Biomass co-firing with the focus on the experience in the Netherlands

Mariusz Cieplik; Willem van de Kamp and Jaap Kiel ECN Biomass, Coal and Environmental research

Clean and Efficient Power Generation from Coal, September 24-25th, 2009, Gliwice (Poland)

2 Biomass co-firing with the focus on the experience in the Netherlands – M.K. Cieplik et al.

Presentation overview

• Brief introduction to ECN

• State-of-the-art biomass co-firing

• Options

• Co-firing activities in the Netherlands

• Biomass co-firing vs total renewables in the Netherlands

• Biomass co-firing in high percentages

• Technical bottlenecks

• R&D needs and exemplified results

• Conclusions

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Energy research Centre of the Netherlands

Independent (non-profit) research institute650 employeesAnnual turn-over:90 million EuroActivities:

• Biomass, Solar, Wind• Clean fossil fuels

(CCS, fuel cells)• Energy efficiency• Policy studies

ECN develops high level knowledge and technology for a sustainable energy system and transfers it to the market

4 Biomass co-firing with the focus on the experience in the Netherlands – M.K. Cieplik et al.

Biomass Co-firing – state-of-the-art options

coal

SCR

ESP

stack

FGD

• Coal (and gas-fired) power plants• Including co-gasification (e.g. IGCC)• Existing (retrofit) and new installations

BM

Direct co-firing

Biomass

gas cooling/purification

LC

V g

as

CFB gasifier

BM

Indirect co-firing

Biomass

5 Biomass co-firing with the focus on the experience in the Netherlands – M.K. Cieplik et al.

4

Biomass Co-firing – details of the state-of-the-art options

Coal mills Coal

Coal burner Boiler

Biomass pellets Coal mills

1

Biomass

2Biomass mills

3

Biomass burner

5

Gasifier

6

1. The milling of biomass pellets through modified coal mills2. The pre-mixing of the biomass with the coal and the milling and firing of the premixed fuel

through the existing coal firing system3. The direct injection of pre-milled biomass into the pulverised coal pipework4. The direct injection of pre-milled biomass into modified coal burners5. The direct injection of the pre-milled biomass through dedicated biomass burners or

directly into the furnace6. The gasification of the biomass, with combustion of the producer gas in the boiler

after W. Livingston, Doosan-Babcock / IEA Task 32 Hamburg 2009 workshop

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Co-firing activities in the Netherlands

coal

SCR

ESP

stack

FGD

gas cooling/purification

LC

V g

as

CFB gasifier

BM

Indirect co-firing

BM

Direct co-firing

coal

SCR

ESP

stack

FGDcoal

SCR

ESP

stack

FGD

gas cooling/purification

LC

V g

as

CFB gasifier

BM

Indirect co-firinggas cooling/purification

LC

V g

as

CFB gasifier

BM

gas cooling/purification

LC

V g

as

CFB gasifier

BM

LC

V g

as

CFB gasifier

BM

Indirect co-firing

BM

Direct co-firing

BMBMBM

Direct co-firing Essent Amer wood gasifier

Essent Amer

E.On BeNeLuxMaasvlakteEPZ Borssele 12

ElectrabelGelderland

NUON Buggenum(IGCC)

7 Biomass co-firing with the focus on the experience in the Netherlands – M.K. Cieplik et al.

Co-firing activities in the Netherlands

Current co-firing status:• All co-firing options in use, but each producer has clear preferences• Co-firing % ~20 % w/w, but many trials at ~30-40 % w/w• Even > 50 % w/w tests scheduled (600+ MWe scale)• Most producers aim at 20-25 % e/e• Popular fuels:

– All producers: clean wood– Essent Amer: certified, sustainable food-processing industry

residues (i.e. coffee-husks in co-operation with Solidaridad fair trade)

– E.On Maasvlakte: MBM and SRS animal fat, “biomass pellets”– EPZ Borssele: cocoa residue, palm kernel (PKS), citrus pulp– Electrabel Gelderland: agro- and food-processing residues– Nuon Buggenum (IGCC): clean wood

• Niche fuels:– E.On Maasvlakte and Nuon Buggenum (IGCC): sewage sludge– Essent: demolition wood (via gasification) and bark pellets

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Amer 9 (600 MWe + 350 MWth) : 300 ktonne/y

Direct biomass co-firing at Essent Amer power station

Source: EssentAmer 8 (645 MWe + 250 MWth) : 320 ktonne/y

Wood pellets

Citrus pellets

Palm kernel chips

Olive residu

Second “bio” mill Amer 9 : 300 ktonne/y

Altogether: ~ 1 Mtonne/y on one site!

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Indirect biomass co-firing at Essent Amer power station

Source: Essent

Amer 12 (600 MWe + 350 MWth) : 60 MWth (~5% e/e)

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0

500

1000

1500

2000

2500

3000

3500

4000

1990 2007 2008 2020

[PJ/

y]

0

500

1000

1500

2000

2500

3000

3500

4000

gros energy consumptionrenewable energy

Renewables in the Netherlands – current data vs ambitions

Implementation legging behind…

Ambition 20 (or even 30) % renewables in 2020

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0

10

20

30

40

50

60

70

1990 2005 2006 2007 2008

avo

ided

foss

il fu

el u

se [P

J/a]

MSWI direct and indirect co-firingwood stoves - industrial wood stoves - residentialother biomass combustion landfill gasbiogas - sewage sludge biogas - aggricultural residuesbiogas - other

Renewables in the Netherlands – biomass contributionA p p r o x i m a t e l y 6 0 % t o t a l r e n e w a b l e f r o m b i o m a s s !

• L a r g e d e c r e a s e i n c o - f i r i n g i n 2 0 0 7 :- c a n c e l l e d f e e d - i n t a r i f f s f o r ( p a l m ) o i l- t i g h t c l e a n w o o d p e l l e t s m a r k e t- d e l a y i n d e v e l o p m e n t o f n e w s u b s i d y s y s t e m

• 2 0 0 8 : c l e a r s i g n s o f r e c o v e r y , d e s p i t e l o w e r e d s u b s i d i e s

12 Biomass co-firing with the focus on the experience in the Netherlands – M.K. Cieplik et al.

Technical bottlenecks in biomass co-firing

coal

SCR

ESP

stack

FGD

BM

gypsum quality

direct co-firing

burner stabilityboiler performance

near-burner slagging burnout

milling/pneumatictransport

fouling & corrosioncatalyst deactivation

ESP performance

fly ash quality

NOx emissionsToMe emissions

Many bottlenecks grindability and/or

ash-related

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R&D needs - biomass co-firing in high percentages

• Biomass upgrading technology to reduce the cost of biomass logistics and improve the compatibility of biomass as a fuel

• Better mechanistic understanding of combustion/gasification-related technical bottlenecks and translation into fuel mixing recipes, design specifications and operating guidelines

• Predictive tools for assessing the co-firing potential of biomass streams and optimising boiler design and operation for co-firing (low-cost screening, modelling)

• Biomass co-firing and future boiler designs (i.e. USC)

• Advanced techniques for (on-line) process monitoring and control

• (Ash recycling strategies and) utilisation options

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De-bottlenecking – R&D approach

Lab-scale experiments

Modelling(thermodynamics, CFD)

Full-scale measurementcampaigns Evaluation / interpretation

Design rules

Operator guidelinesFuel specifications

Predictive tools

Validation

Validation

Lab-scale experiments and modelling allow investigations beyond current full-scale practice (higher co-firing percentages, higher steam conditions, oxy-fuel combustion)

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Friable and less fibrous 19 - 22 MJ/kg (LHV, ar)

HydrophobicPreserved

Homogeneous

Torrefaction and pulverisation

Fuel powder

De-bottlenecking – torrefaction for improved fuel specs

Superior fuel properties:− Transport, handling, storage− Milling, feeding− Gasification, combustion− Feedstock range− Standardisation

Tenacious and fibrous10 - 17 MJ/kg (LHV, ar)

Hydrophilic Vulnerable to biodegradation

Heterogeneous

Agricultural residues

Mixed waste

Woody biomass

Pelletisation

Fuel pelletsBulk density 700-800 kg/m3

Bulk energy density 13-17 GJ/m3

tonne-scale batches of materials availablefrom the ECN torrefaction pilot-scale plant

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De-bottlenecking - example of fuel interactions

KCl (g), KOH (g)

clay minerals (l/s)

SO2 (g)

Ca/Si basedaerosols (s/l)

KCl (g), KOH (g), K2SO4 (g)

biomass coal

KCl (g), KOH (g), K2SO4 (l)

KCl (l/s), KOH (g), K2SO4 (s)

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De-bottlenecking tools - Lab-scale Combustion Simulator

Realistic gas temperature and gas composition profiles, sampling 5-2500 ms

oxygen

gas+

particles

gas

temperaturehigh

high

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1

1000 1200 1400 1600

Temperature [°C]

Dis

tanc

e [m

]

Res

iden

ce ti

me

[ms]

20

90

1300

210

Furnace exit

Burner area

Sampling location

oxygen

temperaturehigh

high

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De-bottlenecking - ash/minerals release for various fuels

Release biomass very different from coal:– total release biomass 30-55% (incl. S and Cl)– total release coal 0.3-2.6% (excl. S and Cl) or 8-36% (incl. S and Cl)

30%

49%

51%

55%

40%

8%

36%

0

5000

10000

15000

20000

25000

30000

Bark (BM1) Wood chips(BM2)

Waste wood(BM3)

Olive residue(BM5)

Straw (BM6) Polish coal (C1) UK coal (C2)

Rel

ease

per

kg

dry

fu

el [

mg

/kg

]

Ca Mg Na K Ti P S Cl Mn Zn Pb

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Developed in co-operation with Hukseflux (subsidiary of Clyde Bergemann) Functionalities:•Deposit composition•Deposit influence on heat transfer

• 700 < Tgas< 1300 °C• 300 < Tsurface< 750 °C

De-bottlenecking tools – lab-scale Horizontal Deposit Probe

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De-bottlenecking tools - full-scale mobile deposition probe

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De-bottlenecking – Full/lab-scale slagging/fouling tests

f l o w

0

5

10

15

20

25

30

35

40

45

50

SiO2 Al2O3 Fe2O3 Na2O K2O CaO MgO TiO2 P2O5 MnO

% w

/w d

.a.b

.

Lab-scale

Full-scale

Approach also proven for:- USC conditions (full/lab-scale)- oxyfuel BM combustion (lab)

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Conclusions

• Biomass co-firing is an established technology for co-firing percentages up to 10-20% (e/e)

• Biomass co-firing at high percentages (30-50% e/e) is feasible, but needs/highly benefits from:

− Innovative biomass upgrading technologies− Better mechanistic understanding of technical bottlenecks− Better predictive and diagnostic tools− On-line monitoring and control (e.g. fouling, corrosion)

• Torrefaction allows for a cost-effective, high-efficiency production of commodity biomass fuels with superior grindability and conversion properties.

• Many technical bottlenecks in biomass co-firing are ash related. Main mechanisms of ash formation and ash behaviour have been mapped. R&D focus now on quantification and incorporation of mechanistic knowledge in predictive tools.

• Combination of predictive tools and on-line monitoring is key to successful management of ash behaviour, particularly for new boiler designs.

• New challenges in biomass co-firing include sustainability, heat utilisation, lower quality (“salty”) biomass, wet biomass.

Thank you for your attention!

M.K. CieplikECN BCEP.O. Box 11755LE PettenThe Netherlandscieplik@ecn.nlTel: +31 224 564700