Evaluating Swedish seaweeds for biorefinery
Doctoral thesis, 2020
This thesis aims to enable future research and development of a seaweed industry in Sweden. A screening of 22 species of seaweeds concluded that the most relevant species for biorefinery applications in Europe (Saccharina latissima, and Laminaria digitata) were also among the most interesting for Sweden. In addition, a few poorly investigated species were found to have interesting properties, such as high mannitol content (Halidrys siliquosa) as well as high sugar and low ash content (Chondrus crispus and Dilsea carnosa).
Composition of Ulva intestinalis, which grows all around Sweden, was studied in natural populations on the west coast and southern half of the east coast. Significant effects were found on carbohydrate, fatty acid and ash content between the sites. Rhamnose and iduronic acid were higher on the east coast, but not significantly. However, an elevated sulphate content motivates further investigation of the effect of salinity (the major differential environmental factor) on the potential high-value component ulvan in Ulva intestinalis. There were large variations in yields and composition of the oil, aqueous and solid phases in hydrothermal liquefaction processing within the different sites. Generally, the yields of bio-oil were low, and the quality of the oil was poor due to high contents of S, N and Fe. Considering the low quality of the oil, hydrothermal liquefaction should probably be utilized to treat side streams from a biorefinery after extraction of more high-value compounds.
Finally, abiotic factors and their effect on the growth and composition of Ulva fenestrata were studied. To overcome the low profitability projection of many biorefinery concepts, the data in this thesis could help maximize the value of algal biomass and launch a successful seaweed biorefinery industry. It was found that the content of the valuable monosaccharide rhamnose and the sugar acid iduronic acid could be increased by 26 and 70% respectively at elevated temperature and irradiance. This indicated an increase in ulvan content.
proteins
carbohydrates
salinity
chemical composition
ulvan
variation
Ulva spp.
Seaweed
macroalgae
hydrothermal liquefaction
Author
Joakim Olsson
Chalmers, Biology and Biological Engineering, Industrial Biotechnology
Biochemical composition of red, green and brown seaweeds on the Swedish west coast
Journal of Applied Phycology,;Vol. 32(2020)p. 3305-3317
Journal article
Olsson, J. Raikova, S. Mayers, J. J, Chuck, C. J, Nylund, G. M, Albers, E. Environmental effects on potentially valuable components of Ulva intestinalis along the Swedish coast
Cultivation conditions affect the monosaccharide composition in Ulva fenestrata
Journal of Applied Phycology,;Vol. 32(2020)p. 3255-3263
Journal article
Effect of Geographical Location on the Variation in Products Formed from the Hydrothermal Liquefaction of Ulva intestinalis
Energy & Fuels,;Vol. 34(2020)p. 368-378
Journal article
I denna avhandling har jag analyserat vad ett flertal svenska makroalger har för övergripande komposition för att utvärdera deras potential som råvara för bioraffinering. Dessutom har jag funnit att genom förändring av tillväxtförhållanden så som temperatur, ljusstyrka och näringstillgång kan kompositionen av makroalger tillhörande släktet Ulva manipuleras. Jag har sett tecken på strukturförändringar hos vissa sockerarter i dessa alger som skulle kunna öka deras potential för tillverkning av mediciner med antikoagulativ effekt. Dessa algers komposition utvärderades också runtom södra Sveriges kust och effekter av de varierande förhållandena vad gäller främst salthalt och näringstillgång sågs på bland annat fettsyror och sockerarter. I en process för tillverkning av bio-olja, på engelska kallad hyrdrothermal liquefaction, testades hur dessa biomassors varierande komposition påverkade de bildade produkterna. Stora negativa effekter sågs på kvalitén av produkterna orsakade av förhöjt innehåll av kväve, svavel och metaller i Ulva.
Seaweed production systems with high value applications (Sweaweed)
Swedish Foundation for Strategic Research (SSF) (RBP14-0045), 2021-01-01 -- 2021-12-31.
Swedish Foundation for Strategic Research (SSF) (RBP14-0045), 2015-01-01 -- 2019-12-31.
Seaweeds for a Biobased Society - farming, biorefining and energy production (SEAFARM)
Formas (213-2013-92), 2013-01-01 -- 2017-12-31.
Driving Forces
Sustainable development
Subject Categories
Ecology
Chemical Process Engineering
Bioenergy
Areas of Advance
Energy
Life Science Engineering (2010-2018)
Roots
Basic sciences
ISBN
978-91-7905-257-7
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 4724
Publisher
Chalmers
KA-salen Kemigården 4
Opponent: Senior Researcher PhD Annette Bruhn, Departement of Bioscience - Marine Ecology, Aarhus University, Denmark