Environmental Life Cycle Assessment applied to microalgae-based technologies: Methodology presentation and case studies analysis --Sophie Sfez & Sue-Ellen Taelman, EnAlgae project, Ugent, BE--

1. Sustainable Pathways for Algal Bioenergy
Environmental Life Cycle Assessment applied to microalgae-based technologies: Methodology presentation and case studies analysis
Sue Ellen Taelman, Sophie Sfez
Department of Sustainable Organic Chemistry and Technology, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
EnAlgae Symposium , Kortrijk, Belgium
18th September 2014

2. Sustainable Pathways for Algal Bioenergy
Introduction EnAlgae: INTERREG IVB North West Strategic Initiative (03/2011 – 06/2015)
9 pilot scale algae cultivation sites (micro- and macroalgae)
•In Lelystad, The Netherlands: Integrated microalgal biorefinery
•In Roeselare, Belgium: Algae-based wastewater treatment

3. Sustainable Pathways for Algal Bioenergy Demand for vegetable protein feed sources increases Import of proteins in the EU: soybean crops, mainly from Brazil Deforestation, fossil fuel use, ..  Sustainable? Alternative : algae as renewable protein source Potential:
–Up to 50% proteins
–Considered to be highly productive
–Cultivation on marginal land possible
–… Goal of this study:
(1) Determining the natural resource footprint of protein rich algal meal for livestock feed applications in The Netherlands
(2) Comparison with soybean crop production in Brazil and transport to The Netherlands
What is the most sustainable protein rich alternative?
Part 1: Integrated microalgal biorefinery

4. Sustainable Pathways for Algal Bioenergy
Env. Sustainability Analysis
Foreground: 95% gathered at the site
Background: database ecoinvent v2.2
Functional unit: basket of products
System boundaries: cradle-to-gate
Resource consumption (CEENE) Dewulf et al. 2007 Life Cycle Assessment (LCA), ISO standards 14040 & 14044

5. Sustainable Pathways for Algal Bioenergy
Cattle manure, maize
straw, feeding residues,
silage maize
Electricity
Biogas
Digestate
Storage
CHP
Digester UNIT
Flue gases 400°C
Electricity
Heat (warm water)
Condenser 1
Condenser 2
Electricity
Electricity
Flue gases 120°C
Heat
(warm water)
Bio-ethanol
unit
Heat (warm water) Flue gases 50°C
Pond
Outside
Pond
Inside
Centr. 1
Centr. 2
Coalescer 1
Coalescer 2
Flue gases
in excess
Electricity
Nutrients (N,P)
Water (rain and fresh)
Electricity Water evaporated CO2
Effluent 1
Effluent 2
Harvested fraction
Harvested fraction
Electricity
Water (fresh)
Centrate 1+ 2
Concentrate 1
Concentrate 2
Sunlight/Land
inoculum T4 T3 T6
dryer Extraction
step
ALGAE OIL
ALGAE MEAL
field
Sewer
Artificial
lighting
500 m²
3241 kg
DW.ha-1.y-1
10.2% DW

6. Sustainable Pathways for Algal Bioenergy
LCA (cradle-to-gate) System expansion based on functionalities to avoid allocation

7. Sustainable Pathways for Algal Bioenergy
LCA results (CEENE method)
MJex/functionalities
Abiotic Renewables
Fossil
fuels
Nuclear
resources
Metal ores
Minerals
Water
Land use
Atmospheric
resources
TOTAL
Relative contribution (%)
Digestion
2.64E+01
6.86E+02
6.66E+01
5.51E-01
9.04E-01
4.64E+01
1.41E+03
0.00E+00
2.21E+03
72.74
CHP process
6.35E+00
1.48E+02
1.53E+01
7.40E-02
3.68E-02
1.17E+01
4.23E+00
0.00E+00
1.86E+02
6.14
Condensation
3.01E+00
7.08E+01
7.30E+00
1.57E-02
1.51E-02
5.58E+00
1.99E+00
0.00E+00
8.87E+01
2.93
Inoculum production
1.76E+00
2.67E+01
5.51E+00
3.22E-02
2.50E-02
8.62E+00
9.40E-01
0.00E+00
4.36E+01
1.44
Algae cultivation T2
7.12E+00
1.68E+02
1.74E+01
8.16E-02
5.12E-02
2.30E+01
7.60E+00
0.00E+00
2.24E+02
7.37
Algae cultivation T1
7.10E+00
1.68E+02
1.73E+01
8.18E-02
5.33E-02
2.30E+01
7.59E+00
0.00E+00
2.23E+02
7.35
Dewatering T2
1.00E+00
2.35E+01
2.42E+00
7.18E-03
5.79E-03
1.85E+00
6.65E-01
0.00E+00
2.94E+01
0.97
Dewatering T1
1.00E+00
2.35E+01
2.42E+00
7.18E-03
5.79E-03
1.85E+00
6.65E-01
0.00E+00
2.94E+01
0.97
Drying
7.69E-03
2.79E+00
1.39E-02
1.95E-04
2.92E-04
5.54E-03
2.54E-03
0.00E+00
2.82E+00
0.09
Crushing
2.06E-03
1.32E-01
5.07E-03
1.29E-05
2.35E-05
4.34E-03
2.10E-03
0.00E+00
1.46E-01
0.00
TOTAL
5.38E+01
1.32E+03
1.34E+02
8.51E-01
1.10E+00
1.22E+02
1.43E+03
0.00E+00
3.03E+03
Relative contribution (%)
1.77
43.44
4.43
0.03
0.04
4.02
47.16
0.00

8. Sustainable Pathways for Algal Bioenergy
LCA (cradle-to-gate) A basket of products delivered by the linear (soybean based) economy and (algae based) biorefinery
Prudêncio da Silva et al. 2010

9. Sustainable Pathways for Algal Bioenergy
MJex/functionalities
Abiotic Renewables
Fossil
fuels
Nuclear
resources
Metal ores
Minerals
Water
Land use
Atmospheric
resources
TOTAL
Relative contribution (%)
LINEAR ECONOMY
Soybean cultivation
1.18E-02
2.69E-01
2.79E-02
7.15E-04
6.91E-04
2.57E-02
4.81E+00
0.00E+00
5.15E+00
91.47
Drying
6.97E-04
2.33E-03
9.15E-04
2.03E-05
3.92E-05
1.76E-04
1.75E-01
0.00E+00
1.80E-01
3.19
Crushing
1.45E-02
7.76E-02
1.68E-03
1.26E-05
2.23E-05
1.28E-03
3.52E-03
0.00E+00
9.86E-02
1.75
Export to The Netherlands
2.96E-03
1.74E-01
1.04E-02
1.46E-04
7.32E-04
4.65E-03
9.29E-03
0.00E+00
2.02E-01
3.58
TOTAL
2.99E-02
5.23E-01
4.08E-02
8.94E-04
1.48E-03
3.18E-02
5.00E+00
0.00E+00
5.63E+00
Relative contribution (%)
0.53
9.29
0.73
0.02
0.03
0.56
88.85
0.00
BIOREFINERY
Algae cultivation
2.04E+01
4.68E+02
5.10E+01
2.20E-01
1.53E-01
6.29E+01
1.91E+01
0.00E+00
6.22E+02
99.53
Drying
7.69E-03
2.79E+00
1.39E-02
1.95E-04
2.92E-04
5.54E-03
2.54E-03
0.00E+00
2.82E+00
0.45
Crushing
1.84E-03
1.18E-01
4.51E-03
1.15E-05
2.09E-05
3.86E-03
1.87E-03
0.00E+00
1.30E-01
0.02
TOTAL
2.05E+01
4.72E+02
5.11E+01
2.20E-01
1.54E-01
6.30E+01
1.91E+01
0.00E+00
6.25E+02
Relative contribution (%)
3.28
75.50
8.18
0.04
0.02
10.08
3.06
0.00
LCA results (CEENE method)
Factor 100 difference could be expected:
mature large scale technology (soybean) versus young small scale technology (algae)

10. Sustainable Pathways for Algal Bioenergy
Conclusion (part 1) Improvements in terms of energy efficiency necessary to become competitive with protein rich soy meal
Modified sensitivity test (electricity based on wind energy, lower working hours for blowers and mixing devices, more energy efficient blower, higher harvested fraction and algal productivity) reveals promising results!
Further research:
–Process optimization (e.g. recycling of centrates, digestate or livestock manure as nutrients for algae, …)
–Protein digestibility
–LCA: emission footprint

11. Sustainable Pathways for Algal Bioenergy Europe is turning toward a zero waste strategy in all industrial sectors WWT is not only considered as an instrument to deliver clean water
New solutions investigated to couple WWT systems with the production of valuable products Aquaculture WWT using microalgae is investigated with 2 valorisation scenarios for microalgae:
•Shrimp feed (subject to validation concerning biosecurity)
•Biogas Goal of this study:
(1) Determining the natural resource footprint of algae-based wastewater treatment plant at pilot and industrial scales
(2) Comparison of two scenarios for microalgae valorisation
Part 2: Algae-based wastewater treatment

12. Sustainable Pathways for Algal Bioenergy
Env. Sustainability Analysis
Functional unit: treatment of 1 m3 of wastewater
System boundaries: cradle-to-gate
Resource consumption (CEENE)
Dewulf et al. 2007 Life Cycle Assessment (LCA), ISO standards 14040 & 14044
System
Pilot scale
Upscaled
Foreground
95% gathered at the site
50% extrapolated from pilot scale
50% based on literature
Background + valorisation
ecoinvent v2.2 + literature review

13. Sustainable Pathways for Algal Bioenergy
Valorisation scenarios
Electricity
Aquaculture farm
Fish sludge
Wastewater
Microalgal
Raceway ponds
MaB-flocs
Maize silage
Digester
Biogas
Carbon
content from
the digestate
Valorization as biogas
Green
certificates
Soil conditioner
Heat
Digestate
Electricity
Heat
Valorization as shrimp feed
Aquaculture farm
Fish sludge
Wastewater
Microalgal
Raceway pondS
MaB-flocs
Valorization
as biogas
Maize silage
Dried MaB-flocs
for
shrimp feed
Drying Milling
Green
certificates
Soil conditioner
Valorisation as shrimp feed
Valorisation as biogas

14. Sustainable Pathways for Algal Bioenergy
Pump
Filter bag
Pump
Electricity
Electricity
Settling
tank
Water
Pump
Influent
Water
Hydropress
Press
filtrate
Water
Dried MaB-flocs
for
shrimp feed
Biogas
Effluent
Water
Electricity
MaB-flocs
liquor
Supernatant
MaB-flocs losses
Flue gas
MaB-flocs losses
Sunlight Land
Natural
gas
Heat
Pump
Pump
Electricity
Drying
(oven)
Milling
Digester
Natural
gas
Heat
Carbon
content from
the sludge
Electricity
Heat
Reactor
to stirring pumps
Wastewater treatment: Pilot scale

15. Sustainable Pathways for Algal Bioenergy
50 m
5 m
Pump
Influent
Water
Reactor
41 reactors
=
1ha of cultivation
Electricity
Effluent
Water
Pump
Flue gas Sunlight Land
Natural
gas
Heat
Settling
pit
Electricity Pump
Pump
Supernatant
Pump
Blower
Filter press
Electricity
a
Dried MaB-flocs
for
shrimp feed
Drying (drum
dryer)
Milling
Valorization into shrimp feed
a
Valorization into biogas
Digester
Biogas
Carbon content
from the
sludge
Electricity
Heat
Reactor
Reactor
Reactor
to stirring pumps
Wind
turbine
Electricity
Wastewater treatment: Upscaled

16. Sustainable Pathways for Algal Bioenergy
0,00
10,00
20,00
30,00
40,00
50,00
60,00
70,00
Pilot scale
Upscaled
Pilot scale
Upscaled
Pilot scale
Upscaled
Pilot scale
Upscaled
Pilot scale
Upscaled
Pilot scale
Upscaled
Pilot scale
Upscaled
Land resource Fossil fuels Metal ores Minerals Nuclear
energy
Water
resources
Abiotic
renewable
resources
MJexCEENE/m3 treated water
WWTP comparison - pilot vs upscaled - CEENE
Electricity production from wind mill
Electricity consumption filter belt
Direct Land occupation
Water consumption
Natural gas consumption
Infrastructure
Electricity consumption for other pumps and
blower
Electricity consumption for stirring pumps
50%
43%
93%
86%
40% 32% 68% 49%
97%
92%
95%
87% 84%
1%
LCA results: impact contribution

17. Sustainable Pathways for Algal Bioenergy
0,00
10,00
20,00
30,00
40,00
50,00
60,00
70,00
Pilot scale
Upscaled
Pilot scale
Upscaled
Pilot scale
Upscaled
Pilot scale
Upscaled
Pilot scale
Upscaled
Pilot scale
Upscaled
Pilot scale
Upscaled
Land resource Fossil fuels Metal ores Minerals Nuclear
energy
Water
resources
Abiotic
renewable
resources
MJexCEENE/m3 treated water
WWTP comparison - pilot vs upscaled - CEENE
Electricity production from wind mill
Electricity consumption filter belt
Direct Land occupation
Water consumption
Natural gas consumption
Infrastructure
Electricity consumption for other pumps and
blower
Electricity consumption for stirring pumps
-62%
-65%
-65%
-59% -62% -55%
LCA results: effect of upscaling

18. Sustainable Pathways for Algal Bioenergy
-30
-20
-10
0
10
20
30
Shrimp feed
AD
Shrimp feed
AD
Shrimp feed
AD
Shrimp feed
AD
Shrimp feed
AD
Shrimp feed
AD
Shrimp feed
AD
Land
resource
Fossil fuels Metal ores Minerals Nuclear
energy
Water
resources
Abiotic
renewable
resources
MJex,CEENE/m3 treated water
Upscaled scenario - CEENE
Phosphorus emission
Nitrogen emission
MaB-flocs cultivation
Co-digestion of MaB-flocs + fish sludge +
mais silage
Co-digestion of fish sludge + mais silage
Shrimp feed production
Electricity from the grid - wind mill
Shrimp feed from wheat
Compost - AD
Electricity from the grid - AD
Heat from boiler - AD
Avoided processes
LCA results: integrated system
Total exergyCEENE extracted from
natural environment:
 Shrimp feed: 32.7 MJex,CEENE
 AD: 40.5 MJex,CEENE

19. Sustainable Pathways for Algal Bioenergy
Conclusion (part 2) Stirring has the highest contribution to most impact categories: 51% of total exergyCEENE extracted from natural environment
New mixing solutions should be investigated (e.g. adjustement of required mixing energy based on Manning formula, feasibility of using paddle wheels…) Upscaling reduces the total exergyCEENE extracted from natural environment by 41% In the integrated system, the extraction of exergy from natural environment is mostly compensated by the production of renewable energy With the assumptions made in this study1,valorisation of MaB- flocs as shrimp feed extracts less exergyCEENE from natural environment
1(e.g. conventional wheat from Europe, intensive silage production etc)

20. Sustainable Pathways for Algal Bioenergy
Thank you!
SueEllen.Taelman@UGent.be
+32 (0) 9 264 58 71
Sophie.Sfez@UGent.be +32 (0) 9 264 99 27