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Energy-efficient cu...
Energy-efficient cultivation of marine microalgae for biomass production : Final rapport: Energimyndigheten P45907-1
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- Spetea, Cornelia, 1968 (författare)
- Gothenburg University,Göteborgs universitet,Institutionen för biologi och miljövetenskap,Department of Biological and Environmental Sciences
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(creator_code:org_t)
- Eskilstuna : Energimyndigheten, 2020
- Engelska.
- Relaterad länk:
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https://gup.ub.gu.se...
Abstract
Ämnesord
Stäng
- This project has demonstrated the principle of rotational cultivation of marine microalgae and that species adapted to cold climates can provide higher productivity during cold periods. By using marine species, and thus seawater instead of freshwater in cultivation, the environmental impact is reduced. Society faces major challenges to produce sufficient amounts of biomass for energy and material, and microalgae have a great potential to complement sources from forestry and agriculture. At Nordic latitudes year-round microalgae cultivation is debatable due to seasonal variations in productivity. Shall the same species be used throughout the year or shall seasonal-adapted species be used? The aims of the project were to identify suitable algal strains for a potential annual rotation model, where different strains are rotated during three cultivation seasons, and to further develop and optimize an energy-efficient cultivation process for the marine environment. To achieve these aims, a laboratory study was performed where two marine microalgal strains out of 167 were selected for intended cultivation at the west coast of Sweden. One strain belongs to the species Nannochloropsis granulata and the other to Skeletonema marinoi. The strains were cultivated in three simulated growth seasons: summer, winter and spring, and thereafter compared. We show that Nannochloropsis produced more biomass with more incorporated energy in lipids during summer and spring (25 MJ kg-1 compared to about 45 MJ kg-1 for diesel), whereas Skeletonema produced more biomass rich in carbohydrates and proteins during winter. Skeletonema was in general more efficient in taking up phosphate. Based on our results, biomass production as energy feedstock would be energy efficient only during the summer on the Swedish west coast. Nevertheless, species could be rotated for different purposes during the year. Biomass production could be combined with nutrient recycling of wastewater, for example, from fish industry. Our project faces a challenge in boosting the biomass produced in winter, but this could be solved, for example, by optimization of the cultivation medium and temperature increase with heat wastewater or other heat waste. The summer species Nannochloropsis proved to withstand winter by activating different lipid metabolic pathways than the cold-adapted species Skeletonema uses. Enhanced synthesis of proteins, such as enzymes, in Skeletonema during winter may compensate for their reduced activities, promoting growth and biomass production even at low temperatures. More species need to be studied to find those with higher productivity under winter conditions. In practice, the work-related consequences of a rotational cultivation should be weighed against its benefits, relative to a shorter cultivation season in each application. Potential applications mainly include cleaning of air and seawater, production of energy, biomass and biomaterials for the industry.
Ämnesord
- TEKNIK OCH TEKNOLOGIER -- Industriell bioteknik -- Bioenergi (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Industrial Biotechnology -- Bioenergy (hsv//eng)
- TEKNIK OCH TEKNOLOGIER -- Industriell bioteknik -- Biomaterial (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Industrial Biotechnology -- Bio Materials (hsv//eng)
- TEKNIK OCH TEKNOLOGIER -- Industriell bioteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Industrial Biotechnology (hsv//eng)
- NATURVETENSKAP -- Biologi -- Mikrobiologi (hsv//swe)
- NATURAL SCIENCES -- Biological Sciences -- Microbiology (hsv//eng)
Nyckelord
- Biomass
- bioenergy
- nitrogen and phosphorus uptake
- lipids
- marine microalgae
- Swedish west coast
- transcriptome
Publikations- och innehållstyp
- vet (ämneskategori)
- rap (ämneskategori)