Synthetic methane: Teréga working today for the future of gas

We are working to encourage acceleration of the development of synthetic methane, making it compatible with injection into grids. In addition to being renewable, this new gas comes from a production method that helps fight greenhouse gas emissions. In fact, it comes from a methanation process that enables the recycling of CO₂ from other processes, such as methanisation, transforming it into methane by adding renewably sourced H₂. This means that methanation allows the energy production efficiency of a methanisation plant to be doubled, reducing its greenhouse gas emissions at the same time.

That is why we are very actively involved in collaborative projects aimed at the production of synthetic methane by different methanation processes on an experimental scale, but also on an industrial scale. It is our desire to encourage the development of the methanation sector to increase the attractiveness of the renewable gas sector. Laboratory-based collaborative projects:

• METHAMAG

• MARS

• SOLARVI

Our industrial and pre-industrial scale projects with the support of the Occitanie Region:

• Jupiter 1000

• CO₂Meth

• DEMETHA

• the SOLIDIA platform

While these two processes have the same aim – to produce methane – they do it under different conditions.

This means that synthetic methane can be obtained by applying a chemical or biological process – methanation – so that hydrogen can be converted into methane, by reaction with CO or CO₂. At the moment, methanation is mainly associated with two energy production routes:

• Pyro-gasification

This consists in heating waste to a high temperature in a low-oxygen environment. The first stage – pyrolysis – breaks the material down into 3 phases (solid, liquid and gas), then the second stage – gasification – transforms the solid and liquid phases into synthetic gas.

In the pyro-gasification process, nearly all the waste can be converted into synthetic methane. Growth of the sector should be boosted by support mechanisms and the emergence of demonstrators. The Ademe (French environmental and energy management agency) estimates that in 2050 potential synthetic methane production by pyro-gasification could be 250 TWh.

• Power-to-Gas

Its aim is to transform electricity into gas so that it can be stored. First of all, excess electricity from renewable sources (wind, solar etc.) is transformed into hydrogen (Power-to-H₂) by electrolysis of water. Then comes methanation: the hydrogen is combined with CO₂ to produce synthetic methane (Power-to-CH₄).

The Power-to-Gas sector therefore plans both to recycle CO₂ (emitted in the production of biomethane, for example) and to solve the problems of modularity, high fluctuations and storage of electricity, when production exceeds consumption. It can be a way to harness excess electricity, by transforming it into gas, which can thus be injected into our gas infrastructures and stored if necessary. Methanation is therefore an essential component in the construction of multi-energy networks.

Synthetic methane is remarkable for its ability to act as a link between different energy networks. Power-to-Gas, for example, allows integration and synergy between electricity and gas networks. CO₂ is recycled, and hydrogen created from surplus unstorable electricity is used. The methanation process therefore occupies a central place in multi-energy systems, allowing different energy networks to be planned and managed together to ensure they complement one another, providing efficiency and avoiding waste. At Teréga, we are conducting industrial-scale experiments in methanation to develop this technology and integrate it as effectively as possible into the multi-energy model:

Jupiter 1000

Convinced of methanation’s place in future energy systems, we have been involved alongside GRTgaz in the Jupiter 1000 project: the first French industrial Power-to-Gas demonstrator. Located in Fos-sur-Mer, its aim is to help determine the shape of this new sector. This is happening through:

• the development of the technologies involved;

• the construction of the associated economic and regulatory models;

• the overcoming of technical limitations that currently exist.

CO2METH

We are participating in the large scale development of biological methanation, an essential technological tool. Through the CO₂METH project, we are studying the technical and economic feasibility of the process, building on its integration into a multi-energy system. In time, this project is expected to become the largest European demonstrator of biological methanation. Located close to the future TotalEnenergies methanisation site in the industrial area at Lacq (Pyrénées-Atlantiques), the project will thus benefit from a source of CO₂. Meanwhile, the green hydrogen will be produced by electrolysis of water. The synthetic methane thus produced could then be injected into the Teréga grid.

This project is part of a broader process led by Teréga to construct the multi-energy grid of tomorrow, for a new and more effective management of energy storage, transport, production and consumption resources. Our innovation process has thus led us to launch the IMPULSE 2025 project in collaboration with scientific experts (University of Pau and the Pays de l’Adour, the Federal Polytechnic School of Lausanne). This is dedicated to the design and construction of a multi-energy system demonstrator, due to come into service in 2025.