Session 2 14h25 champenois_ceva

Sustainable Pathways for Algal Bioenergy

Sustainable Pathways for Algal Bioenergy Sustainable Pathways for Algal Bioenergy

Design and trial of a new structure for seaweed production at sea

Jennifer Champenois, Fleuriane Fernandes


Situation

CEVA is a demonstration pilot for seaweed production

Focus of our research = how to improve the cost-effectiveness of the cultivation of kelp at sea – Increase the productivity of the biomass

(kg/m of rope)

– Optimize the occupation of the area at sea to increase the yield (kg/ha)

Facility – Inland hatchery

– 6 ha at sea

• Depth 12-25 m

• Sheltered area with low wave action (1-1.5m)

• Current 3-4 knots at high tides period

Alt = 210 km

CEVA


Situation

Since the 90’s, seaweed production was done on longlines

Space between lines = 50 m because of strong water currents

Even if a good productivity is achieved, the yield per ha would be low


Design of a new structure

Design of « production units » – 20 m width

– 50/100 m long

Idea = semi-rigid framework to strengthen the structure so it’s possible to reduce the space between the lines

11 ropes/unit



General concept

Bouées chalut 5 L (tous les 10

m)

Aussière « centrale » 20

mm

Tube PEHD Ø 315 mm = main tubes

Tuyau PEHD Ø 90 mm

Mooring

Space between lines = 2 m

50 or 100 m long

1000L buoy

Header rope Ø 32 mm

Tube PEHD Ø 90 mm = spacer

5L buoy



General concept: cross-section view



At scale view



Chaîne liège n°1 - Ø 14 mm – L = 3 m

Corps Mort

n°2 - 2T

Corps Mort n°1 - 3,5T

Chaîne n°2 – Ø 25 mm – L =5 m

Ancre 200 Kg

Mooring line design

Aussière n°4 - Ø 32 mm – L = 20 m

Aussière n°5 - Ø 32 mm – L = 10 m

Anneau de liaison n°1 – CMU 14T

Anneau de liaison n°2 – CMU 14T

Mise en place d’une bouée tendeur de 300 L

Tube PEHD n°1 Ø 315 mm L = 20 m

Aussière n°2 - Ø 32 mm – L = 13m

M1 M2 M3

Bouée 1000 L n°1 -

M4

M5 M6

M7 M

8

M10

M9

Chaîne n°3 – Ø 25 mm – L =10 m

M11

M12

M13

M14 M

15 M16

M17

Mooring study



Total cost = 40 000 €

– For the 4 production units (2 of 50 m long + 2 of 100 m long)

– Including feasibility study + PEHD tubes + anchoring equipment

Pros & Cons

Fall 2013 : set-up of the units at sea

Pros Cons

Higher yield per ha Strong tension

Less moorings to survey Boat should be well-adapted: not too large


Cultivation trial

Two species are grown – Alaria esculenta (AE)

– Saccharina latissima (SL)

Dec 2013-Jun 2014: First trial at the new structure

Species Origin Density 1 (spores/m)

Density 2 (spores/m)

Date of seeding

Date of transfer at sea

Time at hatchery (days)

AE Ile Grande 368 000 61 333 04/12/2013 14/01/2014 41

SL Pors Rand 8 460 000 1 410 000 05/11/2013 11/12/2013 36

Direct seeding of spores onto strings


Monitoring of biological & biochemical data

Monthly monitoring from March to June

Measurement of :

– Productivity ( g FW per m of rope)

– Density of plants (number per m of rope)

– Morphological characteristics of the 12 largest plants (total length, length of stipe, width, weight, weight of stipe)

– Dry matter

– Sampling for biochemical analysis of the biomass

Blade Width

Peteiro et Freire, 2012

Total Length


Monitoring of environmental data

Underwater Light Intensity

Nutrients

Underwater Temperature

0

50

100

150

200

250

0:00

2:00

4:00

6:00

8:00

10:0

0

12:0

0

14:0

0

16:0

0

18:0

0

20:0

0

22:0

0

PAR

(µ

E/m

²/s)

Time

Nov

Dec

Jan

Feb

March

Apr

May

Jun

9

10

11

12

13

14

0:00

2:00

4:00

6:00

8:00

10:0

0

12:0

0

14:0

0

16:0

0

18:0

0

20:0

0

22:0

0

°C

Time

Nov

Dec

Jan

feb

March

Apr

May

Jun

0

5

10

15

20

Jan Feb March Apr May Jun July

µm

ol/

L

month

NO3 + NH4 + NO2

2012

2013

2014

0

0,1

0,2

0,3

0,4

Jan Feb March Apr May Jun July

µm

ol/

L

month

PO4

2012

2013

2014


Results: density of plants

SL: no difference between seeding densities

AE: difference between seeding densities decreases over time. At the end, there is no difference anymore between the two densities 0

200

400

600

800

1000

1200

1400

1600

1800

March April May June

Nu

mb

er

of

pla

nts

pe

r m

ete

r

SL density 1 (8.5 M spores/m) SL density 2 (1.4 M spores/m)

AE density 1 (0.6 M spores/m) AE density 2 (0.4 M spores/m)

540 plants/m

268 plants/m


Results: productivity

For both species: no difference between seeding densities

Higher productivity achieved with SL

Density used to seed AE might have been too low



0

5000

10000

15000

20000

25000

30000

35000


Yie

ld (

g fr

esh

wei

gh p

er

me

ter)

20.3 kg/m

9.9 kg/m


Results: morphological characteristics of plants



0

5

10

15

20

25

30


Fro

nd

Wid

ht

(cm

)

With this low seeding density, AE had higher width than usual possible interest for downstream processing


Results: morphological characteristics of plants



30 cm

Zone épiphytée

60 cm

Zone épiphytée

FF, 2013 0

50

100

150

200

250

300


Tota

l Len

ght

(cm

)

In the last months, seaweeds get epiphyted. It’s especially the case for AE in 2014

It’s recommended to harvest before that time to prevent the loss of biomass and quality. A good time to harvest at our site is April-May.


Results: biochemical composition

0

10

20

30

40

50

60

70

Fin avril Fin mai Fin juin

% D

W

Glucose

Fucose

Ac. Glucur.

Galactose

Ac. Gulur.

Ac. Mannur.

Mannose

Mannitol

Acide glutamique

Protéine

Seasonal variation of biochemical composition of Saccharina

April May June

Time of harvest can be decided depending on biochemical composition


Results to come

Crop management: comparison of two techniques

A) One harvest per year, in Spring

B) Two harvests per year (1st in Spring, 2nd in Autum after regrowth of the blade)

1st harvest, above the meristem

2nd harvest, full plant One harvest, full plant


Results to come

Crop management: comparison of two techniques

Crop management

Species Yield at 1st harvest

Yield at 2nd harvest

Total yield

A Saccharina 140 kg 140 kg

B Saccharina 150 kg To come To come


Perspectives within the EnAlgae project

New trial is planned in 2014-2015 – At 50 m-unit, keeping a distance of 2 m between the lines

– At 100 m-unit, increasing the space between the line to 4 m

4 species – Alaria esculenta

– Saccharina latissima

– Laminaria digitata

– Laminaria ochroleuca

Seeding technique: comparison of two techniques – Direct seeding of spores on strings (which are then coiled around the rope)

– Direct seeding of spores on ropes (which are transfered at sea right after seeding) - No maintenance of plantlets at sea so it’s a cheapest option

Growing demand on the French market


Further perspectives

Production model that is – More profitable than only

seaweeds. Combination of low (seaweeds) and high-value (salmon) products

– More sustainable than only fish. Bioremediation of animal wastes by seaweeds

Future research to be studied at CEVA – N balance within an IMTA site

– Other environmental concerns

– Potential increase in yield of seaweeds

10 tons 20 tons 50 to 100 tons

Objectives:

IMTA: seaweeds + salmon + mussels


Thank you

[email protected]

mailto:[email protected]

Session 2 14h25 champenois_ceva

Technology

Transcript of Session 2 14h25 champenois_ceva