Workshop - 23. august 2006 – Skejby, ÅrhusDansk Landbrugsrådgivning – Landscentret

Optimering af biogasproduktion med fokus på energimajs- Energiafgrødepotentiale til bioraffinering

Jens Bo Holm-Nielsen

Afdelingsleder - BioenergigruppenSyddansk Universitet Esbjerg & Aalborg Universitet Esbjerg

Niels Bohrs Vej 8-10, DK-6700 EsbjergTlf.: 7912 7715, mobil: 2166 2511

E-mail: jhn@aaue.dkHjemmeside: www.acabs.dk & www.sdu.dk/bio

Energy crops Paradigm shift through land productivity and energy balance

Biogas

Gas cleaning

Heat Electricity Fuel

Fermenter

Digestedplant residue

• The Sun as energy source

• Special energy crops that use the entire vegetation period

• Total digestion of the whole plant

• Nutrient cycle possible Low Input High Output

• Large installations work efficiently and are friendly towards the environment

• Upgrading of biogas enables complete utilisation of the crop (the gas can be stored)

Optimisation of the biomass productionVegetation periodAverage intensity of the sun radiation during the year(Simplified model for Göttingen, Germany)

The global sun radiation reaches an average of approximately 1000 KWh/m2 in the southern part of Niedersachsen, Germany.This energy is used by green plants in the photosynthesis to create biomass.At the end of Juli in modern agriculture most of the fields are no longer green.There are no longer active parts available to conduct the photosynthesis.Demand: In order to take full advantage of the energy contained in the sun radiation using photosynthesis, varieties that are utilising the vegetation period to its maximum should be developed and used. This means green fields all year round.

Month

KWh / m2

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Sun light

Source: Report from the Danish working Group on the Co-existence of Genetically Modified Crops with Conventional and Organic Crops (DJF, 2003)

Cultivation target: stepwise increase of the energy yield to approximately 100 % in 10 years

Nowadays silo

maize varieties

Energy Maize

15 - 18 t/ha

30 t/ha

Source:KWS

Objective of the energy maize cultivation

• Implementation of short-day genes

• Cold tolerance in late varieties and late growing season

• Nutrient / water efficiency, drought resistance

First variety announcement in 2005

Commerciel varieties available from 2007(Source KWS)

Growth Progress of a Conventional Silo Maize (SM) and an Energy Maize (EM) Clearly later harvest of the Energy Maize

GTM-yield/ha

Flowering

SM

FloweringEM

HarvestSM

HarvestEM

TimeSource: KWS

Biomassetype Biogasudbytte[L / kg VS]

Methanudbytte[L CH4 / kg VS]

Testmetode Reference

Majsensilage - 181-184 Kontinuerlig Amon et. al.*

Majsensilage - 270-289 Batch do.

Majsensilage 800 - - do.

Majsensilage - 290 Batch (meso, 50 d) AAUE

Majsensilage - 210 Batch (termo, 17 d) do.

Majsensilage - 310-350 Batch (meso, 90 d) DJF

Græsensilage - 199-244 Kontinuerlig Amon et. al.*

Græsensilage - 298-315 Batch do.

Græsensilage 500-600 - - do.

Græs - 433 Beregnet do.

Græs 678-929 - Batch do.

Kløver - 350 Batch do.

Kløver 500-650 - - do.

Kløver 264 152 Kontinuerlig do.

Biogaspotentiale for udvalgte energiafgrøder

*) Amon et. al. (2003): Optimierung der Biogaserzeugung aus den Energiepflanzen Mais und Kleegras

Tørstof Organisk tørstof Methan Biogas

[ ton TS per ha ] [ ton VS per ha ] [ Nm3 per ha ] [ Nm3 per ha ]

10 9,1 2 640 4 790

12 10,9 3 160 5 750

14 12,7 3 690 6 710

16 14,6 4 220 7 670

18 16,4 4 750 8 630

20 18,2 5 270 9 590

22 20,0 5 800 10 550

24 21,8 6 330 11 500

Forudsætninger:

TS = 1,10 x VS; methanudbytte = 290 L per kg VS; methanandel = 55 Vol-%

Biogaspotentiale for energimajs i Danmark

Kilde: Amon et. al. (2003): Optimierung der Biogaserzeugung aus den Energiepflanzen Mais und Kleegras

Biogaspotentiale for energimajsafgrøder

Kilde: Amon et. al. (2003): Optimierung der Biogaserzeugung aus den Energiepflanzen Mais und Kleegras

Biogaspotentiale for energimajsafgrøder

Perspectives for crop cultivation

Source: KWL

Effect of the variety and the ripeness on the methane productionSource: AMON et. al. 2003

180

200

220

240

260

280

15 20 25 30 35 40 45 50 55

GTS %

CH

4 N

l/k

gT

M

Sort B

Sort R

Sort P

Sort A

Sort S

Source: KWS

LP92_ Wesel, 90 BC1S1-lines from (5G3552 x Mex) x Flinttester + 10 Standards

GAVOTT

2

3

4

5

6

7 8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31 32

3334

35

36

3738

39

40

41

4243

44

5F279

46

47

4849

50

MIKADO

52

53

54

55

56

57

58

59

60

MONSONE

62

63

64

66

67

68

69

70

BENICIA

72

7374

7576

77

78

79

80

81

8283

84

85

86

87

88

89

5G355

91

5G355

5G355

94

5F279

96

5F279

98

99

100

220

240

260

280

300

320

340

25 30 35 40 45GTS %

GT

M d

t/h

a

Source: KWS

World energy scenarios – Goals for the futureNo. Source

1. Non collected straw (50%) 75 000 PJ/year Sanders J.: Biorefinery, the bridge between Agriculture and Chemistry. Wageningen University and Researchcenter. Workshop: Energy crops & Bioenergy.

2. Collected waste processing (50%)

45 000 PJ/year

3.Forest/pastures (50%) 150 000 PJ/year

4. 10% of arable land – World Wide (20tTS/ha)

50 000 PJHolm-Nielsen J.B., Madsen M.,

Popiel P.O.: Predicted energy crop potentials for biogas/bioenergy. Worldwide – regions – EU25. AAUE/SDU. Workshop: Energy crops & Bioenergy.

5. 20% of arable land – World Wide (20tTS/ha)

100 000 PJ

6. 30% of arable land – World Wide (20tTS/ha)

150 000 PJ

Sum: 1+2+3+5 370 000 PJ  

Predicted value Source

Total energy required 2050 1 000 000 PJ/year

Sanders J.: Biorefinery, the bridge between Agriculture and Chemistry. Workshop: Energy crops & Bioenergy.

Total energy demand 2050 1 300 000 PJ/year Shell’s World Energy Scenario

Konklusioner:

Methanudbyttet fra energimajs er stærkt afhængigt af dyrkningsoptimering og Høsttidspunktet.

1. Energiafgrøder er et upåagtet eller et endnu ikke værdsat, uopdyrket område med et stort potentiale indenfor biogasproduktionen i Danmark.

2. Der har siden år 2000 foregået en kraftig og interessant udvikling i Tyskland og Østrig. I Østrig er der etableret ca. 200 gårdbiogasanlæg frem til 1/7 2006 efter en specifik ordning der sattes i kraft i 2003. Det største område indenfor afgrøder er majsensilage og græs anvendelse, omsat i biogasanlæg sammen med husdyrgødning eller som rene energiafgrødeanlæg.

3. Der er en spændende udfordring foran os, hvor landbrugets primærproduktion, er råvareleverandør af husdyrgødning og afgrøder, så biogasanlæg primært kan omsætte gårdens egene produkter. Dermed kan man evt. nedtrappe leverancerne af organisk industriaffald.

4. Med husdyrgødning og afbalanceret afgrøde tilsats er biogasudbytter på 35-40 m3 biogas/m3 biomasse opnåelige.