Post on 25-Sep-2020
slide 1
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Study on Multiphase CO2 Capture with Immobilised Activator
Xiaohui Zhang*
David W. AgarUniversity of Dortmund
24th May 2005, Lyon
* Shell Global Solutions international B.V.
Gas/Liquid Treating & Sulphur Processes
Badhuisweg 3, 1031 CM AmsterdamXiaohui.Zhang@Shell.com
slide 2
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
�Conclusions & Outlook
Contents
�Experimental Results
- G/L/S
- G/S
- L/S
- G/S – S/L
�Introduction
- Motivation
- CO2-capture technologies
slide 3
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Theoretical Background
CO2 absorption in amine mixtures (conventional process)A
BS
OR
BE
R
DE
SO
RB
ER
FL
AS
H
Sweet Gas
Sour
Feed
Gas
Lean Amine
Rich Amine
Acid Gas
CO2 loading
pa
rtia
l p
ressu
re
MDEA
MEA
305Capacity (vol CO2/vol solution)
2.74700Kinetics (l mol-1 s-1)
MDEAMEA
Advantages
�High absorption rate
�High capacity
Advantages
�High absorption rate
�High capacity
corrosion
high energydemand
slide 4
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Theoretical Background
AB
SO
RB
ER
DE
SO
RB
ER
FL
AS
H
Sweet Gas
Sour
Feed
Gas
Lean Amine
Rich Amine
Acid Gas
Idea: Immobilisation of activators
slide 5
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Theoretical Background
AB
SO
RB
ER
DE
SO
RB
ER
FL
AS
H
Sweet Gas
Sour
Feed
Gas
Lean Amine
Rich Amine
Acid Gas
�CorrosionCorrosionCorrosionCorrosion
Idea: Immobilisation of activators
slide 6
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Theoretical Background
AB
SO
RB
ER
DE
SO
RB
ER
FL
AS
H
Sweet Gas
Sour
Feed
Gas
Lean Amine
Rich Amine
Acid Gas
Idea: Immobilisation of activators
�CorrosionCorrosionCorrosionCorrosion
�EnergyEnergyEnergyEnergy demanddemanddemanddemand
slide 7
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
polystyrene, macroporous
diameter: 0.5 – 1.0 mm
density: 1.092 g/ml
active group:C
H
H
N
H
H
Immobilised Amine
Immobilisation of Primary Amine
slide 8
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Mechanisms for gas-liquid-solid system
gas ���� liquid ���� solid ���� liquid gas ���� solid ���� liquid
slide 9
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Mechanisms for gas-liquid-solid system
solidliquidgas
H
H
N
H
H
N
H
H
N
CO2
MDEAH+ HCO3-
CO2
MDEA -OOC
slide 10
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Mechanisms for gas-liquid-solid system
gas ���� liquid ���� solid ���� liquid gas ���� solid ���� liquid
CO2 CO2
H
H
N
H
H
N
H
H
N
-OOC
MDEAH+
MDEA
liquidgas
HCO3-
slide 11
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Mechanisms for gas-liquid-solid system
solidgas
H
R1
N
H
R1
N
H
R1
N
-OOCCO2
liquid
H
H
N
H
H
N
solid
H
H
N
-OOC
HCO3-MDEAH+
H2O
MDEA H
slide 12
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Experiments
aerated stirred tank
gas-solid fixed-bed
liquid-solid fixed-bed
Significant effect No effect
Periodic-operated fixed-bed
slide 13
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Gas inlet
Gas outletBaffle
Solution./
Suspension
Experiments in a Aerated Stirred Tank Reactor
� Diameter 15 cm
� Liquid height 15 cm
� Gas flow 2 l/min
� CO2 – Concn. 50 vol%
� Amine–Concn.0.25 M
� Solid fraction 8...10 vol%
� Stirrer speed 1000 rpm
slide 14
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
0
0,2
0,4
0,6
0,8
1
0 20 40 60 80 100
time [min]
ou
tle
t/ i
nle
t c
on
ce
ntr
ati
on
[-
]
water
0
0,2
0,4
0,6
0,8
1
0 10 20 30 40 50 60 70 80 90 100
time [min]
ou
tlet/
in
let
co
nc
en
tra
tion
[-
]
water
Lewatit (400ml)
0
0,2
0,4
0,6
0,8
1
0 10 20 30 40 50 60 70 80 90 100
time [min]
ou
tle
t/ i
nle
t c
on
ce
ntr
ati
on
[-
]
water
Lewatit (400ml)
MDEA (0.25 M)
0
0,2
0,4
0,6
0,8
1
0 10 20 30 40 50 60 70 80 90 100
time [min]
ou
tle
t/ i
nle
t c
on
ce
ntr
ati
on
[-
]
water
Lewatit (400ml)
MDEA (0.25 M)
DEA (0.25 M)
0
0,2
0,4
0,6
0,8
1
0 10 20 30 40 50 60 70 80 90 100
time [min]
ou
tlet/
in
let
co
nc
en
tra
tion
[-
]
water
Lewatit (400ml)
MDEA (0.25 M)
MDEA (0.2 M) + DEA (0.05 M)
0
0,2
0,4
0,6
0,8
1
0 10 20 30 40 50 60 70 80 90 100
time [min]
ou
tlet/
in
let
co
nc
en
tra
tion
[-
]
water
Lewatit (400ml)
MDEA (0.25 M)
MDEA (0.2 M) + DEA (0.05 M)
MDEA (0.2 M) + Lewatit (400 ml)
Results of the Aerated Stirred Tank Reactor
slide 15
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
aerated stirred tank
gas-solid fixed-bed
liquid-solid fixed-bed
Periodic-operated fixed-bed
Significant effect No effect
Experiments
slide 16
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Experiments in a Gas-Solid Fixed-Bed Reactor
� Diameter: 4 mm
� Length: 1.1 m
� Porosity: 0.78 � Temperature: 25 - 55 °C
� Gas flow rate: 0.01~0.07 m/s
� CO2- Concentration: 4~20 vol%
Helium, CO2
Lewatit
slide 17
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Results of the Gas-Solid Fixed-Bed Reactor
0
2
4
6
8
10
12
0 60 120 180 240 300Time [min]
Con
ce
ntr
atio
n C
O2 [
vo
l%]
25 °C
40 °C
55 °C
0
2
4
6
8
10
12
0 60 120 180 240 300Time [min]
Con
ce
ntr
atio
n C
O2 [
vo
l%]
25 °C
40 °C
55 °C
CO2 and Lewatit react
almost
instantly
slide 18
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
aerated stirred tank
gas-solid fixed-bed
liquid-solid fixed-bed
Periodic-operated fixed-bed
Significant effect No effect
Experiments
slide 19
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Experimental Setup W
ate
r
MD
EA
Sample collector
CO2
Fix
ed
-bed
Dete
cto
r1
Detector2
T : 20 / 25 / 30 °CV : 1.2 L T1 :15 / 20 / 25 °C
V : 34.5 mlL : 11 cmD : 2 cm
Input signal
output signal
Experiments in a Liquid-Solid Fixed-Bed Reactor
slide 20
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Results of the Liquid-Solid Fixed-Bed ‘Adsorption’
0
0.2
0.4
0.6
0.8
1
0 50 100 150 200 250 300
time [min]
rati
o o
f o
utl
et
to i
nle
t co
ncn
. [-
]
0
0.2
0.4
0.6
0.8
1
100% CO2
70% CO2
50% CO2
SimulationSimulationSimulation
25 °C
Influence of Concentration
slide 21
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
aerated stirred tank
gas-solid fixed-bed
liquid-solid fixed-bed
Periodic-operated fixed-bed
Significant effect No effect
Experiments
slide 22
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Evaluation
Measured kinetic parameters at 298 K
2.3
6.2
1458
instantaneous
Keff a(10-4 1/s)
Rate-limiting5.6Desorption/regenerationSolid-liquid
Rate-limiting15.4AdsorptionLiquid-solid
Slow3600AbsorptionGas-liquid
InstantaneousinstantaneousAdsorptionGas-solid
assessmentkeff
(10-8 m/s)Mass transfer process
2.3
6.2
1458
instantaneous
Keff a(10-4 1/s)
Rate-limiting5.6Desorption/regenerationSolid-liquid
Rate-limiting15.4AdsorptionLiquid-solid
Slow3600AbsorptionGas-liquid
InstantaneousinstantaneousAdsorptionGas-solid
assessmentkeff
(10-8 m/s)Mass transfer process
slide 23
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
gas ���� liquid ���� solid ���� liquid gas ���� solid ���� liquid
CO2 CO2
H
H
N
H
H
N
H
H
N
-OOC
MDEAH+
MDEA
liquidgas
HCO3-
CO2
H
H
N
H
H
N
H
H
N
-OOC
MDEAH+
MDEA
liquid
gas
-OOC
solid
HCO3-
HHHH2222OOOOHHHH2222OOOO
gas ���� liquid ���� solid ���� liquid gas ���� solid ���� liquid
CO2 CO2
H
H
N
H
H
N
H
H
N
-OOC
MDEAH+
MDEA
liquidgas
HCO3-
CO2CO2 CO2
H
H
NH
H
N
H
H
NH
H
N
H
H
NH
H
N
-OOC-OOC
MDEAH+MDEAH+
MDEAMDEA
liquidgas
HCO3-HCO3-
CO2
H
H
N
H
H
N
H
H
N
-OOC
MDEAH+
MDEA
liquid
gas
-OOC
solid
HCO3-
CO2CO2
H
H
NH
H
N
H
H
NH
H
N
H
H
NH
H
N
-OOC-OOC
MDEAH+MDEAH+
MDEAMDEA
liquid
gas
-OOC-OOC
solid
HCO3-HCO3-
HHHH2222OOOOHHHH2222OOOO
Mechanism
SlowerSlower FasterFaster
New absorber concept
slow
limiting
limiting limiting
instantaneous
Comparision of the two mechanisms
slide 24
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Periodic Trickle Bed
� Periodic operation of trickle bed
H
H
N
H
H
N
H
H
N
gas solid
CO2
-OOC
Sour feed gas
Sweet gasLean amine
Rich amine
H
H
N
H
N
H
H
N
liquid solid
-OOC
MDEAH+ HCO3-
MDEA
Immobilised
Amine
time
Flo
w ra
te time
Flo
w ra
teH
slide 25
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Results of the Periodic-Operated Fixed-Bed Reactor
0 5 10 15 20 25 30 35 40 45
0.0
0.2
0.4
0.6
0.8
1.0
uG= 0,06 ms
-1, u
L= 31,4 m
3m
-2h
-1
p = 2,5 bar (Lewatit), ε = 0,60
p = 2,0 bar (Glass), ε = 0,45
T = 25 °C
Ou
tpu
t/in
pu
t co
ncen
trati
on
[-]
Time [min]
Lewatit dP= 0,7-1,0 mm
Inert glass dP= 1,0 mm
the natural pulsing flow
regime —
marginal effect
slide 26
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
aerated stirred tank
gas-solid fixed-bed
liquid-solid fixed-bed
Periodic-operated fixed-bed
Significant effect No effect
Experiments
Why ?
slide 27
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Mass Transport Resistance of Liquid Film
CO2
A
CO2 A
A
A
A
CO2
CO2
1
CO2
2a
CO2
3
CO2
2b
CO2
A
Aquous CO2
Activator
Liquid
Liquid film
Liquid in pore
Solid
1 External mass transfer
2a
2a Internal mass transfer (pore diffusion)
3 “Adsorption”
2b Internal mass transfer (surface diffusion)
ChallengesChallengesChallengesChallenges
� three-phase system (gas-liquid-solid)
� higher mass transport resistance lies
in the liquid phase
ChallengesChallengesChallengesChallenges
� three-phase system (gas-liquid-solid)
� higher mass transport resistance lies
in the liquid phase
slide 28
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
R
Film-pore diffusion model
Shrinking Core model
or Unreacted-core model
Yagi, S., and Kunii, D.
Chem. Eng. Sci., 16,364, 372, 380 (1961)
Levenspiel O.
Chemical Reaction Engineering, Wiley, New York, (1972)
dN/dt
Dpadsorbed region
liquid film
CO2
free region
concentration-front
kf
Cs
Cb
( )qCGr
CDr
rrt
Cppp ,
1 2
2ρε −
∂
∂
∂
∂=
∂
∂
( )qCGt
q,=
∂
∂
Mass balance in the particle:
R
p
p
pbb
bb
bb
r
CD
m
Rz
CV
z
CD
t
C
∂
∂
−
∂
∂−
∂
∂=
∂
∂
ρεε
32
2
Mass balance in the fixed bed:
;Rr = ( )R
pbfr
CDCCk
∂
∂=−
Boundary condition:
slide 29
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Results of Calculation
Measured kinetic parameters at 298 K
39.6
25.0
16.0
CO2 Conc. [mol/m3]
1.125
0.870
0.900
D_pore[10-9 m2/s]
5.5
6.0
4.0
k_film [10-5 m/s] 2D_pore
k_film.d
18.3
25.9
16.7
Bi =
Pore diffusion is more limiting than film mass transfer
slide 30
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
gasgas
Centrifugal Absorber
Gas Flush
Centrifuge
Vacuum
� reactor diameter 20 mm
� reactor height 200 mm
� solid volume 35 ml
� adsorber temp. 25°C
� Gas flow rate 300 ml/min
� CO2 conc. 10-60 vol %
slide 31
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
0 20 40 60 80 100 1200.0
0.2
0.4
0.6
0.8
1.0
Rati
o o
f o
utl
et
an
d i
nle
t C
on
c.
Time [min]
Flush
Centrifugal Reactor
Liquid phase on the surface and in the pore is rate-limiting step
Centrifuge can only make the liquid on the surface away
After vacuum the particle is totally free of liquid and reaction is much faster0 20 40 60 80 100 120
0.0
0.2
0.4
0.6
0.8
1.0
Ra
tio
of
ou
tle
t a
nd
in
let
Co
nc.
Time [min]
Flush
Centri.
0 20 40 60 80 100 1200.0
0.2
0.4
0.6
0.8
1.0
Rati
o o
f o
utl
et
an
d i
nle
t C
on
c.
Time [min]
Flush
Centri.
Vacuum
slide 32
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Summary
Summary
� Absorption can be accelerated by immobilised activators
� Centrifuge Reactor can only remove the surface liquid
� Idea : Hydrophobic Immobilised Sterically Hindered Amines
� Higher mass transfer resistance in the liquid phaseLiquid
gas
Liquid
gasgas
bubble columnbubble column
aerated stirred tank
PI
double chamber mixed-cell
gas-solid fixed-bed
liquid-solid fixed-bed
Significant effect No effect
periodically operated fixed-bed
aerated stirred tank
PI
double chamber mixed-cell
gas-solid fixed-bed
liquid-solid fixed-bed
Significant effect No effect
periodically operated fixed-bed
aerated stirred tankaerated stirred tank
PI
double chamber mixed-cell
PIPI
double chamber mixed-cell
gas-solid fixed-bedgas-solid fixed-bed
liquid-solid fixed-bedliquid-solid fixed-bed
Significant effect No effect
periodically operated fixed-bedperiodically operated fixed-bed
� Chemical ‚shuttle‘ mechanism via carbamate formation
� Enhancement of carbamate hydrolysis necesssary
� Wettability Modification of Immobilised Amine
slide 33
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Diplom- & Masterstudenten:
Jan MackowiakNuthakki Seshagiri Rao
Yozi Bastian
Acknowledgement
Techniker:
Micheal Schlüter
Julian Gies Max-Buchner Stiftungen
Research group:
Prof. Dr. Agar
Dr. M. Grünenwald
Dr. SchubertM.Sci. Yudy Tan
slide 34
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
EndEndEndEndThanks for your attention!Thanks for your attention!Thanks for your attention!Thanks for your attention!
Thanks!
XiaohuiXiaohuiXiaohuiXiaohui.Zhang@Shell.com.Zhang@Shell.com.Zhang@Shell.com.Zhang@Shell.com
slide 35
Xiaohui Zhang & David W. Agar: Study on Multiphase CO2 Capture withImmobilised Activator
Energy Map in the IA System
2~ 60 /kJ mol CO
2CO
Exothermic
22RNH
m o lkJ /85HR
≈∆ Endothermic
3RNH RNHCOO
+ -
MDEA
3MDEAH HCO
+ -+
2CO
Heat
Endothermic2CO