1. 1
Process design and analysis of
dual-phase membranes for
off-shore post-combustion capture
from gas turbines
Rahul Anantharaman
SINTEF Energy Research
Michael McCann, Thijs Peters, Marie-Laure Fontaine, Partow P. Henriksen, Thor Mejdell
SINTEF Materials and Chemistry
7th
June, 2013

2. Presentation Outline
►Background
►Motivation
►Dual-phase membranes
►Process design considerations
►Process Analysis
►Conclusions
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3. Background
►CO2 capture from industry is an important part of the
solution for climate change mitigation
►Four case studies selected in BIGCCS for CO2 capture
from industry
►CO2 emissions from off-shore facilities are some of the
largest point sources.
►CO2 capture from gas turbines on board an Floating
Production Storage and Offloading (FPSO) unit one of
selected case study.
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4. Case Study
►Aim:
 CO2 capture from 6 x 20 MW Gas Turbines (GT) on board an
FPSO
►GT specifications (each)
 Power: 20 MW (Simple cycle)
 Thermal efficiency: 36.4% LHV
 Exhaust flow: 67.4 kg/s
 Exhaust temperature: 466 °C
 CO2 concentration in exhaust: 3 vol%
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5. Challenges
►All of the challenges offshore are the same as the ones
faced by on-shore industry, in addition to size, weight and
stability (wave motion).
►Space- and weight challenges implies the size of the
capture installations will be of importance when selecting
capture technology
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6. Process concepts
►Post-combustion capture
 MEA – reference case
 Membrane contactors
 Dual phase membranes
 Supersonic expansion of CO2
►Oxy-combustion capture
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7. Motivation
► MEA and other solvent based capture technologies
 Gas-liquid interface
 Steam/utility requirement
 Require large absorber
 GT exhaust needs to be cooled
► Membrane contactors not effective for this case
► Polymeric membranes
 Multi-stage process due to selectivity limitations
 High energy consumption and membrane area/volume
 GT exhaust needs to be cooled
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8. Motivation
►Design conceptual process with
 No gas – liquid interface
 Operate at high temperature
 No steam requirement
 Comparable or lower volume and energy consumption than
reference case
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9. Dual-Phase Membrane Concept
►New interesting membrane type with potential of high
temperature operation (450°C-800°C)
►Interconnected molten carbonate phase in a porous
ceramic support matrix of an oxygen ion conductor
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10. Process design
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( )RTE
CO
permeate
CO
feedside
CO
a
e
p
p
L
a
J /
2 2
2
ln



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=
►For a given membrane
thickness, increase flux by
 Increasing feed pressure
 Decreasing permeate pressure
 Decreasing permeate xCO2
 Increasing operating temperature

11. Process Considerations
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12. Process Design Assumptions
►Membrane thickness: 100 micron
►Membrane geometry: 300 m2
/m3
►CO2 capture rate: 90%
►Permeate side pressure: 0.003 bar – 0.001 bar
►Compressor efficiency: 80%
►Vacuum pump efficiency: 75%
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13. Effect of Temperature and Pressure
ratio on membrane volume
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14. Effect of membrane thickness
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Membrane Operating Temperature = 466°C

15. Process design superstructure
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16. Power consumption evaluation
►NG equivalent power is calculated as
 LHV heat input x Efficiency (36.4%)
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Membrane Operating Temperature = 500°C

17. Membrane volume and power
consumption
Adiabatic compression
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18. Membrane volume and power
consumption
Isothermal compression
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19. Reference case – MEA process
►Reference case simulation for MEA process was
performed in CO2SIM
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20. Reference case - MEA process
Power Consumption
►Exhaust gas fans: 8 MWe
►Solvent circulating pumps: 4.8 MWe
►Reboiler duty: 60.7 MWth
►Steam parameters: 3 bar 145°C
►Equivalent Power: 20 MWe
►Total power consumption: 32.8 MWe
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Gottlicher, G, Energetics of CO2 capture

21. Comparing performance
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MEA Absorber + Stripper volume
MEA Power consumption

22. Comparing performance - Exergy
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MEA Exergy requirement

23. Conclusions
►Dual phase membranes show promising performance
►Preliminary results comparing to MEA process indicate
 lower process equipment volume
 Comparable/lower energy penalty for CO2 capture
►It is expected that dual phase membranes will perform
better for "standard" NGCC post-combustion capture
►Novel technology in early phase of development
►Potential issues
 Membrane development and performance
 Feasibility of high temperature vacuum pump
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24. Acknowledgements
This publication has been produced with support from the BIGCCS
Centre, performed under the Norwegian research program Centres for
Environment-friendly Energy Research (FME). The authors acknowledge
the following partners for their contributions: Aker Solutions,
ConocoPhillips, Gassco, Shell, Statoil, TOTAL, GDF SUEZ and the
Research Council of Norway (193816/S60).