SUBLIME Energie Wins EIC Accelerator Backing to Liquefy Biogas

A French farm that produces biogas has, as SUBLIME Energie's founders describe it, two ways to sell it: burn it in an engine for electricity and heat, or clean it up and inject it into the gas grid, which only works for farms close to a pipe. SUBLIME Energie, a 2019 spin-off of Mines Paris-PSL, proposes a third: liquefy the raw gas, methane and carbon dioxide together, in a tank beside the digester, collect the tank by truck once or twice a week, and separate the two gases at a shared hub into liquefied biomethane (bioLNG) for trucks and liquid bioCO2 for greenhouses and the food industry.

The EIC Accelerator selected the company at its March 2025 cut-off for blended finance. CORDIS records a grant agreement signed on 29 September 2025, worth €2,432,468 in EU contribution, running from 1 October 2025 to 30 September 2027. The project promises to commercialise the liquefaction technology and the hub model for small and remote farms without grid access. A year into it, the first farm unit exists; the commercial network does not yet.

Why biogas is hard to liquefy

Raw biogas is mostly methane and carbon dioxide. Cooled down, the CO2 freezes into dry ice before the methane turns liquid, which, the founders wrote in 2025, is why the two gases could not be liquefied together. In a 2021 interview with Techniques de l'Ingénieur, the founders described their answer: a third substance, a carrier agent whose name they withheld, which changes the mixture's phase behaviour so that it liquefies at about minus 100 °C and no more than 20 bar. At the hub, cryogenic distillation separates methane, CO2 and the carrier agent, which is recycled.

The process was developed at the energy and process research centre of Mines Paris-PSL. According to PSL, the first laboratory prototype was finished in March 2020, when Mines Paris-PSL and Armines filed the patent; the company later bought the patent back, and Armines contributed it to the 2023 funding round. The 2021 interview dates the patent filing to April 2020. A 2024 company presentation in Hydrocarbon Processing names a second patent, on the central purification step, and reports that a laboratory unit liquefied a 50/50 methane and CO2 mixture, with the CO2 freezing point about 4 °C lower than the model predicted.

The business model is a milk round for gas. According to the April 2026 reports, the company buys the raw biogas at the farm, so the farmer invests in no upgrading plant; the CORDIS summary adds that farmers keep ownership of their biogas. In a July 2025 opinion piece, Bruno Adhémar and the company's public affairs officer cited a study for the terminal operator Elengy finding that grid connection costs more than €100,000 per kilometre and that injection becomes less profitable beyond 10 km from the network. They put France's agricultural biomethane potential that cannot be injected at 26 TWh in 2050.

Charlie, a year later than announced

On 14 April 2026 Hydrocarbon Processing and Clubic reported the inauguration of "Charlie", a demonstrator at the Gazéa digester in Plélo, Côtes-d'Armor, which the company presents as the first system in the world to liquefy biogas on a farm. Its stated capacity is about 180 tonnes of bioLNG and 330 tonnes of liquid bioCO2 a year, with first deliveries expected before the end of 2026. A regional farm cooperative federation reported a visit to the site after the April inauguration. The July 2025 opinion piece described the demonstrator as technology readiness level 7: full scale on the farm side, one tenth scale on the hub side.

The date has moved. In 2021 the founders told Techniques de l'Ingénieur that a farm demonstrator funded by ADEME was planned for 2022. In March 2024 Adhémar told Maddyness that the farm unit would start in 2025, producing 350 tonnes of bioCO2 and 200 tonnes of LNG, with commercialisation and series production targeted for 2026; the 2024 Hydrocarbon Processing piece placed the first commercial installation, pooling about ten digesters, at the end of 2026. That network, now called Delta, is scheduled for commissioning in 2028, per the April 2026 reports.

What the EIC project promised

The CORDIS objective describes a patented mobile cryogenic tank on the farm, collection one to two times a week, and upgrading at a central hub that spreads the cost of gas separation over many farms. CORDIS lists no deliverables, reports or results so far, which is normal for a project in its first year. What can be checked today is whether the pieces the project depends on exist.

1. On-farm liquefaction unitBuiltCharlie inaugurated in Plélo in April 2026, per Hydrocarbon Processing and Clubic.
2. Separation into bioLNG and bioCO2Demonstrator scaleHub side at one tenth scale, per the company's July 2025 piece; no purity or output data published.
3. First deliveries of bioLNG and bioCO2Expected 2026No delivery or buyer has been announced in the sources found.
4. Multi-farm hub (Delta)Planned 2028About ten farms in Côtes-d'Armor; no construction start reported.

The money and the accounts

The funding rounds line up across sources, with one discrepancy inside a single text. PSL lists €85,000 raised in July 2020, €1 million in March 2021 from Storengy and business angels, and €11.5 million in December 2023, led by Crédit Mutuel Impact's Révolution Environnementale et Solidaire fund with Armines and existing investors; elsewhere in the same text PSL says the fund would put in €10 million. CFNEWS also reports the €1 million seed round of 2021, and Maddyness the €11.5 million round. The BODACC, France's official gazette of company notices, records capital increases in May 2020, August 2020, March 2021 and April 2024. Storengy sits on the supervisory board, according to the national company directory.

The award was blended finance, which combines the grant with a possible equity investment by the EIC Fund. The EIC Fund's portfolio pages returned "access denied" when checked for this article, and no EIC equity amount for SUBLIME Energie has been announced in the sources found. A 2026 job advertisement says the company is raising a new round in 2026 to build its first collection project; no closing of that round had been reported by 28 October 2026.

The filed accounts, published as open data by the French economy ministry, show a company still in development: revenue of €53,822 and a net loss of €2,236,196 in 2025, after a loss of €1,423,591 in 2024. The national company directory lists the company as active and records ADEME support. The BODACC shows accounts filed for every year from 2020 to 2025 and no notice of an insolvency procedure.

The policy case

The European Commission's biomethane page says production must scale up by 2030, as set out in the REPowerEU plan, and gives the numbers: 3.93 billion cubic metres produced in 2024, against plans reported by EU countries to reach 26 billion cubic metres a year by 2030. The company says more than 80% of biomass is held by farmers in its 2024 presentation and more than 90% on its website, and argues that many farms are too small or too far from the grid for injection. CORDIS rates the project's contribution to climate action at 100%.

SUBLIME Energie has not been asked for comment for this article. The reporting is based on publicly available sources, listed below.