Post on 26-Aug-2018
transcript
Novel Polymer Membrane Process For Pre-Combustion CO2 Capture From
Coal-Fired Syngas
Tim Merkel, Sylvie Thomas, Meijuan Zhou,
Haiqing Lin and Adrian Serbanescu
Membrane Technology and Research, Inc.
2010 NETL CO2 Capture Technology Meeting September 17, 2010
www.mtrinc.com
Project Overview
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Award number #: DE-FE0001124Project period: 9/15/09 to 9/14/11Funding: $950k DOE; $150k MTR and $ 90k Tetramer TechnologiesDOE program manager: Richard DunstProject team:MTR --- membrane and process development
Tetramer Technologies --- specialty polymer synthesisSouthern Company NCCC --- field test
Project scope: The goal of this project is to develop a new polymer membrane and membrane separation process that will provide cost-effective CO2management in future coal-based IGCC power plants.
MTR
Southern
Tetramer
Project Objectives
Membrane development• High-temperature stable polymers for use in H2/CO2
• Composite membranes that have H2/CO2 >10 and H2 permeance >200 gpu at syngas cleanup temperatures (100-200oC)
Membrane performance evaluation• Evaluate membrane performance and lab-scale membrane
modules using simulated syngas
• Evaluate membrane stamps in the field using coal-fired syngas
Process design analysis• Optimize membrane process designs and assess the optimal
integration of a membrane system
• Perform a cost analysis of the polymer membrane process vs. current cleanup technologies, e.g., Selexol3
55 bar
600°C
Membrane Options for Syngas Cleanup
• Hot syngas cleanup membranes offer the potential for process intensification• Warm/cool syngas cleanup membranes offer fewer operating challenges
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GasifierCoal CO2
O2
SyngasQuench
WGSreactors
Steam
ASU
Air
CO2comp
Combustionturbine
210°C 270°C
Syngas cooling
H235°C
2-stageSelexol™
Syngas reheat
40°C
195°C
50 bar
30 bar
150 barCO2storage
N2
Steam
1. Ciferino, J. and Marano, J, “Novel Integration of Gas Separation Membranes for CO2 Capture from IGCC Power Plants,”presented at AIChE New Orleans, April 2008.
55 bar
600°C
Membrane Options for Syngas Cleanup
• Hot syngas cleanup membranes offer the potential for process intensification• Warm/cool syngas cleanup membranes offer fewer operating challenges
5
GasifierCoal CO2
O2
SyngasQuench
WGSreactors
Steam
ASU
Air
CO2comp
Combustionturbine
210°C 270°C
Syngas cooling
150 barCO2storage
N2
Steam
30 bar
H2 membrane150-250°C
50 bar
1. Ciferino, J. and Marano, J, “Novel Integration of Gas Separation Membranes for CO2 Capture from IGCC Power Plants,”presented at AIChE New Orleans, April 2008.
55 bar
600°C
Membrane Options for Syngas Cleanup
• Hot syngas cleanup membranes offer the potential for process intensification• Warm/cool syngas cleanup membranes offer fewer operating challenges
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GasifierCoal CO2
O2
SyngasQuench
WGSreactors
Steam
ASU
Air
CO2comp
Combustionturbine
210°C 270°C
Syngas cooling
150 barCO2storage
N2
Steam
30 bar
H2 membrane150-250°C
50 bar
5 bar
1. Ciferino, J. and Marano, J, “Novel Integration of Gas Separation Membranes for CO2 Capture from IGCC Power Plants,”presented at AIChE New Orleans, April 2008.
H2 + N2
Pros and Cons of Membranes for Syngas Cleanup
Advantages:
• Simple design; small footprint
• Energy efficient compared to sorption processes
• No water used; no leakage or disposal of chemical solvents
Challenges:
• Membrane reactor for hot/warm gas cleanup --- difficult operating conditions, stability in presence of contaminants
• Inorganic membranes --- lack of reproducible, low-cost module fabrication technology
• Polymer membranes --- thermal stability of membrane materials for hot/warm gas cleanup
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New high-temperature membranes show promising performance
1. O’Brien K. et al., “Fabrication and Scale-Up of PBI - Based Membrane System for Pre-Combustion Capture of Carbon Dioxide,” DOE NETL project fact sheet 2009.
2. Low, B.T., et al., “Simultaneous Occurrence of Chemical Grafting, Cross-linking, and Etching on the Surface of Polyimide Membranes and Their Impact on H2/CO2 Separation,” Macromolecules 41(4),1297-1309 (2008).
Permeance conversions:
1 gpu = 10-6 cm3(STP)/(cm2 s cmHg)
1 ft3(STP)/(h ft2 psi) = 1,600 gpu
10-6 mol/(m2 s Pa) = 3,000 gpu
10-2 mol/(m2 s bar) = 300 gpu
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0.
1
10
100
1 10 100 1,000
Upper bound
H2 permeance (gpu)
H2/CO2
selectivity
MTR Proteus TM
mixed-gas; 150°C
PBI (2500C)1
Amine modified PI 2
Membrane performance has improved significantly
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0
5
10
15
20
0 200 400 600 800 1000
H2/CO2 Selectivity
H2 Permeance (gpu)
Target (200, 10)
Initial performance
2nd quarterperformance
3rd quarterperformance
1st quarterperformance
150°C
Mixed-gas performance at 50 psig, 150°C with a 50%/50% H2/CO2 mixture
Key objectives are to• Examine membrane performance with real syngas, including gases difficult to
study in the lab (CO, H2S)
• Investigate the membrane performance, stability and, if degradation occurs, try to identify mechanisms
Two types of membranes were tested• CO2-selective Polaris modules (tested at 40°C, 165 -190 psia)
• H2-selective Proteus membranes (tested at 120°C or 135°C, 165 – 190 psia)
Total of three field tests to date; each test lasted 3 to 6 weeks• November 2009, April 2010 and August 2010
Two types of syngas streams were provided • Unshifted syngas: 10%H2, 69%N2, 1%CH4, 7%CO, and 13%CO2
• Shifted syngas: 13%H2, 69%N2, 1%CH4, 2%CO, 15%CO2 and 780ppm H2S.
Field Tests at the National Carbon Capture Center (NCCC)
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1
10
100
1,000
0 5 10 15 20
Mixed-gaspermeance
(gpu)
Time (days)
CO2
H2
Permeance Selectivity
NCCC Results 1: Stable Performance with Desulfurized Syngas
Tests were conducted on membrane stamps (area = 30.2 cm2) with a coal-derived syngas mixture at 150 psig and 135°C. Average H2 permeance = 260 gpu and H2/CO2selectivity = 16.
0
5
10
15
20
25
30
35
40
0 5 10 15 20
Time (days)
H2/CO
2
selectivity
135°C
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NCCC Results 2: Stable Performance with High Sulfur Syngas
1
10
100
1,000
0 5 10 15 20 25
Mixed-gas permeance
(gpu)
Time (days)
CO2
H2
135°C120°C
120°C
135°C
0
5
10
15
20
25
30
35
40
0 5 10 15 20 25
Time (days)
Mixed-gas H2/CO2
selectivity
120°C
135°C
Permeance Selectivity
Tests were conducted on membrane stamps (area = 30.2 cm2) with a coal-derived shifted syngas mixture at 175 psig and 120°C or135°C.
H2 content was enriched from ~10% to ~60 – 80%. H2/gas selectivities (CH4, N2, CO and H2S) are higher than H2/CO2.
Current membranes show potential to approach the DOE LCOE target
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5
10
15
20
25
30
0 10 20 30 40 50 60
Increase in LCOE
(%)
Membrane H2/CO2 selectivity
90% CO2 capture
300 gpu
600 gpu
900 gpu
H2 permeance
DOE target
Calculations are for shifted syngas from a GE gasifier (case 2 in the DOE Bituminous Coal Baseline Report).
Selexol™ installation and contingency factors were used for the membrane cases.
Base case
SelexolTM
Milestones
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Confirmed that composite membranes made from novel polymers give hydrogen permeances of at least 200 gpu and H2/CO2 selectivities of greater than 10 in bench-scale tests as well as in field tests.
Completed scale up of composite membranes on a commercial coater.
Identified the membrane performance requirement in order to meet the DOE program targets. Determined the overall technical and economic competitiveness of the proposed process as compared to alternative technologies.
Develop bench-scale membrane modules and demonstrate module performance and lifetime consistency with small-scale membrane stamp studies.
Lab-scale module development is on-going
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Lab-scale prototype module: 12’’ length with a membrane area of 0.14 m2
Module components were stable after cycling from 20 to 160°C
Module housing
Lab-scale prototype module
Project timeline: original
Sept 2009 Sept 2010 Sept 2011
Composite membrane development
Membrane process design and optimization
Membrane optimization and scale up
Lab-scale module development
Stamp field test @ Southern
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Sept 2009 Sept 2010 Sept 2011
Composite membrane development
Membrane process design
Lab-scale module development
Stamp field test @ Southern
Membrane optimization scale-up
Project Timeline: update
Module development
Module field test @ Southern
Improve membrane selectivity
All milestones achieved18
Next Steps toward Commercialization
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Improve membrane performance
Develop commerical-scale modules
Evaluate long-term high temperature stability
Test membrane modules
at NCCC in 2011
→ 50 lb/h syngas run
→ 500 lb/h syngas run
Summary
Bench and field tests show that the performance of MTR Proteus™ membranes exceeds the project targets.
NCCC field results demonstrate the membrane performance is stable at high temperature treating coal-derived syngas containing up to 780 ppm H2S.
Average field performance gives a mixed-gas H2/CO2selectivity of 15-25, and a hydrogen permeance of 150-300 gpu at 120-150°C.
Current membrane performance yields an increase in LCOE of ~15%. Higher H2/CO2 selectivity and higher H2permeance are both needed to achieve DOE LCOE targets.
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