NANOBOOSTER · Boosting photosynthetic activity via nanoparticle addition for biogas upgrading coupled with pigments production

The urgent need to reach EU independence from fossil fuel imports, decarbonization and circular economy encourages the development of sustainable technologies for the production of biofuels and high added-value products. Photobiorefineries are a promising platform to produce biofuels and high added-value products. However, the low algal biomass productivities typically limit their application. NANOBOOSTER will engineer a high-performance photobiorefinery based on the addition of nanoparticles (NPs) to boost Haematococcus pluvialis metabolism, resulting in a biomethane that meets the EN 16723 standard (CH4>95%, CO2<2%) along with enhanced astaxanthin productivities. NANOBOOSTER will address two key scientific challenges: the elucidation of the mechanisms of interaction between NPs and microalgae and the single-stage production of astaxanthin. Overcoming the first challenge will allow the synthesis of tailored NPs to boost H. pluvialis growth and astaxanthin content. Then, the optimal conditions of temperature, light, pH, NPs and NH4+ concentration will be determined at lab-scale. These conditions will be validated in an indoors single-stage continuous system using real centrate as a culture broth, which will be pretreated via selective NH3 membrane permeation to achieve optimal NH3 concentration for astaxanthin accumulation. The process will be optimized to reach an upgraded biomethane with CH4 >95% and CO2<2%, and astaxanthin contents of 10%. Finally, the process will be validated under outdoor conditions at demo scale to assess its techno-economic feasibility and draft a business roadmap. NANOBOOSTER will position photosynthetic biogas upgrading as a cost-effective process easy to implement in the biogas sector. The fellow, Dr. Vargas, will conduct this action at the Institute of Sustainable Processes of University of Valladolid under the supervision of Dr. Muñoz, with secondments at Calpech and the University of Almería under the supervision of Dr. Gabriel Acién.