Environmental ImpactEnvironmental Impact

of different Power Production Techniques using Biomassof different Power Production Techniques using Biomass

P.P.A.J. van Schijndel, J. Huisman,

J.M.N. van Kasteren and F.J.J.G. Janssen

Eindhoven University of Technology

12

Entrée’99Entrée’99

ContentsContents• Introduction

• Biomass Conversion Technologies

• Technical / Economical Ranking

• Environmental Life Cycle Assessment, LCA

• Results and Discussion

• Conclusions

2.

12

3.

IntroductionIntroductionNeed for Renewable Energy Sources:

• Gravitational Force– Tidal energy / Hydropower

• Sun (Nuclear Fission)– Wind / Solar / Hydropower– Energy from biomass waste or energy crops

• Radioactive Decay Earth Core– Geothermal energy

2.

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• Wastes:– Organic sludge, garden/agricultural

waste, thinning wood, waste wood

• Energy crops:– Poplar, miscanthus, rapeseed etc.

Possibilities in The Netherlands:– Biomass waste: 150 P(1015) J– Equals 4% of total NL power production

Biomass Biomass SourcesSources

4.

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Waste:

• Municipal solid waste

• Sewage sludge

• Industrial waste

• Scrap wood

• Plastic waste

• Paper sludge

• Shredder waste

Most important (bio)fuelsMost important (bio)fuels12

Biomass:

• Forestry Thinning

• Cutting from parks and

gardens

• Residues from wood

processing

• Agricultural residues

• Energy crops

Novem, 19954a.

Biomass Conversion TechnologiesBiomass Conversion Technologies

5.

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Fuel gasCharcoal

Pyrolysis-oil

Heat

SynthesisGasturbineGas engine

Steam turbineSlurry production

Upgradingetc.

Primary product Process technology Secondary productConversion technology

Gasoline, dieselMethanol

ElectricityHeat

Slurry-fueletc.

GasificationPyrolysis

Combustion

Related Technologies:

•Co-combustion and co-gasification

•Hydro Thermal Upgrading, HTU

Technical and Economical RankingTechnical and Economical Ranking

Criteria:

• Technique proven (Pilot Plant);

• Economical feasible within 5 years;

• Feasible in The Netherlands: different

wastes like wood, 5-30 MWe

Sub criteria: Price, Efficiency, Flexibility

6.

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Final Ranking,Final Ranking,

7.

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Of most promising biomass conversion techniques

Table based on Huisman (1999)

Rank Technique / routePrice electricityEURO / kWh

ElectricalEfficiency

1 Co-combustion in a powder coal powerplant with steam cycle

0,02 – 0,06 32 – 44 %

2 Co-combustion of gasifier gas in a normalgas/coal power plant with steam cycle

0,04 – 0,08 30 %

3 Co-combustion of gasifier gas in a gaspower plant (STEG) Combined cycle

0,045 – 0,10 35 %

4 stand alone gasification (atmospheric) influidised circulating bed with combinedcycle, cold gas cleanup, system

0,055 – 0,12 40 %

5 Stand alone combustion in a circulatingfluidised bed reactor with steam cycle

0,055 – 0,09 22 – 28 %

Fossil Electricity NL 1997: 0,03 EURO/kWh

Structure of LCAStructure of LCA

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1. Goal and scopedefinition

2. Inventarisation

3. Classification andnormalisation

4. Evaluation Weighting effects

Environmental effects

Environmental impacts

Product/ technique Functional unit

Impact table

Environmental profile

Eco-indicator

LCA of Biomass TechniquesLCA of Biomass Techniques

9.

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Comparison of techniques:• Combustion stand alone

• Gasification stand alone

• Co-combustion in coal power plant

• co-combustion in municipal waste incinerator

LCA Method, Goal and Functional Unit

LCA: Goal + Functional UnitLCA: Goal + Functional Unit

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Goal:• Power production from clean waste

biomass (wood)

Functional Unit:

• 425 TJ electrical power from biomass

equal to 966 TJ calorific value (LHV)

1 TJ = 1012J

LCA: Functional UnitLCA: Functional Unit12

11.

Co-combustionCoal Power Plant

η = 44%

Coal Power Plantη = 44%

Waste incinerationno biomass

η = 21%

Waste incinerationwith biomass

η = 21%

NL Electricity Prod.(c+e)-(f+g) MWh

a kton Coal

b kton Biomass

c MWh d ktonwaste

e MWh

a kton Coal f MWh

d ktonwaste

b kton

Biomass

A. Biomass co-combustionA. Biomass co-combustion

+

B. Biomass incineration in MSW B. Biomass incineration in MSW

g MWh

LCA: LCA: Choice of system bordersChoice of system borders12

12.

Biomass formation

Collection and transport

Conversion:Co-combustion, combustion in MSW, gasification, combustion

Electricity supply

System border

Pre-treatment:Drying, size reduction, pelletise

0

2000

4000

6000

8000

10000

12000

14000

Green

hous

e

Ozone

Acid.

Eutro

ph.

H.met

als

Carcin

.

W.s

mog

S.sm

og

Pestic

id

Energ

ySoli

d

MSW incineration Co-combustion Combustion Gasification

LCA results LCA results NormalisationNormalisation

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Simapro 3.0 Eco Indicator ‘95/ Europe g / normalisation

14.

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Simapro 3.0 Eco Indicator ‘95/ Europe g / indicator

LCA results LCA results Eco indicator ‘95Eco indicator ‘95

0,00

20000,00

40000,00

60000,00

80000,00

100000,00

120000,00

140000,00

MSW incineration Co-combustion Combustion Gasification

Solid

Energy

Pesticid

S.smog

W.smog

Carcin.

H.metals

Eutroph.

Acid.

Ozone

Greenhouse

12LCA results energy cropsLCA results energy crops

15.

Simapro 3.0 Eco Indicator ‘95/ Europe g / normalisation

-1000

1000

3000

5000

7000

9000

11000

Green

hous

e

Ozo

neAcid

.

Eutrop

h.

H.met

als

Carcin

.

W.sm

og

S.sm

og

Pestic

id

Energ

ySoli

d

Gasification Gasification poplar as energy crop

12LCA results energy cropsLCA results energy crops

Simapro 3.0 Eco Indicator ‘95/ Europe g / indicator

16.

-50000,00

0,00

50000,00

100000,00

150000,00

200000,00

250000,00

300000,00

350000,00

Gasif ication Gasif ication poplar as energy crop

Solid

Energy

Pesticid

S.smog

W.smog

Carcin.

H.metals

Eutroph.

Acid.

Ozone

Greenhouse

• Co-combustion gives best score due to highest power production efficiency;

• Efficiency of process plays major role;

• Global warming, acidification and heavy metals most important impact scores;

• Choice of functional unit does not influence ranking;

• Biomass wastes score better than energy crops (pesticide/eutrophication).

12LCA ConclusionsLCA Conclusions

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LCA DiscussionLCA Discussion12

• Advantages LCA:– Fully quantitative

– Detailed study

• Disadvantages LCA:– Detailed: data collection– Long-winded– Not taken into account: depletion, solid emissions,

local environmental aspects– Non specified substances– Normalisation and evaluation are subjective

17a.

• Techno. / economic ranking gives same outcome as LCA study;

• Co-combustion: sustainable and economical feasible power source;

• LCA method lacks impact category Abiotic Depletion (exergy analysis);

• Co-generation to be investigated.

General ConclusionsGeneral Conclusions12

18.

LCA inventarisatie

Proces1.

Proces2.

grondstoffen transport

productGebruik

emissies emissies

elektra elektra elektra

Afvalfase

recycling recycling

Emissies ook bij:recycling

Afvalfase

emissies

transport

13.

Milieu effecten bij een LCAMilieu effecten bij een LCA Eco-Indicator ‘95

•Broeikaseffect

•Ozonlaagaantasting

•Pesticiden en Carcinogenen

•Zware metalen in lucht en water

•Zomersmog

•Wintersmog

•Verzuring

•Vermesting

CML (1992)

•Abiotische en Biotische uitputting

•Broeikaseffect

•Ozonlaagaantasting

•Humane toxiciteit

•Ecotoxiciteit

•Fotochemische Oxydantvorming

•Verzuring en Vermesting

•Water warmte en Stank

•Lawaai

•Aantasting landschap / versnippering

•Slachtoffers14.

Milieu effecten bij een LCA Nadelen Eco Indicator:

• Uitputting grondstoffen en brandstoffen

wordt niet meegenomen

• Idem voor andere milieu effecten

• Subjectieve weging van de effectscores

• Milieuthema’s anders geformuleerd

15.

Verschil CML en Eco indicator• CML methode:

∑kg eq. X classif. = effectscore

effectscore / Tot. Nl evaluatie

• Eco indicator

∑ kg eq. X classif. = effectscore

effectscore / Tot. Nl weging evaluatie

16.

• Afweging resultaten met bekende milieu-impact data:– Op Wereldschaal– Op Europese schaal– Op Landelijke schaal

• Milieu equivalenten normaliseren op de gekozen schaal equivalenten.

Normalisatie Stap

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Milieuthema Eenheid Wereld Nederland

Broeikaseffect kg/jr 1012 37,7 0,377

Smog kg/jr 109 3,74 0,0374

Verzuring kg/jr 109 286 2,86

Vermesting kg/jr 109 74,8 0,748

Normalisatie Stap, Normalisatie Stap, 22

Guinée, 1993Normalisatie = Effect / Bijdrage (kg/jr)

23.

• Vergelijken van de scores.

• Gevoeligheids analyse van de data, controle op geldigheid resultaten.

• Aanpak van de studie; peer review.

• Verdere stap:– Optellen milieu effecten tot 1 waarde– vergelijk op basis totaal milieu impact

Evaluatie resultaten

25.

• Wordt vaak niet uitgevoerd!

• Belangrijk voor productie en product ontwerpers (ingenieurs)

• Richten op plaatsen waar belangrijke milieu impacts optreden

• Inkoop beleid aanpassen

• Productie en product aanpassing

De verbeter analyseDe verbeter analyse

29.

ConclusiesConclusies

LCA is een potentieel goede methode,

echter:

• Niet iedereen weet goed wat wel en niet met een LCA kan.

• Onvoldoende gecertificeerde databases (kennis blijft geheim)

• Gevoeligheidsanalyses ontbreken

34.