Periodic Reporting for period 2 - Photo2Fuel (Artificial PHOTOsynthesis to produce FUELs and chemicals: hybrid systems with microorganisms for improved light harvesting and CO2 reduction)
Période du rapport: 2024-03-01 au 2025-08-31
A proposed roadmap for long-term replication and commercialization has been delivered, which emphasizes the necessity for further validation experiments at the laboratory scale (TRL4).
Deployment within the European Carbon Capture and Utilization and Storage (CCUS) field has been initiated, revealing significant stakeholder interest in the future evolution of such carbon utilization technologies. Stakeholders strongly recommend aligning their development with governmental policies and administrative initiatives to ensure successful industrial implementation. Ultimately, technologies like Photo2Fuel, which rely on living organisms, sunlight, and hold the potential to be autonomous and complementary to Direct Air Capture (DAC) technologies in the future, are poised to have a major impact on the decarbonization and circular economy of European industry.
At its conclusion, the project successfully developed, tested, and coupled several photosensitizer types with specific microbial strains to harness solar energy. This biohybrid approach targeted the production of acetic acid (using Moorella thermoacetica) and methane (using Methanosarcina barkeri). The best candidate demonstrating the highest potential for upscaling to higher is the combination of the Moorella thermoacetica bacterium with a specific set of organic photosensitizers.
The initiative has also modelled the process of the acetic acid biohybrid system in two different bioreactors set ups (batch and continuous), based on experimental and literature data, with the intention to optimise it and aid the further development of the technology. Overall, there is room for improvement recommended by the modellisation and simulations made at experimental scale, adjusting parameters such as the volume of the reactor, the concentration of microorganisms, the concentration of cysteine (sacrificial electron donor), etc.
The separation process of the acetic acid has been conducted testing three different methods, and their efficiency as costs are being compared and analysed. The most efficient technique is the ion-exchange resins, although the amount of produced acetic acid should be increase in further optimisations of the process for the separation step to be economically viable.
The project concluded with a comprehensive sustainability assessment of the acetic acid biohybrid system, benchmarking its environmental, social, and economic impacts against conventional and BAU technologies. The sustainability simulations revealed that the system currently underperforms relative to the BAU baseline. This finding mirrors the conclusions from the project’s modelling tasks, underscoring the critical necessity that the Photo2Fuel process must undergo significant experimental enhancement and optimization to evolve into a technology that is environmentally sound, socially sustainable, and economically efficient.
As reported previously, Photo2Fuel project has made possible to test the development of a biohybrid system with Methanosarcina barkeri for the first time, achiving a good viability and paving the way for further research with this archaea specie. In this regard, the most promising results and advancement of the SoA were obtained with the construction of the Moorella thermoacetica biohybrid, which succesfully produced acetic acid at laboratory scale harnessing light energy via the membrane-attached photosensitisers. Seemingly, further research is required with this hybrid to optimise the production of acetic acid to higher scales.
A continuous bioreactor setup has been successfully constructed. This functional unit is capable of harnessing an external light source and allows for the selection of the necessary wavelength to activate the photosensitisers. This setup is designed for continuous operation, utilizing solar-powered batteries for night cycles, thereby posing as a unit for ongoing testing. Further optimization is required to properly couple this setup with the developed biohybrid system to mitigate technical problems and operational issues that may arise during sustained, continuous device operation.
Finally, different procedures for separating acetic acid from the liquid media were tested separately, achieving promising results using the ion-exchange resins methodology at the laboratory scale. However, due to technical difficulties encountered when coupling the biohybrid system with the continuous bioreactor setup, it was not possible to test the separation process within a continuous operation environment.