HoSt constructing innovative large-scale agricultural biomethane-to-grid plant in Noyal-Chatillon, France

HoSt is constructing an innovative large-scale agricultural biomethane-to-grid plant at a cattle farm in Noyal-Chatillon near Rennes, France. Innovative features to enhance energy and maintenance efficiency that result in maximum performance characterize this installation. HoSt is the one-stop supplier for this turnkey project of which completion is planned in November of this year.

HoSt biogas plants are known for its patented insulated double membrane roofs. At this project at cattle farm ‘Castelmetha’ the digestion tanks are equipped with double insulated double membrane roofs. Due to the special design of the insulated roofs maximal heat retention and minimal odor spread is ensured. Together with an advanced heat recovery system and extra tank insulation this results in maximum energy efficiency. An external heat exchange system is used, instead of an internal heat system, to enhance maintenance efficiency.

For optimal feedstock particle size, the solid feeder fuel system is equipped with a double incorporation screw. In addition, the integrated HoSt Ruminator System recirculates feedstock from the digester, grinds the feedstock and feeds it back into the digester. This process prevents floating layers formation of biomass and creates the most ideal anaerobic digestion process for an optimal biogas production.

“This project is full of innovations which indicates that our technology is constantly developing to provide the most optimal installations with the best performance”, says commercial director Jean-Sebastien Tronc from HoSt France.


In the first phase, the biogas plant will produce 140 Nm3 biogas per hour from a maximum of 10,950 tonnes of cattle manure and maize silage per year. This is upgraded in the biomethane system using membrane separation technology to 75 Nm3 biomethane per hour, which is injected into the gas grid. Future plans are to extend the installation to 200 Nm3 biogas per hour and 110 Nm3 biomethane per hour. Thanks to the local available service and maintenance team of HoSt, 24/7 technically expert maintenance and spares service can be guaranteed.