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 [email protected]
M +31 610 909 927 www.ecn.nl
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