cfd simulation of catalytic reactors - · pdf filethermodynamic consistency development of...

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


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


THE DREAM

Olaf Deutschmann


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


THE REALITY

Olaf Deutschmann


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








transport models)




coverage)


simulation


Technical reactor

Cortesey of hte AG

Olaf Deutschmann


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


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


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


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








transport models)




coverage)


simulation


Technical reactor

Cortesey of hte AG

Olaf Deutschmann


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


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








coverage)


transport models)



simulation



Technical reactor

Cortesey of hte AG

Olaf Deutschmann


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








coverage)


transport models)



simulation



Technical reactor

Cortesey of hte AG

Olaf Deutschmann


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


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


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








coverage)


transport models)


simulation



Technical reactor

Cortesey of hte AG


Olaf Deutschmann


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








coverage)


transport models)



simulation



Technical reactor

Cortesey of hte AG

Olaf Deutschmann


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


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


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








coverage)


transport models)



simulation



Technical reactor

Cortesey of hte AG

Olaf Deutschmann


APPLICATIONS

success stories

Olaf Deutschmann


TWC emission control

Olaf Deutschmann


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


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


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


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


Auxiliary power units (APU) with on-board reforming

Courtesy of Steve Shaffer, Delphi, 2008 SECA Review

Olaf Deutschmann


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


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


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


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


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


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


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


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


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


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


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


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


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!

cfd simulation of catalytic reactors - · pdf filethermodynamic consistency development of...

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