1. No category

Nya karaktäriseringsmetoder för fasta bränslen Malbarhet, tändvillighet och sintring
Panndagarna 2011
9-10 februari
S:t Gertrud Konferens Malmö
Johan Wadenbäck
Chemistry & Materials
Outline
1. Background
2. Scope of the EXAS project
3. Grindability
4. Ignitability
5. Sintering
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| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |
1. Background
The demand of an extensive CO2 reduction indicates, that many qualities of
biomass will be utilized in power plant boilers in the future
• The biomass will be used alone or together with coals as co-firing
• The grindability properties for biomass (or biomass/coal blends) are not
characterized by the current ”standard – classic” methods
• The combustion processes for biomass or biomass/coal blends are not
characterized by the current ”standard – classic” methods
• Fly-ash deposits at ”low” temperatures (Sintering) can cause trouble with
biomass firing
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| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |
2. Scope of the EXAS project (1)
• Purchase of three lab-scale apparatus developed by Prof. śelkowski, Berg,
Wadenbäck et al. for the determination of grindability-, sintring- and
ignitiability properties of solid fuels
– Installation in the fuel laboratory at the Amager Power Plant in
Copenhagen
• Initial evaluation of the hardware with a three solid fuels; coal, straw- and
wood pellets
– The results are compared with full-scale experiences in Vattenfall
• Further evaluation of solid fuels and solid fuel blends used within Vattenfall
such as torrified- or steam exploded biomass etc.
continues…
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| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |
2. Scope of the EXAS project (2)
continues…
• The novel methods are intended to be incorporated into the “routine
analysis toolbox” of solid fuels
• Different parts of Vattenfall will gain experience from the project through
reference group attendance as well as seminars/workshops/reports
– In addition: The possibility to test additional solid fuels and solid fuel
blends relevant for different parts of Vattenfall
• The novel methods are applied prior to introduction of new and unfamiliar
solid fuels at power plants throughout Vattenfall
• Ackreditaded analyses and standardization?
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| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |
3. Grindability – Hardgrove index (HGI)
• Simple test with simple device
• 8 steel balls overroll 60 times a 50 g sample of the fraction
• 0.600-1.18 mm
• The mass M [g] of the produced material finer than 75 µm
determines the HGI
HGI = A + B ⋅ M ≈ 13 + 6.93M
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| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |
3. Grindability – CMT-mill principle
Measuring
Ground material
Suspended particles
(staub)
Feed (Mahlgut)
0,25
airsieve
E
m(Staub) /
m(Mahlgut)
0,2
Mahlgut
0,15
0,1
Staub
0,05
0
Recycled material
Raw sample
0
2
4
Durchlaufzahl
Modeling of the
recycling in a large
mill
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| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |
6
3. Grindability - The EXAS CMT-mill
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| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |
3. Grindability – Solid fuels tested so far…
Characteristic particle size vs. energy in the CMT-mill
E [kWh/ton solid fuel]
100
Wood pellets
Black pellets
Straw pellets
10
Coal
1
0
200
400
600
800
1000
Characteristic particle size, ds [µm]
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| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |
1200
3. Grindability – Correlation with full scale (1)
• Loesche mill
• 3 installed in Unit 1 on Amager CHP
• Samples can be taken before and after
the mill
• The grinding energy and capacity can
be recorded
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| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |
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3. Grindability – Correlation with full scale (2)
Good correlation!
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| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |
11
4. Ignitability – Combustion principles
Loo and Koppejan 2008
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| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |
4. Ignitability – Ignitability Index
At the moment: No standardized methods
The EXAS method: Ignitability index „Zündwilligkeitszahl“ (Zelkowski):
Recirculation
(tRez)
Ignition
(tZünd)
The Ignitability index can be interpreted in praxis as the
ability of a fuel to develop and maintain a stabile
“strong” flame.
The Ignition Temperature of a cloud of suspended fuel particles
(tZ150 in °C)
(which models the initial stages in the combustion process), the temperature
of the gases, of a defined particle size probe, which is injected in a defined
gas environment and ignites after 150 msec.
Ignitability Index
The Ignition potential Nz500 (in MJ/kg solid fuel)
is the chemical energy per kg, which is released (volatile
matter) from a dry solid fuel up to 500 °C.
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ZWZ =
N Z 500
t Z 150
| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |


MJ


 kg Kohle ⋅ °C 
4. Ignitability – Ignitability oven
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| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |
4. Ignitability – TU Clausthal / E2
Zündwilligkeitskennzahl
ZWZ kJ/(kg*°C)
25
Steinkohlen
Braunkohlen
ENERGIEKohlen
BIOMASSEN
20
15
Rusva-Spitzbergen
Holz
Kisselewsky
Poduff
10
Stroh
5
ADARO
0
0
15
10
20
30
40
50
60
70
80
flüchtige Bestandteile F(i.waf) %
| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |
90
4. Ignitability – EXAS ignitability oven
Ignitability oven
Jenkner device
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| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |
6. Ignitability – Some results…
0,55
0,55
0,5
0,5
0,45
0,45
BP1
100%
B P1 Fuel 2
RuPod60%+BP40%
60/40
Fuel 1/Fuel 2
RuPod60%+BP40%
80/20 Fuel 1/Fuel 2
RuPod80%+BP20%
RuPod80%+BP20%
100% Fuel
1
RuPod
100%
RuPod 100%
Zündz eit [msec]
Zü n d z e it [m s e c ]
0,4
0,4
0,35
0,35
0,3
0,3
0,25
0,25
0,2
0,2
0,15
0,15
0,1
0,1
0,05
0,05
0
0
550 600 650 700 750 800 850 900 950 1000
550
600
650
700
750 800 850
900
950 1000
Temperatur im Ofen °C
Temperatur im Ofen °C
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| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |
6. Ignitability – Some more results…
d(Probe)
d(Probe)
d(Probe)
<< 200
63 µm
< 63 µm
80% 60%RuPod+
60% 100%Black
0%
80%RuPod+
RuPod 1 100 80%RuPod+ 60%RuPod+ 100%Black
%
20%Black
40%Black
Pellets
%
20%Black
40%Black
Pellets
2: 0%
20%
40%
100%
Pellets
Pellets
Pellets
Pellets
Nz (500) MJ/kg
Nz (500) MJ/kg
ZWZ kJ/(kg*[°C])
ZWZ kJ/(kg*[°C])
Fuel 1:100%
Fuel 2: 0%
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80%
20%
| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |
60%
40%
100% Black
100% B lack
Pellets
P ellets
Fuel
d(Probe)
d(Probe)
< 200
µm
< 200 µm
16
16
14
14
12
12
10
10
8
8
6
6
4
4
60% RuP od+
60% RuP od+
40% Blac k
40% B lac k
Pellets
P ellets
Fuel 1:RuPod
100%
1 100
d(Probe)
d(Probe)
< 200
µm
< 200 µm
80% RuP od+
80% RuP od+
20% Blac k
20% B lac k
Pellets
P ellets
d(Probe)
d(Probe)
< 200
µm
< 200 µm
RuP od 1
RuP od 1
100 %
100 %
tz(150) [°C]
tz(150) [°C]
840
840
820
820
800
800
780
780
760
760
740
740
720
720
700
700
680
680
660
660
Zündtemperatur tz(150)
Zündtemperatur tz(150)
0%
100%
5. Sintering – Classic analysis of ash melting
Often used methods:
Leitz-Method: Determination of the ashmelting behavior (Influence of the
temperature: e.g. DIN 51730, CEN/TS
15370);
Change in physical form of a relatively
fast (10 K/min) heated ash probe.
The EXAS Method:
Determination of ash melting properities: Influence of the temperature
and time on the physical- and mechanical properties of an ash probe.
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| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |
5. Sintering – EXAS sintering oven
Manufacturing of
ash pellets
20
>17 hours
in oven
Strength of
pellets
| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |
Presentation of solid fuel results – An example
R uP o d 1 1
Fuel
R uP o d 1
D ic h te
D ichte
HG I
HG I
Fuel 2
A s c h e (w f ) B la c k P e lle ts
A s che(wf) B lack P e llets
1 ,5 0
1 ,5 0
1 ,2 5
1 ,2 5
F l.B e s t,(w f )
1 ,0 0
F l.B e st,(wf)
1 ,0 0
0 ,7 5
0 ,7 5
0 ,5 0
0 ,5 0
0 ,2 5
0 ,2 5
0 ,0 0
C (i.w a f )
0 ,0 0
C (i.waf)
Rel m(Br)
Rel m (Br)
1,40
1,40
1,20
1,20
1,00
1,00
H u (w f )
Hu(wf)
H (w a f )
H(waf)
0,80
0,80
0,60
0,60
0,40
0,40
tz(150)
tz(150)
S (w a f )
S (waf)
F(wf)
F(wf)
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100%
RuPud
100%
Fuel 1
100% RuP ud
80%
80/20RuPod+20%BP1l
Fuel 1/Fuel 2
80% RuPod+20%B P1l
60%RuPod+40%BP1
60/40 Fuel 1/Fuel 2
60%RuP od+40%B P 1
| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |
Hu(mittl)(i,wf)
Hu(m ittl)(i,wf)
A(i,wf)
A(i,wf)
Acknowledgements
• Prof. śelkowski, TU Clausthal
• Mogens Berg, Vattenfall
• Nader Padban, Vattenfall
• The laboratory staff at AMV
• Troels Christansen, DTU
• Mr, Schäfertöns, SBS, Braunschweig
• Etc.
And the work goes on…
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| Panndagarna 2011, 9-10 February, Malmö | Malbarhet, sintring och tändvillighet | Johan Wadenbäck, Chemistry & Materials |
Thank you for your attention!
02/22/10 | EXAS - EXpanded Analysis of Solid Fuels |
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