This presentation questions whether SCR technology will become a sustainable NOx reduction technology for the cement industry

1. John Kline – John Kline Consulting
April 2013

2. Presentation
 NOx Formation
 SCR & SNCR Technology
 Traditional “High Dust” Installations
 Newer “Medium & Low Dust”
Installations
 Conclusions

3. 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

4. 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)

5. Cement Process Evolution
Smaller
Kilns
Lower Fuel
Consumption
Higher Exit Gas
Temperature

6. Staged
Combustion
Material
Preparation
Thermal
Processing
Finishing
Reducing NOx Formation
Low NOx BurnersAlternative Fuels

7. NOx Reduction after Formation
SCR = NOx + NH3 + Catalyst @ 300 – 400 oC
SNCR = NOx + NH3 @ 800 – 1000 oC
Non-Catalytic – No Catalyst

8. 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

9. Typical SCR System

10. 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

11. 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
`

12. The Raw Mill Area
Preheater
Exhaust
300 – 400 oC
80 – 120 g/m3
Raw Mill
Exhaust
90 – 100 oC
10 – 20 mg/Nm3

13. 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

14. 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

15. Coal Fired Power Plant SCR
C-Flyash
SiO2
CaO Al2O3
OPC
F-Flyash
No Popcorn,
But ……
High CaO =>
CaSO4
Its Sticky

16. 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

17. 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

18. 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)

19. 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)

20. Rohrdorf - Germany

21. Rohrdorf - Germany

22. 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)

23. Joppa – USA
Equipment: Elex Cemcat
Kiln System: Long Dry w/ ESP
To be installed: July 2013

24. Logansport – IN, USA
Slipstream Test
Kiln System: Long Wet
Arrangement: Clean Side
To be installed: July 2013

25. 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

26. 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

27. 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 ???