pollution control for cement kilns · 2011. 12. 6. · cement kilns apcac september 6-9, 2010...

Proprietary and Confidential APCAC September 2010© 2010 The Babcock & Wilcox Company. All rights reserved. .1

Pollution Control for Cement Kilns

APCAC September 6-9, 2010 Presenter: Paul J. WilliamsB&W Technical Fellow

Proprietary and Confidential APCAC September 2010

SO2 and HCl Removal

Presentation Topics

.2

Circulating Fluid Bed Dry Scrubber (CDS) Technology

Technology Comparisons

Wet FGD Technology

Dry FGD – Spray Dryer Absorber (SDA) Technology

© 2010 The Babcock & Wilcox Company. All rights reserved.

Environmental Regulations Review


U. S. Cement MACT & NSPS Emission Limits

Pollutant Existing Kilns8/17/71 - 6/16/08

New Source KilnsAfter 6/16/08

HCl 5 mg/dry Nm3 @ 7% O2 5 mg/dry Nm3 @ 7% O2

SO2N/A

1-3 kg / Metric Tonne 0.2 kg / tonne

PM(10) 0.02 kg / Tonne 0.005 kg / Tonne

Major Source Definition = emits > 10 TPY of single HAP or > 25 TPY combined HAPs

Mass values based on tonne of clinkerEmissions based on 30 day rolling averagePM(10) is used as surrogate for toxic metals other than HgPM(10) = solid particulate (excludes condensables)


SO2 and HCl Removal

Presentation Topics

.5

Circulating Dry ScrubberTechnology


Wet FGD Technology

Dry FGD – SDA Technology




Fuels and Scrubber TypesWet Flue Gas Desulfurization (Wet FGD)

Dry FGDSpray Dryer Absorber (SDA)Circulating Dry Scrubbers (CDS)

FuelsCoal, Oil, Petroleum CokeBiomass, Refuse Tires

Fuel Switching Lower Sulfur – Higher sulfur? Lower Cl Lower Hg

© 2010 The Babcock & Wilcox Company. All rights reserved. .6


HCl Removal in Wet and Dry FGD

≥ 99% Removal Efficiency

HCl Emissions: <1.0 ppmdv (1.7 mg/dNm3)@ 7% O2

MeasurementEPA Method 26APractical Detection Limit: 0.3 ppmdv (0.5 mg/dNm3)

HCl Emission independent of inlet concentration?



0,0

1,0

2,0

3,0

4,0

5,0

0 50 100 150 200 250

Oul

et H

Cl,

mg/

dNm

3

Inlet HCl, mg/dNm3

HCl Outlet vs. Inlet


SO2 RemovalWFGD and CDS 98% - 99% Typical Removal Efficiency

SDA – 95% SO2 Removal

MeasurementEPA Method 6Practical Detection Limit: 3-5 ppmdv (8-14 mg/dry Nm3)

ReagentsWFGD – Kiln Dust, Raw Meal or LimestoneCDS and SDA – Lime (hydrated)



90

91

92

93

94

95

96

97

98

99

100

0,5 1 1,5 2 2,5 3

% R

emov

al

SO2 in coal, kg/kj x 106

SO2 Removal vs. SO2 in Coal 0.2 kg/tonne Emission

7 million kj/tonne6 million kj/tonne5 million kj/tonne4 million kj/tonne


0

0,2

0,4

0,6

0,8

1

1,2

1,4

1,6

1,8

0 0,5 1 1,5 2 2,5

SO2

out,

kg/to

nne

Inlet SO2, kg/kj x 106

SO2 Emissions at 90% Removal

7 million kj/tonne6 million kj/tonne5 million kj/tonne4 million kj/tonne


SO2 and HCl Removal

Presentation Topics

.13

Circulating Fluid Bed Technology


Wet FGD Technology

Dry FGD - SDA Technology




Typical Utility Boiler Wet FGD Configuration

.14

Coal Pulverizers

Boiler

SCR

Fabric Filter

SO3 and Mercury

SO2 Scrubber



Characteristics of Wet FGD Systems

Fuel sulfur levels to 8%98-99% Typical RemovalReagent flexibilityCan use Kiln DustExcellent fuel flexibility

.15© 2010 The Babcock & Wilcox Company. All rights reserved.


B&W PGG Overview

CEMEX Environmental Update

Presentation Topics

.17



Wet FGD Technology

Dry FGD – SDA Technology



Typical Spray Dryer Absorber (SDA) Configuration

.18

Boiler

Coal Pulverizers

SCR

Fabric Filter

DryScrubber



Dry Scrubber – Spray Dryer Absorber

.19

Reagent is slaked lime slurry

Slurry is atomized by rotary atomizer

Critical Design Parameters Inlet temperature Drying of lime slurry Approach to saturation Fabric Filter (baghouse) required

SO2 Removal≈95%Approximate limit of 1.5% sulfur



B&W PGG Overview


Presentation Topics

.21



Wet FGD Technology



Proprietary and Confidential APCAC September 2010 22

CDS

Fabric Filter

Product Silo

Lime Silo

Raw Gas Duct

Stack

ID-Fan

Typical CDS Arrangement

22© 2010 The Babcock & Wilcox Company. All rights reserved.


Simple and reliable process

Long solids retention time

Very high byproduct recirculation

>98% SO2 removal efficiency

High fuel flexibility-high S fuels

Compact plant arrangement

CDS Process Basics

23© 2010 The Babcock & Wilcox Company. All rights reserved.


B&W PGG Overview


Presentation Topics

.24



Wet FGD Technology




Flue Gas Desulfurization

Spray Dryer FGD

• ≥ 98% SO2 removal• High sulfur fuels• Kiln dust reagent – no cost• No second baghouse• Wastewater treatment• Wet stack – converted or

new• Alloy or linings

• ≈ 95% SO2 removal • Lower sulfur fuels <1.5%• Carbon steel• Limited fuel flexibility• Second Baghouse• Expensive Lime reagent

• ≥ 98% SO2 removal• Carbon steel• Compact Footprint• Higher sulfur fuels• Second baghouse• Expensive Lime reagent• Clean gas recirculation

Wet FGD System Circulating Dry Scrubber



Selection of FGD System

Capital Cost Lower for SDA and CDSOperating Cost depends on SO2 removal Sulfur in fuel

Reagent Lime = $75 USD per ton Kiln dust = $0 Limestone = $15 per ton

Lower sulfur and lower removal favor SDAHigher sulfur, higher removal favor WFGD or CDS



Thank You.

B&W and PrecipTech

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Questions?


pollution control for cement kilns · 2011. 12. 6. · cement kilns apcac september 6-9, 2010...

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