Pd-alloy membrane development for application in membrane watergas-shift

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1 1 Pd-alloy membrane development for application in membrane watergas-shift in IGCC power plants Rune Bredesen Thijs Peters Marit Stange Trondheim CCS Conference - June 14-16, 2011

2 2 Outline Introduction Pd-alloy membranes Power generation with CO 2 capture Membrane fabrication SINTEF two-step membrane manufacturing method Pd-alloy development Membrane performance evaluation Lab infrastructure H 2 permeation experiments Conclusions and outlook

3 3 Pd-alloy membranes for H 2 separation Versatile enabling technology dp P f P p H H N H N N Power plant N N H H N N with CO 2 capture H H H N N H Large scale H 2 production e.g. for ammonia H Pd-alloy thickness H 2 recovery from process streams H H H H H 2 production H H for filling stations, etc. Integration with fuel cells in small units, e.g. PC Integration in micro technology Membrane surface area (m 2 )

4 4 Power generation with CO 2 capture CO 2 H 2 O+N 2 N 2 N C C CO CO 2 Natural gas ATR WGS Separation H 2 O/O 2 /N H 2 2 H N 2 H 2 Combustion CH 4 + H 2 O/O 2 /N 2 CO 2 + (H 2 + N 2 ) Air Membrane reactor H 2 for combustion Membrane reactor combining processes H 2 H CO 2 2 CO 2 for sequestration H 2 for fuel cells H 2 for ammonia filling stations petrochemicals etc.

2% CO 2 avoidance costs 121 /ton Membrane water gas shift (MWGS)

5 5 Power generation with CO 2 capture Membrane reformer (MREF) lay-out (process 1+2+3) Capture rate 99% The LHV efficiency ~ 46.2% CO 2 avoidance costs 121 /ton Membrane water gas shift (MWGS) lay-out (process 2+3) Capture rate 99% The LHV efficiency ~ 47,1% CO 2 avoidance costs 81 /ton

6 6 Power generation with CO 2 capture Economic summaries of CACHET technologies Pre-combustion CO 2 capture technologies investigated Reference Base-case HyGenSys CLR(s) CLR(a) MREF MWGS SEWGS Efficiency (%) Avoidance rate (%) Cost of avoidance ( /tco 2 ) Cost of capture ( /tco 2 ) Break-even electricity price ( /MWh) Based on SINTEF Pd-alloy membrane performance

production and long-term stability of Pd

7 7 Power generation with CO 2 capture EU-CACHET-II: Hydrogen Production with Membranes Objective Demonstrate H 2 production and CO 2 capture technology by Pd membrane reactors multitube 1 meter membrane module - 8 Nm 3 /h Demonstrate production and long-term stability of Pd membranes Develop improved Pd membranes for application in sour gases and elevated temperatures (>600 C) enabling application in IGCC Partners: BP (coordinator), Technip, SINTEF, ECN, IMR, DICP, NTUA, and PTM Duration: ; Budget: 5.2 M

8 Power generation with CO 2 capture Pd-alloy membranes are attractive for application in NGfuelled power generation cycles with CO 2 capture High flux Pd 77 Ag 23 or pure Pd membranes are conveniently applied This alloy, however, shows large H 2 flux inhibition due to CO and is not stable in synthesis gas containing sulphur due to adsorption and corrosion effects fcc Pd-Ag: large fluxes: no H 2 S resistance and CO inhibition Application of Pd-alloy membranes in IGCC 1. Improvement in H 2 flux of Pd-Cu alloy, or 2. Increase in H 2 S stability of Pd-Ag alloy system 3. Decreasing the inhibition effect of CO Data after McKinley Patents fcc Pd-Cu: showing some H 2 S resistance, but too low flux

9 SINTEF two-step membrane preparation 1 Membrane preparation on Si support by magnetron sputtering Ar-ions high vacuum Pd +Ag Pd +Ag 2 Membrane pull-off from Si support

9 9 SINTEF two-step membrane preparation 1 Membrane preparation on Si support by magnetron sputtering Ar-ions high vacuum Pd +Ag Pd +Ag 2 Membrane pull-off from Si support Pd-Ag target Pd-Ag membrane (a) a) Free standing membranes b) Microchannel supported membranes c) Composite membrane (b) Bredesen R, Klette H, US Patent , 2000 (c)

10 10 SINTEF two-step membrane preparation Manufacturing of 2-5 µm thick composite membranes Factor 5-10 times thinner compared to commercial membranes resulting in higher permeation flux less membrane area needed

11 11 Powerful tool for Pd-alloy development Sputtering basically any composition possible Binary and ternary alloy composition prepared by (co-) sputtering Pd Pd-Cu Pd-Au Pd-TM Pd-Cu-TM Pd-Au-TM Example for Pd-Cu-Ag EDS [wt.%] Pd Ag Cu Pd/Ag Pd/Cu Pd-Cu-Ag Pd-Cu-Ag Pd-Cu-Ag Pd-Cu-Ag Pd-Cu-Ag

$12 Pd-alloy development X-ray diffraction$ membranes SEM: example of Pd-Cu-Ag Single

observed Strong preferential orientation

substituting Pd in the fcc lattice: unit

12 12 Pd-alloy development X-ray diffraction and SEM XRD: example of Pd-TM alloy membranes SEM: example of Pd-Cu-Ag Single phase fcc structure No contaminants observed Strong preferential orientation favouring the <111> direction TM is substituting Pd in the fcc lattice: unit cell is varying, and thus, changing the H 2 solubility and diffusivity 14% Cu 19% Cu 26% Cu 30% Cu 41% Cu 2.0 µm 2.0 µm 2.0 µm 2.0 µm 2.0 µm

13 13 Single gas permeation Function of pressure H 2 /N 2 or H 2 /CH 4 /CO 2 /CO mixtures Function of pressure, concentration WGS mixtures Long-term stability testing Continuously in H 2 /N 2 and WGS Gas, pressure & T cycling H 2 N 2 CH 4 CO 2 CO H 2 O

14 14 Membrane testing in presence of H 2 S Operating conditions Pressure up to 40 bars Temperature to C Gases & analysis N 2,H 2 = 1.5 NL min -1, Ar = 1 NL min -1 CO 2,CO, H 2 O,H 2 S etc.<0.4 NL min -1 MFM for measuring permeate flow GC for permeate composition Ventilation > 0.7 m 3 / s HSE as high priority

15 15 Membrane testing pure H 2 H 2 permeability of various binary and ternary Pd-alloys Membrane thickness ~2-3 µm, T = 400 C, atmospheric pressure Feed: 90% H 2 in N 2 at 1000 ml min -1, Ar sweep at 500 ml min -1

16 16 Membrane testing H 2 /CO mixtures Evaluation of various Pd-alloys for their CO inhibition Membrane thickness ~2-3 µm, T = 400 C, atmospheric pressure Feed: 90% H 2 in N 2 at 1000 ml min -1, Ar sweep at 500 ml min -1 Solely Pd-Y shows an as dramatic H 2 flux inhibition as Pd-Ag Pd 85 Au 15 and BCC Pd 47 Cu 53 alloy show best performance, both in relative as absolute terms

17 17 Membrane testing - H 2 S inhibition H 2 flux inhibition and recovery after H 2 S exposure 1.9 µm Pd 85 Au 15, atmospheric pressure Feed: 1000 ml min -1 90% H 2 in N 2, Ar sweep = 500 ml min -1 ; H 2 recovery % 2 ppm 20 ppm 2 ppm 100 ppm 100 ppm 350 C 20 ppm 450 C Large decrease in H 2 flux after H 2 S introduction: larger reduction at higher H 2 S concentration and lower temperatures Slow recovery after H 2 S removal nearly full recovery observed at T = 450 C after all above-mentioned exposure, the H 2 flux can be recovered up to 95 % Exposure needs to be expanded to more realistic gas mixtures, like WGS

18 18 Permeability and H 2 S exposure of Pd 85 Au 15 Long-term stability of Pd 85 Au 15 in H 2 /N 2 and (sour) WGS 1.9 µm Pd 85 Au 15, T = 450 C, atmospheric pressure Feed: 125 ml min -1, Ar sweep = 50 ml min -1 ; H 2 recovery ~ 40 % WGS-1 [%] H 2 62 CO 4 CO 2 14 H 2 O 20

Post-process characterisation of Pd 85 Au 15 SEM showing Pd

membrane surface XPS on Pd 85 Au 15 No large segregation

membrane S content can explain the somewhat decrease in H 2

19 Post-process characterisation of Pd 85 Au 15 SEM showing Pd 85 Au 15 after long-term stability study Feed side 5.0 µm 2.0 µm 1.0 µm 1.0 µm Signs of minor pinhole formation detected on the membrane surface XPS on Pd 85 Au 15 No large segregation effects observed Minor S concentrations detected at exposed membrane S content can explain the somewhat decrease in H 2 flux XPS [Pd] [Au] Feed side Permeate side As-prepared feed side As-prepared permeate side

20 20 Conclusions and outlook Membrane manufacturing Pd, Pd-Cu, Pd-Au, Pd-TM, and Pd-Cu-TM prepared by magnetron sputtering demonstrating the high flexibility and versatility of the fabrication method developed by SINTEF More than 50 binary/ternary Pd-alloys prepared so far H 2 permeability of Pd-alloys For some Pd-X a larger flux is obtained compared to pure Pd Permeability of fcc Pd-Cu alloys improved with factor of up to 100 % H 2 S poisoning and stability of Pd-alloy membranes Pd-Au is considered the state-of-the-art for application in sour gases Pd-Au alloys still largely poisoned by H 2 S at [H 2 S] > 20 ppm No membrane failure of Pd 85 Au 15 after 1600 h including 600 h of H 2 S flux needs improvement Screening of less conventional Pd-alloys underway

21 Acknowledgements EU-7FP CACHET-II project (Contract no.: ) RCN-Renergi (Project No: /S60) Thomas Kaleta, Marit Stange, Rune Bredesen at SINTEF

Development of Pd Cu Membranes for Hydrogen Separation

Development of Pd Cu Membranes for Hydrogen Separation Shahrouz Nayebossadri, John Speight, David Book School of Metallurgy & Materials University of Birmingham www.hydrogen.bham.ac.uk The Hydrogen & Fuel