Upload
jporterkline
View
950
Download
0
Embed Size (px)
DESCRIPTION
Citation preview
Mercury Abatement in the US Cement Industry
John Kline
John Kline Consulting
Cement Processing in US
82 Clinker Plants 128 Operating Kilns Source: EPA Web Site
Mercury Emissions in US by Source (metric tons per year)
Source Air Water Soil Mercury from cement production 2.31 0 1.16 Mercury from large combustion plants 43.46 0.17 33.06 TOTAL EMISSIONS (tpy) 109.2 46 2658.2 Cement as % of Total 2.1% 0% 0.04% Large Combustors as % of Total 39.8% 0.4% 1.2%
Source: The US Mercury Emission Inventory for the Arctic Council Action Plan, Karen Rackley and Anne Pope, 1999 National Emissions Inventory for HAPs (NEI) and 2001 Toxic Release Inventory (TRI).
Cement Kiln Regulations
All Cement Plants / Kilns
(NESHAP)
Commercial and Industrial Solid Waste Incinerators
(CISWI)
Hazardous Waste
Combustors (HWC)
Cement Plants that burn
Hazardous Waste
Cement Plants that burn Non-
Hazardous Waste
82 Clinker Plants 128 Operating Kilns
Summary of Standards
Pollutant Existing Sources New Sources EPA expected Emissions Reductions
Mercury 55 lb/million tons clinker 21 lbs/million tons clinker 93%
THC 24 ppmvd 24 ppmvd 82%
O-HAP 12 ppmvd 12 ppmvd
PM 0.07 lb/ton clinker 0.02 lb/ton clinker 91%
HCL 3 ppmvd 3 ppmvd 96%
Bold indicates a change
Monitoring Standards
Original Rule
• Particulate CEM
• Mercury CEM
• THC CEM
• HCl CEM
Final Rule
• Particulate Parametric Testing
• Mercury CEM
• THC CEM
Timing
• Original Compliance Date – Sept, 2013
• Revised Compliance Date – Sept, 2015
• Possibility of one year extension
– Need to demonstrate significant effort, and
– External forces at play
Mercury in Power Plants
• One source – Fuel
• Multiple Outlets – Bottom ash, slag, flyash, FGD solids, FGD liquids, stack
• One pass with no recycle
• Relatively stable gas composition and temperatures
• What goes in – comes out !
Mercury in Power Plants
And Slag
Input
Outputs
Output
Source - Tutorial: Mercury Chemistry in Boilers and Mercury Control Technology (Part 1), C. Senior, April 17-21, 2005 30th International Technical Conference on Coal Utilization & Fuel Systems, Clearwater, Florida
Distribution of mercury concentrations in solid fuels from ICR, Part 2 data for fourth quarter, 1999. Source: Inherent Mercury Controls within the Portland Cement Kiln System—Model of Mercury Behavior within the Manufacturing System, C. Senior, C. Montgomery, A. Sarofim, Portland Cement Association
Mercury in Power Plants
• One source – Fuel => multiple fuel and raw material sources
• Multiple Outlets – Bottom ash, slag, flyash ash, FGD solids, FGD liquids, stack => outlets stack and dust
• One pass with no recycle => multiple potential recycle loops
• Relatively stable gas composition and temperatures => large swings in gas temperature and composition (with in-line mills)
Mercury in Cement Plants
Typical Levels of Mercury in the Cement Industry
Mercury concentration in PPB •Limestone 10 to 100, can be up to 1000 or more •Coal: 20 to 200 (also Cl = 800/2000ppm) •PRB: 40 to 100 (also Cl = 7/35ppm) •Coke: 10 to 20 •Other fuels: <50 •AF generally low – except HWF: up to 6000 (not in EPA) and SSW (up to 200)
•Bottom ash and fly ash: 200 to 400
Flyash – 37 Plants Bottom Ash – 21 Plants
Looking Deeper at Raw Materials
The most common ingredients of cement are: – Limestone (75% - 80%),
– Shale and/or clay (15% - 20%),
– Sand (2% – 5%),
– And Iron Source (1% - 2%)
Limestone, Shale and Clay are sedimentary materials and therefore typically low in metals including mercury
The exception comes when these materials are associated with volcanics
Variations in Raw Materials
Monthly mass balance Hg contributions by raw material (Linero, Read, and Derosa, 2008)
Mercury Cycle in a Modern Cement Plant with In-Line Raw Mill
Kiln Feed
Fuels From Kiln & Precalciner
Raw Mill Feed
BH Catch
Stack
Coal Mill
Source: "Fate and transport of mercury in Portland cement manufacturing facilities", J.K. Sikkema. Theses and Dissertations. Paper 11907. http://lib.dr.iastate.edu/etd/11907
1000 oC
330 oC
90 oC
The Hg cycle / with in-line raw mill: can be 10 to 50 times the inputs
Source: “MERCURY IN THE CEMENT INDUSTRY”, Roberto RENZONI ,Christophe ULLRICH, Sandra BELBOOM, Albert GERMAIN, Universite de Liege, Independently commissioned by CEMBUREAU – CSI
Spot Balance in Preheater Kiln with Raw Mill Running
Spot Balance
Kiln
18-Jun-12 Filter Inlet Exit Gas Calculated
Feed In grams/hr Balance 18.8 PB 75.2 Ox.
369.1 PB Bypass grams/hr CEM Signal 174.4 Ox. 98.7 El.
83.9 Ox. % Capture 98.7 El. Fiter Capture 173.9 Total
30.0 El. 291.9 Total 57% Ox. Only Exit Gas Measured
113.9 Total 76.4 Ox.
100.3 El.
176.7 Total
Cylcone Out
18.8 PB
Fuel In Raw Mill Feed 90.5 Ox.
21.2 PB 293.4 PB 68.7 El.
178.0 Total
Raw Mill
Duct Capture
287.4 Ox. 53% Ox. Raw Mill Out CKD
102.8 El. 554.1 Total 118.0 PB
390.3 Total To Raw Mill
192.0 Ox.
68.7 El.
260.8 Total Raw Mill Product
376.1 PB Coke 0.13 PB Coal Mill
Coal 0.23 PB Exit Gas Calculated
0.16 El.
Exit Gas Measured
0.27 El.
To Coal Mill Coal Mill Product
11.5 Ox. 15.8 PB
4.1 El.
15.6 Total
Mercury Balance Mercury Inputs
From Kiln Feed 54.0%
From Fuel (As-Fried) 3.1%
From Raw Fuel 0.1%
From Raw Mill Feed 42.9%
Mercury Outputs
In Raw Mill Product 55.0%
In CKD 17.3%
Oxidized in Kiln Stack 11.0%
Elemental in Kiln Stack 14.4%
In Fine Coke 2.3%
in Coke Mill Stack 0.0%
All CKD Removed
The Hg cycle / with in-line raw mill: can be 10 to 50 times the inputs
Source: “MERCURY IN THE CEMENT INDUSTRY”, Roberto RENZONI ,Christophe ULLRICH, Sandra BELBOOM, Albert GERMAIN, Universite de Liege, Independently commissioned by CEMBUREAU – CSI
Schreiber & Kellett 2009
Mercury Emissions Raw Mill Off + Raw Mill On Scale Change
Influencing Factors Temperature Cl Available O Available SO3 Available
Source: "Fate and transport of mercury in Portland cement manufacturing facilities", J.K. Sikkema. Theses and Dissertations. Paper 11907. http://lib.dr.iastate.edu/etd/11907
Schreiber & Kellett 2009
Mercury Emissions Averages All Cement Kilns Surveyed
Good Generalization but
each case is specific
Largest Emitters (2010 Data)
0
200
400
600
800
1000
1200
1400
1600
1800
2000
Lehigh Tehachapi AG Durkee Lehigh Cupertino
0
50
100
150
200
250
300
350
400
450
500
Po
un
ds
pe
r M
illio
n T
on
s o
f C
linke
r (2
01
0 T
RI +
GH
G D
ata)
Larger Emitters
0
20
40
60
80
100
120
Po
un
ds
pe
r M
illio
n T
on
s o
f C
linke
r (2
01
0 T
RI +
GH
G D
ata)
Smaller Emitters
Conclusions
• The mercury emission limit remains at 55 pounds per million tons of clinker
• Compliance has been pushed to September 2015, with the possibility of a one year extension
• More than half of the cement plants will have to reduce emissions to meet the new limit
• Roughly a third will have to install some form of control
• Many plants can qualify as CISWI installations which may not be coherent with NESHAP