life cycle assessment and cost analysis of bioenergy...

2010Maria Stenull Tomsk Polytechnic University 1

Life Cycle Assessment and CostAnalysis of Bioenergy Systems

Maria StenullInstitut für Energiewirtschaft und Rationelle Energieanwendung

Uni Stuttgart

22-26.11.2010Tomsk Polytechnic University


• Life Cycle Assessment (LCA) of Bioenergy Process Chains – General Overview

• LCA of Energy Crop and Wood Cultivation

• LCA of Electricity Generation from Biogas

• Cost Analysis

• CO2-Abatement Costs

• Conclusions

Agenda

2010Maria Stenull Tomsk Polytechnic University

Burning / combustion

Pyrolysis-oil

Synthesis-gas

BiodieselRME

Plant-oilFAME Ethanol BiogasChar-

coal

physic.-chem.conversion

pressing/extractionesterification

biochemical conversion

Anaerob.degradat.

Alcohol-ferment.

Aeroberdegradat.

Conversion with heat

Carboni-sation

Liquifi-cation

Gasifi-cation

Biomass (Residues, Energie Crops, Side Products, Waste)

Heat / SteamCold Electricity

Synthetic (BTL) / Liquid Fuels

Mobility

Compost

DirectCombustion

Raw material use

Many Technologies, Process Chains and Products!

2010 4Maria Stenull Tomsk Polytechnic University

Life cycle assessement of bioenergy process chains

Machine DieselMachine DieselFertilizer

Machine DieselPesticides

Process energyCorn Machine Diesel

MachineBuilding Materials

Process energy

Global Warming Potential, Ozone Depletion Potential, Acidification, Eutrophication, Cumulative Energy

Demand, etc.

Life

Cyc

leIn

vent

ory

Ana

lysi

sIm

pact

Ass

essm

ent

Raw material ProductionProduction and Use Recycling

Storage and Pre-

processingTransport


• Life Cycle Assessment (LCA) of Bioenergy Process Chains –General Overview



• Cost Analysis


• Conclusions

Agenda

2010 6Maria Stenull Tomsk Polytechnic University

Fertilizer Machine Pesticides Process energy

Cuttings

Building Materials

recultivationtransport 2 storage –end user

storagetransport 1field –

storage

HarvestOptional

Fertilizing

main-tenance

plantingfield preparation

Diesel Machine Diesel

Machine Pesticides

Diesel Machine Diesel

Machine Diesel

Machine Diesel

Life cycle assessment of bioenergy process chains-cultivation of short rotation coppice (SRC)


185214

312

73101

36

1717

24

1512

10

0

50

100

150

200

250

300

350

400

Silomais WW GPS Grasschnit t Stroh Pappeln WRH CM

L200

1 - T

reib

haus

pote

ntia

l (G

WP

100

Jahr

e)

[kg

CO

2-Ä

qv./t

TM

]

Max. Transportw egeAnbau, Ernte und Lagerung

7

Global Warming Potential –Crop and Wood Cultivation

Biogas plant feedstock: Grass silage production has the highest GHG-Emissions due to higher Nitrogen content Gasification or wood-fired power plant feedstock: Short rotation coppice has the highest GHG emissions due to most demanding cultivation process

biogas plant feedstockTransport: 10 km (Tractor)

gasification plant or wood-fired power plant feedstockTransport: 80 km (Lorry)


Primary Energy Demand –Crop and Wood Cultivation

Primary Energy Demand shows similar characteristics as GHG-Emissions

1789 1955

3100

817 1032557

275259

373

202158

131

0

500

1000

1500

2000

2500

3000

3500

4000

Silo mais WW GPS Grasschnit t Stroh Pappeln WRH Prim

ären

ergi

ebed

arf a

us R

esso

urce

n (u

nter

er

Hei

zwer

t) [M

J/ t

TM]

Max. Transportw egeAnbau, Ernte und Lagerung

biogas plant feedstockTransport: 10 km Traktor

gasification plant or wood-fired power plant feedstockTransport: 80 km Lorry





• Cost Analysis


• Conclusions

Agenda


Biogas Plant Facility - general operating scheme

Source: http://www.ppm-biodiesel.com

ResidueEnergy crops

1. Stable2. Liquid manure storage3. Collecting basin/

Storage area4. Anaerobic digester5. Gas accumulator6. CHP Unit7. Storage tank8. Agricultural crop land

Electricity

Heat

Digestedresidues


System boundary Electricity generation from biogas

(Feedstock: maize silage, liquid manureFunctional unit: 1 kWhel)

Residues(maize silage) CHP-Unit

BiogasElectricity

Heat

Anaerobic digester

Emissions from untreated manure

Anbau

Mineral fertilizer credit

Fertilizing with mineral fertilizer

Fertilizing with digested maize

Electricity-Mix DE

Heat-Mix DE

Legend: Reference system

Emissions from digested manure

Digested residues credit

Residues (liquid manure)

Fallo

w la

nd


47%

42%

22%

15%

30%

8%

6%

4%

5%

5%

24%

34%

50%

53%

43%

5%

3%

6%

7%

5%

11%

12%

13%

13%

12%

4%

2%

4%

5%

4%

0% 20% 40% 60% 80% 100%

≤150 kW

151 - 325 kW

326 - 500 kW

≥501 kW

Gesamtpo

wer

cap

acity

[kW

]

feedstock [% moist mass]

liquid manure solid manure maize silagewhole crop silage corn meadow grass silageanimal feed sorghum others

12

The more corn and whole crop silage is introduced, the larger the plant is.

The smaller the plant is, the greater is the amount of manure used in the facility

Average feedstock composition (in % moist mass) of biogas facilities in Baden-Wuerttemberg for 2009 by plant capacity

others: chicken manure, Sudan grass, fodder beet, rye, “corn-cob-mix”, feed rest, others


Typische Anlage in der untersuchten LeistungsgrößeModel plants for different capacity classes

Paramter Unit Source1)

Model Plant Number - 1 2 3 4Power Capacity el kWel 100 250 370 526 FB08Power Capacity th kWth 130 270 420 530 FB08

Lifetime of Biogas Facility a 20 20 20 20 AnnahmeTechnical Specification

Type of Engine G-Gas G G G G FB08Engine Efficiency el % 37% 38% 38% 40% FB08Engine Efficiency th % 46% 47% 43% 43% FB08

OperationOrganic Loading Rate kg oDM/m³AD 2,62 3,71 4,85 4,73 FB08

Full Load Hours h/a 7779 7704 7760 7573 FB08Covered Storage Tank for Digested Residues yes/no nein nein teils ja FB08

Heat Utiliziation (internal and external) % Total Heat Generation 21% 16% 35% 39% FB08Electricity Purchase % Total Electricity Generation 6,4% 5,6% 5,4% 6,2% FB08

EmissionsMethane leakage % CH4 1 1 1 1 Lit

Methane slip at CHP % CH4 1,45 1,45 1,45 1,45 LitMethane emissions from digested residues Nm³ CH4/kg oDMDigested Residue 10 10 5 2 Lit

Nitrous oxide emissions from digested residues % N2O-N 0,1 0,1 0,1 0,1 LitNitrous oxide emissions from spreading of digested residues % N2O-N 1 1 1 1 Lit

Methane emissions from manure storage kg CH4/m³ Manure 1,64 1,64 1,64 1,64 LitNitrous oxide emissions from manure storage % N2O-N 0,1 0,1 0,1 0,1 Lit

1) FB08 - Questionnaire 2008, Lit - Literature

Modelfacilities


Gabi Model – Electricity generation from biogas


Electricity-Mix DE

Strommix 2008 DEEnergieträger %

Braunkohle 24Kernenergie 23Steinkohle 20

Erdgas 14Mineralölprodukte 1

Sonstige 4Erneuerbare darunter 15

Wasserkraft 3Windkraft 6Biomasse 4

Photovoltaik 1Geothermie 0

Müll 1SUMME: 100

The GHG-Emissions of Electricity-Mix DE equal to 0,619 kg CO2 Äq./kWhel

Electricity from brown coal and hard coal power plants have highest contribution to the GHG-emissions

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7

Strommix DE 2008

Treibhausgaspotenzial [kg CO2 Äq./kWhel]

Holzheizkraftwerk

Braunkohlekraftwerk

Kernkraftwerk

Ölkraftwerk

Steinkohlekraftwerk

Wasserkraft

Photovoltaik

Sonstige

Gasturbine

GuD Kraftwerk

Windkraftanlage

6195,1Electricity-Mix DE 2008

GHG-Emissions[g CO2 Äq./kWhel]

Electricity Generation Costs[Cent/ kWhel]Reference System


GHG-Reduction (Reference System Electricity-Mix DE)

Gesamteinsparung

-0,503

-0,455

-0,502

-0,495

-1,0 -0,8 -0,6 -0,4 -0,2 0,0 0,2 0,4 0,6

100 kW

250 kW

370 kW

526 kW

Anla

geng

röße

[kW

el]

THG-Emissionen [kg CO2 Äq./kWhel]


-0,503

-0,455

-0,502

-0,495

-1,0 -0,8 -0,6 -0,4 -0,2 0,0 0,2 0,4 0,6

100 kW

250 kW

370 kW

526 kW

Anla

geng

röße

[kW

el]


THG-Reduction

Electricity-Mix Credit

Heat-Mix Credit

Crop Cultivation

Construction and Recycling

Anaerobic Digester

CHP-Unit

Storage Tank

Spreading of Digestate

Digestate-Credit

Fallow Credit

Mineral Fertilizer Credit

17

GHG-Reduction (Reference System Electricity-Mix DE) [kg CO2 Äq./kWhel]

The GHG-Reduction for all plant capacities is in the similar range.

CO2-GenerationCO2-Credits


Which measures can improve the operation of biogas plant in terms of GHG-Emissions?

18

GHG-Emissions 250 kW [kg CO2 eq./kWhel]

0,165

0,159

0,116

0,126

-0,045

0,038

-0,5 -0,4 -0,3 -0,2 -0,1 0,0 0,1 0,2 0,3 0,4 0,5

Gesamt Basis

Volllastanteil (8000 Vh)

Methanschlupf (verringerte CH4-Emissionen)

Geschl. Gärrestlager (verringerte CH4-Emissionen)

Wärme (70% Gesamtw ärme)

Max


Anlagengröße

Gesamtemissionen

Prozessstrombedarf

Wärmemix Gutschrift

Anbau

Bau und Entsorgung

Fermenter

BHKW

Gärrestlager

Ausbringung der Gärreste

Gärrestgutschrift

Gutschrift Brache

Mineraldüngerersatzgutschrift

AufwendungenGutschriften

Sensitivity Analysis: Biogas Plant 250 kW

BaseIncrease in full load hous Methane sleep 0,45% Covered storage tanksHeat utlization 70%Max





• Cost Analysis • CO2-Abatement Costs

• Conclusions

Agenda


9 9 15 15 5

3214 17 1423

32 3541

24

2941

6871

69

24

36 10

6

87

7

7

7

6

1211

13

9

10

151143

117

78

160

90

0

20

40

60

80

100

120

140

160

180

200

Silomais WW GPS Grasschnitt Stroh Pappeln WRH

Brennstoff bzw. Substrat

Ber

eits

tellu

ngsk

oste

n fr

ei A

nlag

e [€

/tTM

] Lagerung Transport Schlepper 5kmTransport Feld-Zwischenlager 2kmAnbau und Ernte: Variable KostenAnbau und Ernte: Fixe KostenAnbau und Ernte: PachtAnbau und Ernte: Personalkosten

20

Cost Analysis – Biomass generation system

Biogas feedstock:•Variable Costs (Fertilizers, Diesel, Corn) have highest contribution to the total biomass generation costs

•Storage and transportation costs are in the similar range and independent of production process

Wood-fired power plant feedstock: •Fix costs of wood residues have highest contribution to the total biomass generation costs

WW GPS - Winterweizen GanzpflanzensilageWRH - Waldrestholz


0

5

10

15

20

25

30

35

40

45

50

Silomais WW GP Grünschnitt Stroh Pappeln WRH

Tran

spor

tkos

ten

frei

Anl

age

[€/t

TM]

1 km Entfernung Schlepper2 km Entfernung Schlepper5 km Entfernung Schlepper10 km Entfernung Schlepper20 km Entfernung LKW80 km Entfernung LKW

21

Cost Analysis –Transport distances

• Biogas plant feedstock: Transportation costs do not depend on feedstock type

• Wood-fired power plant feedstock: Transportation costs do not depend on feedstock type at distances of 5km. Straw has highest costs for transportation distances of 20km and 80 km to the facility

0

5

10

15

20

25

30

35

40

45

50

Silomais WW GPS Grasschnitt Stroh Pappeln WRH

Tran

spor

tkos

ten

Lage

rung

sort-

Anl

age

[€/t

TM]

1 km Entfernung Schlepper2 km Entfernung Schlepper5 km Entfernung Schlepper10 km Entfernung Schlepper20 km Entfernung LKW80 km Entfernung LKW


Electricity Generation Costs – Biogas model plant [Cent/kWhel]

Electricity generation costs ranges between 16 and 18 cent/kWhel

Plant capacities 250 kW and 370 kW have lowest generation costs angelehnt an Vidjen 2010

* Mit anteiliger Wärmenutzung in der Größenklasse

15,916,6526 kW

15,516,0370 kW

16,016,1250 kW

18,618,7100 kW

Basis* mit Wärmeerlösohne Wärmenutzung

Stromgestehungskosten [Cent/kWhel]

Stromgestehungskosten

Modellanlage





• Cost Analysis

• CO2-Abatement Costs• Conclusions

Agenda


CO2-Abatement Costs (Reference Electricity-Mix DE)

Die CO2-Abatement costs decrease with increasing plant capacity

Die CO2-Abatement equal on the on the average 226 €/t CO2 eq.

226

269

239

207

217

0 50 100 150 200 250 300

100 kW

250 kW

370 kW

526 kW

Mittel BW

CO2-Vermeidungskosten [€2007/ t CO2 Äq.]


CO2-Abatement Costs - Sensitivity

Die CO2-Abatement costs can decrease depending on the measures

226206 206

219

154127

0

50

100

150

200

250

Base Increase infull load hous

Methanesleep 0,45%

Coveredstorage tanks

Heat utlization70%

MaxCO

2-A

bate

men

t Cos

ts [€

/t C

O2

eq.]

• Full load hours: 8000 h/a

• Covered storage tanks

• Methane slip 0,45%

• 70% of total heatutilization


Potential GHG-Reduction through biogas plants in BW

• According to given assumptions approx. 611 1000 t CO2 eq./a were reduced (Reference System: Electricity-Mix DE)

• The potential for GHG-Reduction is still not exhausted

0

50

100

150

200

250

500 550 600 650 700 750 800 850 900Vermiedene Emissionen der Stromerzeugung

aus Biogas in B-W [1000 t CO2 Äq./a]

CO

2-Ver

mei

dung

skos

ten

[€/t

CO

2 Ä

q.]

Base

Increasein full load

Covered storage tanksDecreased methane slip

70% of heat utlization

Max





• Cost Analysis


• Conclusions

Agenda


• The GHG-Emissions for energy crop and wood cultivation are higher for energy crops mainly due to emission-intensive mineral fertilization.

• The GHG-Emissions for biogas plants of different capacities are in the similar range.

Small facilities use lots of manure and utilize small amounts of heat. Bigger facilities use in comparison to small facilities less manure but utilize much more heat.

• The GHG Emissions can be reduced by:new concepts for heat utilization

covering of storage tanks for digested residues and reduction of methane slip and leakage

increase in the full load hours.

Conclusions – German Examples


• With LCA and Cost Analysis different options of

- production,

- processing and

- utilization of energy crops and wood

can be compared and assessed from comprehensive approach

• LCA and Cost Analysis can be filled with regional databases and thus allows for specific (region-oriented) comparative assessment

Conclusions – Overall Implementation


Thank you for your AttentionAny Questions?

Das Projekt wurde gefördert durch das Ministerium für Ländlichen Raum, Ernährung und Verbraucherschutz mit Mitteln der Landesstiftung Baden-

Württemberg

Maria Stenull

Kontakt: Institut für Energiewirtschaft und Rationelle Energieanwendung, IER - Universität Stuttgart Heßbrühlstr. 49; D - 70565 Stuttgart; www.ier.uni-stuttgart.de , Tel.+49-(0)711-685 87870,

[email protected]

life cycle assessment and cost analysis of bioenergy...

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