Cold flow analysis for a scaled bubbling fluidized bed gasifier: - - PowerPoint PPT Presentation

Benjamin M. Statler College of Engineering and Mineral Resources

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Cold flow analysis for a scaled bubbling fluidized bed gasifier: impact of various feedstocks and fluidizing materials

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1 Center for Alternative Fuels Engines and Emissions (CAFEE)

Department of Mechanical & Aerospace Engineering, West Virginia University

2 Department of Chemical Engineering, West Virginia University

NETL 2018 Workshop On Mult ltip iphase Flo low Scie ience

Benjamin M. Statler College of Engineering and Mineral Resources

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• Cold flow analysis allows us to simulate the process and obtain the hydrodynamic

properties of the reaction bed.

• Good-mixture and good-fluidization conditions have been observed (air volumetric

flow rate, static bed height, fluidizing material type and feedstock)

• Premixed and not premixed cases have been compared.

Objectives

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Experimental Setup

Benjamin M. Statler College of Engineering and Mineral Resources

4 Material Average of particle size (µm) Average of Sphericity Hardwood 432 0.564 Coal 310 0.761 Glass beads 279 0.933 Sand 368 0.863 Table 1. Material size and sphericity analysis

Material Characteristics

Benjamin M. Statler College of Engineering and Mineral Resources

5 Material (Mixtures) Bulk density (g/cc) Voidage (%) Glass beads + coal 1.61 35 Glass beads + hardwood 1.43 38 Sand + coal 1.56 41 Sand + hardwood 1.38 44 Table 2. Material bulk density and voidage analysis

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2 4 6 8 10 12 0.2 0.4 0.6 0.8 1.0 1.1 100 gr 200 gr 300 gr

Glass beads and hardwood 300~350 m

Qair (SLM) Normalized P

Pressure drop versus air volumetric flow rate diagrams

2 1/2” 7 3/4” 5”

• Static bed height effect

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2 4 6 8 10 12 2 4 6 8 10 12 100 gr 200 gr 300 gr

Glass beads and hardwood, MIXED 300~350 m

P (in H2O) Qair (SLM) 2 4 6 8 10 12 0.2 0.4 0.6 0.8 1.0 1.2 100 gr 200 gr 300 gr

Glass beads and hardwood, MIXED 300~350 m Qair (SLM) Normalized P

Norm

• In the premixed case better fluidization obtained

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2 4 6 8 10 12 2 4 6 8 10 12 97 gr 194 gr 291 gr P (in H2O) Qair (SLM)

Sand and hardwood 300~350 m

2 4 6 8 10 12 0.2 0.4 0.6 0.8 1.0 1.2

Normalized P

97 gr 194 gr 291 gr Qair (SLM)

Sand and hardwood 300~350 m

• Bulk density and voidage effect

Benjamin M. Statler College of Engineering and Mineral Resources

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2 4 6 8 10 12 2 4 6 8 10 12 14 16 97 gr 194 gr 291 gr P (in H2O) Qair (SLM)

Sand and hardwood, MIX 300~350 m

2 4 6 8 10 12 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6

Normalized P

97 gr 194 gr 291 gr Qair (SLM)

Sand and hardwood, MIX 300~350 m

Benjamin M. Statler College of Engineering and Mineral Resources

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2 4 6 8 9 2 4 6 8 10 98 gr 196 gr 294 gr P (in H2O) Qair (SLM)

Glass beads and coal 300~350 m

2 4 6 8 9 0.2 0.4 0.6 0.8 1.0

Glass beads and coal 300~350 m Normalized P

98 gr 196 gr 294 gr Qair (SLM)

• Coal and glass beads mixture has the highest bulk density and

the lowest voidage ratio

2 1/4” 4 5/8” 7 1/8”

Benjamin M. Statler College of Engineering and Mineral Resources

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2 4 6 8 9 2 4 6 8 10 98 gr 196 gr 294 gr

Glass beads and coal, MIX 300~350 m

P (in H2O) Qair (SLM) 2 4 6 8 10 0.2 0.4 0.6 0.8 1.0

Normalized P

98 gr 196 gr 294 gr

Glass beads and coal, MIX 300~350 m

Qair (SLM)

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2 4 6 8 10 12 2 4 6 8 10 12 95 gr 190 gr 285 gr P (in H2O) Qair (SLM)

Sand and coal 300~350 m

2 4 6 8 10 12 0.2 0.4 0.6 0.8 1.0 1.2 95 gr 190 gr 285 gr

Normalized P

Qair (SLM)

Sand and coal 300~350 m

Benjamin M. Statler College of Engineering and Mineral Resources

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2 4 6 8 10 12 2 4 6 8 10 12 95 gr 190 gr 285 gr

Sand and coal, MIX 300~350 m

P (in H2O) Qair (SLM) 2 4 6 8 10 12 13 0.2 0.4 0.6 0.8 1.0 1.2

Normalized P

95 gr 190 gr 285 gr

Sand and coal, MIX 300~350 m

Qair (SLM)

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High speed imaging

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Movie 1. Glass beads and coal

Mixture analysis

30 fps

• Mostly homogenous

bubbling

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Movie 2. Sand and coal

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FCC Catalyst Movie 3. Sand and hardwood with FCC catalyst

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Movie 4. Glass beads and hardwood with FCC catalyst FCC Catalyst and wood mixture

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Summary and Conclusions

• Better fluidization obtained for glass beads and coal because of its

higher bulk density and lower voidage ratio.

• Good-mixture case for hardwood and fluidizing material mixture
• btained between 2-2.5 times of minimum fluidization velocity.
• FCC catalyst acted like a bottom ash for sand and hardwood mixture.
• In addition to this study, studies of parametric reaction kinetics of

biomass, coal, catalytic and non-catalytic gasification based on thermogravimetric analysis (TGA) and fixed bed reactor have been done by our group to develop optimized reaction operating conditions for fluidized bed gasifier.

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Acknowledgements

Special thanks to Department of Energy and National Energy Technology Laboratory, Morgantown Centre for their technical and financial support.

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Thank You

Questions