Aqueous Extraction of the Sulfated Polysaccharide Ulvan from the Green Alga Ulva rigida-Kinetics and Modeling

The incentives for utilizing a versatile range of renewable feedstocks in novel ways are continuously increasing. Sulfated polysaccharides from green algae, such as ulvan, are interesting due to the rare sugar constituents which can be utilized for new materials and chemicals in industry. However, before valorization fractionation needs to be performed in a controlled way. In the current work, the kinetics of the aqueous extraction of ulvan was studied in the temperature range 60-130 degrees C. The highest yield of 97.6 wt.% was attained after 2 h of extraction at 130 degrees C, and the extraction efficiency was observed to be heavily temperature dependent. Interestingly, two regimes of extraction kinetics were observed, presumably due to