International Development in Biogas Utilization

A. Schattauer

Johann Heinrich von Thünen Institut (vTI)

Federal Research Institute for Rural Areas, Forestry and Fisheries

Braunschweig / Germany

Renewable Energy Asia 2008

June, 4th 2008 / BITEC, Bangkok

Outline

• Introduction

• Biogas plants & renewables in Germany

• Activities at vTI-Institute

• Process Design and Operating Conditions

Energy Potential

Source: FNR

Biogas plants in Germany

100 120 139 159 186274

370 415617

8501050

1300

16001750

2050

2700

35003750

0

500

1000

1500

2000

2500

3000

3500

4000

Nu

mb

er

of

Pla

nts

1990 1992 1994 1996 1998 2000 2002 2004 2006

Feed-in tariffs for biogas-based electricity

10,99

6

2

2

9,46

6

2

2

8,51

4

2

2

8,03

2

0

5

10

15

20

25

Eu

ro-C

t / k

Wh

el

<150 kW >150 kW - 500 kW >500 kW - 5 MW >5 MW - 20 MW

CHP- Bonus

Technology Bonus

Biomass Bonus

Basic fee

Renewables in Germany

Biogas plants in Germany

100 120 139 159 186274

370 415617

8501050

1300

16001750

2050

2700

35003750

0

500

1000

1500

2000

2500

3000

3500

4000

Nu

mb

er

of

Pla

nts

1990 1992 1994 1996 1998 2000 2002 2004 2006

???

Amendment of EEG (2008)

• The actual draft for the amendment of the EEG has planned to open the input of biogas plants forspecific by-products and residues from industrywithout loosing the biomass bonus.

� Application of biorefinery concepts possible

Activities at vTI

Projects & Programs

EU-Agro-Biogas Project (2007 – 2009)

Objectives:• To improve the degree of efficiency in the fermenter of about 35%

• To increase the biogas yield of about 40%

• To optimise and guarantee quality and safety of digested material

• To improve, optimise and demonstrate selected conversiontechnologies (CHP, heat utilisation)

• To reduce the investment and operational costs of medium and large agricultural biogas plants of about 20 to 30%

European Biogas Initiative to improve the yield of agricultural biogas plants

EU-Agro-Biogas Project

• 14 Partners from 8 countries

• European online substrate atlas / database and standardised methane energy valuation model

• Innovative feeding technology

• Monitoring, management and early-warning system foragricultural biogas plants

National Biogas Evaluation Program (2005 – 2008)

Aims:

Evaluation of new biogas plants build after 2004

• State of the art

• Type of substrates

• Operating conditions

Procedure:

• Pre-evaluation of 346 biogas plants

• Detailed techno-scientific investigation of 60 representativebiogas plants

Substrate application in agricultural biogas plants (2005-2007)

83

152

Energy crops & manure Energy crops Manure

Use of raw materials (2005-2007)

Applied process temperature

0

10

20

30

40

50

60

70

80

90

100

Re

lati

ve

fre

qu

en

cy

[%

]

mesophilic thermophilic combined

Process temperature [°C]

Biogas plants in Germany

Techniques & Design

Two-stage agricultural biogas plant

Dry-fermentation plants with garage fermenters

System BIOFerm® System Bekon®

Discontinously operated dry-fermentation with perkolation

Linde, KCA plant in Hoheneggelsen, Germany

Continuosly operated dry-fermentation plant

DRANCO-FARM plant in Bassum, Germany

Dranco – Verfahren (O.W.S.)

Continously operated dry-fermentation plant with silofermenter (DRANCO-FARM, OWS)

Thank you very much...

…for your

attention !

Use of fermentation residues

• Approx. 80 – 90 % of Input

– Depends on substrates

• Utilization as organic fertilizer

– Decrease of dry matter content

• Improved field application

• fewer losses of ammonia

– Increase of the ammonia content

• Organic nitrogen is converted into ammonia

• Improved availability for plants

Biogas yield & Production rate

hydraulic retention time [HRT]

0 5 10 15 20 25 30

Biogas yield [m³/kg]

Production rate [m³/m³*d]

A

Quelle: Linke, ATB

Simple & Fast: VFA/TAC - Analysis

• Advantages:

– Easy to use (Titration)

– Reliable results for specific plant

• Disadvantages

– VFA = cummulative value

– Redundant dimensioning of VFA

– Sample conditioning affects result

Empiric Method from waste water treatment

anicCarbonTotalAnorg

ttyAcidsVolatileFaTACVFA =/

Conditioning of biogas

Raw biogas

Drying

Water

Filtration

Particles

Desulfuration

H2S

Precision

Cleaning

H2S, NH3,

Cl-Verb.

Reforming

Methane-

enrichment

CO2

Biogas as vehicle fuel

Hydrogen as fuel (fuel cell)

H2

Compression

Biogas

Frequency of use of different substrates

0

10

20

30

40

50

60

70

80

90

Mai

ze s

ilage

Gra

s si

lage

Gra

in h

uskFat

ty W

aste

s

Lawn g

ras

Whey

Food

Veg

etab

les

Pot

atoe

sP

otat

oe p

ulp

Fre

qu

en

cy o

f u

se [

%]

Biogas yield of different substrates

960

714

600

550

230

180

160

130

90

60

60

30

25

0 200 400 600 800 1000 1200

Fatty wastes

Bakery residues

Bread

Grain husk

Maize Silage

Rye silage

Gras silage

Sudan grass

Fodder beets

Beet leaf

Cow dung

Pig manure

Cow manure

m3 Biogas per t Substrate (FM)