Biomethane plant in France. Pic credit WELTEC
Biomethane plant. Pic credit WELTEC
70 standard m³ per hour of biomethane is now supplied to the natural gas grid of the French gas distributor GrDF. Pic credit: WELTEC

Earlier this month, the Longchamps biomethane plant in the Franche-Comté region in eastern France went live and is now supplying biogas to the country’s natural gas grid.

Through the biomethane plant, 70 standard m³ per hour of biogas is now supplied to the natural gas grid of the French gas distributor GrDF (Gaz réseau Distribution France).

Biomethane membrane technology

To ensure the plant’s biogas processing effectiveness, German plant manufacturer WELTEC deployed flexible, compact membrane technology for the biomethane plant.

In the three-stage separation procedure, methane is separated from carbon dioxide (CO2), water vapour and other components with the help of special polymer membranes.

According to the company, this membrane procedure is highly efficient and delivers a methane yield of about 99%.

The upstream compression is another advantage of the procedure. In this way, the separated methane already has the needed pressure for feed-in to the natural gas grid without being compressed again.

Saving biomethane process costs

This method saves costs by eliminating the need for an additional compressor and enables economic use of biogas processing even for smaller biomethane plants.

In addition, costs are saved as the molecules are separated at ambient temperature and without the need to add chemicals.

This membrane technology stands out with its compact setup in the container, reducing the installation overhead, stated the company.

To optimise the plant synchronisation, a custom-developed LoMOS SPS control was integrated with the system.

One of the special features of this system is an SQL database-based task management. This enables the user to enter individual tasks for the biogas plant in the calendar, after which the LoMOS control automatically executes the entries.

Biomethane potential in France

France’s agricultural sector has a wealth of raw and waste materials that are suitable for biogas plants. However, only half of the available materials are presently used for energy production.

Thus, ambitious development plans have been drawn up by government stating that by 2020, the biomass share in the field of renewable energies in France is to increase by 50%.

The Longchamps biomethane plant operator, David Peterschmitt, uses about 6,000 tons of agricultural leftovers a year for the production of biogas from anaerobic digestion.

With reference to the user-interface, Peterschmitt said: “I am convinced that the technologies employed […] will ensure optimum efficiency as well as permanently stable, economic operation of my biomethane plant.”