Michal Glazer, Vattenfall, Sweden

Practical experiences with mitigating HT
corrosion by the ChlorOut concept in full scale
boilers
Dr. Michal Glazer – Project manager - Business Development
Vattenfall/ChlorOut AB
04.06.2014
Confidentiality class: Low (C1)
Challenges in new and existing plants
• High levels of alkali chlorides (KCl) can cause enhanced deposit formation.
• A high content of KCl in deposits may cause accelerated superheater corrosion
when firing biomass.
• Super heater corrosion can be reduced by co-combustion or by the use of
sulphur/sulphate-based additives.
2 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
Strategies to reduce alkali-related problems
• Elemental sulphur (S) and sulphates such as ammonium sulphate (AS) can be used
for sulphation of KCl. The additive (S or AS) converts KCl to a less corrosive alkali
sulphate.
Ammonium sulphate (AS) (NH4) 2SO4
No additive (Ref)
Direct decomposition into ammonia + SO3
Additive (AS)
3 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
The ChlorOut concept
Vattenfall has developed and patented:
• An instrument that measures KCl(g) on-line (IACM)
• A sulphate containing additive which converts KCl to a less corrosive
alkali sulphate and HCl
• IACM used for control of the required amount of additive and for on-line
quality control of the incoming fuel mix by measuring KCl
4 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
In situ alkali chloride monitor (IACM)
• IACM measures the concentration of gaseous alkali chlorides (KCl +
NaCl) on-line at flue gas temperatures above 650ºC
• The measuring principle is based on molecular absorption at
characteristic wavelengths in the UV-vis region
Measurement
path
Sender
UV-light
Receiver
Spectrometer
Fan
Hot
flue
gas
Fan
Computer
5 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
IACM – Measurement of gaseous alkali chlorides
Transmitter (light source)
Receiver (spectrometer)
6 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
IACM – A tool for fuel quality control
Influence of potassium and chlorine supply for formation of KCl
80
I
II
III
• Molar ratio Cl/(K+Na) less
than 1.0 during combustion
of biofuels.
KCl (ppm wg)
60
pure wood
pellets
wood
pellets
+straw
wood pellets
+straw+PVC
• Lack of chlorine to form KCl.
40
• KCl increased in III despite no
additional alkali was
supplied.
20
0
0
40
80
120
Time (minutes)
160
7 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
The ChlorOut concept
IACM
Injection nozzles
ChlorOut
solution
8 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
Reduction of alkali chlorides and NOx
50
90
III.
II.
I.
Ammonium sulphate
KCl ppm (as measured)
60
30
45
20
30
10
NO ppm (as measured)
75
40
15
0
0
0
25
50
Time (minutes)
75
100
9 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
Sulphation of KCl
Sulphation of gaseous KCl is more efficient with ChlorOut compared to
elemental sulphur.
KCl koncentration (ppm)
35
ChlorOut
30
Sulphur
25
20
15
10
5
0
0,0
0,1
0,2
0,3
0,4
Added S (kg/MWh)
0,5
0,6
0,7
10 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
Influence of injection location
60
λ=1.1
• AS was injected at the same
air excess ratio (λ= 1.1) at
three locations.
Comb
Inlet
Cycl
KCl (ppm wg)
45
• Sulphation of KCl (g) was
significantly less efficient
when injected in the Top of the
Combustion Chamber.
30
15
0
0
1
2
3
4
5
• This indicates that the
concentration of SO3 had been
decreased due to the presence
of combustibles.
S/Cl
11 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
Reference case - Munksund
Boiler: 98 MWth CFB
Fuel: Mainly bark>80%, sawdust, wood chips, 6%
plastic waste (from cardboard recycling)
Steam data: 420°C after SH2, 480°C 60 bar after an
Intrex
Two separate cyclones, the flue gases mix again
prior to SH2
An important advantage of the ChlorOut concept in
this application is the simultaneous reduction of
dioxin emissions
12 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
Munksund – The research campaign
IACM
SH1
SH2
Corrosion-/deposit probes, FTIR
• Short-term campaign: Normal fuel mix, ChlorOut,
co-comb. of peat, IACM, deposit probes, impactor,
FTIR
• Right side injection of ChlorOut: Normal, Normal +
ChlorOut, IACM, deposit-/corrosion probes
Injection
• Long-term measurements: IACM, ChlorOut,
Corrosion probes, data recording from the plant
including stack emissions
Intrex
13 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
Reference case - Munksund
The use of IACM for control of the level of gas phase alkali chloride
20
Ref - KCl
AS - KCl
KCl (ppm wg)
15
10
5
0
85
95
105
Load (ton/h)
115
125
14 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
Munksund – Short term / Deposit growth
Deposit growth - right sided injection of ChlorOut
Weight increase (g/m2*h)
10
Normal
ChlorOut
8
6
4
2
0
400
500
550
Ring temperature
15 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
Reference case – Munksund
Gas phase analysis of KCl and chemical analysis of deposits (S and Cl)
KCl (ppm), S, Cl (weigh %)
15
Ref
No Cl detected
AS
10
5
0
KCl
S
Cl
16 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
Munksund – Long term / Corrosion and deposits testing
The corrosion probe.
1. inlet cooling air; 2. outlet cooling air.
The material and positions (pos) for the test rings were:
15Mo3 pos 1, 4, 7, 10
10CrMo910 pos 2, 5, 8 13, 15
13CrMo44 pos 3, 6, 9, 11, 14, 16
X20 pos 12, 18
Esshete 1250 pos 17.
17 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
Munksund – Long term / Corrosion and deposits testing
• Corrosion probes exposed for 4 weeks
• Left side: Normal fuel mix
• Right side: Normal fuel mix + ChlorOut (AS)
18 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
Munksund – Long term / Corrosion rates
The corrosion was significantly lower during ChlorOut injection
Corrosion rates during a four week measurement for Ref and AS and during a ten
week measurement for AS.
The exposed ring materials and their individual positions were: 15Mo3 pos 1, 4, 7,
10; 10CrMo910 pos 2, 5, 8 13, 15; 13CrMo44 pos 3, 6, 9, 11, 14, 16; X20 pos 12, 18;
and Esshete 1250 pos 17
19 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
Munksund – Long term / Corrosion rates
The corrosion rate did not increase as much with increasing temperature with
ChlorOut as without
The corrosion rate for 15Mo3 at 430°C without was similar as at 510°C with
ChlorOut. The same results were observed for the other low-alloyed materials
10CrMo910 and 13CrMo44
The stainless steel X20 was only tested at higher temperatures, and the
corrosion rate was reduced more than 90 % with ChlorOut
The corrosion rate for the austenitic stainless steel Esshete 1250 was at
550°C reduced from a rather low rate to a very low rate with ChlorOut
20 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
Reference case - Jordbro
Steam data: Designed for 470°C for 100% demolition wood and 490°C for 100% forestry
waste
Aim to maintain steam data at 490°C also when firing demolition wood by utilising the
ChlorOut concept
21 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
Reference case - Jordbro
100
KCl
NOx
Reduction (%)
80
60
40
20
0
0
30
60
90
120
150
Flow of ammonium sulphate (l/h)
22 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
Reference case - Jordbro
Chemical analysis of deposits from probe measurements
16
Na+K
S
Cl
14
12
Weight %
10
8
6
4
2
0
Reference
ChlorOut 60 l/h
ChlorOut 90 l/h
ChlorOut 120 l/h
23 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
The ChlorOut concept
• A large number of installations in operation focusing on reduced
superheater corrosion, deposit formation and/or NOx and CO reduction.
• Long-term experience (>10 years). ChlorOut is an established and well-
known commercial concept.
• Fuels: Biomass, waste wood, straw, municipal solid waste (MSW) and co-
combustion.
• Boiler types: CFB, BFB, PF, Grate
24 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
ChlorOut reference plants
Plant
Plant owner
Type
Fuel
Size (MWth fuel)
Concept operational
Helsingborg
Öresundskraft Kraft & Värme AB
PF
Virgin wood
185
2003 -
Workington
Iggesund Paperboard Ltd.
BFB
Virgin wood
148
2013 -
Brista
AB Fortum Värme
CFB
Virgin wood
122
2003 - 2008
Växjö
Växjö Energi AB
BFB
Virgin wood, peat
105
Under construction
Navia
Ence Energia y Celulosa S.A.
BFB
Virgin wood
100
2013 -
Munksund
Vattenfall AB
CFB
Waste wood, plastic reject
100
2005 -
Idbäcken
Vattenfall AB
BFB
Waste wood
100
2001 -
Poznan
Dalkia Poznan S.A.
BFB
Virgin wood
90
2011 -
Karlstad
Karlstad Energi AB
BFB
Virgin wood
88
Under construction
Jordbro P34
Vattenfall AB
PF
Virgin wood
80
2010 -
Strongoli
Biomasse Italia SpA
CFB
Virgin wood, agricultural reject
2 x 75
2013 -
Jordbro CHP
Vattenfall AB
BFB
Waste wood
70
2012 -
Ingelheim
Boehringer Ingelheim Pharma GmbH & Co. KG
Grate
Waste wood
65
2006 -
Kassel
Städtische Werke Energie + Wärme GmbH
CFB
Waste wood
38
2009 -
Sala
Sala-Heby Energi AB
BFB
Virgin wood
32
2002 -
Ludvika
Västerbergslagens Energi AB
Grate
Virgin wood
2 x 10
2010 -
Kalix
Vattenfall AB
Grate
Peat, bark
10
2009 -
Vetlanda
Vetlanda Energi & Teknik AB
2 x Grate Virgin wood
6&9
2005 -
25 | Practical experiences with mitigating HT corrosion by the ChlorOut concept in full scale boilerss| Michal Glazer, Vattenfall | 04.06.2014
Confidentiality class: Low (C1)
Thank you for your attention!
www.chlorout.com

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