Hydrogen research, given its key role in the transition towards a cleaner and more sustainable economy, faces the challenges of production efficiency and costs, as well as the emissions associated with certain production methods. It is precisely on this aspect that the Hi2BIO project focuses, achieving a sustainable way of producing green hydrogen from industrial wastewater, integrating different biological processes.
The results of the first tests show that the bacterium Clostridium butyricum plays a fundamental role in hydrogen production, although other species of the genera Clostridium, Bacillus, Pseudomonas or Rhodopseudomonas are also involved. Three matrices were used to carry out these comparative studies: a mixture of sugars, waste from the fruit industry and effluents from the dairy industry. This first experimental block has made it possible to identify the most effective bacterial pools for increasing hydrogen production, both in dark fermentation and in photofermentation.
The Hi2BIO project involves researchers from the University of Zaragoza who are part of the Agri-Food Institute of Aragon (IA2, a joint Unizar-CITA centre of Aragon) and the Aragon Institute of Engineering Research (I3A), both centres collaborating with the company Ingeniería de Obras Zaragoza.
The research ‘makes a significant contribution to sustainable hydrogen production by developing a biotechnological process that uses organic waste - from the food industry - as feedstock to generate hydrogen through dark fermentation and photofermentation. Unlike conventional methods, which tend to rely on fossil fuels and energy-intensive processes, this strategy is based on the use of renewable resources and by-products of low economic value, which reduces environmental impact and promotes the circular economy,’ the team explains.
The objectives of the project included evaluating different bacterial inocula for dark fermentation and selecting the most efficient one. Now, after the first results, the team stresses that they are ‘very encouraging and reinforce the feasibility of the proposed approach. The identification of bacterial species and their matrix-dependent behaviour and the key role of certain bacterial species in hydrogen production not only validate the work done, but also open up new opportunities for future lines of research.
Next steps
The Hi2BIO project will continue until December 2026. Now, the aim is to identify the bacterial pool that offers the best performance within each of the matrices studied for a more precise characterisation and to apply it on a larger scale and industrial relevance.
Currently, 40-litre reactors are in operation and 600-litre reactors are in the design and development phase for future deployment in industrial environments.
The project team wants to move towards a system that is more efficient, scalable and adaptable to industrial environments. ‘The project not only provides a clean and viable alternative for hydrogen generation, but also contributes to the development of sustainable energy technologies in line with the goals of decarbonisation and ecological transition.
About Hi2BIO and the Hydrogen PERTE
Hi2BIO is a strategic project framed within the Plan for Recovery, Transformation and Economic Resilience (PERTE) of critical sectors for the future. Funding comes from the European Union through NextGenerationEU, as well as from the Ministry for Ecological Transition and the Institute for Energy Diversification and Saving (IDAE). These projects play a key role in fostering collaboration between the public and private sectors, making a significant contribution to the transformation of the national economy. Hi2BIO will run for a period of three years, from July 2023 to July 2026.
