Aqueous extraction of the sulfated polysaccharide ulvan from the green alga Ulva rigida—kinetics and modeling

Ricardo Pezoa Conte, Allison Leyton, Andrea Baccini, María Cristina Ravanal, Päivi Mäki-Arvela, Henrik Grénman, Chunlin Xu, Stefan Willför, María Elena Lienqueo, Jyri-Pekka Mikkola

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14 Citations (Scopus)


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 °C. The highest yield of 97.6 wt.% was attained after 2 h of extraction at 130 °C, and the extraction efficiency was observed to be heavily temperature dependent. Interestingly, two regimes of extraction kinetics were observed, presumably due to the different ulvan fractions contained within the cell wall of green algae. The experimental data was modeled with first-order kinetics, and an apparent activation energy of 53.8 kJ mol−1was obtained for the process. The algal residue was processed using simultaneous saccharification and fermentation, and 0.48 g ethanol g−1 of sugars was obtained.

Original languageUndefined/Unknown
Pages (from-to)915–928
JournalBioEnergy Research
Issue number3
Publication statusPublished - 2017
MoE publication typeA1 Journal article-refereed


  • bioethanol
  • Extraction
  • Ulvan
  • l-rhamnose
  • Green algae
  • Kinetics

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