HoSt’s manure biogas plant in Marrum (NL) upgraded with nitrogen stripper

2 April 2024
A nitrogen stripper system will be integrated at HoSt's own biogas plant in Marrum. This upgrade will result in improved sustainability and efficiency: the nitrogen stripper allows the anaerobic digestion of manure streams with higher nitrogen content, including chicken manure. The nitrogen stripper will produce a sustainable nitrogen-based fertilizer (called RENURE) from the digested manure. The biogas plant is a mono-manure digester and has successfully been producing biogas and biomethane from manure since 2019, and is now expanding with a nitrogen stripper.
HoSt biogas plant - organic residues and manure - Marrum, Netherlands

Nitrogen stripper after anaerobic digestion

The nitrogen stripper allows for the anaerobic digestion of manure streams with higher nitrogen content. Simultaneously, the technology enables different types of manure compositions, including chicken manure, enhancing the biogas production. After the anaerobic digestion, the digestate is divided into a thick and thin fraction. The nitrogen stripper can largely denitrogenize – to reduce the nitrogen – the thin digestate fraction, up to about 6 m3 per hour. The technology removes ammonium from the thin fraction and converts the stripped ammonium into a sustainable fertilizer, RENURE. By feeding the thin fraction without ammonium back into the digester, the nitrogen concentration in the digester tank can be lowered while enabling different types of manure compositions.

The technology comes in a plug-and-play system and is placed after the digester. At the biogas plant in Marrum, the technology will be built completely indoors. Optimal synchronization between the mono-manure digester and the nitrogen stripper can result in an impressive amount of stripped nitrogen annually.

Subsidy Waddenfonds

Biogas Marrum received together with van Hall Larenstein and Biosintrum a subsidy from the ‘Waddenfonds’ as the project contributes to the Waddenfond’s main objective of sustainable economic development in the Wadden Region and a transition to sustainable energy management and circular farming. The subsidy supports R&D work related to the nitrogen stripper and supports the demonstration of the nitrogen stripping to process (local) manure surpluses, resulting in a sustainable fertilizer that offers a viable alternative to fossil fertilizers in the Wadden region in the Netherlands. This development is especially of great interest, as the use of RENURE by the agricultural sector as a fertilizer without an animal manure status is currently being legalized by the European Commission.

Nitrogen stripper at Marrum - manure biogas plant - HoSt Group

Sustainable energy from manure

Combining a mono-manure digester and nitrogen stripper has many advantages regarding sustainability, cost efficiency, and emission reduction. The facilitated biogas production combined with the impressive amount of nitrogen stripped annually, make this development a valuable investment for biogas plant owners.