1. Torrefaction Quality Control
based on logistic & end-user requirements
Robin Zwart, Jaap Kiel, Fred Verhoeff and Jan Pels
Energy research Centre of the Netherlands (ECN)
2. Content
• ECN and torrefaction
• Lab-scale torrefaction tests
Different types of wood and waste streams with different shapes
• Production of BO2 pellets
The BO2 technology and the Patrig pilot plant
• Performance and quality control
Milling and densification behavior, yields, composition
• Conclusions and outlook
Market acceptance, scale-up & demonstration of technology
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3. ECN and torrefaction
Frontrunner in torrefaction
ECN has 20 years experience in biomass
co-firing R&D, identified the potential of
torrefaction in this framework and played a
pioneering role in adapting torrefaction to
bioenergy applications since 2002
ECN’s torrefaction technology has been
proven on pilot-scale and together with
industrial partners is taken to demonstration
and commercial market introduction
ECN conducts contract R&D for industry to
assess the torrefaction potential of specific
feedstock, produce test batches and
optimise product quality
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4. ECN and torrefaction
Torrefaction reactors
20 l batch reactor 50 - 100 kg/hr pilot • Main product groups:
moving bed reactor solids, permanent gases,
organics, lipids, water
• Permanent gases:
CO, CO2, CH4, CxHy, …
• Organics:
5kg/hr auger reactor acetic acid, methanol,
furaldehyde, hydroxyaceton,
hydroxybutanon, phenol,
formic acid, propionic acid,
…
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5. TorTech project:
Public ECN report ECN-E--11-039
PhD thesis M. van der Stelt (TUe, 2010)
Lab-scale torrefaction tests
Torrefaction behavior of a variety of biomass streams
BAGASSE
20 l batch reactor Raw ~250°C/~30 min ~280°C/~30 min
GRASS SEED HAY
Raw ~250°C/~30 min ~280°C/~30 min
5kg/hr auger reactor
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6. Lab-scale torrefaction tests
Torrefaction behavior of a variety of biomass streams
ROAD SIDE GRASS
20 l batch reactor Raw ~255°C/~30 min ~295°C/~30 min
STRAW
Raw ~260°C/~30 min ~270°C/~30 min
5kg/hr auger reactor
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7. Lab-scale torrefaction tests
Torrefaction behavior of a variety of biomass streams
PINE
20 l batch reactor Raw ~275°C/~30 min Raw ~320°C/~30 min
SPRUCE
Raw ~285°C/~30 min Raw ~290°C/~30 min
5kg/hr auger reactor
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8. Lab-scale torrefaction tests
Torrefaction reactions overall exothermal
300
250
Temperature (°C)
200
Ambient
Surface
150 Shifted middle
utlet Middle
100 Results from
8
Torgas outlet single-particle
N2 inlet
50
8 testing
5 N2 inlet
0
0 5 10 15 20 25 30 35 40 45 50 55
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Time (min)
6
1. Thermal ceramic bricks 2 2
2. Screws 3
1. Thermal ceramic bricks
3. Glass sphere cut by the middle 2. Screws
4. Woody ball 1 4 3. Glass sphere cut by the mi
5. Themocouples and their inlet 4. Woody ball
6. Gas inlet-outlet 5. Themocouples and their in
6. Gas inlet-outlet
7. Steel ball with double tube to act as inlet and outlet of gases 1 7. Steel ball with double tube
8. Gas heater 8. Gas heater
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9. Lab-scale torrefaction tests
Torrefaction behavior of a variety of waste streams
REFUSE DERIVED FUEL (RDF)
20 l batch reactor Raw ~245°C/~30 min ~265°C/~30 min
DRY STABILATE SOME COMMENTS
Raw ~250°C/~30 min
Thermal run away
5kg/ hr auger reactor =
Meltdown
Inhomogenity
Waste in
=
Waste out
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11. 1,600
1,400
Lab-scale torrefaction tests
1,200Grindability of a variety of torrefied biomass streams
Power consumption consumption (kJ/kg)
1,000 Coal AU GS01 GS01(250,29) RG01 ST01 ST01(259,29)
BE BE(264,34) WI PI01(268,30) PI01(277,30) SP(289,29)
Power (kJ/kg)
1,600
800
800
1,400
600
600
1,200
Power consumption (kJ/kg)
1,000 400
400
800
200
200
600
-
400 - 0.1
0.1 0.2
0.2 0.3
0.3 0.4
0.4 0.5
0.5 0.6
0.6 0.7
0.7
200 Average particlevolume based)
average particle size (mm,
size (mm)
-
12
- 0.1 0.2 0.3 0.4 0.5 0.6 0.7
12. Lab-scale torrefaction tests grass
Bagasse
Beech
Grass seed hay
Willow
Road side
Larch
Straw
Pine
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LHV of a variety of RDF
Spruce torrefied biomass streams
Trockenstabilat
33
Bagasse Grass seed hay Road side grass Straw
Lower heating value [MJ/kg d.a.f.]
Beech Willow Larch Pine
31 Spruce RDF Trockenstabilat
35
29
33
27
31
25
29
23
27
21
25
19
23
17
21
15
19
220 230 240 250 260 270 280 290 300
17 Temperature [°C]
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13
220 230 240 250 260 270 280 290 300
13. Production of BO2 pellets
The BO2 technology Support fuel
Flue gas
Torrefaction
gas Combustion
Gas
recycle
Biomass BO2-pellets
Pre-drying Torrefaction Cooling Pelletisation
DP
Flue gas Heat
exchange
Flue gas
Features conventional drying and pelletisation combined with dedicated moving bed technology with direct heating
High energy efficiency (> 90%) / Cost effective / IP is patent protected
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14. 1 - 10 tonne
Production of BO2 pellets test batches
Patrig pilot plant
Torrefaction
50 - 100 kg/hr
feeding Pelletisation
Pre-drying Conditions: Cooling and storage
––––––––––––––
220 - 300°C
30 - 60 minutes
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15. Performance and quality control
Torrefied biomass pellets in perspective
Wood chips Wood Torrefied Charcoal Coal
pellets wood pellets
Moisture content (wt%) 30 – 45 7 – 10 1–5 1–5 10 – 15
Calorific value (LHV, MJ/kg) 9 – 12 15 – 17 18 – 24 30 – 32 23 – 28
Volatile matter (wt% db) 70 – 75 70 – 75 55 – 65 10 – 12 15 – 30
Fixed carbon (wt% db) 20 – 25 20 – 25 22 – 35 85 – 87 50 – 55
Bulk density (kg/l) 0.20 – 0.25 0.55 – 0.65 0.65 – 0.80 0.18 – 0.24 0.80 – 0.85
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Vol. energy density (GJ/m ) 4.5 – 6.0 8 – 11 15 – 19 6.0 – 6.4 18 – 24
Hygroscopic properties Hydrophilic Hydrophilic Moderately Hydrophobic Hydrophobic
Hydrophobic
Biological degradation Fast Fast Slow None None
Milling requirements Special Special Standard Standard Standard
Product consistency Limited High High High High
Transport cost High Medium Low Medium Low
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16. Lower LHV acceptable
Performance and quality control Less transport gas
Bulk density versus heating value
2
3
+20% 6
+40%
+30% 4
-30%
5
1
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21. Biomass
Conclusions and outlook
Product quality optimization
Torrefaction
Pilot, demo and 1st commercial plants produce kg
to tonne scale batches allowing representative Densification
logistics & end-use performance testing by industry
Many coal-fired power plants want to be early
adaptors and perform successful co-firing trials Logistics testing
(e.g. RWE, Vattenfall, CEATI consortium)
End-use testing
Product quality optimisation requires a systematic
iterative approach (2 iterative loops)
For this purpose, European torrefaction Validated and optimised
developers, combustion and gasification solid biofuel
technology providers and end-users have joined
forces in the EU-FP7 project SECTOR
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22. Conclusions and outlook
Scale-up & demonstration torrefaction technology
Vattenfall supports ECN in upscaling torrefaction technology
The Energy research Centre of the Netherlands (ECN) and Vattenfall in June 2010
agreed on a partnership for upscaling ECN’s BO2 technology. This marked an
important step towards the commercial application of ECN’s BO2 technology for
upgrading biomass into high-quality solid fuel.
ECN closes deal with Andritz OY
The Energy research Centre of the Netherlands (ECN) and Andritz OY in June 2011
agreed on a partnership for developing and commercialising torrefaction technology.
Andritz has acquired the exclusive right to use the patents and knowledge of the
ECN torrefaction technology. ECN will also provide Andritz with technical support,
starting with the joint development of a demonstration plant.
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23. More information
Robin Zwart
phone +31 224 56 4574
mobile +31 6 3073 6496
e-mail zwart@ecn.nl
internet www.ecn.nl
Production of tonne-scale test batches
at ECN for industrial trials
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