Development of Membrane Technology for CO 2 Capture at MTR

Transcription

1 Development of Membrane Technology for CO 2 Capture at MTR Tim Merkel MTR Director of R&D September 28, 2012 Symposium for Innovative CO 2 Membrane Separation Technology Tokyo, Japan

2 Personal Connection to Japan Koizumi Yakumo (Lafcadio Hearn) Lives in Japan Teaches in Matsue and Tokyo University Translates Japanese stories to English (Kwaidan) Was Tim s great, great, great uncle 2

3 Introduction to MTR Japan ~8,000 km 3

4 Introduction to MTR MTR designs, manufactures, and sells membrane systems for industrial gas separations Petrochemicals: Propylene/Nitrogen Hydrogen (Refinery): H 2 /CH 4, CO, CO 2 Natural Gas: CO 2 /CH 4, CH 4 /N 2 NGL/CH 4 Customers include: BP, Chevron, Dominion Exploration, Ercros, ExxonMobil, Formosa Plastics, Innovene, Sabic, Sasol, Sinopec, Solvay, and Statoil. 4

5 The Climate is Changing Muir Glacier, Alaska 63 years later 5

6 Fossil Fuel Use And Atmospheric CO 2 Concentration Are Increasing 6 Slide courtesy of Dr. S. Julio Friedmann, Lawrence Livermore National Laboratory

7 How To Cut Emissions: The Wedge Approach Use multiple CO 2 reduction strategies including CO 2 capture from large sources 8 wedges needed to maintain CO 2 at 500 ppm (each wedge 4 billion tons/y CO 2 ) Japan is world leader in CO 2 emission reductions (Kyoto Protocol 1997) Wedges include: Improved energy efficiency Alternative energy (wind, solar) Nuclear power Efficient biofuels Conservation of natural sinks Carbon capture and sequestration Source: Pacala and Socolow, Science,

8 Power Plants Generate >40% of CO 2 Emissions World CO 2 Emissions by Sector Rules of thumb: Coal power Oil transportation Natural Gas mixed 5,000 coal-fired power plants worldwide Fossil fuel share of electricity generation (IEA WEO 2010): % % Source: International Energy Agency (IEA) (2008), CO2 Emissions from Fuel Combustion, 2008 Edition.

9 CO 2 Capture Options for Fossil Fuel Power All options involve separations where membranes could play a role To use membranes effectively, important to understand the process

10 Pre-Combustion CO 2 Capture Membranes Steam Steam Polymer membranes; CO 2 or H 2 -selective CO 2 comp CO 2 storage 150 bar Coal O 2 Gasifier 55 bar 600 C Syngas Quench WGS reactors 210 C 270 C Syngas cooling 50 bar 40 C CO 2 2-stage Selexol 35 C H 2 ASU Air Dirty, hot syngas Membrane reactors; metal and ceramic membranes H 2 -selective Air N 2 Combustion turbine Increasingly harsh operating conditions 30 bar 195 C Syngas reheat Relatively clean, cool syngas Membrane advantages: simple passive operation, small footprint, no water or hazardous chemicals used, energy efficient - no steam used Hot syngas cleanup membranes offer potential for process intensification

11 H 2 -Selective Membranes Offer Advantages Steam Steam CO 2 comp CO 2 storage 150 bar Coal 55 bar Syngas WGS CO 50 bar Gasifier 2 H 2 membrane Quench reactors O C 210 C C ASU Combustion Air N turbine 2 diluent H 2 + N 2 Air H 2 -selective membrane advantages: Can operate warm/hot to reduce the need for heat exchange Can use nitrogen sweep to maintain permeate fuel gas at turbine pressure Water goes with fuel gas; reduces CO 2 dehydration costs

12 Need Membranes With Good H 2 /CO 2 Selectivity 1,000 Crosslinked modified 100 Upper bound a polyimides c PBI b (250 o C) PBI-based d (mixed gas at 250 o C) Pure-gas H 2 /CO 2 selectivity 10 MTR Proteus (mixed gas at 150 C) ,000 H 2 permeance (gpu) a) Robeson et al., JMS 320, (2008); assumes a 1 μm selective layer. b) O Brien K. et al., DOE NETL project fact sheet 2009; assumes a 1 μm selective layer. c) Low, B.T., et al., Macromolecules 41(4), (2008); assumes a 1 μm selective layer. d) Krishnan, G., 2010 NETL CO 2 Capture Technology Conference, Pittsburgh, PA and Klaehn, J., et al., NAMS 2011, Las Vegas, NV.

13 High Temperature Improves Performance Permeance Trade-off Plot 1,000 MTR Proteus TM H Proteus TM K 383 K Pure-gas permeance (gpu) CO 2 H 2 /CO 2 selectivity K 350 K 300 K 250 K K Temperature ( C) Assumes a selective layer thickness of 0.1 micron ,000 H 2 permeance (gpu) Figure adapted from: B. W. Rowe et al., JMS 360, (2010).

14 Field Tests with Coal-Derived Syngas The National Carbon Capture Center (NCCC) in Wilsonville, Al allows slipstream testing of precombustion and post-combustion capture technologies

15 Field Tests Show Stable Performance Permeance Selectivity 1, C 135 C H Mixed-gas permeance (gpu) C 135 C CO 2 Mixed-gas H 2 /CO 2 selectivity C 135 C Time (days) Time (days) Tests were conducted at the National Carbon Capture Center (NCCC) run by Southern Company The coal-derived syngas feed contained 780 ppm H 2 S

16 Process Economic Analysis With DOE/NETL 16 Collaborated with DOE NETL and WorleyParsons to analyze MTR process Comparison made with Case 2 of DOE Bituminous Baseline report (GEE Gasifier with 2-stage Selexol) Several sulfur handling options considered (cosequestration, warm gas cleanup, etc); post membrane MDEA selected as low cost Membrane process uses 5% less energy and gives a 7% lower cost of electricity compared to Selexol Higher membrane H 2 /CO 2 selectivity would help (particularly up to 40, beyond which diminishing returns)

17 Pre-Combustion Summary H 2 -selective membranes have greater potential than CO 2 -selective membranes for oxy-blown gasifiers because: They can be operated hot (>100 C) so that syngas cooling/water KO equipment and syngas reheat/humidification can be reduced or avoided They can be swept with N 2 available from the ASU to reduce energy requirements They send water to the fuel gas, reducing CO 2 dehydration costs Polymer membranes are low cost and sulfur tolerant a huge advantage Membranes are already competitive with absorption, but better selectivity would lower energy use and cost Not much data on polymer membranes above 100 C significant potential to uncover better materials

18 Post-Combustion CO 2 Capture with Membranes Steam to turbines 600 MW e 500 Nm 3 /s = 1,540 MMscfd flue gas 10 15% CO 2 in N 2 = 10,000 ton CO 2 /day at low pressure Coal Air Boiler ESP FGD Ash Sulfur CO 2 Generating affordable pressure ratio is the key challenge for membranes Limited use for high selectivity because of pressure ratio limitations Volumetric flow is enormous; membranes must have high CO 2 permeance Single-stage membrane process will not give high purity and recovery

19 The MTR CO 2 Capture Process 18 % O 2, 8 % CO 2 CO 2 depleted flue gas 20% CO 2 U.S. Patents 7,964,020 and 8,025, Combustion air sweep provides driving force w/o compression or vacuum Pre-concentrated CO 2 decreases membrane area and power required

20 Promising Membrane Development Pure-gas CO 2 /N 2 selectivity 1, Upper bound (2008) a RITE, NTNU U. Twente (2010) d GKSS (2010) e UT Austin (2006) b ,000 10, ,000 CO 2 permeance (gpu) MTR (2008) c a) Robeson et al., JMS 320, (2008); assumes a 1 μm selective layer. b) Lin et al., JMS 276, (2006); assumes a 1 μm selective layer. c) Merkel et al., ICOM 2008, Honolulu, HI. d) Reijerkerk et al., JMS 352, (2010); assumes a 1 μm selective layer. e) Yave et al., Nanotechnology 21, (2010); and Yave et al., Macromolecules 43, (2010).

21 High CO 2 Permeance Most Important to Reduce Cost Polaris TM 1 CO 2 permeance 1,000 gpu Capture cost ($/ton CO 2 ) ,000 gpu 10 Polaris TM 3 4,000 gpu 0 90% CO 2 capture Pressure ratio = Membrane CO 2 /N 2 selectivity 21 Limited affordable pressure ratio reduces the benefit of high selectivity.

22 1 TPD Test System at NCCC 22 1 TPD system installed Oct/Nov 2011; continuous operation spring 2012

23 Test Results: Modules Are Stable Fresh module After 45 days operation at Cholla Module Number 5839 (Cross-flow) 5879 (Sweep) Normalized CO 2 Permeance After Test Normalized CO 2 /N 2 Selectivity After Test 110% 118% 108% 96%

24 1 TPD NCCC Results: Stream Compositions 100 CO 2 -enriched permeate As expected, membrane enriches CO 2 by about 6 times in the permeate CO 2 content (%) 10 Feed CO 2 -depleted residue Initial low feed CO 2 content due to air ingress Most variation in compositions due to daily temperature swings Overall, membrane module performance is stable ,000 1,500 Operating time (hours) 24 Analyzer malfunction Flue gas outage

25 1 TPD NCCC Results: CO 2 Capture Rate 100 CO 2 capture rate (%) Initially system operating at ~2/3 capacity After 1,000 hours, additional modules loaded to increase capture rate to 85% Operating time (hours) 25 Analyzer malfunction Flue gas outage

26 Next Steps: 20 TPD System Estimate installation at NCCC in 2 nd quarter 2013 Operate system at NCCC for 6+ months; at least 3 months of continuous SS operation System demonstrates large bundled spiral-wound modules 26

27 20 TPD System at NCCC 0.5 MW e pilot solvent test unit Flue Gas Return 1 MW Flue Gas In 27 Picture courtesy of Mr. Tony Wu, Southern Company

28 Future Scale-Up One module skid, 2500 m 2 40 modules plant, 100MW e 27 ft 5.5 ft 64 ft Smaller foot print Low pressure drop Reduced manifolding Lower cost 44 ft 62 ft 28

29 Other Concepts: Sweep-Assisted Hybrids Sweep operation: Increases the CO 2 in the flue gas from 4% to 20% for gas turbines Reduces the quantity of flue gas going into the CO 2 capture unit by a factor of 3 Hybrid design with absorption avoids the use of compression/vacuum equipment

30 Post-Combustion Membrane Summary Energy and cost constraints limit the practical pressure ratio available; high permeance, modest selectivity membranes are preferred A large research effort is producing better membranes Selective recycle is a useful way to pre-concentrate CO 2 Membranes can play a role in post-combustion capture, probably in a hybrid system (cryogenic, amine, etc) Membrane testing is at the small slipstream stage

31 Acknowledgements

32 Acknowledgements MTR Xiaotong Wei, Zhenjie He, Karl Amo, Steve White, Haiqing Lin, Meijuan Zhou, Sylvie Thomas, Richard Baker, Hans Wijmans, Saurabh Pande U.S. Department of Energy, National Energy Technology Laboratory Rick Dunst and Jose Figueroa Southern Company Tony Wu, Frank Morton, and John Wheeldon

33 Effect of Membrane Properties on COE 90 MEA (DOE Case 10) 80 1 st Generation Polaris Change in COE (%) nd Generation Polaris MTR Membrane Process (1.2 Bar Feed) All calculations for 90% CO 2 capture Design uses minimal feed compression (booster fan only) Higher permeance (lower cost) membranes are key to approaching DOE goals 40 Advanced Polaris 30 Higher permeance membranes DOE Target Permeance-normalized membrane cost ($/m 2 gpu)