Application of On-line Coal Analyzer
to Plant Performance
Steve Benson
Minnesota Energy Ingenuity Conference
November 6-7, 2008
Great River Energy & Holiday Inn & Suites
Presentation Overview
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Background on Microbeam Technologies Inc.
Fuel quality challenges for existing and future power systems
Microbeam advanced analysis database and predictive methods
Application of On-line analyzer
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Technology
Standards
Accuracy and precision
Optimizing plant performance – Integration with MTI Indices for
predicting plant performance
Conclusions and directions
2
Background of Microbeam Technologies,
Inc.
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Mission is to provide advanced analysis and interpretations of
the impacts of fuel properties on combustion and gasification
system performance.
Began performing analysis of samples using advanced electron
microscopy methods in 1992
Client base includes electric utilities, state and federal
government, coal companies, consultants, universities, law
firms, research organizations, and others
Conducted >1000 projects, >5000 samples analyzed
Recipient of two Phase I Small Business Innovative Research
(SBIR) grants from Department of Energy and National Science
Foundation (NSF)
Completed and currently commercializing Phase II NSF SBIR
technology for recovery of valuable materials from coal
gasification systems
3
Annual Cost of Ash Deposition and
Coal Quality in US

Ash Deposition – $943 million
Coal Quality – $267.3 million
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Total estimated cost $1.2 billion
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(Harding and O’Connor, 2007)
4
Fuel Property Impacts on
Performance
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Moisture - efficiency, gas flow
Sulfur - emissions control
Nitrogen - emission control
Ash forming materials
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Slagging and fouling
Abrasion and erosion
Particulate emission
Heating value – firing rate
5
MTI Extensive Database
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Over 5000 fuel and deposit analysis database
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Worldwide coal – brown, lignite, subbituminous,
bituminous, anthracite
Biomass – wood, switch grass, rice hulls, sunflower
hulls, corn, lawn waste, manure, municipal solid
waste, sewage sludge, and other
Oil – Fuel oil (various grades) and petroleum cokes
6
MTI Extensive Database
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Ash deposits and fly ash – combustion systems
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Pulverized fired boilers – wear (abrasion and erosion), wall slag,
burner and overfire air eyebrows, pendent deposits, fouling deposits
(secondary, reheat, primary, economizer heat transfer surfaces), SCR,
air heaters, electrostatic precipitators, fabric filtration, SO2 scrubber
materials (sludge, deposits).
Cyclone fired boilers – wear (abrasion and erosion), cyclone slag,
cyclone refractory, wall slag, fouling deposit (secondary, reheat,
primary, economizer heat transfer surfaces), SCR, air heaters,
electrostatic precipitators, and scrubber materials.
Fluidized bed combustion systems (bubbling and circulating) – wear
(abrasion and erosion), bed materials, bed agglomerates, in-bed heat
transfer deposits, wall deposits, cyclone deposits, j-leg agglomerates,
fouling deposits (convective pass).
7
Indices for PC and Cyclone-Fired Systems
•
Wear
–
–
•
Slag Flow Behavior
–
–
•
T250, T80, Tcv
Base/Acid, ash quantity
High
temperature
Accumulation, strength , thermal conductivity
Soot blower Removability (Peak Impact
Pressure (PIP))
Convective Pass Fouling
–
Silicate (High-Temperature) Index
•
•
–
Low
temperature
Slagging
Accumulation , strength, thermal
conductivity
PIP
Sulfate (Low-Temperature) Index:
•
•
•
Convective pass fouling
Wall Slagging Index
–
–
•
Abrasion – fuel handling equipment
Erosion – heat transfer surfaces
Accumulation, strength, thermal conductivity
PIP
Burners
Particulate Control
–
–
Ash particle size – fine particulate index
Ash resistivity and cohesivity
8
On-line analyzers - Prompt Gamma
Neutron Activation Analysis
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Califonium-252 neutron source
Neutrons emitted from the Cf-252 source are directed
at the coal material.
Neutrons are captured by the nuclei of elements in the
coal. The nucleus of the element becomes excited, and
a gamma ray is released (prompt).
Energy of the gamma ray is characteristic of each
element.
Gamma rays are detected by a sodium iodide detector.
9
On-Line Analyzer - ETI
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Moisture meter
Ash meter – dual
gamma
Elemental analyzer
– prompt gamma
neutron activation
analysis
10
On-line Analyzer Output (ETI)
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Ash content
Heating values
Sulfur
Carbon
Major inorganic constituents (ash-forming
components)
11
Challenges
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Standards
Data acquisition time – belt loading and
speed
Precision and accuracy
Use of data
12
Standards – Impact of Averaging
Times
60
60
Coal
standard 5
Coal
standard 3
Coal
standard 2
Coal
standard 4
50
50
40
40
30
30
20
20
10
10
0
0
8/19/2003
09:07 AM
8/19/2003
09:36 AM
SiO2
8/19/2003
10:04 AM
Fe2O3
8/19/2003
10:33 AM
Na2O
8/19/2003
11:02 AM
SiO2-5 min
8/19/2003
11:31 AM
Fe2O3-5 min
8/19/2003
12:00 PM
5-minute averages
1-minute averages
Coal
standard 1
8/19/2003
12:28 PM
Na2O-5 min
13
Error as a function of acquisition
time for base/acid ratio
25.00%
Percent error (B/A)
20.00%
15.00%
10.00%
5.00%
0.00%
1 min.
5 min.
10 min.
30 min.
60 min.
90 min.
120 min.
ASTM
M VTL
Time (minutes)
B/A<0.4
0.4<B/A<0.8
B/A>0.8
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Analyzer Location – Unit 1 MRY
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Analyzer Location – Unit 2 MRY
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Example of Application
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Assessed fuel variability – in mine and as-fired
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Developed criteria for managing coal quality
Simplified slag flow, slagging, fouling, and ESP performance criteria
were developed
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Software developed for FSEA to predict performance of coal as
delivered
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Example
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Transition in coal quality
Calculated using MTI-developed software
to predict:
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slag flow
water wall slagging
convective pass fouling
deposit strength development
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Change in Fuel Quality - CaO
50.00
45.00
wt %, as-received
40.00
35.00
30.00
25.00
20.00
15.00
10.00
5.00
0.00
12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003
7:40
8:52
10:04
11:16
12:28
13:40
14:52
CaO
average
max
min
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Change in Fuel Quality – SiO2
80.00
wt %, as-received
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0.00
12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003
7:40
8:52
10:04
11:16
12:28
13:40
14:52
SiO2
average
max
min
20
Change in Fuel Quality –
Base/Acid Ratio
5.00
4.50
wt %, as-received
4.00
3.50
3.00
2.50
2.00
1.50
1.00
0.50
0.00
12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003
7:40
8:52
10:04
11:16
12:28
13:40
14:52
B/A
average
max
min
21
wt %, as-received
Change in Fuel Quality – Fe2O3
50.00
45.00
40.00
35.00
30.00
25.00
20.00
15.00
10.00
5.00
0.00
12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003
7:40
8:52
10:04
11:16
12:28
13:40
14:52
Fe2O3
average
max
min
22
Predictions based on On-Line
Analyzer output
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Cyclone performance – T250, Cyclone
index
Deposit strength
Wall slagging
Convective pass fouling
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Slag T250
3000
60.00
2500
50.00
2000
40.00
1500
30.00
1000
20.00
500
T250
SiO2
SiO2, measured, wt%
Temperature, °F
Predicted T 250
10.00
0
0.00
12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003
9:36
9:50
10:04
10:19
10:33
10:48
11:02
11:16
11:31
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Cyclone Performance Index
6
60.00
5
50.00
4
40.00
3
30.00
2
20.00
1
Cycl Slag
SiO2
SiO2, measured, wt%
Index value
Predicted Cyclone Slagging
10.00
0
0.00
12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003
9:36
9:50
10:04
10:19
10:33
10:48
11:02
11:16
11:31
25
Deposit Strength --
Calculated at 2250°F
Predicted Strength
1.4
60.00
1.2
1
Index value
40.00
0.8
30.00
0.6
20.00
0.4
0.2
SiO2, measured, wt%
50.00
10.00
Strength
SiO2
0
0.00
12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003
9:36
9:50
10:04
10:19
10:33
10:48
11:02
11:16
11:31
26
High Temperature Fouling – Growth
Rate
Predicted Silication Index
250
60.00
Index value
40.00
150
30.00
100
20.00
50
SiO2, measured, wt%
50.00
200
10.00
Silicate
SiO2
0
0.00
12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003
9:36
9:50
10:04
10:19
10:33
10:48
11:02
11:16
11:31
27
Low Temperature Fouling – Growth
Rate
6
60.00
5
50.00
4
40.00
3
30.00
Sulfate
SiO2
2
20.00
1
10.00
SiO2, measured, wt%
Index value
Predicted Sulfation Index
0
0.00
12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003 12/4/2003
9:36
9:50
10:04
10:19
10:33
10:48
11:02
11:16
11:31
28
Future Applications
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Thermal Conductivity – based on deposit
composition, growth rate, and strength
development
Deposit removability – Peak Impact
Pressure – based on deposit composition,
growth rate, strength development, and
thermal properties
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Thermal Conductivity - Database
(Calculated at 450°C)
60%
Cyclone slag, wall slag, radiant
section
50%
Platen, panel
Secondary superheater
Frequency
40%
Reheater
30%
Primary superheater, bed drain
materials
20%
Economizer, ESP
10%
0%
0.1 to 0.5
0.5 to 1
1 to 1.5
1.5 to 2
Thermal conductivity (k, in W/mK) at 450°C
30
Predicted Peak Impact Pressure
(PIP) – Database
80%
Wall slag, radiant section
70%
60%
Platen, panel
Frequency
50%
Secondary superheater
40%
30%
Economizer, ESP
20%
10%
0%
<1
1 to 10
10 to 20
20 to 30
30 to 40
>40
Adjusted peak impact pressure (PIP), MPa
31
Summary and Conclusions
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On-line coal analyzer technology is being
installed at power plants and coal mines
Provides sufficient data for assessment of many
operational problems
Utilized On-line analyzer to provide composition
of coal delivered to plant to provide insight into
slag flow challenges – significant cost savings
Data analysis and integration need more work
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Future Directions
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Advanced predictions
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Neural network applications
Advanced indices
Integrate into operations
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Operating conditions
Cleaning cycles
Blending
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Contact Information
Microbeam Technologies, Inc.
4200 James Ray Drive, Ste. 191
Grand Forks, ND 58203
Tel.: (701) 777-6530
Fax: (701) 777-6532
Email: info@microbeam.com
www.microbeam.com
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