Cultivation of Ulva lactuca for bioenergyfileadmin.cs.lth.se/luarchive/ · NATIONAL ENVIRONMENTAL...

NATIONAL ENVIRONMENTAL RESEARCH

INSTITUTE

AARHUS UNIVERSITYMalmö 29.11.2010

Cultivation of Ulva lactuca for bioenergy

Bruhn A, Rasmussen MB, Dahl J, Nikolaisen LS, Nielsen HB,

Thomsen AB, Sander B and Ravn E


INSTITUTE

AARHUS UNIVERSITY Malmö 29.11.2010Cultivation of Ulva lactuca for bioenergy

Ulva lactuca

› High growth rates in natural Danish

habitats (35% d-1)1

› High production potential 2,3

› Green tide species

› Easy to grow

› High content of carbohydrates

(>50%) 4

› Good model macroalgae for R & D

on energy production from marine

biomass

1: Pedersen & Borum 1996. 2: Msuya & Neori 2008. 3: Robertson-Anderson et al 2008. 4: Smith & Montgomery 1959.


INSTITUTE


”Energy production from marine biomass (Ulva lactuca)”

› Funded by Energinet.dk (8.5 mio DKR = 1.5 mio USD)

› 2008-2011

› Aims:

› Production potential

› Suitability for energy conversion› Combustion

› Gasification

› Bioethanol

› Biogas (methane)

› Integration into power plants› CO2 capture

› prolonging of growth season by heat from cooling water


INSTITUTE


Project and partners

Harvest,

conditioning and

characterisation

Integration into

powerplants

Bioethanol and

biogas

Cultivation and

optimisation

http://www.dongenergy.com/DA/


INSTITUTE


Publication

http://dx.doi.org/10.1016/j.biortech.2010.10.010


INSTITUTE


Midway status

Results

› Production potential

› Optimisation of growth by CO2 capture

› Conditioning and storage

› Energy conversion

› Combustion

› Ethanol

› Biogas (methane)

Summary

Future aims


INSTITUTE


Production potential

Cultivation facility 5

› 56º 47’ 16’’ North (Mors)

› 1 m2 tanks

› continuous aeration

› addition of N and P

› water exchange 6 times

per day

› salinity 25-28.5 psu

› weekly adjustment of

stocking density

5: Bidwell 1985


INSTITUTE


0

100

200

300

400

1 2 4 6 8

Biomass density (kg ww m-2

)

Bio

ma

ss

yie

ld

(g w

w m

-2 d

ay

-1)

0

5

10

15

20

Gro

wth

ra

te (

% d

-1)

Production potential

Optimal stocking density = 4 kg m-2 (N=3)

Light

limitation

Nutrient

limitation

6: Bruhn et al, 2010


INSTITUTE


Production potential (4 kg m-2)

-100

0

100

200

300

400

500

600

12-05-2008 01-06-2008 21-06-2008 11-07-2008 31-07-2008 20-08-2008 09-09-2008

Date

Yie

ld m

-2 d

ay

-1 (

g w

w)/

irra

dia

nce (

mo

l p

ho

ton

s d

ay

-1 m

-2

-4

0

4

8

12

16

20

24

Wate

r te

mp

era

ture

(d

eg

rees C

)

Biomass yield

Light

Temperature

RGR (% d-1): Average: 3.03 ± 2.85 (SD). Range: -2.07 to 9.38.



INSTITUTE


CO2 capture from fluegas

› pH controlled (7.5)

› three treatments

› atmospheric air

› CO2 12%, O2 6%

› flue gas from wood pellets

› nutrient replete

› three replicates

› duplicate experiments

› increase of production

by up to 25%

› fluegas = CO2

0

10

20

30

40

50

1

Treatments

Gro

wth

ra

te (

% d

-1)

Air CO2 Flue gas


INSTITUTE


Production potential - summary

› 45 T dw ha-1 season-1

› 2-5 times landbased

energy crops

› production can be

optimised regarding

› CO2 addition

› fertilisation – more N and P

› minimising sporulation

› more light

0

10

20

30

40

50

Willow

Switc

hgrass

Pop

lar

Hemp

Misca

nthu

s

Ulva lactuc

a

Energy crop

Yie

ld (

odt ha

-1 y

ear-1

)


INSTITUTE


Conditioning and storage

› For futher processes

› Avoid sand at harvest

› Avoid salt – or rinse

› Screwpress

› reduction to 30 % water content

› Pelletisation

› Unproblematic

› Water content of 17.5 % and a

density of 800 kg m-3

› Compression of biomass by a

factor 12


INSTITUTE


10.0

12.0

14.0

16.0

18.0

20.0

22.0

wood pellets

wheat straw

Ulva pool 08

Lower heating value, MJ/kg (dry)

wood pellets wheat straw U. lactuca

Combustion

Heating value

0.4 % 6 % 14-30 %Ash % DW


INSTITUTE


Combustion

› Ash analysisUnit(dry basis)

Ulva lactuca

Laminaria digitata7

Wheat straw

Debarked softwood

Ash Wt% 16.5 25.75 6 0.4

K mg/kg 26,400 36,600 2,725 183

Na mg/kg 16,500 43,300 177 7

Mg mg/kg 18,150 9,325 781127

S mg/kg 19,800 - 2,100 150

Cl mg/kg 15,840 - 3,522 76

P mg/kg 1,617 8,750 155 20

6: Bruhn et al, 2010. 7: Jenkins et al 1998. 8: Ross et al 2008.

Alkali index (moderate to severe fouling): 0.17-0.34 7

Alkali index algae ulva/brown: 1.2–5.036/2.034-6.1638


INSTITUTE


Combustion – summary

› High ash content – lower heating

value

› High alkali content

› Not recommendable for direct

combustion

› Potential for use in co-firing with

other fuel types


INSTITUTE


Bioethanol

› Large fraction of Ulva

lactuca sugars are C5

sugars

› Poor Saccaromyces

fermentation

› Approximately 4 % ethanol

yield (ww) (9)

› Salt inhibits fermentation

› alternative microorganisms

for fermentation

9

9: Isa et al 2009

C6 C6 C6

C5C5 C5

From Isa et al 2009


INSTITUTE


Biogas187

157

200

171174

271

176162

0

50

100

150

200

250

300

350

Batch 1,

control

Batch 2 Batch 3 Batch 4 Batch 5 Batch 6 Batch 7 Batch 8

Me

tha

ne

yie

ld (

ml g

VS

-1)

(b)

0

50

100

150

200

250

300

350

0 10 20 30 40 50 60 70

Time (days)

Me

tha

ne

pro

du

ctio

n (

ml)

Batch 1

Batch 2

Batch 3

Batch 4

Batch 5

Batch 6

Batch 7

Batch 8

Inoculum 55

Inoculum 37

(a)

12

96

1810 11

1311

13

0

20

40

60

80

100

120

Batch 1,

control

Batch 2 Batch 3 Batch 4 Batch 5 Batch 6 Batch 7 Batch 8

We

igh

t sp

eci

fic m

eth

an

e p

rod

uct

ion

(m3 t

-1)

(c)

› washed - - + + + + - -

› dried - - - - - - + -

› macerated/chopped C M C M C C - C

› 55°C/37°C 55 55 55 55 55 55 55 37

› pretreatment 110°C/20 min 130°C/20 min


INSTITUTE


0

0,1

0,2

0,3

0,4

0,5

0,6

M. p

orife

ra

A. n

odos

um

S. lat

issim

a

S. f

luita

ns

G. t

ikva

hiae

Cha

etom

orph

a sp

.

U. lac

tuca

Whe

at s

traw

Turf g

rass

Man

ure

m3 C

H4 k

g-1

VS

Biogas - summary› yield in same range as other

algae 10

› lower/same range as landbased

energy crops and manure 10,11, 12

› optimisation by N starvation

› removal of inhibitors – salt &

sulphur

10: Gunaseelan et al 1997. 11: Lehtomäki et al 2008. 12: Hansen et al 2006


INSTITUTE


Midway project summary

› High production potential – 45T DW ha-1 season-1

› Potential for increase of production by CO2/fluegas

addition

› Excellent pellitisation

› Not recommendable for direct combustion

› Low bioethanol yields with Saccharomyces

› Reasonable biogas yields with existing technology


INSTITUTE


Future aims - 2011and beyond› Production

› growth on municipal waste water and manure

› optimisation of carbohydrates composition through nutrient starvation

› Combustion

› co-firing capacities

› gasification

› Bioethanol

› alternative strains

› Biogas

› sulphur stripping

› optimisation of inoculum

› Integration into power plants

› effect on growth of flue gas from coal and straw


INSTITUTE


Algae Center Denmark• 12 tanks of 2 m3

• 2 separate lines * 6 tanks

• recirculated seawater (freshwater)

• automated addition of air/nutrients/CO2/heat

• National Environmental Research Institute,

Technological Institute, Kattegatcentret, House of

the Ocean


INSTITUTE


In a broader perspective

› landbased cultivation of Ulva will not be economically

viable for energy production only

› extraction of high value products – then use waste products for energy

› protein fraction for feed/food/fertiliser

› applications for the ulvan fraction (up to 29%of DW) 13

› value of ecosystem services - biomitigation› CO2 capture

› N and P removal and recycling

› sustainable harvest from natural populations› necessary studies on the management of wild stocks

13: Lahaye & Robic 2007.


INSTITUTE


Thank you for your attention

[email protected]

Bruhn, et al, 2010: http://dx.doi.org/10.1016/j.biortech.2010.10.010

www.AlgeCenterDanmark.dk


INSTITUTE


Productivity and light

-20



INSTITUTE


Tissue C:N and light



INSTITUTE


Monosaccharides and light



INSTITUTE


-2

0

2

4

6

8

5 10 15 20 25 30

C:N ratio

Gro

wth

rate

(%

d-1

)

Production limitations

› Nutrient limitation at low biomass densities


INSTITUTE


Production limitations

› Light limitation at high biomass densities

0

50

100

1 kg 4 kg 8 kg

Biomass m-2

Irra

dia

nc

e (

% o

f

su

rfa

ce

irr

ad

ian

ce

)

Surface Mid-depth (30 cm) Bottom (60 cm)Irradiance at


INSTITUTE


Combustion Ash content 6

Daylength / sea temperature 6

6: Lamare & Wing 2001

Cultivation of Ulva lactuca for bioenergyfileadmin.cs.lth.se/luarchive/ · NATIONAL ENVIRONMENTAL...

Documents

Transcript of Cultivation of Ulva lactuca for bioenergyfileadmin.cs.lth.se/luarchive/ · NATIONAL ENVIRONMENTAL...