Ferme du Faascht: a symbol of agricultural innovation supported by LIST

Set in the heart of the Greater Region, Ferme du Faascht stands as a symbol of agricultural innovation and environmental sustainability. As part of the Persephone European research project, the Luxembourg Institute of Science and Technology (LIST) has been looking to increase the synergy between farming and biomethanization at this farm, which inaugurated its horticultural greenhouse and biomethanization site on 25 August 2023.

LIST researchers have concentrated their efforts on designing a demonstrator that aims to transform carbon dioxide (CO2) contained in biogas into biomethane (CH4) using a natural and innovative process known as biological methanation. The Institute has filed a patent on this technology.

Storage and flexibilisation of green electricity

The transition to a low-carbon economy relies heavily on the increased use of renewable energy sources, such as wind and solar photovoltaic power. However, the intermittent production of these energy sources poses a major challenge to the stability of the electricity grid. By seeking to integrate a biological methanation process into its infrastructure, Ferme du Faascht is demonstrating its commitment to converting peak renewable electricity production into biomethane, a safe and controlled form of energy with a wide distribution network. To achieve this objective, the farm plans to install a water electrolyser to convert excess electricity into hydrogen, which will be mixed with biogas to be converted into methane (using a biological reactor), developed by LIST researchers. The excess biomethane thus produced will enable the Farm to reduce the consumption of organic inputs in its digesters, while recovering large quantities of CO2 that would otherwise be released into the atmosphere.

The Persephone project has also shown that biomethanization units can play an essential role in making green electricity storage more flexible. In fact, by injecting 'electrically' produced biomethane into the natural gas network, such units would make it possible to exploit an energy storage capacity equivalent to 3 to 4 months of the European Union's electricity consumption. The process of converting carbon dioxide into biomethane developed at LIST therefore offers an innovative solution for making renewable energy more reliable and adaptable to electricity needs. This storage capacity, equivalent to several months' electricity consumption, is a major step towards a sustainable and resilient energy future.

Sébastien Lemaigre, an engineer in LIST's Environmental Research & Innovation department, said:

"This innovative storage model opens up new prospects for integrating and optimising renewable energies in the energy mix, thereby strengthening the transition to a low-carbon economy while guaranteeing the reliability of the energy supply. Ferme du Faascht embodies the successful convergence between renewable energies and technological advances, notably supported by the research teams of LIST".

Digestate fractionation and refining

The project also aimed to revolutionise the fractioning and refining of digestate, an organic residue from the methanization process, using innovative approaches such as solid-liquid phase separation, membrane techniques including nanofiltration and reverse osmosis, and vacuum evaporation. These methods have resulted in a diverse range of new products like compost, litter and formulated fertilisers with high nutrient and humus content, meeting the varied needs of modern agriculture. LIST has submitted a patent for the development of these models.

One of the major stages of the project was the implementation of solid-liquid phase separation techniques, combining the advantages of nanofiltration and reverse osmosis. These methods have enabled valuable components of the digestate, such as nutrients and humic substances, to be recovered efficiently, while reducing the amount of solid residue.

The PERSEPHONE project has laid the foundations for circular and sustainable agriculture in the heart of the Greater Region, including the production of bioenergy. This collaboration between LIST and other project partners has paved the way for a more efficient use of agricultural resources while promoting the transition to environmentally friendly practices.

Under the JUMP funding programme of the Luxembourg National Research Fund (FNR), LIST is continuing its research by exploring the commercial potential of the biological methanation demonstrator developed as part of the Persephone project. The aim of this demonstrator is to produce more biomethane from renewable electricity.