The company Athéna Recherche et Innovation has developed a bacteriological process to produce hydrogen from wastewater and agri-food waste. Biology is being put to the service of a circular economy with the production of energy, the capture of CO2but also by-products that can be used as fertilizer for agriculture.
Athéna was created in 2017 with the aim of producing energy from waste. “We took over the work carried out in 1940 by a researcher from the Pasteur Institute who had found a bacterium capable of transforming biomass into oil,” says its president, Ludovic Briand, an energy engineer and co-founder of the company with Romain Irague, a doctor in microbiology. “We have not found this ancient bacteria; however, we selected another one capable of producing hydrogen from a mixture of wastewater and agri-food waste.
Energy performance
Hydrogen is a molecule that is never alone in nature and all production processes consist of breaking the molecules to extract dihydrogen. But not all are equally efficient. “Steam reforming separates the carbon from the hydrogen gas (CH4) with a ratio of 1 unit of energy consumed for 0.8 units of energy produced. Electrolysis separates the water molecule into oxygen and hydrogen with a ratio of 1 unit of energy consumed for 0.7 units produced. Another process, pyrolysis uses a high temperature to break organic chains. As for our bacteria, it extracts hydrogen from organic matter. Hydrogen is in fact a waste that it rejects during its growth. With the selection of this strain, we then worked on the optimum inputs to feed this bacteria so that it produces the maximum amount of hydrogen. Thus, our process produces 4 units of energy while consuming only one! The energy yield is therefore particularly efficient.
Circular biological process
Athéna initially focused on wastewater and waste from the agri-food industry as well as digestate from methanisation. “We offer manufacturers the opportunity to set up waste management that allows the production of hydrogen, but also that of by-products: compost or biochar depending on the incoming materials. The recovery of by-products allows us to generate no waste. This also allows us to have a very reasonable cost of hydrogen of €8/kg. Our expertise is used to calculate the concentration between water and organic matter (sugars, proteins, lipids) that best meets the needs of our bacteria so that they produce the maximum amount of hydrogen. This is done on a case-by-case basis with each manufacturer: dairy, paper pulp, production of ready meals, but also digestate from methanisation. For the latter, we also use a pre-treatment that breaks down the woody materials from the plant fibres. Our process is energy efficient since it uses water that is already hot at the outlet (40 to 60°C in a dairy for example, or even 80 to 100°C for rice cooking water or ready meals). This water also helps to deconcentrate other waste. Indeed, organic matter that is too concentrated creates a saturation of volatile fatty acids that inhibits the bacterial process.
Business model
Takes the example of a medium-sized dairy. “It can produce 120 tonnes of hydrogen, which is the equivalent of the production of a 1 MW electrolyser. With 1 unit of energy, we produce 4 of hydrogen, but we also save the dairy 8 to 10. In fact, we avoid the evaporation of milk permeate and the treatment of its wastewater, both of which consume energy. This allows it to claim energy saving certificates. Furthermore, in a circular economy approach, it will be able to use the hydrogen produced to run 75% of its fleet of trucks with current performance, and we hope to soon reach 100% in this example by improving our process. In fact, Athena’s model is to develop an ecosystem behind each agri-food unit or each paper manufacturer: we take the waste, we produce the hydrogen, we resell it directly to the factory or to nearby local authorities, we sell the by-products for return to the soil.
“Our bacteria produce over a short period of 36 hours. Our process therefore allows for a gradual renewal of the material, with different tanks in parallel to ensure sufficient contact time of the material with our bacteria colonies (which are fixed in these tanks). Once the hydrogen has been extracted, a fermentation must remains composed of bacteria corpses, minerals and volatile fatty acids: we then recover this solid phase and dry it to make worm compost or biochar, depending on the composition. These by-products are currently being evaluated, but the first elements that we have already collected show their agronomic quality for a return to the soil with fairly rapid assimilation. Third bonus, we also recover CO2 biogenic which can be used by manufacturers as a substitute for CO2 fossil fuel generally used (market gardening, soft drinks, etc.). They thus reduce their carbon footprint. This recovery of CO2 is an integral part of the economic equation of our process.”
Athena s’investit
CThe recycling model is quite complex, it optimizes the industrial process by real recycling of all products, which is the condition of a real circular economy: energy production, local use, recovery of CO2 and by-products. Athéna Research and Innovation offers a virtuous and biomimetic model adapted on a case-by-case basis to the different industries that produce organic waste. “Before any project, we first study the potential of the waste. Then we carry out tests over several weeks to understand how to optimize the process and also analyze possible hazards (breakage, change of supply, etc.). If these results are good, we then study the local energy needs and uses, then we move on to the design phase. We enter into a partnership with manufacturers. To do this, we do not ask them to invest, because we are the ones who invest in the tool. We are currently raising two million euros in funds to move from our already operational demonstrators to industrial scale, with the aim of having our first plant operational by 2025.”
For more information: Ludovic Briand (06 95 25 50 73)
(contact@athena-recherche.fr)
