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Multiscale simulation
for adsorption process development
[Ch. 7]
Major: Interdisciplinary program of the integrated biotechnology
Graduate school of bio- & information technology
Youngil Lim (N110), Lab. FACS Youngil Lim (N110), Lab. FACS
phone: +82 31 670 5200 (secretary), +82 31 670 5207 (direct)phone: +82 31 670 5200 (secretary), +82 31 670 5207 (direct)
Fax: +82 31 670 5445, mobile phone: +82 10 7665 5207Fax: +82 31 670 5445, mobile phone: +82 10 7665 5207
Email:Email: limyi@hknu.ac.kr limyi@hknu.ac.kr , homepage:, homepage: http://hknu.ac.kr/~limyi/index.htmhttp://hknu.ac.kr/~limyi/index.htm
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Ch. 7. Computational methods on Mesoscopic/Macroscopic scale
+Euclidean space in classical mechanics
+Hilbert space in quantum theory
+Sobolev space in fluid or solid mechanics ++-space in thermodynamics
+non-Euclidean curved space and time in general relativity
theory
+Minkowski space in special relativity theory
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Equations linkage in CFD
Thermal Decomposition in a Parallel Plate Reactor
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Introductions
Chemical Engineering Module
± Fully coupled momentum, energy and mass transport
± Strategies for Multiphysics modeling
Inlet
outlet
Heated cylinder
R O O
R
R O H
R O H
A Fk
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Coupled Three phenomena
Momentum
(Navier-Stokes Equations)
Energy
(Convection and Conduction, Heat transfer)
Mass
(Convection and Diffusion, Reaction)
Velocity, pressure
Temperature
Density, viscosity
Thermal conductivity
Heat capacity
Reaction rate
(Re=4) (C A/C= 0.02)
reaction rate =r(CA)(exothermic or endothermic)
Concentration
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1 ± One-way coupled
The momentum transport is independent of the energyand mass transport
The energy transport depends only on the momentum
transport
The mass transport depends on both the momentumtransport and the energy transport
The heat of reaction, Q, is neglected
momentum Heat
Mass
Sequential solution approach
(1)
(3)
(2)
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Momentum : Navier-stokes equations
0!
!x
x F p
t
T uuuu
u VL V
Energy : Convection and Conduction
T C QT k t
T C P P !
x
xu V V
Mass : Convection and Diffusion
iiiii c Rc Dt
c
x
xu
u
T
i
g
i cT R
E A R
¹¹
º
¸
©©
ª
¨ ! exp
Ci
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Simulation procedure in COMSOL
/
Model Navigator (Momentum / Heat / Mass Transport)
CAD
(1D, 2D or 3D)
Subdomain / Boundary Settings
(Momentum / Heat / Mass Transport)
Mesh
Solver (processing)
Post-processing
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Coupled Three phenomena
Momentum
(Navier-Stokes Equations)
Energy
(Convection and Conduction, Heat transfer)
Mass
(Convection and Diffusion, Reaction)
Velocity, pressure
Temperature
Density, viscosity
Thermal conductivity
Heat capacity
Reaction rate
reaction rate =r(CA)(exothermic or endothermic)
Concentration
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Results - Temperature
Sequential
(constant parameters: V, L, k, Cp, Q)
Simultaneous
(time dependent parameters)
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Results - Concentration
Sequential
(constant parameters: V, L, k, Cp, Q)
Simultaneous
(time dependent parameters)
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T C QT k t
T C
P P !
x
xu V V
Momentum : Navier-stokes equations
0!
!x
x F pt
T uuuuu VL V
Energy : Convection and Conduction
Mass : Convection and Diffusion
ii
iiiii
Rt
n
c Rc Dt
c
!x
x
!x
xu
u(t,x,r)
T(t,x,r)
ii
iiimi
C K n
nnk R
!
!
*
*
,)(
Ci(t,x,r)
External linage in Multiscale simulation for adsorption problems
ni(t,x,r)
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T C QT k t
T C
P P !
x
xu V V
Momentum : Navier-stokes equations
0!
!x
x F pt
T uuuuu VL V
Energy : Convection and Conduction
Mass : Convection and Diffusion
ii
iiiii
Rt
n
c Rc Dt
c
!x
x
!x
xu
u(t,x,r)
T(t,x,r)
ii
iiimi
C K n
nnk R
!
!
*
*
,)(
Ci(t,x,r)
External linage in Multiscale simulation for adsorption problems
ni(t,x,r)Q: adsorption heat
Di: axial/radial diffusivity
k m,i: mass transfer coeff.K : adsorption heat
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External linage in Multiscale simulation for adsorption problems
Tools for calculation
FS
Fluid dynamics simulation
Internal coupling Velocity, u: Mm-H-M
Fluid density, V(T): Mm-H
Viscosity, Q(T): Mm-H
Heat capacity, C p(T): H-H
Thermal conductivity, k (T): H-H
Adsorption kinetics, R i(T): H-M
Adsorption heat, Q(R i): M-H
Axial/radial diffusivity, Di(T): H-M
External coupling
Adsorption isotherms, ni(T, Ci): MS-
FS
Adsorption heat, Q(T): MS-FS Pore diffusivity, D pore: MS-MFS-FS
Geometry effects of equipments: FS-
PS
Momentum
(Mm)Heat (H)
Mass (M)
P S
Process simulation
MFS
Micro-flow dynamics simulation
MS
Molecular simulation
1D Mass balance
(1DM)
Boundary conditions
(Node model, NM)
Internal coupling
Operating conditions (X, Qi): NM-
1DM
Design parameters (Lc, Dc, Ni, I b):
NM-1DM
Computational parameters ( Nmesh, (z,
(t): NM-1DM
External coupling (Model
parameters)
Adsorption isotherms, ni(T, Ci): MS-
PS
Mass transfer coefficient, k (T): MS-MFS-PS
Axial dispersion coefficient, Dax: FS-
PS
Molecular force field
(MFF, e.g., COMPASS)
Internal coupling
Molecular formulation: Predefined input
(experiment)
Particle Density, V p: MFF
Specific surface area, A: MFF
Porosity, I p: MFF
Adsorption heat, Q(T): MFF-GCMC
Adsorption isotherms, ni(T, pi): MFF-GCMC
Pore size distribution (PSD): MFF-GCMC Pore diffusivity, D pore(T): MFF-NVT
External coupling
Force field parameters from DFT
(density functional theory) or ab-init io methods
Grand Canonical Monte Carlo
(GCMC)
NVT molecular dynamics
(Canonical ensemble; NVT)
Dissipative particle dynamics
(DPD)
Lattice Boltzmann Method
(LBM)
Internal coupling (?)
Pressure drops, ( p: LBM
Pore diffusivity, D p(T): LBM-
DPD
External coupling(?)
Adsorption isotherms, ni(Ci):
MS-MFS
Pore size distribution: MS-MFS
MaterialStudio (Accelrys Inc.,
USA)
Forcite Plus & Sorption modules
COMSOL Multiphysics
(Comsol Inc., Sweden)
COMSOL Multiphysics
(CFD standard)
FAST-Chrom/SMB
(CESE PDE solver)
DFT(GAUSSIAN)
MC/MD(Accelrys)
Coarse-grainedparticle simulation
Lattice-Boltzmannsimulation
CFD(Comsol/Fluent)
Process model(FAST-Chrom/SMB)
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)(
1
, iiii
ii
b
biii
nC K k t
n
c Rc Dt
c
!x
x
!x
x
uI
I
Mass (process model) : Convection and Diffusion + node model
Ci(t,x,r)
External linage in Multiscale simulation for adsorption problems
ni(t,x,r)
Di: axial diffusivity
k m,i: mass transfer coeff.
K : adsorption heat
°¯®
!!
!!!
) z ,0t ( n )0 , z( n
) z ,0t ( C )0 , z( C IC
init ial
init ial
±±
°
±±
¯
®
!x
x
x
x!
!
!
!
!
t ,0 z
C
t , z
C DC C v
BC
c L z
0 z
axin0 z L
±°
±¯
®
!
!|
r aff inatenod eine xt r act
nod eind esor bent d esor bent f eed f eed
nod ein
nod eininin
r aff inatee xt r act d esor bent f eed nod ein
nod eout in
QC QC QC QC QC QC
QQQQQQQ
H K FE
H K FE
Operating conditions: X, Qdesorbent, Qextract, Qfeed, Qraffinate
Column model
Node model
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Ch 7. Mesoscale to Macroscale
Ch 7. Computational methods on
mesoscopic & macroscopic scale
± FEM
± Dissipative particle dynamics
± Theory of elasticity
± «
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