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
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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
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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.
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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
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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