Florida Department of Environmental Protection

David Read

Cement Subproject ManagerBureau of Air Regulation

Cement Mercury Subproject

Florida Cement Industry

• 10,000,000 tons per year clinker

• Ten cement kilns

• Demand is down

• Five in operation

• Two are temporarily down

• Three at/near startup

Suwannee American

Vulcan

AmericanCEMEX N. Brooksville

CEMEX S. Brooksville

Titan America

CEMEX Miami

Fuel and Materials Hg – Plant AConcentrations in parts per billion (ppb)

0

50

100

150

200

250

300

Pa

rts

pe

r b

illi

on

(p

pb

)

Limestone Sand Iron Ore Fly Ash HC fly Ash Coal

Other

Coal Ash

Fuel and Materials Hg – Plant AContribution to total emissions in percent (%)

44.02

42.16

10.26

3.56

Limestone Coal Ash Coal Other

EPA and Florida Kiln Emission Estimatesin pounds (lb) of Hg per million tons of clinker

10

100

1000

10000

0 10 20 30 40 50 60 70 80 90 100

Kiln Number

U.S. Kilns FL Kilns (Mass Balance) New FL Kilns (Potential) FL Kilns (DEP Estimate)

Lowest ~ 10 lb/million tons clinker

Highest ~ 3,300 lb/million tons clinker

Best 12% by EPA ranking

40

Raw Mill On – Most Hg Captured, Stored

CoalHg in

(to Cement Mill)

Meal & Hg Removed

Hg in(from Raw Mix)

Meal & Hg Stored

RAW

MEAL

SILO

(Hg)

Filter

FuelHg in

ClinkerNo Hg out

Hg outLittleLOTSRaw Mill Off – Hg Emitted

LEGEND

GasSolid

Filter Dust

Raw Mill

Separators

Preheater Exhaust

Preheater Feed

Hg Control Options

• Limit high carbon coal ash, raw materials/fuels Hg• Add-on control equipment prior to stack

Baghouse, activated carbon (Norcem Brevik and Ash Grove Durkee, Oregon) Wet Scrubber (such as for SO2 in TXI Midlothian, Holcim Holly Hill)

• Heat and return filter dust, recover Hg in activated carbon Much smaller gas volume than end-of-process controls (F.L. Smidth offers)

• Heat problem fuels/material, recover Hg in activated carbon Also much smaller volume (F.L. Smidth describes in patent)

• Filter dust shuttling to cement product Typically practiced in some European countries (allowed in Florida?)

RAW

MEAL

SILO

Hg out(to Cement Mill)

Hg out Some

Hg in(coal)

No Hg out(to Cement Mill)

Hg outSome

Hg in(from Raw Mix)

Hg in(fuel)

Filter

Scrubber

(Hg Stored)(Hg Removed)

Filter Dust Shuttling – Mill OffProblem Raw Material/Fuel Treatment

MercuryPlant

Hg in(Alternate

Material/Fuel)

Hg in

Mercury Plant

(Filter Dust)

Hg

(Filter Dust)

Filter Dust Treatment, Return

LEGEND

GasSolid

Hg Removed by ScrubberHg Removal by Activated Carbon

Hg Removed

Some

Most

Hg out

Removed

Comparison of Florida Kilns with Best 12%

at 25, 50, and 75% reduction from present estimates

10

100

1000

10000

0 10 20 30 40 50 60 70 80 90 100

Kiln Number

U.S. Kilns Florida Kilns FL 75% Reduction FL 50% Reduction FL 25% Reduction

40

Florida Cement Industry Summary

• Florida kilns emit ~ 100 lb Hg/million tons clinker

• At full capacity emissions will be ~ 1,000 lb Hg/year

• A well-controlled coal power unit emits < 20 lb Hg/year

• EPA will propose draft limit by March 31, 2009

• May need significant reductions to achieve EPA limit

• Start with more careful materials and fuel selection

• Avoid high carbon fly ash (abated power plant emissions)

• Shuttle filter dust to product to extent cement meets specs

• Treat problem alternative fuels/materials

• Only then get to end-of-process add-on controls

Additional Thoughts• Need better data at some existing kilns• Material testing, sorbent traps, Hg-CEMS• Total Maximum Daily Load (TMDL) driver• May require limits beyond EPA MACT*• We ought to try out dust shuttling first• We will visit FDOT** to see if allowed

* Maximum Achievable Control Technology

** Florida Department of Transportation