Oslo, February 17th, 2010 - SINTEF
Transcript of Oslo, February 17th, 2010 - SINTEF
HIGH DUST SELECTIVE CATALYTIC NOx REDUCTION AT WTE P LANT IN BRESCIA
Paolo Rossignoli – Mario Nenci – Lorenzo Zaniboni A2A, Brescia, Italy
Oslo, February 17th, 2010
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
••Waste preventionWaste prevention
••Separate collection (for material recycling)Separate collection (for material recycling)
••Composting of organic wasteComposting of organic waste
••Energy from remaining waste (renewable energy)Energy from remaining waste (renewable energy)
••LandfillingLandfilling minimization (only safe residues)minimization (only safe residues)
INTEGRATED WASTE MANAGEMENT SYSTEM
1. ENVIRONMENTAL PROTECTION
2. HIGH EFFICIENCY OF ENERGY RECOVERY
3. SAFETY, RELIABILITY, AVAILABILITY
DESIGN GOALS:
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
584 584 km of double pipekm of double pipe
130.000 inhabitants supplied130.000 inhabitants supplied
38,538,5 MmMm33 heated volumeheated volume
17.391 17.391 connected buildingsconnected buildings
695 695 MWMWthth
230 230 MWMWelel
1 km
P.Plant north
P.Plant south
WTE
DISTRICT HEATING SYSTEM OF BRESCIA
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
Mm3
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2.00
2 2.
003
2.00
4 2.
005
2.00
6
YEARS
CONNECTED BUILDINGS VOLUMES
DISTRICT HEATING SYSTEM OF BRESCIA
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
DISTRICT HEATING SYSTEM OF BRESCIA
0
200
400
600
800
1.000
1.200
1.400
1.600
1.800
2.000
2.200
2.400
2.600
2.800
3.000
3.200
3.400
3.600
3.800
4.000
GW
h
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
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1984
1985
1986
1987
1988
1989
1990
1991
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2006
ANNI
USED FUELS
• NAT. GAS
• OIL
• COAL
• SOLID WASTE and BIOMASSES
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
WASTE BUNKER
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
Combustion grate under construction
MAIN TECHNICAL DATA
• Heat capacity of treated waste (3 boilers) 310 MW
• Waste throughput 3 x 33 t/h
• Electrical generation capacity (net) 80 MWel
• Heat generation capacity 170 MWth
ISO 14001 Environmental certification in april 2006
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
OPERATIONAL DATA 2008
• Treated waste 801,000 tons( of which biomass 270.000 tons )
• Electricity production (net) 570 GWhel
• District heating 568 GWhth
• Fossil fuels saving (Tons of Oil Equivalent) > 150,000 TOE
• CO2 avoided emissions > 400,000 tons
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
NOx CONTROL METHODS
• PRIMARY (NOx prevention)
- staged combustion (gradual O 2 supply)
- combustion temperature control
• SECONDARY (NOx reduction)
- SNCR (Selective Non-Catalytic Reduction)
- SCR (Selective Catalytic Reduction):- “High dust” (on raw gas)- “Tail-end” (after gas cleaning)- “Low dust” (after gas de-dusting)
HIGH DUST SCR LOCATION
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
HIGH DUST SCR LAYOUT
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
MIXER
CATALYST LAYER
(SPACE FOR UP TO 5LAYERS)
FLUEGAS
DAMPERS
NOx NOx
IMPLEMENTED NOx CONTROL IN BRESCIA WTE(starting situation - since 1998)
• PRIMARY
- low combustion excess air
- 30 compartment grate
- infrared camera for optimization of primary andsecondary air supply
- flue gas recirculation
• SECONDARY (NOx reduction)
- SNCR (NH3 injection with 27 nozzles, positioned atthree levels)
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
SNCR DENOX SYSTEM
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
INSTALLATION AND TESTING OF A SCR “HIGH DUST” SYSTEM(non industrially available yet)
GOALS:
- further NOx reduction (120 ���� 80 mg/Nm 3)
- ammonia slip improvement
- lowering ammonia consumption
- keep high energy plant efficiency
PROBLEMS:
- catalyst clogging- catalyst poisoning
ADVANTAGES:
- much higher energy efficiency (no need of gasreheating and lower gas pressure losses)
- simpler installation- lower investment and operating cost
SCR “HIGH DUST” SYSTEM(non industrially available yet)
• installation: 2005 Sep. – 2006 Feb.
• operation: started 2006 Mar. (1 st phase – one cat. layer)
• inspection: Sep. 2006 (cleaning and catalyst analysi sshowing some pore plugging and catalystpoisoning with sulphates)
• 2nd phase: started 2006 Oct. after inspection (2 cat. la yer)
• inspections: 2007 Apr. and Sep. (only cleaning)2008 Apr. (erosion starts to become evident)
November: removal of one layer and installation of a new 2008 layer
SCR “HIGH DUST”History highlights
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
SPACE FOR SCR HIGH DUST INSTALLATION
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
TERMOUTILIZZATORE(The waste to energy plant of Brescia
HIGH DUST SCR
SPACE FOR
SCR HIGH DUST
INSTALLATION
CATALYST UNDER CONSTRUCTION
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
NOx- NH3 emissions
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90
1/1/06 1/5/06 29/8/06 27/12/06 26/4/07 24/8/07 22/12/07 20/4/08 18/8/08 16/12/08 15/4/09 13/8/09 11/12/09
NO
x -
NH 3
stac
k em
issi
ons
[mg/
Nm
³]
0
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NH 3
cons
umpt
ion
[l/h]
NOx
NH3slip
NH3cons.
74
12
4,4
8
1,3 1,83,7
SCR operation start (1 layer)
Start with
2nd layer
217
2,5
70
44
33
53
66
61
67
58
69
179
166
184186
219200
44,9
NOx – NH3 consumption – ammonia slip
HIGH DUST SCR RESULTS
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
HIGH DUST SCR RESULTST , ∆∆∆∆p SCR
0
25
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75
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125
150
175
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225
250
275
300
325
3/7/06 31/10/06 28/2/07 28/6/07 26/10/07 23/2/08 22/6/08 20/10/08 17/2/09 17/6/09 15/10/09
T [°
C]
0,00
0,25
0,50
0,75
1,00
1,25
1,50
1,75
2,00
2,25
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2,75
3,00
∆∆ ∆∆p
[mba
r]
T SCR [°C]
Dp [mbar]
Start with
2nd layer
T gas – ∆p SCR
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
NOx and NH3 emissions monthly media 2006 - 2007 - 2 008 - 2009
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May-09
month
mg/
Nm
3
L1 NOx
L1 NH3
L2 NOX
L2 NH3
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
L1: SNCR only ���� L2: SNCR + HD SCR (2 layers)
• NOx: 80 - 90 ���� 60 - 70 mg/Nm 3
• NH3 slip: 10 - 30 ���� 2 - 6 mg/Nm 3
• NH3 consumption: 0.22 ���� 0.18 m3/h (25% concentrated )
• Pressure losses: negligible
SCR “HIGH DUST”
TEST RESULTS
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
• new geometry in order to increase plates stiffness
• increasing plates thickness
• new composition of the catalyst material in order t o
increase plates hardness
“HIGH DUST” SCR
Modifications of the catalyst to reduce erosion
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
CATALYST AFTER 2 YEARS OF OPERATION
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
Before Cleaning
After Cleaning
INSPECTION OCTOBER 2009CATALYST REMOVED AFTER 32 MONTHS OF OPERATION
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
HIGH DUST SCR
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
HIGH DUST SCR
INSPECTION OCTOBER
2009
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
HIGH DUST SCR
CATALYST REMOVED AFTER 32 MONTHS OF OPERATION
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
HIGH DUST SCR
CATALYST REMOVED AFTER 32 MONTHS OF OPERATION
HIGH DUST SCR
FUTURE TEST STEPS :
� monitoring of fouling and activity of catalyst with new g eometry
� optimization of catalyst layout (single / multiple la yers)
� optimization of duct cleaning with modified geometry
� lifetime assessment of the catalyst with new materials
� industrial cost evaluation
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
HIGH DUST SCR
CONCLUSIONS:
� improving the reaction between ammonia and NOx
TERMOUTILIZZATORE(The waste to energy plant of Brescia)
� low impact on the plant efficiency: small pressure l osses and low impact on fan consumption
� life-time rather short, but costs relatively small in comparison with other SCR systems:
• costs for reheating the flue gas and energy for IDf an (vs Tail-end)
• costs for ammonia consumption (vs pure SNCR)