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KIT – University of the State of Baden-Wuerttemberg and National Research Center of the Helmholtz Association
Institute for Chemical Technology and Polymer Chemistry (ITCP)
www.kit.edu
Institute for Catalysis Research and Technology (IKFT)
CFD simulation of catalytic reactors
Olaf Deutschmann, Karlsruhe Institute of Technology (KIT)
Topsøe Catalysis Forum, Munkerupgaard, August 29-30, 2013
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry2
THE CHALLENGE
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry3
Multi-scale modeling:From 10-10 m and 10-13 s to 1m and 10 s
1 m 10 s
1 mm10 ms
10 m 100 s10 nm1 nm0.1 nm
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry4
THE DREAM
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry5
Multi-scale modeling in catalysis:From fundamental understanding to technology
Complexity
Leng
th a
nd T
ime
Elementary reactions on surfaces
Single catalyst particles
Porous supports
Reactors
DFT
kMC
Reactor components
Multi-components, Additives
DGM
Fluid mechanics
Transients in heat & mass transfer
Process simulation
MF
Plants
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry6
THE REALITY
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry7
Thermodynamic consistency
Development of micro kinetic models for simulations of catalytic reactors
Surface ScienceExperimental
Surface ScienceTheoretical
Reaction mechanismand kinetics (idea)
Modeling of lab reactors(including gas phase kinetics and
transport models)
Sensitivity & reaction flow analyses
Lab experiments(conversion, selectivity,
ignition/extinction temperatures,spatial & temporal profiles,
coverage)
Comparison of experiment and
simulation
Revised reaction mechanism
Technical reactor
Cortesey of hte AG
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry8
Thermodynamic consistency
Development of micro kinetic models for simulations of catalytic reactors
Surface ScienceExperimental
Surface ScienceTheoretical
Reaction mechanismand kinetics (idea)
Modeling of lab reactors(including gas phase kinetics and
transport models)
Sensitivity & reaction flow analyses
Lab experiments(conversion, selectivity,
ignition/extinction temperatures,spatial & temporal profiles,
coverage)
Comparison of experiment and
simulation
Revised reaction mechanism
Technical reactor
Cortesey of hte AG
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry9
Density Functional Theory (DFT) - simulation: Periodic Slab approach
J.A. Keith, J. Anton, T.Jacob. Chapter 1 in Modeling and Simulation of Heterogeneous Catalytic Reactions. O. Deutschmann (Ed.), 2011
Binding energy of an oxygen atom as a function of surface coverage
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry10
DFT - Simulation: Periodic Slab approach:H2 oxidation over Pt(111)
J.A. Keith, J. Anton, T.Jacob. Chapter 1 in Modeling and Simulation of Heterogeneous Catalytic Reactions. O. Deutschmann (Ed.), 2011
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry11
Kinetic Monte Carlo Simulation of surface reactions and diffusion: CO oxidation on Pt nanoperticle
2 CO + O2 -> 2 CO2CO: blue O: redCatalyst atom (Pt): white Washcoat molecule (Al2O3): greyAdsorption sites: yellow
L. Kunz et al., Chapter 4 in Modeling Heterogeneous Catalytic Reactions. O. Deutschmann (Ed.), 2011
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry12
Modeling heterogeneous reactions: Concept of rate equations (mean-field approximation)
SR j
jk
ikijk
kcks
'
f
Surface reaction rate
ΓcΘ ii
i
Surface coverage
ΓMs
tΘ iii
Locally resolved reaction rates depending on gas-phase concentration and surface coverages
O. Deutschmann. in Handbook of Heterogeneous Catalysis, 2nd Ed.,, G. Ertl, H. Knözinger, F. Schüth, J. Weitkamp (eds.), p. 1811, Wiley-VCH, 2008
Rate expression
s
1
expexpN
i
iiμi
aβkf RT
ΘεΘ
RTE
TAk kkikk
k
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry13
Thermodynamic consistency
Development of micro kinetic models for simulations of catalytic reactors
Surface ScienceExperimental
Surface ScienceTheoretical
Reaction mechanismand kinetics (idea)
Modeling of lab reactors(including gas phase kinetics and
transport models)
Sensitivity & reaction flow analyses
Lab experiments(conversion, selectivity,
ignition/extinction temperatures,spatial & temporal profiles,
coverage)
Comparison of experiment and
simulation
Revised reaction mechanism
Technical reactor
Cortesey of hte AG
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry14
Example
Development of a microkinetic model for
over Ni-based catalysts
to be used for numerical simulation of technical reactors
CH4 + 2 O2 2 H2O + CO2
CH4 + ½ O2 2 H2 + CO
CH4 + H2O 3 H2 + CO
CH4 + CO2 2 H2 + 2 CO
DryRef: FKZ 0327856
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry15
Micro kinetic model for conversion of methane over NiReaction A(cm,mol,s) β(-) Ea(KJ/mol)
R1 H2 +2(Ni) >H(Ni) +H(Ni) 1.000E-02 0.0 0.00R2 H(Ni) +H(Ni) >2(Ni) +H2 2.545E+31 0.0 92.21R3 O2 +2(Ni) >O(Ni) +O(Ni) 1.000E-02 0.0 0.00R4 O(Ni) +O(Ni) >2(Ni) +O2 4.283E+20 0.0 420.95R5 CH4 +(Ni) >CH4(Ni) 8.000E-03 0.0 0.00R6 CH4(Ni) >(Ni) +CH4 8.705E+15 0.0 37.55R7 H2O +(Ni) >H2O(Ni) 1.000E-01 0.0 0.00R8 H2O(Ni) >(Ni) +H2O 3.732E+12 0.0 60.79R9 CO2 +(Ni) >CO2(Ni) 7.000E-06 0.0 0.00R10 CO2(Ni) >(Ni) +CO2 6.447E+07 0.0 25.98R11 CO +(Ni) >CO(Ni) 5.000E-01 0.0 0.00R12 CO(Ni) >(Ni) +CO 3.563E+11 0.0 109.27-50ƟCO(Ni)R13 O(Ni) +H(Ni) >OH(Ni) +(Ni) 5.000E+22 0.0 97.90R14 OH(Ni) +(Ni) >O(Ni) +H(Ni) 1.781E+21 0.0 36.09R15 OH(Ni) +H(Ni) >H2O(Ni) +(Ni) 3.000E+20 0.0 42.70R16 H2O(Ni) +(Ni) >OH(Ni) +H(Ni) 2.271E+21 0.0 91.76R17 OH(Ni) +OH(Ni) >O(Ni) +H2O(Ni) 3.000E+21 0.0 100.00R18 O(Ni) +H2O(Ni) >OH(Ni) +OH(Ni) 6.373E+23 0.0 102.86R19 O(Ni) +C(Ni) >CO(Ni) +(Ni) 3.400E+19 0.0 148.00 R20 CO(Ni) +(Ni) >O(Ni) +C(Ni) 1.759E+11 0.0 100.24-50ƟCO(Ni)R21 CO2(Ni) +(Ni) >O(Ni) +CO(Ni) 4.653E+23 -1.0 89.32 R22 O(Ni) +CO(Ni) >CO2(Ni) +(Ni) 2.000E+19 0.0 123.60-50ƟCO(Ni)R23 CO2(Ni) +H(Ni) >COOH(Ni) +(Ni) 7.230E+18 0.0 166.00R24 COOH(Ni) +(Ni) >CO2(Ni) +H(Ni) 3.230E+19 0.0 87.00 R25 COOH(Ni) +(Ni) >CO(Ni) +OH(Ni) 2.740E+23 0.0 38.00R26 CO(Ni) +OH(Ni) >COOH(Ni) +(Ni) 3.200E+23 0.0 111.00R27 CO(Ni) +CO(Ni) >C(Ni) +CO2(Ni) 3.200E+18 0.0 326.00-50ƟCO(Ni)R28 C(Ni) +CO2(Ni) >CO(Ni) +CO(Ni) 3.700E+21 0.0 155.00R29 HCO(Ni) +(Ni) >CO(Ni) +H(Ni) 3.700E+21 0.0 0.00+50ƟCO(Ni) R30 CO(Ni) +H(Ni) >HCO(Ni) +(Ni) 4.019E+20 -1.0 132.23R31 HCO(Ni) +(Ni) >O(Ni) +CH(Ni) 3.792E+15 0.0 81.91 R32 O(Ni) +CH(Ni) >HCO(Ni) +(Ni) 4.604E+20 0.0 109.97R33 CH4(Ni) +(Ni) >CH3(Ni) +H(Ni) 3.700E+21 0.0 57.70R34 CH3(Ni) +H(Ni) >CH4(Ni) +(Ni) 6.034E+21 0.0 61.58R35 CH3(Ni) +(Ni) >CH2(Ni) +H(Ni) 3.700E+24 0.0 100.00R36 CH2(Ni) +H(Ni) >CH3(Ni) +(Ni) 1.293E+23 0.0 55.33R37 CH2(Ni) +(Ni) >CH(Ni) +H(Ni) 3.700E+21 0.0 97.10R38 CH(Ni) +H(Ni) >CH2(Ni) +(Ni) 4.089E+24 0.0 79.18R39 CH(Ni) +(Ni) >C(Ni) +H(Ni) 3.700E+23 0.0 18.80R40 C(Ni) +H(Ni) >CH(Ni) +(Ni) 4.562E+21 0.0 161.11R41 O(Ni) +CH4(Ni) >CH3(Ni) +OH(Ni) 1.700E+24 0.0 75.30R42 CH3(Ni) +OH(Ni) >O(Ni) +CH4(Ni) 9.876E+22 0.0 30.37R43 O(Ni) +CH3(Ni) >CH2(Ni) +OH(Ni) 3.700E+24 0.0 110.10R44 CH2(Ni) +OH(Ni) >O(Ni) +CH3(Ni) 4.607E+21 0.0 23.62R45 O(Ni) +CH2(Ni) >CH(Ni) +OH(Ni) 3.700E+19 0.0 126.80R46 CH(Ni) +OH(Ni) >O(Ni) +CH2(Ni) 1.457E+23 0.0 47.07R47 O(Ni) +CH(Ni) >C(Ni) +OH(Ni) 3.700E+21 0.0 48.10R48 C(Ni) +OH(Ni) >O(Ni) +CH(Ni) 1.625E+21 0.0 128.61R49 H(Ni) +CO(Ni) >C(Ni) +OH(Ni) 4.945E+21 -0.7 110.05-50ƟCO(Ni)R50 OH(Ni) +C(Ni) >H(Ni) +CO(Ni) 2.769E+22 0.7 30.00
R21 CO2(Ni) +(Ni) >O(Ni) +CO(Ni)R22 O(Ni) +CO(Ni) >CO2(Ni) +(Ni)
R23 CO2(Ni) +H(Ni) >COOH(Ni) +(Ni)R24 COOH(Ni) +(Ni) >CO2(Ni) +H(Ni)
R25 COOH(Ni) +(Ni) >CO(Ni) +OH(Ni)R26 CO(Ni) +OH(Ni) >COOH(Ni) +(Ni)
R27 CO(Ni) +CO(Ni) >C(Ni) +CO2(Ni)R28 C(Ni) +CO2(Ni) >CO(Ni) +CO(Ni)
R19 O(Ni) +C(Ni) >CO(Ni) +(Ni)R20 CO(Ni) +(Ni) >O(Ni) +C(Ni)
R27 CO(Ni) +CO(Ni) >C(Ni) +CO2(Ni)R28 C(Ni) +CO2(Ni) >CO(Ni) +CO(Ni)
R39 CH(Ni) +(Ni) >C(Ni) +H(Ni)R40 C(Ni) +H(Ni) >CH(Ni) +(Ni)
R47 O(Ni) +CH(Ni) >C(Ni) +OH(Ni)R48 C(Ni) +OH(Ni) >O(Ni) +CH(Ni)
R49 H(Ni) +CO(Ni) >C(Ni) +OH(Ni)R50 OH(Ni) +C(Ni) >H(Ni) +CO(Ni)
L. Maier, B. Schädel, K. Herrera Delgado, S. Tischer, O. Deutschmann, Top Catal: 54 845 (2011)
O2(g) O*
CH4(g)
H2O(g)
CO2(g)
CHO*
H2O*
H*
H*
CH4*
CH3*
CH2*
CH*
*
*
*C*
*
H2(g)
OH*
O*
H*
*
CO*O*
CO(g)
*
H*
*
CO2*
*
* COOH*OH*
OH*
H*
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry16
Development of micro kinetic models for simulations of catalytic reactors
Surface ScienceExperimental
Surface ScienceTheoretical
Reaction mechanismand kinetics (idea)
Lab experiments(conversion, selectivity,
ignition/extinction temperatures,spatial & temporal profiles,
coverage)
Modeling of lab reactors(including gas phase kinetics and
transport models)
Sensitivity & reaction flow analyses
Comparison of experiment and
simulation
Revised reaction mechanism
Thermodynamic consistency
Technical reactor
Cortesey of hte AG
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry17
Dry-reforming of CH4: Small olefins can lead to gas-phase molecular-weight growth and carbon deposits
A. Li, O. Deutschmann. Chemical Engineering Science, 62 (2007) 4976.L.C.S. Kahle, T. Roussière, L. Maier, K. Herrera Delgado, G. Wasserschaff, S.A. Schunk, O. Deutschmann. Ind. & Eng. Chem. Res. 52 (2013) 11920
CH4/CO2 = 1; 10 % H2; 5 % Aru0 = 0,366 m/s, ~1200 K, 20 bar
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry18
Development of micro kinetic models for simulations of catalytic reactors
Surface ScienceExperimental
Surface ScienceTheoretical
Reaction mechanismand kinetics (idea)
Lab experiments(conversion, selectivity,
ignition/extinction temperatures,spatial & temporal profiles,
coverage)
Modeling of lab reactors(including gas phase kinetics and
transport models)
Sensitivity & reaction flow analyses
Comparison of experiment and
simulation
Revised reaction mechanism
Thermodynamic consistency
Technical reactor
Cortesey of hte AG
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry19
Spatially - resolved sampling techniques for catalytic reactors
Stagnation flow reactor (0d)
N.E. McGuire, N.P. Sullivan, O. Deutschmann, H. Zhu, R.J. Kee. Appl. Catal. A 394 (2011) 257. C. Karakaya, O. Deutschmann, Chem. Eng. Sci. 89 (2013) 171
Monolithic Catalysts (1d)
G. Fischer et al., 2006R. Horn, N. J. Degenstein, K. A. Williams, L. D. Schmidt Catal. Lett. 110, 169-178 (2006) A. Donazzi, D. Livio, M. Maestri, A. Beretta, G. Groppi, E. Tronconi, P. Forzatti, Angew. Chem.
Int. Ed. 2011, 50, 3943.D. Livio, C. Diehm, A. Donazzi, A. Beretta, G. Groppi, O. Deutschmann, Appl. Catal. A (2013)
Reactors with catalytic surfaces (2d)
OH LIF
U. Dogwiler, J. Mantzaras, C. Appel, P. Benz, B. Kaeppeli, R. Bombach, A. Arnold. Proc. Combust. Inst. 27 (1998) 2275
A. Zellner, O. Deutschmann, 2012O. Deutschmann, J.-D. Grunwaldt. Chem.Eng. Technol. 85 (2013) 595
NO LIF
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry20
Stagnation flow reactor for kinetic studies: Resolution of external and internal boundary layer
Oxidation of CH4over Rh/Al2O3
Tsurf = 700°C
C. Karakaya, O. Deutschmann, Chem. Eng. Sci. 89 (2013) 171
catalyst gas-phase
Software: DETCHEMSTAG, H. Karadeniz, S. Tischer, O. Deutschmann
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry21
Resolution of species profiles and temperature in flow direction with movable capillaries: CPOX of EtOH over Rh/Al2O3
M. Hettel, C. Diehm, B. Torkashvand, ,O. Deutschmann, Catal. Today (2013) D. Livio, C. Diehm, A. Beretta, G. Groppi, O. Deutschmann, Appl. Catal. A (2013)
-15 -10 -5 0 5 10 15 20 250,0
0,5
1,0
1,5
2,0
Sto
ffmen
gena
ntei
l (%
)
Axiale Koordinate (mm)
C/O = 0,65 C/O = 0,70 C/O = 0,75 C/O = 0,80 C/O = 0,85
Acet-aldehyd
-15 -10 -5 0 5 10 15 20 250
5
10
15
20
CO
CO2
H2O
H2
O2
Sto
ffmen
gena
ntei
l (%
)
Axiale Koordinate (mm)
EtOH
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry22
Development of micro kinetic models for simulations of catalytic reactors
Surface ScienceExperimental
Surface ScienceTheoretical
Reaction mechanismand kinetics (idea)
Lab experiments(conversion, selectivity,
ignition/extinction temperatures,spatial & temporal profiles,
coverage)
Modeling of lab reactors(including gas phase kinetics and
transport models)
Comparison of experiment and
simulation
Revised reaction mechanism
Thermodynamic consistency
Technical reactor
Cortesey of hte AG
Sensitivity & reaction flow analyses
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry23
H2 O2 CO O2
H2 O2 CO
CO2
H2 oxidation CO oxidation
Preferential oxidation of CO
H2 CO H2OR-WGS WGS
Sub-mechanism for CO/O2/H2/CO2/H2O systems
CH4 O2
CH4 H2OCH4CO2
Final mechanism for CO/O2/H2/CO2/H2O/CH4 systems
POx of CH4
Dry reforming of CH4
Sub-mechanism for H2/O2 systems Sub-mechanism for CO/O2 systems
SR of CH4
Strategy for mechanism development:Hierarchical approach
CH4 O2
Ox of CH4
Varyingcomposition, temperature,
residence time
Ni/Al2O3 (KIT)New Ni cat (BASF)
Ni … cats (lit.)
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry24
Development of micro kinetic models for simulations of catalytic reactors
Surface ScienceExperimental
Surface ScienceTheoretical
Reaction mechanismand kinetics (idea)
Lab experiments(conversion, selectivity,
ignition/extinction temperatures,spatial & temporal profiles,
coverage)
Modeling of lab reactors(including gas phase kinetics and
transport models)
Sensitivity & reaction flow analyses
Comparison of experiment and
simulation
Revised reaction mechanism
Thermodynamic consistency
Technical reactor
Cortesey of hte AG
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry25
Experimental conditions:Nickel based catalyst (BASF) 100-900oC , 4 SLPM, 1bar1.6%CH4, 2.1%CO2, 1.8%H2 in N2
Dry reforming of natural gas over Ni-based catalyst:Influence of H2 addition
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry26
Dry reforming of natural gas over Ni-based catalyst:Influence of H2O addition
Experimental conditions:Nickel based catalyst (new BASF catalyst) 100-900oC, 4 SLPM , 1bar1.7%CH4, 2.1%CO2, 2.1%H2O
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry27
Partial oxidation of CH4 in a fixed-bed reactor
Experimental conditions:
Nickel based catalyst (new BASF catalyst)200-900 oC, 4 SLPM, CH4/O2=1.6 in N2, 1bar
No coke formation according to spent catalyst analysis
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry28
Development of micro kinetic models for simulations of catalytic reactors
Surface ScienceExperimental
Surface ScienceTheoretical
Reaction mechanismand kinetics (idea)
Lab experiments(conversion, selectivity,
ignition/extinction temperatures,spatial & temporal profiles,
coverage)
Modeling of lab reactors(including gas phase kinetics and
transport models)
Sensitivity & reaction flow analyses
Comparison of experiment and
simulation
Revised reaction mechanism
Thermodynamic consistency
Technical reactor
Cortesey of hte AG
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry29
APPLICATIONS
success stories
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry30
TWC emission control
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry31
Simulation at real driving conditions is very challenging: Continuous variation of all inlet variables
J. Braun, T. Hauber, H. Többen, J. Windmann, P. Zacke, D. Chatterjee, C. Correa, O. Deutschmann, L. Maier, S.Tischer, J. Warnatz, SAE paper 2002-01-0065
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry32
DETCHEMMONOLITH: Computer program for the numerical simulation of transients in catalytic monoliths
MONOLITHTemperature of the solid structure incl. canning
by a 2D / 3D heat balance
CHANNEL or PLUG 1D or 2D-flow field simulations for a representative number of
channels using boundary layer or plug flow equations
temperature profileat the wall heat source term
time scale ~ 1 s
residence time < 100 msquasi-steady-statetransient
gas phase concentrationstemperature
chemical source termtransport coefficients
DETCHEM - LibraryThermodynamic and transport properties
Detailed reaction mechanisms for gas-phase & surface
S. Tischer, O. Deutschmann, Catal. Today 105 (2005) 407, www.detchem.de
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry33
Pollutant reduction in a three-way catalyst during cold start-up: Simulation of a driving cycle
J. Braun, T. Hauber, H. Többen, J. Windmann, P. Zacke, D. Chatterjee, C. Correa, O. Deutschmann, L. Maier, S.Tischer, J. Warnatz, SAE paper 2002-01-0065
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry34
Cumulative CO emission in MEVG cycle:Experiment vs. simulation
0
1
2
3
4
5
6
7
8
0 200 400 600 800 1000 1200time [s]
CO
em
issi
on [%
]
0
20
40
60
80
100
cum
ulat
ive
CO
em
issi
on [g
]
inletinlet (cum.)experiment (cum.)simulation (cum.)
Tischer et al. SAE Technical paper 2007-01-1072 2007Funded by Corning, 2006-2009
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry35
Auxiliary power units (APU) with on-board reforming
Courtesy of Steve Shaffer, Delphi, 2008 SECA Review
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry36
SOFC
PEM
Catalytic Converter
Exhaust Exhaust
H2
H2, CO
WGS
AIR CPOx Reformer
Improved Start‐up
H2 ‐ SCR
Tailgas recycling (CO2/H2O)
Fuel
40‐60% el. efficiency
Idle state: < 5%Full load: < 30%el. efficiency
On-board catalytic partial oxidation of logistic fuels provides electricity and reduces pollutant emissions
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry37
Conversion of logistic fuels (i-octane) to hydrogen: Computed profiles in the reformer
L. Maier, M. Hartmann, O. Deutschmann, Combust. Flame 158 (2011) 796–808.
Rh catalyst at ~1000°C converts hydrocarbons fuels to CO and H2in less than 5 ms without any additional energy supply
H2
CnHm+ n/2 O2 n CO + m/2 H2
Surface: 111 reactions / 31 surface speciesGas-phase: 7193 reactions/ 857 species
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry38
CPOX of i-octane: Coke precursors are formed in the gas phase both in the catalytic zone and downstream
L. Maier, M. Hartmann, O. Deutschmann, Combust. Flame 158 (2011) 796–808.
catalyst catalyst
C/O = 1.0 5 slpm
10 nm
Rh
RhAl2O3support
carbon layer
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry39
SOFC operated with HC fuels: Complex interaction of electro-chemistry, thermo-catalytic chemistry, mass and heat transport
H. Zhu, R. J. Kee, V.M. Janardhanan, O. Deutschmann, D.G. Goodwin. J. Electrochemical Soc. 152 (2005) A2427
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry40
H. Zhu, R. J. Kee, V.M. Janardhanan, O. Deutschmann, D.G. Goodwin. J. Electrochemical Soc. 152 (2005) A2427
Modeling Solid-Oxide Fuel Cells:Spatial profiles in the fuel channel and Ni/YSZ anode
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry41
Anode-supported, planar SOFC: Computed temperature distribution in the electrodes (adiabatic condition)
V.M. Janardhanan, O. Deutschmann. Chem. Eng. Sci. 62 (2007) 5473
Fuel stream: 40% CH4, 60% H2O at 800°CCathode stream: Air at 650°C
Impact of endothermic reforming and temperature difference between fuel and air streams on temperature distribution
Anode750 m
Cathode30 m
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry42
Anode-supported, planar SOFC: Impact of anode thickness on current density (adiabatic condition)
Competition of H2 production/consumption, endothermic reforming, and heat release
Fuel stream: 40% CH4, 60% H2O at 800°CCathode stream: Air at 650°C
V.M. Janardhanan, O. Deutschmann. J. Power Sources 177 (2007) 296
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry43
Anode-supported, planar SOFC: Impact of anode thickness on efficiency and power density
V.M. Janardhanan, O. Deutschmann. ECS Transactions 7 (2007) 1939
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry44
SOFC Stack Structure
Planar architecture Membrane-electrode
assembly Interconnect carries current Stacked layers build voltage
Electrolyte (e.g.,YSZ) Polycrystalline ceramic O2- ion conductor Electrical insulator Impervious to gas flow
Electrodes Porous cermet composite Anode supports MEA
Interconnect High electrical conductivity Maintains equal potential
Flow channels Formed in interconnect
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry45
SOFC stack: Simulation of stack temperature caused by change in voltage
V. Menon, V.M. Janardhanan, S. Tischer, O. Deutschmann. J. Power Sources 214 (2012) 227
Start-up and step change in voltage from 0.7V to 0.8V in a SOFC stack
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry46
Simulation of technical catalytic reactors from first principles:STILL A LONG WAY TO GO
Complexity
Leng
th a
nd T
ime
Elementary reactions on surfaces
Single catalyst particles
Porous supports
Reactors
DFT
kMC
Reactor components
Multi-components, Additives
DGM
Fluid mechanics
Transients in heat & mass transfer
Process simulation
MF
Plants
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry47
Acknowledgements
Many colleagues at KIT
R.J. Kee, A.M. Dean, N.P. Sullivan (CSM)L. D. Schmidt (U Minnesota)G. Eigenberger, U. Nieken (U Stuttgart) V.M. Janardhanan (IIT Hyderabad)H.-G. Bock (U Heidelberg)A. Beretta (Politecnico Milano)K. Norinaga (Fukuoka U)R.J. Behm (U Ulm)T. Bauer, R. Lange (TU Dresden)U. Riedel (DLR Stuttgart)A. Worayingyong, P. Viravathana (Kasetsart U)W. Zhang (Beijing), S. Zhang (Xi’an)Deutschmann group at KIT 2011
Olaf Deutschmann
Institute for Chemical Technology and Polymer Chemistry48
Ö. Keskin, M. Wörner, H.S. Soyhan,T. Bauer, O. Deutschmann, R. Lange. AIChE J 56 (2010) 1693
Hydrodynamics and mass transfer in Taylor flow Rising bubble swarm
Thank you for your attention!