SETAC Conference November 2013 Rome, Italy
11
The (Exergetic) Life Cycle Assessment ((E)LCA) of microalgae production as feed for aquaculture: an environmental sustainability analysis Sue Ellen TAELMAN (a) S. De Meester (a) , L. Roef (b) , M. Michiels (b) , J. Dewulf (a) (a) Research Group EnVOC, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium (b) Proviron Holding nv, G. Gilliotstraat 60, 2620 Hemiksem, Belgium SETAC Conference 11-13 November 2013 Rome, Italy
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Introduction Aquaculture: feeding fish to fish principle is not sustainable Alternative for fish oil/meal production = ALGAE Microalgae are unicellular, mostly photo-autotrophic organisms They need water, light and inorganic nutrients to grow Some advantages: Very rich biomass Able to live of waste streams Higher photosynthetic efficiency Marginal land is sufficient Known disadvantages: Low cell density cultivation -> reflection on harvesting and processing Claimed to be a sustainable biomass resource -> correct? .
Transcript of SETAC Conference November 2013 Rome, Italy
The (Exergetic) Life Cycle Assessment ((E)LCA) of microalgae production as feed for aquaculture:
an environmental sustainability analysis
Sue Ellen TAELMAN(a)
S. De Meester(a), L. Roef(b), M. Michiels(b), J. Dewulf(a)
(a) Research Group EnVOC, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium(b) Proviron Holding nv, G. Gilliotstraat 60, 2620 Hemiksem, Belgium
SETAC Conference11-13 November 2013
Rome, Italy
2
Aquaculture: feeding fish to fish principle is not sustainable
Alternative for fish oil/meal production = ALGAE
Microalgae are unicellular, mostly photo-autotrophic organismsThey need water, light and inorganic nutrients to grow
Some advantages:• Very rich biomass• Able to live of waste streams• Higher photosynthetic efficiency• Marginal land is sufficient
Known disadvantages:Low cell density cultivation -> reflection on harvesting and processing
Claimed to be a sustainable biomass resource -> correct?
Introduction
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• Examining the environmental sustainability of algae production in the new ProviAPT system Scenarios:
• Pilot 2012 (based on actual production runs)• Two upscaling scenarios (2013 and 2015)
• Determining the potential of microalgae as fish feed application + benchmarking with traditional fish feed
Research questions
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• Exergy analysis on process level– Thermodynamics: ‘all real processes generate entropy’
‘all real processes generate loss of work potential’– Quality/quantity measurement of material & energy flows– Process improvement
• Life Cycle Assessment (LCA), ISO standards 14000 & 14040
Methods
Functional unit: 1MJex
System boundaries: cradle to gateForeground: provided by Proviron
Background: database ecoinvent v2.2
Climate change (IPCC,2007)Resource consumption (CEENE, 2007)
5Michiels, M. 2009 : Bioreactor. EP 2039753
Cultivation
240 m²
Pilot 2012
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Foreground system pilot 2012
Centrate Permeate
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Pilot 2012 Forecast:Pilot 2013
Forecast: First production scale 2015
Scenario (generic) Scale 240 m² 1320 m² 2.5 ha
Location Belgium Belgium SpainRecycling of permeate and centrate (process C and D)
No Yes, extra filtration on centrate
Yes, extra filtration on centrate
Photobioreactor Area PBR 12 m² 12 m² 26 m²
Reactive area PBR 7 m² 7 m² 21 m²Photosynthetic efficiency 1.2% on 12 m² 1.2% on 12 m² 2.4% on 26 m²
Areal productivity 4.59 g/m²/d 4.59 g/m²/d 15.1 g/m²/dVolumetric productivity 0.53 g/l/d 0.53 g/l/d 1.25 g/l/d
Efficiency fan 25 % 35 % 80 % (a)
Efficiency circulation pump 11 % 11 % 80 % (b)
Source CO2 bottled bottled Flue gasesHeat 200 W/m², 50% of the year
at 50% of the peak power200 W/m², 50% of the year at 50% of the peak power
No extra heat necessary
Upscaling analysis (1)
(a) based on document UNEP, 2006a (b) based on document UNEP, 2006b (c) Piek et al., 2012 (d) Sheehan et al., 1998
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Pilot 2012 Forecast:Pilot 2013
Forecast: First production scale 2015
Centrifuge Type Bowl centrifuge Bowl centrifuge Hydrostop centrifuge
Electricity consumption 15 kWh/m³ 3.5 kWh/m³ 0.95 kWh/m³(c)
Drying Type Freeze dryer Freeze dryer Drum dryer
Electricity consumption 59 kWh/kg DW 13 kWh/kg DW /Natural gas consumption / / 0.98 kWh/kg H2O(vapour)
(d)
Upscaling analysis (2)
(a) based on document UNEP, 2006a (b) based on document UNEP, 2006b (c) Piek et al., 2012 (d) Sheehan et al., 1998
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LCA: results (1)
Pilot plant (2012)
Forecast:Pilot plant
(2013)
Forecast: First production scale
(2015)
Cumulative Energy Extraction from the Natural Environment (CEENE)MJex,CEENE/MJex DM 55.5 21.6 2.46
Renewable 0.58 0.18 0.11
Fossil 21.26 8.04 1.24
Nuclear 24.45 9.32 0.23
Metal ores 0.02 0.01 0.00
Minerals 0.17 0.01 0.01
Water 4.47 1.34 0.20
Land use 4.57 2.66 0.68
Atmosphere 0.00 0.00 0.00
Carbon Footprint (CF) kg CO2,eq/MJex DM
1.76 0.64 0.09
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Pilot 2012 Pilot 2013 First production scale 2015
Reference fish feed*
0102030405060 55.5
21.6
2.46 7.7
CEENE (MJex,CEENE/MJex DM)
LCA: results (2)
*(Huysveld et al., 2011; Huysveld et al., 2013)
3% 5%
8%
84%
Renewable Fossil Nuclear Metal ores MineralsWater Land use Atmosphere
Pilot 2012 Pilot 2013 First production scale 2015
Reference fish feed*
0
0.5
1
1.5
2 1.76
0.64
0.09 0.05
IPCC (kg CO2,eq / MJex DM)
CEENE (MJex,CEENE/MJex DM)
IPCC (kg CO2,eq/MJex DM)
Forecast Pilot 2013
Forecast First Production scale 2015
Pilot 2012
Pilot 2012 Forecast Pilot 2013
Forecast First Production scale 2015
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• Recycling of water/nutrients and savings on energy use show important routes to make the overall production more sustainable
• Also upscaling, reactor design improvements, enhancement of photosynthetic yield and good choice of location contribute to an environmental progress
• Although additional efforts are required to improve the carbon footprint, in the near future algae production can reach a lower resource footprint (2.46 MJex,CEENE/MJex DM) than traditional fish feed (7.70 MJex,CEENE/MJex DM)
Contact:
[email protected]+32 9 264 58 71
Conclusions and future research
