Is scr technology coming back to cement

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



Installed: June - 2006

Catalyst: Honeycomb 11.9 mm

pitch


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



Installed: April 2010


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


Installed: March - 2011


Layers Designed: 3

Layers Used: 2

Dust Loading: <20 mg/m3

NOx Out: 122 mg/m3 (test)

Aqueous Ammonia


(design)

Rohrdorf - Germany

Rohrdorf - Germany

Mannersdorf - Austria

SCR

ESP

GCT

FAN

Equipment: Scheuch

Arrangement: Semi Clean


Installed: April 2012


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


(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 ???