled: end of 2025

Soon the year is coming to an end and we want to take this opportunity to thank you for your confidence in us and for the convenient co-operation. The team of AAT wishes you and your families some peaceful and joyous holidays and a good start into the new year 2025! This year we support the charity „Netz für Kinder (net for children)“.

 The new AAT emergency flare for the Sappi pulp mill at the Gratkorn plant in Austria has been in operation since September 2024. We are pleased about the many years of successful cooperation. Project data: - Flare for 600 m³/h gas flow - Thermal power 5,100 kW - LOGO control system - with pilot burner - Winter package with insulation and trace heating - gravel filter included in AAT scope of supply

Energy recovery from industrial wastewater AAT is taking part in the EU research project SYMSITES which is about circular economy and energetic utilisation of industrial wastewater. AAT built a hydraulic digester in pilot scale for the Austrian Ecosite. Project data: - Commissioning: 2023 - Substrates: flotation sludge, membrane retentate and slaughterhouse waste - Daily wastewater input: 4 m³ - Daily gas production: 6.6 m³ This pilot plant was specifically developed and built for an industrial company to take wastewater treatment to a new level. The pilot plant at a glance: - A 20-foot container houses the control system, the buffer tank, the pump technology, the gas technology and the centrepiece of the plant: a hydraulic digester with a capacity of 2.8 m³. - A 10-foot container serves as a gas storage. The energetic utilisation of industrial wastewater is not only an important step towards sustainability and environmental protection, but offers also valuable perception for the future of wastewater treatment. Related Links SYMSITES project website

The waste water treatment plant in Nemetin, Croatia has been expanded  AAT designed and delivered the gas line consisting of: gravel filter, gas cooling, gas warming, active carbon filter for the reduction of siloxanes and hydrogen sulphides as well as pressure boosters, a double-membrane-gas storage the emergency flare and agitators. This increases the service life of the CHP units for power generation and the operation reliability of the plant. Design data: - Gas cooling and warming Quantity: 200 Nm³/h - Active carbon filter: Quantity: 2x 200 Nm³/h Gas purification of the hydrogen sulphides to < 5 ppm H2S and siloxanes to < 2,0 mg/m³ - Double membrane gas storage: Nominal volume: 1.530 m³ - Gas emergency flare: Quantity: max. 250 m³/h