Towards a biorefinery processing Sargassum seaweed: Techno-economic assessment of alginate and fucoidan production through SuperPro Designer® process simulation

The emergence of Sargassum spp. (brown seaweed) along the coasts of the Mexican Caribbean poses a significant challenge because of climate change, which affects various economic sectors in the region. To address this issue, it is crucial to adopt a comprehensive and multifaceted approach to mitigate its effects and find sustainable solutions. This study focused on exploring the biotechnological potential of Sargassum through a waste upcycling approach, specifically utilizing a biorefinery scheme. The aim of this study was to extract valuable biotechnological products, primarily alginate and fucoidan. Alginate extraction was performed at a laboratory scale and then simulated at an industrial scale (base case) to assess the economic and technical viability. A second approach incorporating fucoidan extraction was evaluated. The simulation results in SuperPro Designer® showed that the base case is not economically viable, with a net present value (NPV) of -$2,736,000 USD, a gross margin of 4.89%, and an internal rate of return of 2.20%. This is due to the excessive ethanol solvent use and the low selling price of alginate. However, the second approach is economically feasible, with an NPV of $3,844,000 USD, representing a 3.27-fold increase in the gross margin and a 4.23-fold increase in the internal rate of return. Therefore, including more Sargassum-derived value-added products in the base case scenario can lower the operating costs and initial investment, making the biorefinery process economically viable. These findings emphasize the potential of the biorefinery scheme in addressing Sargassum emergence in the Mexican Caribbean, contributing to sustainable solutions.