www.ecn.nl

Indirect gasification for high

efficient conversion of high ash

coal and lignite

Bram van der Drift

20 May 2014, Dresden

FB combustion

ECN DEVELOPMENTS and competences and facilities

500°C 1000°C 1500°C 0°C

1

10

100

1 000

time [s]

PF combustion

EF gasification

FB gasification

FB: Fluidized Bed EF: Entrained Flow PF: Pulverized Fuel

Torr

e-fa

ctio

n

Tor-

was

h

GASIFICATION principle

3

+

25%

75%

energy production:

fuel + air (l > 1) flue gas + heat

energy consumption:

fuel + heat gas

gasification:

fuel + air (l~0.3) gas

GASIFICATION indirect gasification: second generation

4

+

25%

75%

energy production:

fuel + air (l > 1) flue gas + heat

energy consumption:

fuel + heat gas

gasification:

fuel + air (l~0.3) gas + char/coke

+ char/coke

GASIFICATION indirect gasification: second generation

5

• Gas production (pyrolysis and gasification) in reactor 1

• Combustion of non-converted carbon with air in reactor 2

• Coupled fluidized bed technology: – Bed material circulated between reactors

– Bed material transports char from reactor 1 to reactor 2

– Bed material transports energy from reactor 2 to reactor 1

– Temperature difference between the reactors typically 50-100°C

– Bed material can also e.g. capture S, reduce tar, transport CO2 (chemical looping)

• No carbon left

• No N2 in syngas

DEVELOPED for BIOMASS/WASTE gasification/pyrolysis and combustion separated

FICFB (TU Vienna)

MILENA DEMONSTRATION PLANT 4 MW wood-to-SNG plant in Alkmaar (NL)

MILENA DEMONSTRATION PLANT 22 MW waste-to-power plant in UK

MILENA DEMONSTRATION PLANT 4 MW soya residue-to-power in India

CONVERSION vs. TEMPERATURE indirect/direct fluidized bed – entrained flow

Co

nve

rsio

n [

%]

100%

500°C 1000°C 1500°C

Entrained Flow

Gasifier

Direct Fluidized

Bed

Volatiles escape (fast)

Indirect Fluidized

Bed

tar

Minimum conversion: unconverted fuel would suffice to supply energy

for gasification of biomass

Fuel

nee

ded

for

ener

gy s

up

ply

~70%

INDIRECT GASIFICATION

• Whereas for “normal” (direct) gasification, a higher temperature leads to higher conversion…

• For indirect gasification, the temperature can be much lower and yet have full conversion!

• For biomass and waste, releasing only the volatiles (pyrolysis) is enough, all the remaining fixed carbon energy is needed for energy supply

• For coals, fixed carbon content is too high and would produce too much energy when combusted, real gasification of part of the carbon is required

• But full carbon gasification is not required, temperature can be chosen to be relatively low

CONVERSION vs. TEMPERATURE indirect/direct fluidized bed – entrained flow

Co

nve

rsio

n [

%]

100%

500°C 1000°C 1500°C

Entrained Flow

Gasifier

Direct Fluidized

Bed

Volatiles escape (fast)

Indirect Fluidized

Bed

Minimum conversion: unconverted fuel would suffice to supply energy

for gasification of coal

Fuel

nee

ded

for

ener

gy s

up

ply

~60%

CONVERSION vs. TEMPERATURE indirect/direct fluidized bed – entrained flow

Co

nve

rsio

n [

%]

100%

500°C 1000°C 1500°C

Entrained Flow

Gasifier

Direct Fluidized

Bed

Volatiles escape (fast)

Indirect Fluidized

Bed

Minimum conversion: unconverted fuel would suffice to supply energy

for gasification of coal

Fuel

nee

ded

for

ener

gy s

up

ply

~60%

30% gasification is enough to have 100%

conversion overall

FROM BIOMASS GASIFIER

to

COAL GASIFIER

THE MILENA FAMILY

MILENA (biomass/waste) iMILENA (coal)

iMILENA RESULTS

• Tests performed with 5 kg/h lab-scale facility

• Coals used from India and Turkey

• Containing over 50% ash

• Co-financed by EU Optimash project

iMILENA RESULTS

iMILENA

high-ash coal

CO (vol%) 14.9

H2 (vol%) 48.3

CO2 (vol%) 28.5

CH4 (vol%) 6.0

N2 (vol%) 2.6

C2Hy (vol%) 1.3

C6H6 & C7H8 (ppmv) 3200

H2S & COS (ppmv) 5000

Tar (g/Nm3) 9

Combustor temp. (°C) 889

Gasifier temp. (°C) 853

Bottom ash

FINAL REMARKS

• iMILENA can produce syngas from high-ash coals (>50% ash) – Without the need for an air separation unit

– At 100% conversion (no carbon in ash)

– At relatively low temperature: <1000°C

– Showing high cold gas efficiency: 70%

– Syngas heating value: >10 MJ/Nm3

• Gas for co-firing, engine, combined cycle, SNG, …

• Next step: pilot testing (ECN) and demonstration

• Technology available for licensing

• Contact us to discuss the options 0.8 MW pilot plant ECN

30% gasification is enough to have

100% conversion overall

THANKS FOR THE ATTENTION

publications: www.ecn.nl/publications

fuel composition database: www.phyllis.nl

tar dew point calculator: www.thersites.nl

IEA bioenergy/gasification: www.ieatask33.org

Milena indirect gasifier: www.milenatechnology.com

OLGA: www.olgatechnology.com / www.renewableenergy.nl

SNG: www.bioSNG.com /www.bioCNG.com

Bram van der Drift

ECN

Westerduinweg 3 P.O. Box 1

1755 LE Petten 1755 ZG Petten

The Netherlands The Netherlands

T +31 224 56 45 15 vanderdrift@ecn.nl

M +31 610 909 927 www.ecn.nl

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