Circular resource flow from algae production

Transcription

1 03 OCTOBER 2013 DCE-Danish Center for environment and energy Circular resource flow from algae production Michele Seghetta Kaisa Manninen Milla Suutari Kristian Spilling Berit Hasler Annette Bruhn Jacob Carstensen Marianne Thomsen UNI VERSITET

2 Algae as feedstock Why algae? Different products: Bioethanol, biodiesel, biogas. Biorefinery in a complex world Valuable co-products i.e. Proteins, Fertilizers. Type of management Closed system vs Open system Cultivation Reduced biological competition No damage to sea bottom ecosystems 2

3 Aim of the study Compare 4 algae based production systems to biogas considering: Impacts from LCA Circular flows of nutrients Mitigation potential 3

4 1 st Case study = macroalgae in Limfjorden (DK) Cultivation site: 1km seeding line every 200m headlines (total area 3ha). First harvest: Saccharina latissima in Nursery and Seeded phase Best production achieved: 1,5kg dw/m of head line 4

5 2 nd Case study = macroalgae in Aarhusbugten (DK) Cultivation site: head lines 250m. Cultivated species: Saccharina latissima Best production achieved: 18kg dw/m of head line Photos and data from Skøtt 2009,Forskning i Bioenergi nr. 30 5

6 Salinity a main growth enhancing parameter? Salinity and probability of presence of wild Saccharina latissima Growth optimum at 22 PSU Salinity of Limfjorden 26 PSU vs Aarhusbugten 22PSU 6

7 3 rd Case study: macroalgae in Rymättylä and Tvärminne (FI) Low input cultivation system No seeded lines Head lines 23m Mixed culture of macroalgae and mussels Figure and photos from Milla Suutari 7

8 4 th Case study = microalgae in Finland Potential production system based on Chlorella vulgaris. Growth calculated based on light availability Open ponds system Nutrient assimilation from Suomenoja WWTP CO 2 assimilation from Suomenoja power plant 8

9 Macroalgae- Limfjorden/Aarhusbugt Macroalgae-Finland Microalgae-Finland AARHUS Systems visualization Nursery Cultivation Biomass production Seeding Deployment Deployment CO2 injection Harvest Paddlewheel Harvest Harvest Preconcentration Centrifugation Process Anaerobic digestion Considered insignificant variation among the systems Output Methane Fertilizer From cradle to gate Functional unit = 1m 3 CH 4 Avoided product = Mineral fertilizer production and use BioProd S1 + Process S1 > BioProd S2 + Process S2 Assuming Process S1 Process S2 Then BioProd S1 > BioProd S2 9

10 Life Cycle Assessment results Climate change Macro FI vs Macro DK = Emissions nursery phase and seeding phase are greatly compensated by the increased productivity Limfjorden vs Aarhusbugten = water chemical parameters affect the overall ecoefficiency Method utilized: ReCiPe Midpoint (H) V1.06 / World ReCiPe H 10

11 Life Cycle Assessment results Climate change Macro vs Micro = comparable emissions but coproduct emissions savings higher in Macro Method utilized: ReCiPe Midpoint (H) V1.06 / World ReCiPe H 11

12 Characteristics Feedstock kg VS / kg TS m3 CH4 / kg VS kg N / kg DW kg P / kg DW Mg algae DW / (ha year) Bioavailable P Saccharina latissima Limfjorden a % Saccharina latissima Aarhusbugten b % Chlorella vulgaris c % Polysiphonia sp. d % a) Data from Alvarado-Morales 2013; Gevaert et al. 2001; Annette Bruhn personal communication. b) Data from Alvarado-Morales 2013; Gevaert et al. 2001; Skøtt c) Data from Ras et al. 2011; Collet et al d) Data from Biswas

13 kg P eq / m3 CH4 AARHUS Life Cycle Assessment results Freshwater eutrophication Harvest Monitoring Deployment Seeded lines Mineral fertilizer substitution (Bio_P) Centrifuge (EL_Mix) Preconcentration (EL_Mix) Paddlewheel (EL_Mix) CO2 injection (EL_Mix) MIcro FI MAcro Limfj MAcro Aarhus MAcro FI Pond (concrete) Method utilized: ReCiPe Midpoint (H) V1.06 / World ReCiPe H Avoided product = Mineral fertilizer production and use 13

14 Nutrient/Carbon cycle 14

15 Nutrient/Carbon cycle 15

16 Nitrogen assimilation from macroalgae Assuming 10% of the water surface covered by macroalgae cultivation sites Limfjorden Aarhusbugten Miljøministeriet Forslag til vandplan, Hovedvandopland 16

17 Phosphorus assimilation Assuming 10% of the water surface covered by macroalgae cultivation sites Limfjorden Aarhusbugten Miljøministeriet Forslag til vandplan, Hovedvandopland 17

18 Area required to prevent/remediate Nitrogen Total flow N Fish farms Aquaculture Limfjorden Aarhusbugt Limfjorden Aarhusbugt Limfjorden Area Area Area Area (km2) Area (%) Area (%) Area (%) Area (%) Area (km2) Area (%) (km2) (km2) (km2) MAcro Limfj 270, % 19, % 4, % % % MAcro Aarhus 22, % 1,618 94% % % % MAcro FI 2,139, % 153, % 32, % % % Phosphorus Total flow P Fish farms Limfjorden Aarhusbugt Limfjorden Aarhusbugt Area (km2) Area (%) Area (km2) Area (%) Area (km2) Area (%) Area (km2) Area (%) MAcro Limfj 55, % 4, % 2,417 58% % MAcro Aarhus 4, % % 201 5% % MAcro FI 630, % 54, % 27, % % Miljøministeriet Forslag til vandplan, Hovedvandopland 18

19 Conclusions At this point the low input system does not allow a feasible production The productivity of the biomass crucial for all impact categories Ongoing researches are identifying the influencing growth factors in addition to the seeding technique Integration of micro and macro algae creates the most efficient nutrient loop and i.e. reduced eutrophication 19

20 References Alvarado-Morales, M, Boldrin, A., Karakashev, D.B., Holdt, S.L., Angelidaki, I. and Astrup, T., Life cycle assessment of biofuel production from brown seaweed in Nordic conditions. Bioresource Technology 129, pp Biswas, R., Biomethanation of red algae from the eutrophied baltic sea. Linkoping Univeristy pp 65. Collet, P., Hélias, A, Lardon, L., Ras, M., Goy, R.A. and Steyer, J.P., Life-cycle assessment of microalgae culture coupled to biogas production. Bioresource Technology 102, pp Gevaert, F., Davoult, D., Creach, A., Kling, R., Janquin, M.A., Seuront, L. and Lomoine, Y., Carbon and nitrogen content of Laminaria saccharina in the eastern English Channel: biometrics and seasonal variations. Manninen et al. (in prep) Miljøministeriet Forslag til vandplan, Hovedvandopland. Ras, M., Lardon, L., Bruno, S., Bernet, N. and Steyer, J.F., Experimental study on a coupled process of production and anaerobic digestion of Chlorella vulgaris. Bioresource Technology 102, pp Seghetta, M., Bruhn, A., Carstensen, J., Hasler, B., Bastianoni, S. & Thomsen, M., (In prep.). Factors to be considered to establish a cultivation of Laminaria digitata and Saccharina latissima in Denmark. Skøtt 2009, Fang alger med liner. Forskning i Bioenergi nr. 30 Suutari, M., Seppälä, J., Leskinen, E., Kostamo, K. (In prep.). Artificial substrates in cultivation of macroalgae in the Baltic Sea 20

21 Yearly flow of Nitrogen and Phosphorus Nitrogen yearly inflow Limfjorden Aarhus Bugt Area (km2) Natural Agriculture backgroun (Mg) d (Mg) WWTP (Mg) Rainwater (Mg) Industry (Mg) Scattered houses (Mg) Fish farm (Mg) 1, , , , Aquaculture (Mg) Retention (Mg) Net supply (Mg) 1, , Phosphorus yearly inflow Open land contributions (Mg) WWTP (Mg) Rainwater (Mg) Industry (Mg) Fish farm (Mg) Retention (Mg) Net supply (Mg) Limfjorden Aarhus Bugt

22 1500 km2 water surface 7600 km2 catchment area 1718 km2 water surface 776 km2 catchment area