Microchannel Catalytic Process for Converting Biomass Derived Syngas to Transportation Fuels

Microchannel Catalytic Process for Converting Biomass Derived Syngas to Transportation Fuels

Chunshe Cao, Yong Wang, John Hu, Doug Elliott, Sue Jones, Don Stevens

ACS Meeting

New York City

September 8, 2003

2

OutlineOutlineOutline

Biomass derived syngas to fuelsBackground Challenges

Conventional GTL technology vs. Microchannel Reactor TechnologyMicrochannel reactor-engineered catalysts performance demonstrationModeling for catalyst optimizationMicrochannel GTL reactor conceptual design

3

Clean Fuels from BiomassClean Fuels from BiomassClean Fuels from Biomass

Compared to the fossil fuels, BiomassRenewable energy source when CO2 emissions for its use is absorbed by newly grown biomass.

Growing interest: Fuels from biomass ---Environmental concerns such as green house gas emission control.

4

DOE Biomass SYNGAS Platform

Gasification

Heat& Power

Generation

Liquid fuels

Electricity

PNNL R&D Efforts

Pyrolysis

syngas

Biocrude oil

Fuel Synthesis:

MeOH/ DMEEtOH,FT gasoline/diesel

Upgrading

FeedstockHandling

Fuels& Chemicals

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Fischer-Tropsch Fuels From BiomassFischerFischer--Tropsch Fuels From BiomassTropsch Fuels From Biomass

microchannel application

Gas cleaning: H2S, alkalis, tars

Gas turbineGas processing: SMR or WGSFT synthesis

HydrocrackingFT fuel

Pre-Treatment Grinding Drying

Gasification air or O2

CO2 removal

6

Fischer-Tropsch Synthesis ReactionsFischerFischer--Tropsch Synthesis ReactionsTropsch Synthesis Reactions

Paraffins: (2n+1) H2 + nCO ---> CnH2n+2+ nH2OOlefins: 2n H2 + nCO ---> CnH2n+ nH2OAlcohols: 2n H2 + nCO ---> CnH2n+1OH+(n-1) H2OWater gas shift: CO+ H2O---> CO2 + H2 Boudouard Reaction: 2 CO ---> C+ CO2Coke formation: H2 + CO ---> C+ H2O

Multiphase (G-L-S) Strongly exothermic (Hr = -180 kJ/mol) Mass transfer limited

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Degree of Polymerization Affects F-T Product DistributionDegree of Polymerization Affects FDegree of Polymerization Affects F--T Product DistributionT Product Distribution

12)1( = nn nWASF distribution:

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Challenges of Biomass Syngas to FuelsChallenges of Biomass Syngas to FuelsChallenges of Biomass Syngas to Fuels

Stranded feedstockNo existing pipelines to move syngas to large central facilities

Conversion facilities are small in scale:

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Conventional GTL Plant Capital InvestmentConventional GTL Plant Capital InvestmentConventional GTL Plant Capital Investment

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

0 20,000 40,000 60,000 80,000 100,000 120,000GTL Plant Capacity, bbl/day

Spec

ific

Cap

ital I

nves

tmen

t, U

S$/d

bbl

SasolShellEnergy InternationalExxonSyncrude Technology

Biomass scale

Conventional GTL plant is not cost competitive at the capacity typical of biomass feedstocks

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Characteristics of Microchannel ReactorCharacteristics of Microchannel Reactor

0.05 0.1cm

5 10 cm

Heat and mass transfer advantages -- Intensifies syngas-to-fuel processEnhances productivityImproves product selectivityMinimizes catalyst deactivation

Provides a potential cost-competitive solution at the scale relevant to biomass

Allows potential integration of unit operations (simplification of gas conditioning with synthesis step

Achieves advanced performance throughMicrochannel reactorEngineered catalyst

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Temperature Gradients in FT ReactorsTemperature Gradients in FT ReactorsTemperature Gradients in FT ReactorsCT=0.3sec, P=20atm, catalyst vol = 0.8cc

Microchannel Reactor: 0.03x0.6x2.725Packed Bed Reactor: 0.25ID x 1 L

Hot spot: 262 C

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Microchannel reactor development @ PNNL

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Engineered CatalystsEngineered CatalystsEngineered CatalystsMicrochannel

~ 0.002 cm

1 .2 5

0 .5

0 .0 6

0 .0 1 0 .0 1 0 .0 2 5

1 .2 5

0 .5

0 .0 6

0 .0 1 0 .0 1 0 .0 2 5

Catalyst tailored for microchannel reactor

Conventional

~ 0.2 - 1 cm

Limited

Low

Low

Porous Ceramic

High

High

High

Porous Metal and Metallic Structured Monolith

Activity

Mass TransportEfficiency

Heat Transport Efficiency

Support

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Accomplishments to DateAccomplishments to DateAccomplishments to Date

Preliminary results indicate the potential of no costly CO2 separation

Promising economics low capital cost

High throughput: 60 x greater than conventional (GHSV=60,000hr-1 at 15 atm, H2/CO = 1-2.5)

Demonstrated tailored product distribution in gasoline and diesel slates ---potentially eliminate hydrocracker

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P=15atm, 60,000 GHSVP=15atm, 60,000 GHSVP=15atm, 60,000 GHSVBF009

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

850 870 890 910 930 950TOS (hr)

CO

Con

vers

ion

/ pro

duct

se

l(%)/

P (a

tm)

0.0

50.0

100.0

150.0

200.0

250.0

300.0

T(C

)

CO Cov(%)P (atm)

CH4SelectivityCO2SelectivityC2=+C2

C3=+C3

C4+

flow rate

T

H2/CO= 2/1, WHSV=12.98

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Tailoring of Product DistributionsH2/CO=2, 250C, similar WHSV (3.73 gCO/gcat/hr)

Tailoring of Product DistributionsTailoring of Product DistributionsHH22/CO=2, 250/CO=2, 250C, similar WHSV (3.73 C, similar WHSV (3.73 ggCO/CO/ggcat/cat/hrhr))

C#

0

1

2

3

4

5

6

7

7 11 15 19 23 27 31 35 39 43 47 51 55 59

wt%

Conventional, CH4 sel = ~ 10%

Recent results, CH4 sel = ~10%

-16

-12

-8

-4

0

4

0 5 10 15 20 25 30 35 40 45 50 55 60 65n-1

Ln(W

t%/n

)

Recent results, = 0.78

Conventional, = 0.9

Narrower product distributionLower CH4 selectivity and alpha

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Catalyst Modeling:--Optimizing coating thickness

Catalyst Modeling:Catalyst Modeling:----Optimizing coating thicknessOptimizing coating thickness

Coating Thickness Effect on RTDBackmixing Analysis

0

0.5

1

1.5

2

2.5

3

0 0.5 1 1.5 2 2.5

t/Tao

E(t/T

ao)

60 um coating15 um coatingPFRAxial Dispersion:

zc

zc

Pec

=

2

21

18

Catalyst Modeling:--Optimizing coating thickness

Catalyst Modeling:Catalyst Modeling:----Optimizing coating thicknessOptimizing coating thickness

)(),( 22

2

2

yc

xcD

zcyxu

+

=

)( 22

2

2

yc

xcDeffcke RT

E

+

=

Wash coating catalyst phase

Gas phase

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Conceptual Design of Fischer Tropsch Synthesis Reactor for Biomass to Fuel ProductionConceptual Design of Fischer Tropsch Synthesis Reactor for Conceptual Design of Fischer Tropsch Synthesis Reactor for Biomass to Fuel ProductionBiomass to Fuel Production

Module Design:

Cell dimension: 12x18x10

Channel dimension: 12x0.1x10

Number of channels: 5057

Number of cells: 168 (each cell contains 30 channels)

Total footprint: 210 cft

Hydrodynamics and RTD

Pressure Drop: 16 psiRe: 1,072Pe: 27,000

Max temperature gradient: 7 C

Throughput: 1000 bbl/day

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SummarySummarySummaryDeveloped a unique structured catalyst system suitable for the deployment in microchannel reactor applications. Provides high throughput GTL technology in converting biomass derived syngas to liquid transportation fuels.

Experimentally demonstrated tailored product distribution for synfuel production with engineered catalysts integrated with microchannel reactors.

Modeling approach was used for reactor/catalyst design and optimization.

Compared to the conventional petroleum/natural gas based GTL technology, biomass-derived feedstock has the nature of small scale, and the use of microchannel reactor technology is potentially cost-competitive.

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AcknowledgementsAcknowledgementsAcknowledgements

This work is sponsored by the US DOE EE Renewable Energy, Office of the Biomass Program.

Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

Microchannel Catalytic Process for Converting Biomass Derived Syngas to Transportation FuelsOutlineClean Fuels from BiomassFischer-Tropsch Fuels From BiomassFischer-Tropsch Synthesis ReactionsDegree of Polymerization Affects F-T Product DistributionChallenges of Biomass Syngas to FuelsConventional GTL Plant Capital InvestmentTemperature Gradients in FT ReactorsEngineered CatalystsAccomplishments to DateP=15atm, 60,000 GHSVTailoring of Product DistributionsH2/CO=2, 250C, similar WHSV (3.73 gCO/gcat/hr)Catalyst Modeling:--Optimizing coating thicknessCatalyst Modeling:--Optimizing coating thicknessConceptual Design of Fischer Tropsch Synthesis Reactor for Biomass to Fuel ProductionSummaryAcknowledgements