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: Liqiang.Lu@netl.doe.gov, Jia Yu@netl.doe.gov, Mehrdad.Shahnam@netl.doe.gov,

Diane.Madden@netl.doe.gov, William.Rogers@netl.doe.gov

Rolf E. Maurer, David P. Thimsen

Hamilton Maurer International, Inc. Hudson, IL, USA

Contact Information: rem-hmi2@att.net, thimsendavid@gmail.com

Brent J. Sheet

University of Alaska Fairbanks, Fairbanks, AK, USA

Contact Information: bjsheets2@alaska.edu

Alberto Pettinau

Sotacarbo – Società Tecnologie Avanzate Low Carbon S.p.A., Carbonia, ITALY

Contact Information: alberto.pettinau@sotacarbo.it

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?

William.Rogers@netl.doe.gov

Bill Rogers