Waste wood gasification in an allothermal gasifier · Waste wood gasification in an allothermal...
Transcript of Waste wood gasification in an allothermal gasifier · Waste wood gasification in an allothermal...
Waste wood gasification in an allothermal gasifier
A. van der Drift
C.M. van der Meijden
Presented at the 19th European Biomass Conference and Exhibition (EU BC&E), ICC Berlin, Germany (Conference 6-10 June 2011 - Exhibition 6-9 June 2011)
ECN-L--11-061 June 2011
Waste wood gasification
in an allothermal gasifier
Bram van der Drift, Christiaan van der Meijden
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ECNbusiness units
Solar energy Wind energy
Policy
Studies
Efficiency &
Infrastructure
Biomass
Biomass conference,
Berlin, 6 June 2011
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CONTENTS
1. Why development of a new gasifier?
2. Working principles Milena technology
3. 30 kWth Lab scale installation
4. 800 kWth Pilot plant
5. Results demolition wood tests
6. Demo plant Alkmaar
7. Conclusions
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6 June 2011
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WHY DEVELOPMENT of MILENA GASIFIER?
• MILENA produces a medium calorific value gas that can be
efficiently upgraded into Bio-SNG or can be used in CHP’s for
heat and electricity production
• Cold gas efficiency for MILENA gasifier is higher than of
competing processes. Waste is minimized (no char containing
char)
• High efficient production of SNG
• High initial CH4 yield.
• Limited dilution of product gas with N2
• High overall efficiency in CHP applications
• Limited adaptation to gas engine because of relatively high
calorific value of gas
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6 June 2011
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OVERALL EFFICIENCIES WOOD-to-SNG
calculations for large-scale plants
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6 June 2011
53%
70%
58%
67%
64%
54%
50%
55%
60%
65%
70%
75%
Entrained Flow CFB Indirect
effic
ien
cy
BioSNG
BioSNG and net power
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EFFICIENCIES MILENA – CHP calculations of 4 MWe plant
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ECN MILENA
gasification technology
• MILENA indirect gasifier
• developed for high efficient
SNG-production
• MILENA-exit:
- 11-15 vol% CH4
- 20-25 vol% H2
- 30-35 vol% CO
- 10-15% vol% CO2
- 6 vol% C2Hx, tars, N2, ...
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MILENA CHARACTERISTICS
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• Medium calorific gas, low N2
• Complete conversion, no carbon in ash
• High CH4 content, suitable for Bio-SNG
production
• Reactor concept is suitable for scale up
(> 100 MWth) and pressurized
operation.
• High tar content
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MILENA, 5 kg/h
lab-scale facility
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LAB-SCALE MILENA + OLGA + SNG FACILITY
MILENA
gasification OLGA
gas cleaning methanation
• First MILENA tests in 2004
• First integrated tests in 2006
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6 June 2011
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MILENA 30 kWth LAB-SCALE FACILITY
• More than 2000 hours of operation in gasification mode
• Tested fuels: wood, sewage sludge, grass (not successful)
and lignite
• Bed materials: olivine, dolomite, and sand
• Interesting results:
No agglomeration problems with wood as fuel
Co-gasification of lignite reduces tar content significantly
Transports of O between combustor and gasifier when
olivine is used as bed material
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MILENA PILOT PLANT
• Thermal input 160 kg/h (800 kW)
• In operation since 2008
• Connected to OLGA tar removal in
2009
• Design fuel: wood
• Gasifier / riser diameter: 0.2 m
• Combustor diameter: 0.8 m
• Total height: 8 m
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MILENA PILOT TEST FACILITY
•Biomass
•Flue gas
•Steam •Tar + dust
•White ash
•Burner
•Boiler
•OLGA
•Flue gas
•Wet
•Scrubbing
•MILENA
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MILENA PILOT PLANTstatus
• In operation since 2008, connected to OLGA
• Autumn 2010 duration test on demolition wood (250 hours)
• Fuel: wood, throughput between 120 and 160 kg/h
• Fluidization agent gasifier: Steam (15 kg/h) or Air (20 Nm3/h)
• Bed material -> Sand / Olivine
• Gas composition similar to lab-scale installation (tar content approx. 40 gram/Nm3
• OLGA can handle high tar load
• Improvements:
Bottom ash discharge system is modified / extended to remove glass and prevent accumulation of large particles
Piping between MILENA and OLGA is replaced, because it was designed for previous gasifier, local cold spots caused problems
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DEMOLITION WOOD
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• painted
• incl. plywood and MDF
• incl. glass
• milled/sieved for pilot
test
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PRODUCER GAS COMPOSITION
MILENA pilot tests
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6 June 2011
DEMOLITION WOOD TEST RESULTS
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• Gas composition main compounds
according expectation / similar to clean
wood
• No major difference in tar production.
OLGA is able to remove tar sufficiently
• Bottom ash discharge required to prevent
accumulation of glass in the gasifier
• High concentrations of NH3 and HCN in
producer gas, removal required
• Bag house filter is sufficient for cleaning
flue gas, possible additives required to
lower HCl concentration in flue gas (50
ppm)
Bottom ash
after sieving
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6 June 2011
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11.6 MWth MILENA Bio-SNG DEMONSTRATION
• Location: Alkmaar
• Fuel: wood approx. 3000 kg/h - 25wt%
moisture
• Basic engineering MILENA + OLGA +
Gas Engine done in 2010 (ECN +
Dahlman)
• Changes in subsidies -> Gas Engine will
be replaced by methanation unit
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• New application for bio-SNG production at the end of 2011
• Probably new location
• Methanation technology still undecided.
• Extension of consortium with additional partners interested in
demonstrating Bio-SNG technology
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MILENA DEMO PLANT ALKMAAR
MILENA
gasifier
OLGA tar
removal
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OUTLOOK
• Strong interest in Bio-SNG production from commercial
partners, consortium is growing
• Bio-SNG demo will part of Biomass Expert Centre located in
Alkmaar -> possibilities for testing innovative processes using
real biomass producer gas
• Cooperation with Thermax to realize 1 MWe demo in India
using Soya stalk
• Preparations / offers for Several Bio-CHP’s using demolition
wood, typically 2 – 5 MWe
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CONCLUSIONS
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• Waste wood can be used as a fuel for the MILENA gasifier
• OLGA can handle the tars
• Sufficient bottom ash should be distracted to prevent
accumulation of glass, which will result in agglomeration
• Pollutants like NH3 and HCN will increase significantly
compared to clean wood, gas cleaning should be designed
for this
• At a typical scale of 1 – 10 MWe, the energetic efficiency
of a MILENA gas engine combination is significantly higher
than of a combustion system
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MORE INFORMATION
Bram van der Drift
e: [email protected] PO Box 1
t: +31 224 56 4515 NL 1755 ZG Petten
w: www.ecn.nl the Netherlands
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 tar removal: www.olgatechnology.com
SNG: www.bioSNG.com and www.bioCNG.com
Biomass conference,
Berlin, 6 June 2011