Bio360 Expo, an exhibition entirely dedicated to bioenergy, took place in Nantes at the end of March 2022. In particular, green hydrogen resulting from the thermochemical treatment of dry biomass was discussed. Several companies have also presented their technologies for producing hydrogen from biomass.
How can we diversify the methods of producing hydrogen, and in particular green hydrogen? Because between gray hydrogen and green hydrogen, there is a significant difference in terms of ecological cost. This essential question was of course highlighted during the Bio360 Expo exhibition, which took place in Nantes on March 30 and 31. The production of green hydrogen from biomass is a theme which was also the subject of a conference.
If the production of green hydrogen from the thermochemical treatment of dry biomass is already deployed, several players presented their innovations and new approaches for the production of this energy of the future.
The Sakowin microwave plasma reactor
Sakowin, a Var start-up created in 2017, has developed a microwave plasma reactor which converts natural gas or biomethane into gaseous hydrogen and solid carbon (nanometric powder) capable of being recovered and reused. This technology is reminiscent of that of the Canadian company Aurora Hydrogen (see page 14). Gérard Gatt, president of Sakowin, explains: “We start from the same molecule as for the steam reforming process (methane), but our process is very different and does not release CO2. This involves breaking down this methane without oxygen. » At the outlet, the hydrogen reaches 95% purity.
Sakowin’s technology reaches a TRL 5 technological maturity level. “We have a prototype that already works for several hours, and we are looking to make it work over an eight-hour day,” says Gérard Gatt. Sakowin’s objective: a 100 kW reactor to produce 200 kg of hydrogen per day by 2025.
What about the cost of a kilo of hydrogen? It is estimated between 2.5 and 4 euros, “depending on the cost of gas,” adds Gérard Gatt. Sakowin’s solution is based on microwave plasma, but it is still poorly developed at the industrial level. With larger volumes, the start-up will be able to reduce investment expenses.
Sakowin has signed several partnerships in the sector of hydrogen recharging stations (Paris Airport), in that of industry (Saint-Gobain), in the agricultural sector, but also in that of oil and gas exploitation .
Microorganisms that produce hydrogen
For its part, Athena Research and Innovation has developed a solution for producing hydrogen from wastewater from the food industry (biscuit factories, dairies, etc.). Ludovic Briand, president of Athena, explained: “This water, which ends up in wastewater treatment plants, is composed of organic matter and minerals allowing the micro-organisms that we have identified to develop and release hydrogen”.
The fermentation process generates CO2but this is valued for cryogenic cleaning, soft drinks or agriculture. Finally, the fermentation musts are transformed into biochar (generated by pyrolysis of biomass) by carbonization.
Athena, also created in 2017, hopes to quickly produce 40 tonnes of hydrogen per year using 320,000 tonnes of recovered effluent. The company hopes to complete the development of its 30 m³ reactor between 2023 and 2025 in order to be able to industrialize it.
Producing hydrogen from wood waste
Present in a large number of materials, such as wood, but especially biomass, it is quite natural that the process of gasification of biomass of plant and animal origin has developed. It indeed offers very interesting solutions for the production of renewable hydrogen. Haffner Energy, a Strasbourg company, has built the first commercial unit for the production of hydrogen from biomass. Moreover, during the HyVolution trade show in October 2021, Haffner Energy announced the deployment of two new hydrogen production stations from biomass transformed by thermolysis. They will be located in Montmarault (Auvergne-Rhône-Alpes) and Chamboeuf (Bourgogne-Franche-Comté). Each of them will produce 720 kg of hydrogen per day, or 250 tonnes per year, by 2023. This hydrogen is intended primarily for industrialists who consume little. Haffner Energy has joined forces with Ets Roussel, which produces energy wood such as forest chips and firewood, and with Thevenin & Ducrot (energy distribution).
Haffner Energy is now ready to industrialize its green hydrogen production technology. The company has just validated the Hynoca (Hydrogen no carbon) process for producing carbon-free, hydrogen-rich synthesis gas by thermolysis and steam cracking of biomass.
In Austria, in Graz, the Bioenergy and Sustainable Technologies institute has succeeded in extracting hydrogen from biomass. The experimental reactor called ROMEO (Reactor optimization by membrane enhanced operation) is capable of sustainably producing hydrogen from wood waste. ROMEO gasifies the biomass before separating the hydrogen from the carbon dioxide via a catalyst. This process, unlike many others, consumes little energy. Conversion starts at 120 oC instead of 500 oC. This is possible thanks to the catalyst equipped with new separation membranes.
