Renewable gases and the circular economy

Renewable gases offer a response to real-life economic and environmental challenges. They contribute to waste recovery, decarbonizing industry and transport, job creation, and generating extra income for farmers.
Bretagne Sud network - October 2019

Renewable gases:
a new energy
for the twenty-first century

Renewable gases are a multi-source energy that can come from:

  • agriculture,
  • the agri-food industry,
  • mass catering,
  • the collection of household waste or organic waste,
  • the collection of waste wood,
  • water treatment plants,
  • non-hazardous waste storage facilities.  

The different production techniques mean that these types of waste and materials become a recoverable, virtuous resource for reducing our ecological footprint. Some non-recyclable waste such as solid recovered fuel can even be used to produce low-carbon gas, removing the need for incineration or landfill.  

Renewable and low-carbon gases support the growth of the circular economy, which aims to restrict wastage and create local value by recycling previously used materials.

Renewable gases:
diversified sectors

Anaerobic digestion involves processing organic materials from various sectors including agriculture, manufacturing, catering waste, community waste, etc. Fermenting this material in the absence of oxygen (i.e. “anaerobically”) produces biogas, which, once purified, becomes biomethane. 

This anaerobic digestion process creates residues known as “digestates”. These can be used as effective, organic crop fertilizers. And renewable gases benefit alongside the earth. 

With 514 injection sites in the French natural gas distribution and transmission network, biomethane plays a role in the decarbonization of the French economy. These sites have a production capacity of 6.4 TWh/year in local, renewable gas: enough to fuel 325,000 households or power 13,000 bioNGV buses. Of these, 58 biomethane production sites are connected to the GRTgaz network.

From anaerobic digestion to injection: key steps
Source: 2019 Renewable Gas Panorama/ GRDF

From methanisation to injection: key steps

Pyrogasification takes solid renewable and non-renewable residues that are poorly recovered or non-recovered (e.g. biomass residues, tyres, plastics, etc.) and transforms them into gas for injection into the network by heating them to extremely high temperatures (between 800 and 1,500°C) with little or no oxygen. This emerging sector is structured to produce low-carbon energy on a local scale. The first industrial units are scheduled for launch in 2023. GRTgaz also supports the Titan V, Synthane, Plainergie and Cométha demonstrators in researching pyrogasification’s potential as a residual waste recovery solution supporting public policies aimed at reducing waste and increasing recycling.

Pyrogasification for the injection of gas into the networks
Source: 2020 Renewable Gas Panorama/ GRTgaz

The pyrogasification process

>> Launch of a Call for Expression of Interest (CEI) relating to pyrogasification for injection into the gas network

>> Replay of the pyrogasification conference : 21 October 2021 - french version

>> Pyrogasification projects for CH4/H2 injection in France (ODRÉ website)

 Hydrothermal gasification involves heating effluents and wet biomass residues at high pressure (200 to 300 bars) and high temperatures (400 to 700°C) to produce a carbon-based renewable gas that is rich in methane. The process offers a renewable gas conversion solution to a wide range of urban and suburban business, as well as local authorities and even waste processing operators. The first industrial hydrothermal gasification facilities are planned to be in place by 2025.

The hydrothermal gasification process
Source: 2019 Renewable Gas Panorama/ GRTgaz

The hydrothermal gasification process

White Paper Hydrothermal Gasification

Livre blanc gazéification hydrothermale et vue aérienne du site d’Alkmaar de SCW Systems (source :

>> White Paper Hydrothermal Gasification acces form

Hydrogen: a catalyst for the energy transition

As for other renewable and low-carbon gas sectors (anaerobic digestion, pyrogasification, hydrothermal gasification), hydrogen has a key role to play in reaching the goal of zero carbon emissions in an affordable way. Renewable and low-carbon hydrogen can replace the fossil fuels used in some carbon-intensive industrial processes, in particular in the chemicals and steel sectors, as well as in refineries. Hydrogen can also be used as an energy carrier for a wide range of mobility uses, in particular HGVs, public transport, or even rail travel. Furthermore, with the growth of variable renewable energy in Europe, Power to Gas technology will make hydrogen a solution for the mass integration of renewable energies by connecting the various hydrogen, electricity and gas networks. 

Different methods for producing renewable and low-carbon hydrogen are either being researched or under development. Power to Gas technology is already able to transform surplus intermittent renewable electrical energy into hydrogen for injection into the networks. Jupiter 1000, an industrial Power to Gas demonstrator located in Fos-sur-Mer and overseen by GRTgaz, aims to test the viability of this process. Other means of producing hydrogen also exist, e.g. from the pyrogasification of waste and biomass, or by natural gas reforming with carbon capture and storage.

Beyond production, the transmission of hydrogen is a major challenge for developing its uses. 
GRTgaz is sure that hydrogen’s future depends to a large extent of the availability of an infrastructure that can transport and store large quantities, while connecting production and consumption sites at local, national and European scales. GRTgaz is also certain that changes to the existing gas network will allow for the development of a profitable hydrogen network. The company is working to develop a network specifically for the transmission of hydrogen in France. This will mainly involve the conversion of existing pipelines while maintaining the transmission of natural gas, which will gradually be phased out in favour of biomethane. 

At the European level, gas infrastructure operators are working together to develop hydrogen in line with the EU’s strategy for a climate-neutral Europe. In July 2020, GRTgaz and ten other gas infrastructure managers presented their vision for a European “hydrogen backbone”: a potential 6,800 km network by 2030. GRTgaz’s Hy-Fen project (1.200 km of pipeline between Fos-Marseille and the Grand-Est region) is France’s first domestic step towards this goal. Hy-Fen will connect geographically distant production and consumption sites while guaranteeing the security of transmission, with consumers able to choose their hydrogen provider from a range of competing sources. 

Another of GRTgaz’s projects is the mosaHYc (Moselle Sarre HYdrogène Conversion) project in partnership with CREOS. The aim is to convert two existing gas pipelines to 100% hydrogen transmission, connecting Völklingen, Perl (Sarre), Bouzonville and Carling (Moselle) over a distance of 70 km. This project between the two gas transmission operators will support the development of a regional, cross-border hydrogen ecosystem spanning three countries.

R&D: a powerful driver for renewable gases 

GRTgaz’s Research and Innovation Center for Energy (RICE) places it at the forefront of renewable gas innovations. Its teams of around 100 researchers and two research centres are focussing their efforts on the energy transition. RICE is carrying out the following hydrogen-centred projects:

  • FenHYx, an open R&D platform to assess the performance of network materials and equipment in the presence of hydrogen,
  • A partnership with Ontras, a German gas transmission network manager. The agreement between Ontras and GRTgaz is centred on sharing knowledge and research on the transmission and mixing of hydrogen and natural gas in their networks. The collaboration supports the deployment of hydrogen and new decarbonized gases and is based around two projects: developing a technology for separating natural gas and hydrogen, and hydrogen leak testing the natural gas network equipment.

New opportunities, new jobs

Fluctuations in the price of raw materials, variable consumption habits, climate risks... farmers' incomes are far from certain. Renewable gas allows them to play a role in the energy transition and presents new opportunities with anaerobic digestion and the recovery of materials produced by farming.
For farmers, this type of project involves either an agricultural anaerobic digestion unit (so-called "farm-level" units), which can be either individual or group-owned by several farms, or a anaerobic digestion unit operated by a mixed collective.

Renewable gases are also a chance to create jobs that cannot be outsourced. The boom in renewable gas sectors increases the need for manpower and new skills. For anaerobic digestion, development opportunities over the coming decade will create thousands of jobs near to French production sites, including engineers, financial and administrative assembly specialists, workers and technicians. Four thousand jobs were already identified in the sector in 2019 (sources: Transitions 2019 and 2019 Renewable Gas Panorama).

Decarbonized uses

Renewable gas is taking over from fossil fuels in industrial production processes. The chemical, refineries, electronics and agri-food sectors all make use of biogas.

When it comes to mobility, GRTgaz is developing the fuelling system for vehicles using NGV (Natural Gas for Vehicles) – a fuel that contributes to reducing greenhouse gases (- 25% and -10% of CO2 compared with petrol and diesel, respectively). NGV from biomethane (bioNGV) is 100% renewable. By allowing economically viable stations to connect to the transmission network, the French Mobilities Framework Law (Loi d’Orientation des Mobilités, or LOM) enables new projects to connect to the GRTgaz network. At end-December 2019, 162 NGV/bioNGV fuelling sites were already connected in France. NGV has also emerged as an alternative for marine fuel. 

Taking all sectors together, 7 billion euros will be invested in France between 2020-2030 as part of the national strategy to develop decarbonized hydrogen, in connection with the economic stimulus package.



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