Integrated biorefinery process for sustainable fractionation of Ulva ohnoi (Chlorophyta): process optimization and revenue analysis

Blue economy, the sustainable and effective use of ocean resources for economic growth, is a major challenge to coastal communities. Marine macroalgae are potentially sustainable feedstock for future food, materials, chemicals, and fuels. For seaweed biorefinery, the fractionation of the biomass to co-produce multiple products is crucial in the efficient valorization of the marine biomass. In this work, we developed a protocol for co-production of six different products from the green macroalga Ulva ohnoi using green extraction methods. A total of 90.31 ± 1.94% of the initial biomass was recovered in separated products. The fraction of the recovered products from initial dry weight biomass was 45.42 ± 1.91% salts, 3.67 ± 1.38% starch, 3.81 ± 1.26% lipids, 13.88 ± 0.40% ulvan, 14.83 ± 1.06% proteins, and 8.70 ± 1.87% cellulose. A potential revenue analyses, based on these experimental data and current market prices, suggests that total the revenue fluctuates between US$1.56 and US$3.93 kg⁻¹ of dry biomass and depends on recovered products fraction in the seaweed biomass and products market value.