is scr technology coming back to cement
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John Kline – John Kline Consulting April 2013
Presentation
NOx Formation
SCR & SNCR Technology
Traditional “High Dust” Installations
Newer “Medium & Low Dust”
Installations
Conclusions
NOx Formation
Nitrogen Oxides are formed when nitrogen from the fuel and / or combustion air is combined with oxygen during combutsion
NOx formation increases with:
Fuel Nitrogen Level
Amount of Air available for combustion
The combustion temperature
Typical NOx Formation Controls
Reduced NOx Formation
Improved Efficiency (Less Fuel)
Lower Nitrogen Fuels
Reduced Combustion Air Quantity
Staged Combustion
NOx Control after Formation
Selective Catalytic Reduction (SCR)
Selective Non-Catalytic Reduction (SNCR)
Cement Process Evolution
Smaller
Kilns
Lower Fuel
Consumption Higher Exit Gas
Temperature
Staged
Combustion
Material
Preparation
Thermal
Processing
Finishing
Reducing NOx Formation
Low NOx Burners Alternative Fuels
NOx Reduction after Formation
SCR = NOx + NH3 + Catalyst @ 300 – 400 oC
SNCR = NOx + NH3 @ 800 – 1000 oC
Non-Catalytic – No Catalyst
Selective Catalytic Reduction (SCR)
Requires a catalyst and a reducing
agent
Technology has been around for many
years
Patented by Englehard Corp. in 1957
First large scale installed by IHI in 1978
Is widely used in coal fired utilities
Is also commonly used in some
automobile and truck exhaust systems
Typical SCR System
Why Chose SCR over SNCR ?
Pros
Higher level of NOx
reduction
Lower level of
ammonia slip
Utilizes ammonia
coming from raw
materials
Cons
Much higher
investment cost
Higher operating
costs
More down time
Larger footprint
required
Difficult to retrofit
SNCR & SCR Locations
Precalciner Exhaust
850 – 950 oC
200 – 300 g/m3
Preheater Exhaust
300 – 400 oC
80 – 120 g/m3
Kiln Exhaust
950 – 1050 oC
100 – 200 g/m3
`
The Raw Mill Area
Preheater
Exhaust
300 – 400 oC
80 – 120 g/m3
Raw Mill
Exhaust
90 – 100 oC
10 – 20 mg/Nm3
Solnhofen - Germany Equipment: Lurgi – GEA
Bischoff
Arrangement: High Dust
Kiln System: Preheater
Installed 2001
Catalyst Supplier: KWH
Operating Temp 320 – 340 oC
Layers Designed: 6
Layers Used: 3
Dust Loading: 80 – 100 g/Nm3
NOx In Design: 1050 mg/Nm3
NOx Out Design: 200 mg/Nm3
Aqueous Ammonia
Ammonia Slip: <1 mg/Nm3
(test)
Taken out of service in 2006, as
SNCR could meet permit
requirements
So What About the Dust ?
The catalyst needs to be in contact with the
NOx and Reducing agent
This requires a large surface area
Large surface areas requires smaller
openings between catalyst layers
Small Openings get plugged with dust
Coal Utilities operate at 10 – 20 gms/Nm3
Solnhofen operated at 80 – 100 gms/Nm3
Coal Fired Power Plant SCR
C-Flyash
SiO2
CaO Al2O3
OPC
F-Flyash
No Popcorn,
But ……
High CaO =>
CaSO4
Its Sticky
Monselice - Italy
Equipment: ELEX – Cemcat
Arrangement: High Dust
Kiln System: Preheater
Installed: June - 2006
Catalyst: Honeycomb 11.9 mm
pitch
Operating Temp 320 – 330 oC
Layers Designed: 6
Layers Used: 3
Dust Loading: 100 g/m3
NOx In: 1100 – 1300 mg/m3
NOx Out: 200 – 400 mg/m3
Aqueous Ammonia
Ammonia Slip: <5 mg/m3 (test)
Installed to reduce ammonia
smell from raw materials
Sarche - Italy
Equipment: In-House Design
Arrangement: Medium Dust
Kiln System: Lepol Grate
Dust Loading: <15 g/m3
Installed: January - 2007
Installed to reduce ammonia
smell from raw materials
Mergelstetten - Germany
Equipment: ELEX – Cemcat
Arrangement: High Dust
Kiln System: Preheater
Installed: April 2010
Operating Temp 380 – 400 oC
Layers Used: 4
Dust Loading: 80 - 90 g/m3
NOx In: 1100 – 1300 mg/m3
NOx Out: 200 mg/m3
Ammonia Slip: <5 mg/m3
(design)
Rohrdorf - Germany
Equipment: GEA Bischoff
Arrangement: Clean Side
Kiln System: Preheater
Installed: March - 2011
Operating Temp 250 – 260 oC
Layers Designed: 3
Layers Used: 2
Dust Loading: <20 mg/m3
NOx Out: 122 mg/m3 (test)
Aqueous Ammonia
Ammonia Slip: <10 mg/m3
(design)
Rohrdorf - Germany
Rohrdorf - Germany
Mannersdorf - Austria
SCR
ESP
GCT
FAN
Equipment: Scheuch
Arrangement: Semi Clean
Kiln System: Preheater
Installed: April 2012
Operating Temp 320 – 330 oC
Layers Designed: 4
Layers Used: 2
Dust Loading: <10 g/m3 (design)
NOx In: 500 mg/m3 (design)
NOx Out: <200 mg/m3 (design)
Aqueous Ammonia
Ammonia Slip: <5 mg/m3
(design)
Joppa – USA
Equipment: Elex Cemcat
Kiln System: Long Dry w/ ESP
To be installed: July 2013
Logansport – IN, USA
Slipstream Test
Kiln System: Long Wet
Arrangement: Clean Side
To be installed: July 2013
Rezatto - Italy
SCR Technology to be
installed as part of a
plant upgrade project
Arrangement: High
Dust
Installation to be
complete by 2015
Reduction in NOx and
ammonia emissions
targeted
1996 – 1998
Slip Stream
Tests
Germany,
Austria,
Sweden, & Italy
2001 – 2006
Full Scale,
High Dust SCR
Solnhofen,
Germany
Jun-06 Full
Scale High
Dust SCR
Monselice,
Italy
Jan-07 Full
Scale High
Dust SCR
Sarche, Italy
Apr-10 Full
Scale High
Dust SCR
Mergelstetten,
Germany
Mar-11 Full
Scale Clean
SCR
Rohrdorf,
Germany
Apr-12 Full Scale
Semi-Clean SCR
Mannersdorf,
Austria
Jul-13 Full Scale
Semi-Clean SCR
Grand Chain, Il,
USA
Jul-13
Slip Stream
Clean SCR
Logansport, IN,
USA
2015 Full
Scale High
Dust SCR,
Rezatto, Italy
SCR Installation Timeline
Game Changers
Tighter NOx Emissions Limits
(Europe <200 mg/m3)
Low Temperature Catalyst Development
(+/- 100 oC)
Tighter Ammonia Limits
(Europe 5 – 10 mg/m3)
Plus ???
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