Conceptual design and environmental evaluation of the Biorefinery approach for R-phycoerythrin extraction and purification.

Marine algae are considered promising resources both at present and in the near future. Their availability, together with their molecular structure and properties, increases their applicability in various sectors: food and feed, cosmetics, pharmaceuticals and bioenergy. However, the "bio" qualification does not always imply a lower impact compared to fossil-based process schemes. Therefore, to verify the suitability of algae-based scenarios from a sustainable and circular perspective, it is necessary to assess their sustainability potential through process modelling (scaling up from laboratory scale to evaluate their potential at commercial level), environmental assessment (using the Life Cycle Assessment (LCA) method) and circularity analysis (by quantifying circularity indicators focusing on recovery, waste management and effective use of resources). In this context, this research report focused on the techno-economic assessment (TEA) and LCA of three alternative scenarios based on the extraction of R-phycoerythrin from offshore harvested macroalgae: water extraction followed by enzymatic digestion (S01), ultrasound-assisted extraction (S02) and water extraction (S03). In addition, the evaluation of environmental, social and circularity indicators and the application of the Greenness Grid methodology were included. According to the results obtained, S01 is the most promising alternative among the three scenarios due to its process productivity, lower environmental impact and potential sustainable scenario score according to the Green Chemistry assessment. Regarding the economic perspective, S03 is the only one that does not reach economic viability. Future studies should focus on improving process efficiency, promoting the use of renewable energy resources and supporting technological progress in emerging extraction processes.