Presentation to
Expanded Transient Multi-Fuel Modeling of the HMI Updraft Moving bed Gasifier Performance for Industrial Scale CHP Applications38th Annual International Pittsburgh Coal Conference, September 2021
Yupeng Xu1,3, Liqiang Lu1,3, Jia Yu2,3, Mehrdad Shahnam3, Diane R. Madden3, William A. Rogers3
1Leidos Research Support Team – National Energy Technology Laboratory, USA2ORISE Postdoctoral Research Program – National Energy Technology Laboratory, USA
3U.S. Department of Energy – National Energy Technology Laboratory, USA
Contact Information: [email protected], Jia [email protected], [email protected],
[email protected], [email protected]
Rolf E. Maurer, David P. Thimsen
Hamilton Maurer International, Inc. Hudson, IL, USA
Contact Information: [email protected], [email protected]
Brent J. Sheet
University of Alaska Fairbanks, Fairbanks, AK, USA
Contact Information: [email protected]
Alberto Pettinau
Sotacarbo – Società Tecnologie Avanzate Low Carbon S.p.A., Carbonia, ITALY
Contact Information: [email protected]
Outline
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❖ Background and Objective • Co-gasification of Coal & Biomass
• Updraft Moving-bed gasifier for CHP
❖ Numerical Approach• HMI moving bed gasifier design
• MFiX software
• Validation of reaction kinetics
❖ Results• 100 % Coal feeding
• Coal and Biomass co-gasification
• Different load conditions
❖ Acknowledgement and disclaimer
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❖ It is the fastest way to increase the use of renewable biomass for electric power generation.
❖ It utilizes biomass at higher efficiency in coal-fired plants compared to direct biomass-fired plants.
❖ It saves capital cost by using existing plant infrastructure.
❖ It offers environmental advantages, such as reduced carbon dioxide CO2, sulfur dioxide SO2,
and NOx emissions [1].
Co-gasification of Coal & Biomass
Background and Objective
[1] Tabet, F., & Gökalp, I. (2015). Review on CFD based models for co-firing coal and biomass.
Renewable and Sustainable Energy Reviews, 51, 1101-1114.
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Updraft Moving-bed Gasifier for CHP
Background and Objective
Raw Syngas Out/Fly ash
Feedstock In
Pre-heated Air and Steam In
Ash Out
Drying
Pyrolysis
Char Gasification
Char Combustion
Ash
Fuel 267 (2020) 117303
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Simulate gasifier using MFiX Software
1) Divide reactor into small cells
2) Solve a PDE set to get gas velocity/pressure/temperature/species in each cell
3) Track each particle’s size, location, velocity, temperature, and species
Interphase exchange of momentum, mass, and heat
Open source and Parallel on HPC
Other models such as TFM,MP-PIC not used in this study.
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SOTACARBO Pilot Gasifier [1]
• Upflow configuration, 300mm ID x 2m height
• Refractory-lined
• Steam and Air-blown
• Variety of feedstocks fed through lock-hopper
• Micro GC and Analyzers for:• H2, CO, CO2, N2, O2, CH4, H2S, COS,
C2H6, C3H8, ...
Test program for Usibelli Coal• 5-15mm particle size
• 16-hour run• 8 hours to stable operating
condition
Simulate SOTACARBO Pilot Unit with Usibelli Coal
[1] Frau, C., Ferrara, F., Orsini, A., Pettinau, A., 2015, Characterization of Several Kinds of Coal and Biomass for Pyrolysis and Gasification, Fuel, 152, pp. 138-145
Validate Modeling Approach with Pilot Scale Data
Syngas Exit Composition (Averaged over 30s)
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Develop Prototype Gasifier Design – FEED Data and Geometric Scaling of HMI Design
UAF FEED study guides design geometry
10 ft/ 3.05m
10
ft/
3.0
5m
0.5m0.4m
1.82m
1.04m
0.075m
Scale the height and piping diameters from FEED drawings
Diameter is specified
Scale the grate geometry from the HMI 5MW systemat Sotacarbo
2.86m
0.09m0.075m
Schematic
Develop a Commercial-Scale Prototype
[1] Final Report: Making Coal Relevant for Small Scale Applications: Modular Gasification for Syngas/EngineCHP Applications in Challenging Environments, DOE-FE0031446- Small Scale Modularization of Gasification Technology Components for Radically Engineered Modular Systems 2019, UAF.
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Designed Operating Conditions & Coal analysis
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Different load conditions
UAF Gasifier
• Complete simulations using the 22 MWth UAF gasifier model for Usibelli coal feedstock,
studying a range of gasifier operating conditions
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Key operating parameters to guide design
Simulate Plant Design Conditions (100% load)
Bed Temperature Gas Temperature Pyrolysis Rate Steam Gas. Rate
CO2 Gas. Rate Char Comb. Rate CO2 Mass Fraction CO Mass Fraction
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Syngas composition at gasifier exit
Simulate Plant Design Conditions
Transient Syngas Exit Composition
Steady operating condition was obtained
Predicted performance compares well to the FEED design
Transient Behavior for 25% load reduction
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Explore A Range of Operating Conditions
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Explore A Range of Operating Conditions Transient Behavior for 50% load reduction
Gasifier responds well to large step changes in load
• Syngas composition can be maintained
• Bed Level can be controlled
Syngas composition at gasifier exit
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Explore A Range of Operating Conditions
Solid and gas temperature profiles at the beginning of the shutdown and after 4.56 hours and 6.39 hours after the shutdown.
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Shutdown Study: No purge gas
Solid temperature history after shutdown
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Shutdown Study: With purge gas
Solid temperature profiles history after the shutdown.
With purge gas, the bed took 4.4 hours to cool down and it cools faster compared the case without purge gas.
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Advanced Gasifier Design-Net Zero Carbon, H2
• Exercise prototype gasifier model with coal biomass co feed over a range of operating
conditions for Net Zero Carbon Energy and H2 Production
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Bed Temperature Gas Temperature Pyrolysis Rate Steam Gas. Rate
CO2 Gas. Rate Char Comb. Rate CO2 Mass Fraction CO Mass Fraction
Novel Coal FIRST GasifierReplace 100% of inlet air with O2 and steam
• Simulations show that the prototype gasifier is adaptable to a wide range of oxygen enriched conditions with steam and CO2 diluents
• This meets key requirements for candidate gasifiers for Net Zero Carbon and H2 production
• Oxygen-blown with steam produces higher H2 as expected
Syngas Exit Composition with Oxygen Enrichment
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Novel Coal FIRST Gasifier
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Advanced Gasifier Design-Net Zero Carbon, H2
• Exercise prototype gasifier model with coal biomass co-feed over a range of operating
conditions for Net Zero Carbon Energy and H2 Production
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Coal-biomass mixture: Usibelli coal and Pine
Usibelli Coal Pinus Pinea Ortacesus
Proximate analysis (wt%)
Fixed Carbon 29.82 21.87
Moisture 26.93 9.56
Volatiles 35.42 67.24
Ash 7.83 1.33
100.0 100.0
Ultimate analysis (wt%)
Total Carbon 45.35 57.27
Hydrogen 3.60 6.148
Nitrogen 0.53 0.4
Sulphur 0.24 0.09
Oxygen 15.52 25.202
Moisture 26.93 9.56
Ash 7.83 1.33
100.0 100.0
• biomass pyrolysis
mechanism and kinetics
validated with Sotacarbo
tests (Cali et al, 2017)
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5MW Sotacarbo gasification demonstrative plant
Pinus Pinea Biomass Reaction Kinetics Validation
Calì, G., Deiana, P., Bassano, C. and Maggio, E., 2017. Experimental activities on Sotacarbo 5 MWth gasification demonstration plant. Fuel, 207, pp.671-679.
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• Evaluated the 22MW th prototype as a candidate gasifier for Net Zero Carbon and H2
• Simulate with Coal biomass co-feed: 90% Coal, 10% biomass by mass, Air blown
Advanced Gasifier Design - Net Zero Carbon, H2
Full Load, 22MWth , Air Blown
• Simulations show that the prototype gasifier is stable at the 90% coal 10% biomass co-feed at air blown conditions
• CO/CO2 ratio higher than coal only
Bed Temperature
CO2 Mass FractionChar Comb. RateCO2 Gas. Rate
Steam Gas. RatePyrolysis RateGas Temperature
CO Mass Fraction
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• Evaluated the 22MW th prototype as a candidate gasifier for Net Zero Carbon and H2
• Simulate with Coal biomass co feed: 90% Coal, 10% biomass by mass, Oxygen blown
Advanced Gasifier Design - Net Zero Carbon, H2
Full Load, 22MWth , Oxygen Blown
• Simulations show that the prototype gasifier is stable for 90% coal 10% biomass co-feed conditions at oxygen blown conditions• CO/CO2 ratio higher than coal only
• H2 concentration lower than coal only
Bed Temperature
CO2 Mass FractionChar Comb. RateCO2 Gas. Rate
Steam Gas. RatePyrolysis RateGas Temperature
CO Mass Fraction
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• Evaluated the 22MW th prototype as a candidate gasifier for Net Zero Carbon and H2
• Simulate with Coal biomass co feed: 70% Coal, 30% biomass by mass, Air blown
Advanced Gasifier Design - Net Zero Carbon, H2
Full Load, 22MWth , Air Blown
• At 70% Coal 30% biomass air blown conditions, simulations show syngas composition is similar to the
100% coal case but the prototype gasifier becomes less stable
Bed Temperature
CO2 Mass FractionChar Comb. RateCO2 Gas. Rate
Steam Gas. RatePyrolysis RateGas Temperature
CO Mass Fraction
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• Evaluated the 22MW th prototype as a candidate gasifier for Net Zero Carbon and H2
• Simulate with Coal biomass co feed: 70% Coal, 30% biomass by mass, Oxygen blown
Advanced Gasifier Design - Net Zero Carbon, H2
Full Load, 22MWth , Oxygen Blown
• At 70% Coal 30% biomass Oxygen blown conditions, simulations show CO/CO2 ratio increased compared to the 100%
Coal case but the prototype gasifier becomes less stable
Bed Temperature
CO2 Mass FractionChar Comb. RateCO2 Gas. Rate
Steam Gas. RatePyrolysis RateGas Temperature
CO Mass Fraction
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Bed becomes “less stable”
70% Coal, 30% Biomass, Air
• As the biomass mass ratio increased to 30%, the moving bed becomes
less stable, especially at the near wall region.
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Bed Distortion Noted at High Biomass Loading
100% Coal 90% Coal+10% Biomass 70% Coal+30% Biomass
• As biomass loading goes up
char combustion zone is
distorted
• This is caused by segregation
of coal and biomass particles
as they are fed into the bed
• Segregation results from
differences in feedstock size
and density
• This segregation behavior is
seen in granular flows in
hoppers and piles
• Cold flow simulations of coal
and biomass granular flow
exhibited segregation
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Coal and Biomass Segregation in Cold Flow
From Hastie and Wypych, 2000, Zhang et al. 2018
Zhang et al.. 2018, Size-induced segregation of granular materials during filling a conical hopper Powder Technology, Vol. 340, pp 331-343Hastie and Wypych, Segregation during gravity filling of storage bins, A. Rosato, D. Blackmore (Eds.), IUTAM Symposium on Segregation in Granular Flows, Springer, Netherlands (2000), pp. 61-72
• Larger particles move to
outer layer of the pile and
hopper
• Size and density differences
will cause segregation in
granular flow
Coal and Biomass Segregation in Cold
Flow – Interaction of feedstock piles
90% Coal + 10% Biomass 70% Coal + 30% Biomass
• Biomass moves to
the center and
walls of the reactor
• Segregation and
complex interactions
of kinetics and gas
velocities cause
problems
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Acknowledgements
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• FE Program• Regis Conrad• Bhima Sastri• Jai-Woh Kim• K. David Lyons• Diane R. Madden
• Experimental• ARS Perovskite Team
• Jonathan Lekse
• Eric Popczun
• Sittichai Natesakhawat
• ARS REACT Team• Dushyant Shekhawat
• Mark Smith
• Computational• ARS Multiphase Flow Science
• Mehrdad Shahnam
• MaryAnn Clarke
• Deepthi Chandramouli
• Liqiang Lu
• Jia Yu
• Yupeng Xu
• Collaborators• UAF Team
• Brent Sheets
• Rolf Maurer
• Alberto Pettinau
• David Thimsen
• Harvey Goldstein
• ORNL
• James Parks
• Charles Finney
• Costas Tsouris
VISIT US AT: www.NETL.DOE.gov
@NationalEnergyTechnologyLaboratory
@NETL_DOE
@NETL_DOE
CONTACT:
Thank youQuestions?
Bill Rogers