Fifth Annual Conference on Carbon Capture & Sequestration
Capture – Membranes (2)
Energy Analysis of CO2 Separation Process with Hollow Fiber Membrane
Using ASPEN Simulation Method
Hyung-Taek Kim and Hyun-Min ShimDept. of Energy Studies
Ajou University, Suwon Korea
Contents
Background
Purpose of the Study
Simulation & Analysis Method
Schematic of Process
Results of Simulation
Conclusion
Future Work
Background• Carbon Dioxide (CO2)- Major source of greenhouse gas from Power Plant & Industrial Process- CO2 Emission : Korea ranked 10th in the world- Kyoto Protocol : Expected to add carbon tax, emission trade
• For sustainable development, Korea must prepare for the duty for reduction of CO2 emission.
• Methods of CO2 separation : Absorption, Adsorption, Membrane- Absorption : Low conc. CO2 recovery process & large scale
Commercial plant / Blazing of absorbent, Leakage
- Adsorption : High conc. CO2 recovery process & middle scaleShort lifetime of adsorbent
- Membrane : More environmental-friendly than absorptionHigh conc. CO2 recovery process & small scaleNeed to construct commercial plant in Korea
Purpose of the study
• Perform simulation of CO2 separation process with hollow fibermembrane by ASPEN plus & Excel.
• It is possible to analyze the actual process including unit equipments, and obtain optimum operation parameters of product or intermediate.ex) pressure, temperature, enthalpy, flow, composition etc
• Evaluating energy analysis of CO2 separation process and calculating cost of operation are required for CO2 separation & recovery.
Scale : 1,000 Nm3/day of LNG Flue GasTarget Recovery rate : 90%
Purity of CO2 : 99%
Schematic of Hollow Fiber Membrane
H2O > CO2> O2>N2 N2
CO2N2
flue Gasflue Gas
2.01.7O2
100100Total11.018.2H2O13.98.8CO2
72.271.3N2
Wt %Vol %Composition
0.167Pressure ratio (P2/P1)60 GPUPermeability [CO2]50 cmLength of HF20Selectivity [CO2/N2]
1000 m3/dayFeed rate0.1P2 (atm)16,000Num of HF6P1 (atm)
AmountParameterAmountParameter
2) Parameters of Hollow Fiber Membrane
1) Composition of LNG Flue Gas
Simulation & Analysis Method (1/2)• Operating Conditions
Simulation & Analysis Method (2/2)
• Final Results
- Volume of Permeate (VP)- Volume of Retentate (VR)- CO2 Purity at Permeate - CO2 Recovery (%)- Required Surface Area of Membrane (A)
- Required amount of MembraneModule (n)
Initial Input Parameters for Membrane Module
- Permeability (Barrer) - Selectivity(CO2/N2) - Thickness of Selective layer (mm)
• Initial Input Parameters for Variables of Process
- Pressure Ratio( R ) : P feed / P perm- Stage-cut : Q feed / Q perm- Operating Temperature- Plasticizing
• Operating Conditions → Simulation for CO2 Separation Process (Supplement ofMembrane Model with Excel in ASPEN code) → Simulating Results → FindingOptimal Conditions → Energy Analysis by Exergy Method → Calculating Capital Cost
Schematic of Process• Evaluated CO2 Separation Plant (Capacity: real exhaust gas, 1000 Nm3/day)at the Korea Research Institute of Chemical Technology (KRICT)
1. H2O removal process
2. CO2 separation process
3. CO2 liquefaction process (Not yet)
Simulation of H2O Removal Process
FLUEGAS
COOLIN1
HTFLUG1
COOLOUT1
PHTFLUE
COOLIN2
COOLFLUE
COOLOUT2 DRYFLUE
DRN-H2O
PRECOOL
COMP
CONDENSCO2SEP
• Simulation of H2O Removal Process by ASPEN code
Gas Pre-CoolerT: 150 / 40P: 1 kg/cm2
CompressorTmax : 150OP : 6 kg/cm2
CondenserT: 150 / 25P: 6 kg/cm2
H2O SeparatorTmax : 25OP : 5.6 kg/cm2
•
••••
•
Simulation of H2O Removal Process
•
Simulation of H2O Removal Process
Simulation of 1 Membrane Module
•
2 1 ( 1)( 1) 1 0i ix xy y
R R Rα αα α −⎛ ⎞− + − − − + =⎜ ⎟
⎝ ⎠
1 2
( ) ( )( ) ( )
( ) ( )
out out
A out A i ave
out
i ave
Vy VyAJ Q Px P y
VyPermeate flux x Ry
= =−
=× −
1
2
2 1
: selectivity : Feed composition : Permeate composition: Feed Pressure: Permeate Pressure : Pressure ratio( ) : Permeate rate : membrane area
i
xyPPR P PVA
α
flux and conc. of
2. Simulation with variation of membrane property1) Fix permeability as 20, then change selectivity 20~1002) Fix selectivity as 20, then change permeability 20~1003) Change permeability as well as selectivity 20~100
Simulation of 1 Membrane Module
•
� � � � � � � � � � � � � , � � � �
3636.5
3737.5
3838.5
3939.5
40
5 6 7 8 9 10 11 12 13 14 15
� � (atm)
� � (%)
9.49.59.69.79.89.91010.110.210.310.4� � (m3/hr)
ya V
� � � � � � � � � � , � � � � � �
0
50
100
150
200
250
300
350
5 6 7 8 9 10 11 12 13 14 15
� � (atm)
� � � (m2)
0102030405060708090100� � � �
Area Module
Simulation of 1 Membrane Module
� � � � � � � � � � � � � � �
02468
101214
10 20 30 40 50 60 70 80 90 100
� � � � �
� � (m3/hr)
V
� � � � � � � � � ,� � � � � �
0
1020
30
40
5060
70
10 20 30 40 50 60 70 80 90 100
� � � � �
� � (%)
0.00E+001.00E+002.00E+003.00E+004.00E+005.00E+006.00E+007.00E+008.00E+009.00E+00� � (%)
ya XT
Simulation of 1 Membrane Module
1. Permeability = 20, selectivity = 20~100
� � � � � � � � � � � � � � � � � �
02468
1012
20 30 40 50 60 70 80 90 100
� � �
� � �(m3/hr)
00.10.20.30.40.50.60.7� � � �
permeate rate CO2 conc of permeate
� � � � � � � � � � � � � � � � � �
240
245
250
255
260
20 30 40 50 60 70 80 90 100
� � ����
(m2)
75
77
79
81
83
�����
membrane area No of modules
Simulation of 1 Membrane Module
� � � � � � � � � � � � � � � � � � �
050
100150200250300
20 30 40 50 60 70 80 90 100
� � �
� � � (m2)
0
20
40
60
80
100� � � � �
membrane area No of modules
2. Selectivity =20, permeability = 20~100
Simulation of 1 Membrane Module
� � � ,� � � � � � � � � � � � � � � � � �
02468
1012
20 30 40 50 60 70 80 90 100
� � � � � � �
� � � (m3/hr)
00.10.20.30.40.50.60.7� � � �
permeate rate CO2 conc of permeate
� � � ,� � � � � � � � � � � � � � � � � � �
050
100150200250300
20 30 40 50 60 70 80 90 100
� � � � � � �
� � � (m2)
0
20
40
60
80
100� � � � �
membrane area No of modules
3. Permeability & selectivity = 20~100
Simulation of 1 Membrane Module
Simulation of 4 membrane
DRYFLUE PERM1
RET1
4
PRET-11
DRNW-1
PRET-12
PRET-13
DRNW-2
CWIN-1
PRET-14
CWOUT-1
PERM2
RET2
PRET-21
DRNW-3
PRET-22
PRET-23
DRNW-4
CWIN-2
PRET-24
CWOUT-2
PERM3
RET3
PRET-31
DRNW-5
PRET-32
PRET-33
DRNW-6
CWIN-3
CWOUT-3
PRET-34
RET4
PERM4
MEMB-1
PUMP-1
BTK-1 COMP-1
BTK-2
AFCOOL-1
MEMB-2
BTK-3
COMP-2
BTK-4
AFCOOL-2
MEMB-3
BTK-5 COMP-3
BTK-6
AFCOOL-3
MEMB-4
User Model (Excel) for Membrane Modules in ASPEN code
• Simulation of CO2 Separation Process by ASPEN (Excel) code (Peng-Rob equation)
Linkage
→ 4 cascade of hollow fiber membraneCO2 Separation Process
Simulation of 4 membrane
-98.7498.6171.9554.45Recovery (%)
110.06( 1 )0.27 ( 1)1.17( 2)6.03( 7)Required Module (EA)
-41.641.8105.5145.91Flow rate (m3/day)
Total4321Stage
• 4 cascade membrane modules without recycling retentate
feedfeed
permeatepermeate
COQCOQ
CO][][
)(2
22 ×
×=ψ
• Recovery, ψ (%)
Qfeed
[CO2]feed
Qretemtate
Qpermeate
[CO2]permeate
Pfeed
Ppermeate
Simulation of 4 membrane• 4 cascade membrane modules without recycling retentate
875154.4516/0.1
Pfeed / Pperm328071.9526/1
119498.6136/1
1(0.5)199.098.7446/1
119798.3446/1218994.4036/1347067.8426/1
20403225.6716/1
Pfeed / Pperm
EXPSIMEXPSIM
Required amount of Module (7m2)Recovery (%)
StageValue (kgf/cm2)Parameter
Comparison of result for Experiment/SimulationOperating Conditions
Simulation of CO2 Liquefaction Process
LPERCO2
LCOMP
PLPERCO2
LCONDS
CBS
CPLPRCO2
CBR
LQCO2TK
VCO2
LCO2
VCO2MIX
MXCO2
• Simulation of CO2 Liquefaction Process by ASPEN code (Peng-Rob equation)
ChillerT: 25 / -57P: 51.8 kg/cm2
CompressorT: 25P: 52 kg/cm2
CO2 V-L Separator
Conclusions
1. Simulation method for CO2 membrane separation is developed- Simulation program composed with H2O removal, membrane modules and CO2 liquefaction processes
2. Evaluation of optimal condition of 1 membrane - Obtaining optimum parameters with fixing the concentration of
retreate and pressure as well as the variation of permeability and selectivity
3. Development of membrane model using ASPEN & EXCEL - Performing the simulation between ASPEN and EXCEL (User model)
Future Work
1. Refine of membrane model using ASPEN & EXCEL - Link between ASPEN and EXCEL (User model)
2. Evaluation of optimum operation parameter - Obtaining the optimum parameters with change of pressure,
selectivity, permeability etc. with 4 membrane module
3. Simulation for detail equipments- Energy requirement calculations for Vacuum pump, Compressor,
Condenser for CO2 liquefaction process
4. Energy requirement & cost calculations through exergy analysis - Using each stream results by simulation for exergy calculation
Thank you