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Effects of Oxygen Concentration and Coal Composition on Aerosol Chemistry in Oxy Firing. William J. Morris Dunxi Yu Jost O. L. Wendt Department of Chemical Engineering University of Utah, Salt Lake City, UT 84112. 2010 AIChE Annual Meeting Salt Lake City, Utah November 7-12, 2010. - PowerPoint PPT Presentation
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Effects of Oxygen Concentration and Coal Composition on Aerosol
Chemistry in Oxy Firing
2010 AIChE Annual Meeting Salt Lake City, Utah
November 7-12, 2010
William J. MorrisDunxi Yu
Jost O. L. WendtDepartment of Chemical Engineering
University of Utah, Salt Lake City, UT 84112
Outline
• Objectives• Coals examined• Furnace, sampling, and analysis• Results• Conclusions
Objectives• Provide a comparison of three different coal aerosols under two
different oxy fired scenarios for predicting effects of coal composition on oxy firing.
• Examine aerosol chemistry under two different oxy fired scenarios: 27% O2 (~match heat flux of air) and 32% O2 (~match adiabatic flame temperature of air).
• Use aerosol chemistry to provide information for those who wish to make predictions of fouling/slagging within the furnace.
• Determine whether there are any significant differences in aerosol chemistry at varying O2 concentrations at conventional temperatures.
Coal ChemistryCoal Analysis (on an as-received basis)
Sample LOD Ash C H N S O (diff) VolatileMatter
FixedCarbon
HHVBTU/lb
% % % % % % % % %
Utah 3.18 8.83 70.60 5.41 1.42 0.53 13.21 38.60 49.39 12606
PRB 23.69 4.94 53.72 6.22 0.78 0.23 34.11 33.36 38.01 9078
Illinois 9.65 7.99 64.67 5.59 1.12 3.98 16.65 36.78 45.58 11598
Ash Analysis
Alas Al2O3
Caas CaO
Feas Fe2O3
Mgas MgO
Mnas MnO
Pas P2O5
Kas K2O
Sias SiO2
Naas Na2O
Sas SO3
TiAs
TiO2
% % % % % % % % % % %
Utah 14.52 6.11 5.09 1.39 0.02 0.59 0.57 60.89 1.41 2.33 0.88
PRB 14.78 22.19 5.2 5.17 0.01 1.07 0.35 30.46 1.94 8.83 1.3
Illinois 17.66 1.87 14.57 0.98 0.02 0.11 2.26 49.28 1.51 2.22 0.85
Coal Firing Rates and Combustion Conditions
Coal Coal feed rate (kg/h) Coal firing rate (kW)
Utah Skyline 4.50
36.64PRB 6.26
Illinois Bituminous 4.89
Combustion Mode
Oxidant Composition Practical Significance
OXY27 Oxyfuel Combustion 27%O2/73%CO2 Match AIR gas radiant heat flux
OXY32 Oxyfuel Combustion 32%O2/68%CO2 Match AIR adiabatic flame temperature
Sampling Systems
Laboratory CombustorPrimary
Coal feeder
3.8 m
Secondary
1.2 m
Heat exchanger #1 - 8
Flue gas1. Maximum capacity: 100 kW2. Representative of full scale units:
1. Self sustaining combustion2. Similar residence times and
temperatures3. Similar particle and flue gas
species concentrations3. Allows systematic variation of
operational parameters
Sampling port
This work: Uses once-through CO2 to simulate cleaned flue gas recycle with all contaminants and water removed.
Future work: Will use recycled flue gas.
Analysis
• Samples were collected with a Berner low pressure impactor.
• Size segregated samples were then analyzed using ICP-MS.
• Due to the difference in flue gas volume (m3) of OXY27 and OXY32 conditions, results were also normalized to ug per g of coal burned.
Results
0.01 0.1 1 100.01
0.10
1.00
10.00
100.00
1000.00
10000.00
100000.00
1000000.00
Utah Skyline OXY27
Na2OMgOAl2O3SiO2P2O5K2OCaOTiO2MnOFe2O3As2O3SeO2
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/m
3)
Results
0.01 0.1 1 100.01
0.10
1.00
10.00
100.00
1000.00
10000.00
100000.00
1000000.00
Utah Skyline OXY32
Na2OMgOAl2O3SiO2P2O5K2OCaOTiO2MnOFe2O3As2O3SeO2
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/m
3)
Results
0.01 0.1 1 100.01
0.10
1.00
10.00
100.00
1000.00
10000.00
100000.00
1000000.00
PRB OXY27
Na2OMgOAl2O3SiO2P2O5K2OCaOTiO2MnOFe2O3As2O3SeO2
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/m
3)
Results
0.01 0.1 1 100.01
0.10
1.00
10.00
100.00
1000.00
10000.00
100000.00
1000000.00
PRB OXY32
Na2OMgOAl2O3SiO2P2O5K2OCaOTiO2MnOFe2O3As2O3SeO2
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/m
3)
Results
0.01 0.1 1 100.01
0.10
1.00
10.00
100.00
1000.00
10000.00
100000.00
1000000.00
Illinois OXY27
Na2OMgOAl2O3SiO2P2O5K2OCaOTiO2MnOFe2O3As2O3SeO2
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/m
3)
Results
0.01 0.1 1 100.01
0.10
1.00
10.00
100.00
1000.00
10000.00
100000.00
1000000.00
Illinois OXY32
Na2OMgOAl2O3SiO2P2O5K2OCaOTiO2MnOFe2O3As2O3SeO2
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/m
3)
Results
0.01 0.1 1 1010.00
100.00
1000.00
10000.00
Utah Fe2O3
Utah OXY27 FeUtah OXY32 Fe
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/g
coal
)
Results
0.01 0.1 1 101.00
10.00
100.00
1000.00
PRB Fe2O3
PRB OXY27 FePRB OXY32 Fe
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/g
coal
)
Results
0.01 0.1 1 101.00
10.00
100.00
1000.00
Illinois Fe2O3
Ill OXY27 FeIll OXY32 Fe
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/g
coal
)
Results
0.01 0.1 1 1010.00
100.00
1000.00
10000.00
Utah CaO
Utah OXY27 CaOUtah OXY32 CaO
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/g
coal
)
Results
0.01 0.1 1 1010.00
100.00
1000.00
10000.00
PRB CaO
PRB OXY27 CaOPRB OXY32 CaO
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/g
coal
)
Results
0.01 0.1 1 101.00
10.00
100.00
Illinois CaO
Ill OXY27 CaOIll OXY32 CaO
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/g
coal
)
Results
0.01 0.1 1 1010.00
100.00
1000.00
10000.00
Utah Na2O
Utah OXY27 Na2OUtah OXY32 Na2O
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/g
coal
)
Results
0.01 0.1 1 101.00
10.00
100.00
1000.00
PRB Na2O
PRB OXY27 Na2OPRB OXY32 Na2O
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/g
coal
)
Results
0.01 0.1 1 10100.00
1000.00
10000.00
Illinois SiO2
Ill OXY27 SiO2Ill OXY32 SiO2
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/g
coal
)
Results
0.01 0.1 1 10100.00
1000.00
10000.00
100000.00
Utah SiO2
Utah OXY27 SiO2Utah OXY32 SiO2
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/g
coal
)
Results
0.01 0.1 1 10100.00
1000.00
10000.00
PRB SiO2
PRB OXY27 SiO2PRB OXY32 SiO2
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/g
coal
)
Results
0.01 0.1 1 10100.00
1000.00
10000.00
Illinois SiO2
Ill OXY27 SiO2Ill OXY32 SiO2
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/g
coal
)
Results
0.01 0.1 1 100.01
0.10
1.00
PRB As2O3
PRB OXY27 As2O3PRB OXY32 AsO3
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/g
coal
)
Results
0.01 0.1 1 100.01
0.10
1.00
10.00
Illinois As2O3
Ill OXY27 As2O3Ill OXY32 As2O3
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/g
coal
)
Results
0.01 0.1 1 100.01
0.10
1.00
10.00
100.00
Utah SeO2
Utah OXY27 SeO2Utah OXY32 SeO2
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/g
coal
)
Results
0.01 0.1 1 100.01
0.10
1.00
10.00
Illinois SeO2
Ill OXY27 SeO2Ill OXY32 SeO2
Aerodynamic Particle Diameter (um)
dM/d
logD
p (u
g/g
coal
)
Conclusions
• Fine fragmentation mode (~1 um) is not affected by small changes in PO2 at conventional temperatures.
• Coal composition still plays the dominant role in aerosol chemistry.
• Only differences are noticed in the ultra-fine region <100nm. This is the condensed vapor phase mode and is likely due to a hotter flame temperature yielding increased vaporization.
Acknowledgements
• Financial support from the Department of Energy under Awards DE-FC26-06NT42808 and DE-FC08-NT0005015
• David Wagner, Ryan Okerlund, Brian Nelson, Rafael Erickson, and Colby Ashcroft Institute for Clean and Secure Energy, University of Utah
• Diego Fernandez and his team of analytical chemists in the Department of Geology and Geophysics, University of Utah
