Biogas plant, Iowa, USA

The biogas plant in Iowa, USA, will use chicken manure from nearby poultry farms as a raw material, in an amount of up to 150,000 tons per year. The final product is biomethane, which will be injected into the local natural gas network. In addition, granular and liquid fertilizer products will be produced, as well as CO₂ capture and liquefaction will be implemented. The plant will be built in close proximity to a high-quality liquid ammonium fertilizer production plant, creating synergy with the existing industrial infrastructure. The project has been designed with future development opportunities in mind.

The station project consists of more than 20 different engineering structures and buildings. They include:

• Four receiving tanks with water connection and mechanical stirring, which ensure the supply of homogeneous raw material for the fermentation process. The tanks are equipped with suction equipment and a biological filter for odor and emission treatment.
• Eight fermentation tanks equipped with mechanical stirrers and a heating circuit for efficient biogas production. The tanks are covered with a double membrane system for gas collection and discharge, safety valves and process control sensors. Custom-designed doors are provided for tank maintenance, providing access for heavy machinery for efficient cleaning.
• Biological pre-treatment station for the removal of sulfur and ammonia from biogas.
• A biogas production building that will integrate biomethane production technology and a raw material processing line. The biogas will be purified to biomethane and fed into the local natural gas network. The raw material processing line includes separation, drying and granulation, ensuring the production of green and high-quality granular fertilizer.
• Four post-fermentation tanks, where the separated digestate is stored. The tanks are equipped with a gas capture system to increase the efficiency of the process.
• A CO₂ capture and liquefaction station that will ensure the capture and preparation of 17,000 tons of CO₂ for further use or sale.

The plant will process 150,000 tons of chicken manure per year and produce:

• ~135 GWh of biomethane;
• 45,000 tons of granular fertilizer;
• 55,000 tons of fertilizer concentrate;
• 16,000 tons of liquid fertilizer production (ammonia water);
• 17,000 tons of CO₂.