Advanced search
1 file | 41.78 KB

Exergy and life cycle analysis of microalgae as feed for aquaculture

Author
Organization
Project
interreg Energetic Algae
Abstract
In this study, the environmental sustainability of 3 algal production scenarios is analysed by using Exergy Analysis (EA) and Exergetic Life Cycle Assessment (ELCA). Next to the pilot plant of 240m² photobioreactors (pilot 2012), also 2 upscaled scenarios have been developed to examine the entire production process and to optimize the configuration for a more sustainable algae cultivation. The second scenario uses 1320 m² PBR bags (pilot 2013) and the first production scale scenario 2.5 hectare (2015). Patented ProviAPT photobioreactors are used to cultivate the oil-rich microalgae Nannochloropsis sp. and the biomass is semi-continuously harvested through an overflow system. This renewable resource is then purified and concentrated in a filtration and centrifugation step. At the end, the algal biomass is dried to obtain 95% dry weight (DW) in order to have good conservation properties. The biomass has a promising application in aquaculture as fish feed because algae could substitute traditional fish oil and fish meal, lowering the intensive fish farming. The EA reveals that the drying and cultivation step have the lowest efficiencies at process level, even at the 2.5 ha scale (72.8% and 3.58% respectively). The results of the ELCA clearly shows an improvement in resource efficiency upon upscaling: 1280.7 MJex,CEENE is extracted from the natural environment in the first scenario to produce 1 kg DW biomass, which is reduced to 499.6 and 56.83 MJex,CEENE/kg DW for the second and third scenario respectively. Also due to upscaling and optimization, the impact on climate change declines with a factor 20 (2.1 kg CO2,eq/kg DW at 2.5 ha scale). Comparing these results to the resource consumption and impact on climate change of traditional fish feed containing terrestrial biomass products (133.29 MJex,CEENE and 0.8 kg CO2,eq per kg DW), it becomes clear that algae production for aquacultural purposes is possible from a resource sustainability point of view but only when upscaling, recycling and reuse of waste streams are implemented into microalgae biorefineries.

Downloads

    • full text
    • |
    • UGent only
    • |
    • PDF
    • |
    • 41.78 KB

Citation

Please use this url to cite or link to this publication:

Chicago
Taelman, Sue Ellen, Steven De Meester, Luc Roef, Mark Michiels, and Jo Dewulf. 2013. “Exergy and Life Cycle Analysis of Microalgae as Feed for Aquaculture.” In Renewable Resources and Biorefineries 9, Abstracts, 86–86.
APA
Taelman, S. E., De Meester, S., Roef, L., Michiels, M., & Dewulf, J. (2013). Exergy and life cycle analysis of microalgae as feed for aquaculture. Renewable Resources and Biorefineries 9, Abstracts (pp. 86–86). Presented at the 9th International conference on Renewable Resources and Biorefineries (RRB-9).
Vancouver
1.
Taelman SE, De Meester S, Roef L, Michiels M, Dewulf J. Exergy and life cycle analysis of microalgae as feed for aquaculture. Renewable Resources and Biorefineries 9, Abstracts. 2013. p. 86–86.
MLA
Taelman, Sue Ellen, Steven De Meester, Luc Roef, et al. “Exergy and Life Cycle Analysis of Microalgae as Feed for Aquaculture.” Renewable Resources and Biorefineries 9, Abstracts. 2013. 86–86. Print.
@inproceedings{4127825,
  abstract     = {In this study, the environmental sustainability of 3 algal production scenarios is analysed by using Exergy Analysis (EA) and Exergetic Life Cycle Assessment (ELCA). Next to the pilot plant of 240m{\texttwosuperior} photobioreactors (pilot 2012), also 2 upscaled scenarios have been developed to examine the entire production process and to optimize the configuration for a more sustainable algae cultivation. The second scenario uses 1320 m{\texttwosuperior} PBR bags (pilot 2013) and the first production scale scenario 2.5 hectare (2015). Patented ProviAPT photobioreactors are used to cultivate the oil-rich microalgae Nannochloropsis sp. and the biomass is semi-continuously harvested through an overflow system. This renewable resource is then purified and concentrated in a filtration and centrifugation step. At the end, the algal biomass is dried to obtain 95\% dry weight (DW) in order to have good conservation properties. The biomass has a promising application in aquaculture as fish feed because algae could substitute traditional fish oil and fish meal, lowering the intensive fish farming. The EA reveals that the drying and cultivation step have the lowest efficiencies at process level, even at the 2.5 ha scale (72.8\% and 3.58\% respectively). The results of the ELCA clearly shows an improvement in resource efficiency upon upscaling: 1280.7 MJex,CEENE is extracted from the natural environment in the first scenario to produce 1 kg DW biomass, which is reduced to 499.6 and 56.83 MJex,CEENE/kg DW for the second and third scenario respectively. Also due to upscaling and optimization, the impact on climate change declines with a factor 20 (2.1 kg CO2,eq/kg DW at 2.5 ha scale). Comparing these results to the resource consumption and impact on climate change of traditional fish feed containing terrestrial biomass products (133.29 MJex,CEENE and 0.8 kg CO2,eq per kg DW), it becomes clear that algae production for aquacultural purposes is possible from a resource sustainability point of view but only when upscaling, recycling and reuse of waste streams are implemented into microalgae biorefineries.},
  author       = {Taelman, Sue Ellen and De Meester, Steven and Roef, Luc and Michiels, Mark and Dewulf, Jo},
  booktitle    = {Renewable Resources and Biorefineries 9, Abstracts},
  language     = {eng},
  location     = {Antwerp, Belgium},
  pages        = {86--86},
  title        = {Exergy and life cycle analysis of microalgae as feed for aquaculture},
  year         = {2013},
}