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20/10/2015 | Fachbereich Maschinenbau | TVT | Prof. Dr.-Ing. Hampe | Dipl.-Ing. T.J. Kazdal | 1
Technische Universität Darmstadt
Dipl.-Ing. T.J. Kazdal, Prof. Dr.-Ing. Hampe
Virtual functional product development of a
micro steam methane reformer
20/10/2015 | Fachbereich Maschinenbau | TVT | Prof. Dr.-Ing. Hampe | Dipl.-Ing. T.J. Kazdal | 2
Air cooled exothermal micro reactor
20/10/2015 | Fachbereich Maschinenbau | TVT | Prof. Dr.-Ing. Hampe | Dipl.-Ing. T.J. Kazdal | 3
Energiewende
energy efficiency
renewable energy
energy saving
Situation in Germany
€-
€0.05
€0.10
€0.15
€0.20
€0.25
€0.30
Price of 1 kWh
20/10/2015 | Fachbereich Maschinenbau | TVT | Prof. Dr.-Ing. Hampe | Dipl.-Ing. T.J. Kazdal | 4
Steam Methane Reformer Fuel Cell Process
20/10/2015 | Fachbereich Maschinenbau | TVT | Prof. Dr.-Ing. Hampe | Dipl.-Ing. T.J. Kazdal | 5
Process simulation with Aspen Plus
for a 1kWhel µ-SMR-FC plant
20/10/2015 | Fachbereich Maschinenbau | TVT | Prof. Dr.-Ing. Hampe | Dipl.-Ing. T.J. Kazdal | 6
COMSOL model library: Steam reformer
COMSOL (2010): Chemical Reaction Engineering Module Model Library. Steam Reformer (models.chem.steam_reformer).
20/10/2015 | Fachbereich Maschinenbau | TVT | Prof. Dr.-Ing. Hampe | Dipl.-Ing. T.J. Kazdal | 7
Micro Structured Catalytic Reactors (MSR)
heat & mass transport:
• transfer capacities increase by
several magnitudes
• homogenous ignition can be avoided
• less catalyst is needed, due to
increased catalyst utilisation
• no runaway, hot spot, cold spot
formation
S. Cruz, O. Sanz, R. Poyato, O.H. Laguna, F.J. Echave, L.C. Almeida, M.A.
Centeno, G. Arzamendi, L.M. Gandia, E.F. Souza-Aguiar, M. Montes, J.A.
Odriozola, Design and testing of a microchannel reactor for the PROX
reaction, Chemical Engineering Journal 167 (2011) 634–642.
20/10/2015 | Fachbereich Maschinenbau | TVT | Prof. Dr.-Ing. Hampe | Dipl.-Ing. T.J. Kazdal | 8
Catalytic combustion
• Stability over wide concentration ranges
• High selectivity → No NOx formation
• lower temperature
• total conversion
Kinetic data for the heterogeneous oxidation of H2 and CH4 Song, X.; Williams, W. R.; Schmidt, L. D.; Aris, R. (1991): Ignition and extinction of homogeneous-heterogeneous combustion: CH4 and C3H8 oxidation on PT.
In: Symposium (International) on Combustion 23 (1), S. 1129–1137. DOI: 10.1016/S0082-0784(06)80372-3.
Schefer, R. W. (1982):Catalyzed combustion of H2/air mixtures in a flat plate boundary layer: II. Numerical model.
In: Combustion and Flame 45, S. 171–190. DOI: 10.1016/0010-2180(82)90043-8.
20/10/2015 | Fachbereich Maschinenbau | TVT | Prof. Dr.-Ing. Hampe | Dipl.-Ing. T.J. Kazdal | 9
Catalytic combustion of H2 and CH4
The reaction engineering module 1D
0
100
200
300
400
500
600
700
800
900
1000
0
1
2
3
4
5
6
7
8
9
10
0 0.002 0.004 0.006 0.008 0.01 0.012
Te
mp
era
ture
[K
]
Co
ncen
trati
on
[m
ol m
^-3
]
Time [s]
c_H2
c_O2
c_H2O
c_CH4
c_CO
T
20/10/2015 | Fachbereich Maschinenbau | TVT | Prof. Dr.-Ing. Hampe | Dipl.-Ing. T.J. Kazdal | 10
Calculation domains
2D axisymmetric time dependant model
Insulation
Insulation
Inlet
CH4+H2+air
Inlet
Coolant
Outlet
Outlet
T T T T T
Catalyst
coated
Wall
T1-T5
Thermocouples
optional
Heater
cartridge
20/10/2015 | Fachbereich Maschinenbau | TVT | Prof. Dr.-Ing. Hampe | Dipl.-Ing. T.J. Kazdal | 11
Interim results
0
50
100
150
200
250
300
350
400
0 500 1000
Te
mp
era
ture
[°C
]
Time [s]
Conversion CH4
Conversion H2
T1
T2
T3
T4
T5
20/10/2015 | Fachbereich Maschinenbau | TVT | Prof. Dr.-Ing. Hampe | Dipl.-Ing. T.J. Kazdal | 12
Experimental design
20/10/2015 | Fachbereich Maschinenbau | TVT | Prof. Dr.-Ing. Hampe | Dipl.-Ing. T.J. Kazdal | 13
2D axisymmetric boundary conditions
influence of the inlet and outlet
20/10/2015 | Fachbereich Maschinenbau | TVT | Prof. Dr.-Ing. Hampe | Dipl.-Ing. T.J. Kazdal | 14
2D axisymmetric boundary conditions
influence of the cooling jacket
20/10/2015 | Fachbereich Maschinenbau | TVT | Prof. Dr.-Ing. Hampe | Dipl.-Ing. T.J. Kazdal | 15
COMSOL aided experimental design
20/10/2015 | Fachbereich Maschinenbau | TVT | Prof. Dr.-Ing. Hampe | Dipl.-Ing. T.J. Kazdal | 16
Final design
12 Thermocouples
2 Mass flow controller
Coolant: 20 – 90°C
Heater: 0 – 350W
Temperature: 50 – 900°C
Variable gap size < 1000μm
exhaust gas analysis by gas
chromatography
20/10/2015 | Fachbereich Maschinenbau | TVT | Prof. Dr.-Ing. Hampe | Dipl.-Ing. T.J. Kazdal | 17
Reactor validation with heat cartridge
(15, 24, 33, 42W)
20
50
80
110
0 10 20 30 40 50 60
Tem
pera
ture
[°C
]
Time [min]
T1 EXP
T2 EXP
T3 EXP
T4 EXP
T5 EXP
T1 SIM
T2 SIM
T3 SIM
T4 SIM
T5 SIM
20/10/2015 | Fachbereich Maschinenbau | TVT | Prof. Dr.-Ing. Hampe | Dipl.-Ing. T.J. Kazdal | 18
100
120
140
160
180
200
220
240
260
280
300
0 10 20 30 40 50 60 70
Te
mp
era
ture
[°C
]
Time [min]
Simulation
T1
T2
T3
T4
T5
Transition from heater to H2-Air reaction
100
120
140
160
180
200
220
240
260
280
300
0 10 20 30 40 50 60 70
Te
mp
era
ture
[°C
]
Time [min]
Experiment
T1
T2
T3
T4
T5
20/10/2015 | Fachbereich Maschinenbau | TVT | Prof. Dr.-Ing. Hampe | Dipl.-Ing. T.J. Kazdal | 19
How to obtain an unsteady line
as a simulation result?
Solution:
Import the actual volume flow from the experiment as a boundary condition
in COMSOL:
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
100
120
140
160
180
200
220
240
260
280
300
0 10 20 30 40 50 60 70
Vo
lum
e f
low
[N
l/m
in]
Te
mp
era
ture
[°C
]
Time [min]
T1
T2
T3
T4
T5
V. H2 Inlet
20/10/2015 | Fachbereich Maschinenbau | TVT | Prof. Dr.-Ing. Hampe | Dipl.-Ing. T.J. Kazdal | 20
Conclusion & outlook
Powerful development tool for chemical engineering.
• NASA polynomials | CHEMKIN → cp(T), ∆HR(T), Transport properties
Virtual functional product development due to multiphysics
• Prediction of the dynamic behaviour of a chemical reactor
Superior pre and post processing
• Import time dependant boundary conditions
• Evaluation of ‘miscarried’ experiments
Catalyst deposition method needs revision:
