application of on-line coal analyzer to plant performance steve benson minnesota energy ingenuity...
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Application of On-line Coal Analyzer to Plant Performance
Steve Benson
Minnesota Energy Ingenuity Conference
November 6-7, 2008Great River Energy & Holiday Inn & Suites
Presentation Overview 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
Technology Standards Accuracy and precision Optimizing plant performance – Integration with MTI Indices
for predicting plant performance Conclusions and directions
2
3
Background of Microbeam Technologies, Inc.
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
Annual Cost of Ash Deposition and Coal Quality in US
Ash Deposition – $943 million Coal Quality – $267.3 million
Total estimated cost $1.2 billion
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(Harding and O’Connor, 2007)
Fuel Property Impacts on Performance Moisture - efficiency, gas flow Sulfur - emissions control Nitrogen - emission control Ash forming materials
Slagging and fouling Abrasion and erosion Particulate emission
Heating value – firing rate
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MTI Extensive Database Over 5000 fuel and deposit analysis
database 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
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MTI Extensive Database Ash deposits and fly ash – combustion systems
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).
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Burners
Slagging
Convective pass fouling
High temperature
Low temperature
• Wear– Abrasion – fuel handling equipment– Erosion – heat transfer surfaces
• Slag Flow Behavior– T250, T80, Tcv
– Base/Acid, ash quantity
• Wall Slagging Index – Accumulation, strength , thermal
conductivity– Soot blower Removability (Peak Impact
Pressure (PIP))
• Convective Pass Fouling – Silicate (High-Temperature) Index
• Accumulation , strength, thermal conductivity
• PIP
– Sulfate (Low-Temperature) Index:• Accumulation, strength, thermal
conductivity• PIP
• Particulate Control– Ash particle size – fine particulate index– Ash resistivity and cohesivity
Indices for PC and Cyclone-Fired Systems
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On-line analyzers - Prompt Gamma Neutron Activation Analysis 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.
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On-Line Analyzer - ETI Moisture meter Ash meter – dual
gamma Elemental
analyzer – prompt gamma neutron activation analysis
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On-line Analyzer Output (ETI) Ash content Heating values Sulfur Carbon Major inorganic constituents (ash-
forming components)
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Challenges Standards Data acquisition time – belt loading
and speed Precision and accuracy Use of data
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Standards – Impact of Averaging Times
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0
10
20
30
40
50
60
8/19/200309:07 AM
8/19/200309:36 AM
8/19/200310:04 AM
8/19/200310:33 AM
8/19/200311:02 AM
8/19/200311:31 AM
8/19/200312:00 PM
8/19/200312:28 PM
1-minute averages
0
10
20
30
40
50
60
5-minute averages
SiO2 Fe2O3 Na2O SiO2-5 min Fe2O3-5 min Na2O-5 min
Coal
s tandard 1
Coal
s tandard 5
Coal
s tandard 3
Coal
s tandard 2
Coal
s tandard 4
Error as a function of acquisition time for base/acid ratio
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0.00%
5.00%
10.00%
15.00%
20.00%
25.00%
1 min. 5 min. 10 min. 30 min. 60 min. 90 min. 120 min. ASTM MVTL
Time (minutes)
Percent error (B/A)
B/A<0.4 0.4<B/A<0.8 B/A>0.8
Analyzer Location – Unit 1 MRY
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Analyzer Location – Unit 2 MRY
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Example of Application Assessed fuel variability – in mine and as-fired
Developed criteria for managing coal quality Simplified slag flow, slagging, fouling, and ESP
performance criteria were developed Software developed for FSEA to predict performance of coal
as delivered
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Example Transition in coal quality Calculated using MTI-developed
software to predict: slag flow water wall slagging convective pass fouling deposit strength development
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Change in Fuel Quality - CaO
0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
40.00
45.00
50.00
12/4/20037:40
12/4/20038:52
12/4/200310:04
12/4/200311:16
12/4/200312:28
12/4/200313:40
12/4/200314:52
wt %, as-received
CaO average max min
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Change in Fuel Quality – SiO2
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
12/4/20037:40
12/4/20038:52
12/4/200310:04
12/4/200311:16
12/4/200312:28
12/4/200313:40
12/4/200314:52
wt %, as-received
SiO2 average max min
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Change in Fuel Quality – Base/Acid Ratio
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
5.00
12/4/20037:40
12/4/20038:52
12/4/200310:04
12/4/200311:16
12/4/200312:28
12/4/200313:40
12/4/200314:52
wt %, as-received
B/A average max min
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Change in Fuel Quality – Fe2O3
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0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
40.00
45.00
50.00
12/4/20037:40
12/4/20038:52
12/4/200310:04
12/4/200311:16
12/4/200312:28
12/4/200313:40
12/4/200314:52
wt %, as-received
Fe2O3 average max min
Predictions based on On-Line Analyzer output Cyclone performance – T250,
Cyclone index Deposit strength Wall slagging Convective pass fouling
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Slag T250
Predicted T250
0
500
1000
1500
2000
2500
3000
12/4/20039:36
12/4/20039:50
12/4/200310:04
12/4/200310:19
12/4/200310:33
12/4/200310:48
12/4/200311:02
12/4/200311:16
12/4/200311:31
Temperature, °F
0.00
10.00
20.00
30.00
40.00
50.00
60.00
SiO2, measured, wt%
T250 SiO2
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Cyclone Performance Index Predicted Cyclone Slagging
0
1
2
3
4
5
6
12/4/20039:36
12/4/20039:50
12/4/200310:04
12/4/200310:19
12/4/200310:33
12/4/200310:48
12/4/200311:02
12/4/200311:16
12/4/200311:31
Index value
0.00
10.00
20.00
30.00
40.00
50.00
60.00
SiO2, measured, wt%
Cycl Slag SiO2
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Deposit Strength -- Calculated at 2250°F
Predicted Strength
0
0.2
0.4
0.6
0.8
1
1.2
1.4
12/4/20039:36
12/4/20039:50
12/4/200310:04
12/4/200310:19
12/4/200310:33
12/4/200310:48
12/4/200311:02
12/4/200311:16
12/4/200311:31
Index value
0.00
10.00
20.00
30.00
40.00
50.00
60.00
SiO2, measured, wt%
Strength SiO2
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High Temperature Fouling – Growth Rate
Predicted Silication Index
0
50
100
150
200
250
12/4/20039:36
12/4/20039:50
12/4/200310:04
12/4/200310:19
12/4/200310:33
12/4/200310:48
12/4/200311:02
12/4/200311:16
12/4/200311:31
Index value
0.00
10.00
20.00
30.00
40.00
50.00
60.00
SiO2, measured, wt%
Silicate SiO2
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Low Temperature Fouling – Growth Rate
Predicted Sulfation Index
0
1
2
3
4
5
6
12/4/20039:36
12/4/20039:50
12/4/200310:04
12/4/200310:19
12/4/200310:33
12/4/200310:48
12/4/200311:02
12/4/200311:16
12/4/200311:31
Index value
0.00
10.00
20.00
30.00
40.00
50.00
60.00
SiO2, measured, wt%
Sulfate SiO2
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Future Applications 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)
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0%
10%
20%
30%
40%
50%
60%
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
Cyclone slag, wall slag, radiant section
Platen, panel
Secondary superheater
Reheater
Primary superheater, bed drain materials
Economizer, ESP
Predicted Peak Impact Pressure (PIP) – Database
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0%
10%
20%
30%
40%
50%
60%
70%
80%
<1 1 to 10 10 to 20 20 to 3030 to 40 >40
Adjusted peak impact pressure (PIP), MPa
Wall slag, radiant section
Platen, panel
Secondary superheater
Economizer, ESP
Summary and Conclusions 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 Advanced predictions
Neural network applications Advanced indices
Integrate into operations Operating conditions Cleaning cycles Blending
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Contact InformationMicrobeam Technologies, Inc.
4200 James Ray Drive, Ste. 191Grand Forks, ND 58203
Tel.: (701) 777-6530Fax: (701) 777-6532
Email: [email protected]