Florida Department of
Environmental Protection
Mercury Puzzle
Hg(0), Hg(II), Hgp
Alvaro Linero, P.E.
Administrator, Special Projects
Bureau of Air Regulation
Emissions and Processes
• DEP Contract to Test some Facilities
• Three Coal- Fueled Power Plants
• Two Cement Kilns, plus a Compliance Test
• Waste-to-Energy (WTE) Compliance Tests
• Miscellaneous Industries
• Hg-CEMS (Continuous Emissions Monitoring Systems)
Some Nomenclature, Proportion
• Micrograms Hg per dry standard cubic meter
• Pounds Mercury per Year (lb Hg/yr)
• Little Substantial
• 0.1
•
1
a Lot
1
10
10
100
Potent
100 µg Hg/dscm
1000 lb Hg/year
More Nomenclature
• Kilowatt-hour (KWH)
• 1,000 KWH = Megawatt-hour (MWH)
• Million (or 106) MWH = Terawatt-hour (TWH)
• 1 x 10-6 lb/MWH = 1 lb Hg/TWH = 0.1 lb/TBtu
• ppb = parts per billion
• lb Hg/million tons of clinker = lb Hg/MT clinker
Old 360 MW Coal-fueled Unit High NOX
Hg(0) = Elemental (gas)
Hg(II) = Reactive (salts like HgCl2)
Hgp = Particle Bound
Flue Gas
Higher NOx
Lower CO
150 lb Hg/yr
75%
Cold Electrostatic Precipitator (ESP)
Coal & XS Air
25% Removal
200 lb Hg/yr
Hgp
Eastern Coal
Hg0
25%
>2500 °F
50 lb Hg/yr
Fly Ash to Concrete, Cement Kiln Storage, Waste
I don’t actually have data for this case
360 MW Coal-fueled Unit Tuned for Low NOX
110 lb Hg/yr
Flue gas carbon (C) can
behave much like activated C
Flue Gas C
55%
Cold Electrostatic Precipitator (ESP)
Overfire Air
Coal & Air
45% Removal
Hgp
200 lb Hg/yr
72 lb/TWH
90 ppb Hg
10.5% Ash
Eastern Coal
Hg0
>2500 °F
Low NOx
Burners (LNB)
45%
90 lb Hg/yr
Carbon and Hg-Enriched Fly Ash
to Concrete, Cement Kiln, Storage, Waste
385 ppb
40 lb/TWH
4.9 µg/dscm
64% Hg(II)
Vacated EPA Hg limit for new units was 21 lb/TWH
Wet Flue Gas Desulfurization (FGD) for SO2
Limestone or Lime Slurry
Soluble Hg salts absorbed
or reacted in FGD Scrubber
Flue Gas C
40 lb Hg/yr
20%
FGD
ESP
OFA
45% Removal
Coal & Air
200 lb Hg/yr
Hgp
Hg0
Hg(II)
45%
LNB
>2500 °F
90 lb Hg/yr
Carbon and Hg-Enriched Fly Ash
to Concrete, Cement Kiln, Storage, Waste
385 ppb
35%
70 lb Hg/yr
16 lb/TWH
2 µg/dscm
85% Hg(0)
Sludge, Gypsum
Hg Salts
Selective Catalytic Reduction (SCR) for NOX
Limestone or Lime Slurry
10 lb Hg/yr
Elemental Hg (0) oxidized
to Hg (II) by catalyst
Flue Gas C
SCR
FGD
ESP
Overfire Air
45% Removal
Coal & Air
Hgp
200 lb Hg/yr
Hg(II)
Hg0
Ammonia (NH3)
LNB
>2500 °F
45%
90 lb Hg/yr
NH3, Carbon, Hg-Enriched Fly Ash
Concrete, Cement Kiln, Waste or
Fly Ash Remediation
3.2 lb/TWH
0.5 µg/dscm
100 lb Hg/yr 69% Hg(0)
50%
Sludge, Gypsum
Hg Salts
Florida Cement Industry
Suwannee American
Vulcan
• 10,000,000 tons per year clinker
• Ten cement kilns
• Demand is down
American
CEMEX N. Brooksville
CEMEX S. Brooksville
• Five in operation (slack demand)
• Two are temporarily down
• Three new startups (also slack)
Titan America
CEMEX Miami
1 MT Clinker
Raw Mill
Cement
Off, Little
Kiln, Hg
Raw
In Mill On
0.8 µg/dscm
400
µg/dscm
92%
oftime
time
8% of
3 lb/yr
117
lb/yr
Hg(0)
Hg(II)
Scrubber ?
Filter
New Kiln Limit
41 µg/dscm
LEGEND
Gas
Solid
Preheater Exhaust
Filter Dust
To Cement Mill
Separators
Preheater Feed
1 MT/yr of Clinker
Meal & Hg Stored
Fuel
Fuel Hg
Hg
RAW
Raw
Meal,
Raw
Meal,
Hg Hg
Inventory
Falls
Inventory
Increase
MEAL
Fuel Hg
Meal & Hg Removed
SILO
Clinker
(Hg)
Raw Mill
Raw Materials Hg
Limestone, Sand, Fly Ash, Mill Scale
120 lb Hg/yr in
600 tons per day (TPD) WTE Process and Controls
2 - 20 µg/dscm
4 to 40 lb/yr
All have spray dryer/absorbers
and fabric filter baghouses
600 TPD
Municipal Waste
February 10, 2009 | 11
Activated Carbon Injection (ACI)
< 5 µg/dscm
< 10 lb/yr
Fabric Filter
Bottom Ash
ACI means greater certainty
of Continuous Control
Fly Ash Containing Reacted
Lime, Spent Carbon, Hg
February 10, 2009 | 13
12,000
But are Underlying Tests Truly Representative?
Highly Variable Inputs make Snapshot In-stack Test
Unreliable Estimators of Maximum Emissions.
February 10, 2009 | 14
Hg-CEMS
• WTE Tests were Short-Term In-Stack Tests
• Sorbent Traps and Speciation at Cement, Power
• Hg-CEMS are in Place at JEA Northside
• Soon American Cement, Hillsborough WTE Unit 4
• Diagnostic Hg-CEMS at CEMEX Brooksville South
• Used for Years at WTE and Cement in Germany
• Incorporate Industry/Instrument-Specific Manuals
0
1
7
13
19
25
31
37
43
49
55
61
67
73
79
85
91
97
103
109
115
121
127
133
139
145
151
157
163
169
175
181
187
193
199
205
211
217
223
229
235
241
247
253
259
265
271
277
283
289
295
301
307
313
319
250
Hg-CEMS Time Series
µg/dscm @ 7% O2
200
150
100
50
Next Steps
• Reports for One Power Plant and Cement Kiln
• EPA Informational Collection Requests (ICR)
• Industrial Boilers, Coal Power, Fertilizer
• Look at Secondary Steel
• Examine Reliability of New Hg-CEMS
• Comments to EPA on Hg Rulemaking
Thank You – From Pompeii