In March 2021, GRDF launched a call for projects on Optimising the methanation process.

For two months, candidate companies submitted proposals involving innovative technologies to improve methanation performance. After an initial selection stage, the panel convened on 30th June for discussions with the chosen candidates, and then to select the projects deemed most promising.

Context of the Call for Projects

Methanization is a biological process that produces renewable gas via the decomposition of organic material. As a central component of the circular economy, it plays a major role in decarbonising the activities of the gas distribution sector. The injection of biomethane actually redirects the flows of carbon generated by the decomposition of organic waste and biomass to gas applications, as a substitute for fossil gas. Today, nearly 300 injection sites are operating in France, with an annual growth rate of more than 70% for the last four years. Methanation also produces digestate, a fertiliser and organic amendment to be spread over fields.

Crédit photo : © Stéphane Compoin

The Law has set a target of 10% renewable gases in 2030, meaning around 40 TWh to be produced almost entirely by methanation. The sector is currently growing thanks to government support and is pursuing its cost-reduction efforts alongside the greening of the gas mix.

The most widespread methaniser technology is wet process methanation with continuous mixing. The biomass is shredded and then sent into a heated concrete tank called a digester, where it is mixed by agitators.

This technology has room for improvement, and new processes are emerging. Identifying and developing such innovations is the goal of the “Optimising the methanation process” call for projects. Candidates were invited to propose disruptive improvements with the potential to optimise biomethane production.


The call for projects closed on 31 May 2021. 16 companies (of which 14 were French, one Irish, and one Norwegian) submitted proposals. Seven finalists met GRDF’s panel of experts, and three winners were chosen. The jury noted the high quality of all the submissions and the diversity of the projects, and finally agreed on three especially promising technologies.

Third place goes to EASYMETHA. Its dry process methanation technology offers a low-tech and low-cost solution for small operations, which currently produce the most expensive biomethane. It requires no pre-treatment of the materials or any mixing, and needs very little water. The digestate has the consistency of manure in a dry process, and moves along in a semi-buried concrete tunnel. The unsophisticated but clever design generates a major cost reduction whilst maintaining biomethane production similar to a classic methaniser for the same inputs.

The runner-up is Irish company ASHLEIGH ENVIRONMENTAL. Its BIOWAVE technology uses microwaves to break down the long-chain fatty acids in the waste water, releasing their energetic potential. By cutting these large molecules into smaller molecules that can be degraded by methanation, BIOWAVE allows a significant increase in biogas production and a decrease in water treatment costs. Preliminary data suggest that comparable results could be obtained with agricultural inputs.

Finally, the winner of this call for projects is Norwegian company ANTEC BIOGAS. ANTEC is developing a high-performance methanation technology inspired by the digestive system of the cow. This innovation can extract the energy from the biomass in seven days instead of the usual forty in a standard methaniser, so that a smaller installation can provide the same processing capacity. The process takes place in mass-produced glass fibre tanks requiring very little maintenance. The capacity of the site can be increased easily by using several tanks in parallel.

In this way, ANTEC is paving the way for a more mature methanation process, with high-performance mass-produced modular installations. The company has several customers in Norway and wishes to set up operations in France.

GRDF will support the three winners so that they can pass on their technological advances to the project initiators. These three projects will give additional impetus to the development of methanation in France and help us work towards the use of an ever greener gas mix.