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RTI International
RTI International is a trade name of Research Triangle Institute. www.rti.org
Advanced Solid Sorbents and Process Designs for Post-Combustion CO2 Capture (DE-FE0007707)
RTI InternationalAtish Kataria, Paul Mobley, Thomas Nelson, Mustapha Soukri, Jak Tanthana
Pennsylvania State UniversityChunshan Song, Dongxiang Wang, Xiaoxing Wang
2016 NETL CO2 Capture Technology Meeting
Copyright © 2016 RTI. All rights reserved.
August 11, 2016
RTI International Project Overview
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ObjectiveAddress the technical hurdles to developing a solid sorbent-based CO2 capture process by transitioning a promising sorbent chemistry to a low-cost sorbent suitable for use in a fluidized-bed process
This project combined previoustechnology development efforts:RTI (process) and PSU (sorbent)
$
Period of Performance:• 10/1/2011 to 12/31/2015
• Project management• Process design• Fluidized-bed sorbent
• PSU’s EMS Energy Inst.• PEI and sorbent
improvement
• Masdar New Ventures• Masdar Institute• TEA of NGCC
application
RTI International Solid Sorbent CO2 Capture
Advantages• Potential for reduced energy loads and
lower capital and operating costs• High CO2 loading capacity; higher
utilization of CO2 capture sites• Relatively low heat of absorption; no
heat of vaporization penalty• Avoidance of evaporative emissions• Superior reactor design for optimized
and efficient CO2 capture performance
Challenges• Heat management / temperature control• Solids handling / solids circulation control• Physically strong / attrition-resistant• Stability of sorbent performance
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70ºC 110ºC
Primary: CO2 + 2RNH2 ⇄ NH4+ + R2NCOO-
Secondary: CO2 + 2R2NH ⇄ R2NH2+ + R2NCOO-
Tertiary: CO2 + H2O + R3N ⇄ R3NH+ + HCO3-
Sorbent Chemistry (PEI)
Technology Features• Sorbent: supported polyethyleneimine• Process: fluidized, moving-bed
RTI International Technical Approach & Scope
Prototype Testing (2015)PrototypeTesting Milestone: Operational prototype capable of 90% CO2 capture Milestone: Completion of extensive parametric and long-term
testing campaigns
Updated Economics Milestone: Favorable technical, economic, environmental study
(i.e. meets DOE targets)
Proof-of-Concept / Feasibility
Laboratory Validation (2011 – 2013)Economic analysis Milestone: Favorable technology feasibility study
Sorbent development Milestone: Successful scale-up of fluidized-bed sorbent
Process development Milestone: Working multi-physics, CFD model of FMBR Milestone: Fabrication-ready design and schedule for
single-stage contactor
Pilot0.5 - 5 MW (eq)
Demo~ 50 MW
Commercial
Previous Work RTI’s Project Future Development< 2011 2011-15 2016 - 18 2018-22 > 2022
Relevant Environment Validation (2013 – 2014)
Process development Milestone: Fully operational bench-scale FMBR unit capable of absorption / desorption operation Milestone: Fabrication-ready design and schedule for high-fidelity, bench-scale FMBR prototype
Sorbent development Milestone: Successful scale-up of sorbent material with confirmation of maintained properties and performance
8 97654
2 31
Technology Readiness Level
RTI International Test Equipment – PBR and vFBR
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Packed-bed Reactor
“visual” Fluidized-bed Reactor
• Fully-automated operation and data analysis; multi-cycle absorption-regeneration
• Rapid sorbent screening experiments• Measure dynamic CO2 loading & rate• Test long-term effect of contaminants
• Verify (visually) the fluidizability of PEI-supported CO2 capture sorbents
• Operate with realistic process conditions• Measure P and temperature gradients• Test optimal fluidization conditions
RTI International Sorbent Development & Scale-upObjective Improve the thermal and performance stability and production cost of PEI-based
sorbents while transitioning fixed-bed MBS materials into a fluidizable form.
PEI-impregnated Silica (“Gen1”)• Stability improvements through addition of
moisture and PEI / support modifications.• Suitable low-cost, commercial supports
identified (1000x cost reduction).• Converted sorbent to a fluidizable form.• Optimized Gen1 sorbent through: solvent
selection; drying procedure; PEI loading %; regeneration method; support selection; etc.
Co-Precip Amine/Silica (“Gen2”)• Extremely stable sorbent, high CO2 loadings (10
- 14 wt%).• Key benefits: stability in liquid water, high CO2
loadings, tailoring potential, diverse applications• Challenges: density, physical strength, cost• Mixed results with most promise identified in
the use of blended amines and templates
RTI International Sorbent Scale-upInitial Scale-up (150 kg)• 30 wt% PEI on commercially-available silica• Scaled-up sorbent matches performance and properties of lab sorbent
Amount PEI loading
CO2Capacity FBR test PSD
Lab Sorbent 100+ g 30 % 8.5 wt% Pass 75 – 250 um
Scaled-up Sorbent 150 kg 30 % 8.9 wt% Pass 80 – 250 um
Sorbent Make-up Batch (100 kg) – following Oxidative Degradation• Improved silica selection, optimized PEI loadings• 6 months of bench-scale testing exhibited little to no
degradation
Scale-up Batch (100 kg) – made for RTI’s project with Norcem (cement application)• Improved commercial preparation• Sorbent exhibits improved CO2 capture performance
RTI International RTI’s Bench-scale Prototype SystemSpecifications
• Flue gas throughput: 300 and 900 SLPM • Solids circulation rate: 75 to 450 kg/h• Sorbent inventory: ~75 kg of sorbent• Adsorber temperature range: 40 - 90˚C• Regenerator temperature range: 100 - 130˚C• Heat exchange fluids: CW in Adsorber; Steam in Regenerator• Footprint / Height: 15’ x 5’ / 35’ H• Pneumatic conveying of sorbent (Regen Adsorber)• Sorbent circulation rate controlled and monitored by
measurement of the riser pressure drop
FG Compositon
CO2 H2O N2
15 vol% 3 vol% Balance
Operational improvements• Optimized loop seal aeration to maximize solids circulation• Eliminated static electricity build-up which caused agglomeration• Added pneumatic vibrators to downcomers, improving circulation • Modified gas entrance arrangement to primary cyclone and added
secondary cyclone to improve sorbent recovery• Added larger downcomers for additional circulation reliability• Full system reconfiguration:
• Original configuration: 4-stage Ads, 1-stage Regen• Reconfiguration to 2-stage Ads, 2-stage Regen
RTI International Bench-scale System – Baseline Testing
0%
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CO2
capt
ure,
%
Stage-1 Stage-2 Stage-3 Stage-4
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2.25
2.5
2.75
3
3.25
3.5
3.75
4
2 2.25 2.5 2.75 3 3.25 3.5 3.75 4
Expe
rimen
tally
mea
sure
d re
gene
rato
r hea
t dut
y,
MJ/
kg-C
O2
Calculated regenerator heat duty, MJ/kg-CO2
0
0.5
1
1.5
2
2.5
3
3.5
0 0.5 1 1.5 2 2.5 3 3.5
Expe
rimen
tally
mea
sure
d co
olin
g du
ty, k
Wth
Calculated cooling duty, kWth
CO2 Mass Balance CO2 Capture Efficiency
Regen Heating Duty Ads. Cooling Duty
Good correlation between calculated and experimentally measured heating and cooling duties (within +/- 10%)
RTI International Oxidative Degradation
ChallengeScaled-up sorbent was observed to have a steady decline in the sorbent’s CO2 capacity over several hundred hours of testing. CO2sorption capacity was impacted while fluidizability and other key physical parameters remained unaffected.
Potential Degradation Pathways
• PEI-leaching• Dry flue gas• Dry stripping gas• Exposure to oxygen• Combination of the
conditions listed above.
• A Design of Experiments (DoE) study was implemented and a half factorial test campaign for five parameters
Conclusions
• Two most important factors: O2 concentration (i.e. exposure to O2) and the temperature at which O2 exposure occurs
• 3rd factor (absence of H2O in stripping gas), important but is reversible• Sorbent O2 exposure at < 70˚C is acceptable• Sorbent cooler is recommended when conveying with air
RTI International Reactor Staging
Bench system reconfiguration• Removed bottom two adsorber stages which do not
participate in CO2 capture but act as dead/inert volume• 2-stage Adsorber, 2-stage Regenerator
• Reactor staging required to maximize performance; well-mixed single-stage reactors limit achievable rich and lean loadings
• Adsorber: equilibrium loading calcs and experimental observations suggest 2 stages are sufficient
• Regenerator: 2 stages, minimum required
RTI International Bench-scale Prototype Testing
S/G Ratio Adsorber Temp FG Velocity
Highlights of prototype testing• Cumulative testing: 1,000+ circulation hours;
420+ CO2 capture hours.• The sorbent is capable of rapid removal of
CO2 from the simulated flue gas• Sustained 90% capture of the CO2 in
simulated flue gas stream is easily achieved• Collected a wealth of performance data,
identified how system performance varies due to process variables, and proved the reliable nature of bench-scale testing
RTI International Bench-scale Prototype Testing
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Highlights of prototype testingHeat Management• Complicated by large heat losses to environment• Able to demonstrate superior CO2 capture
performance with heat managementOperating Parameters• Able to quantify system response and
performance due to changing parameters• Able to identify optimal conditions, balancing
performance with other economic factors:• 70˚C Absorber temperature• 120˚C Regen temperature• > 1 ft/s FG velocity• Higher S/G ratios better, but energy and footprint
impacts taken into account• Performance at a range of FG CO2
concentrations was quantified Sorbent Stability• CO2 capacity stable between 8.5 – 9.0 wt% CO2
loading after 6 months of testing• Thermal and oxidative degradation avoided
RTI International Long-term Performance Testing
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Long-term testing• 100+ hr continuous testing, maintaining the
performance target of 90% CO2 capture while varying sorbent circulation rate
• Sorbent maintained CO2 working capacity between 4 and 7 wt.%
• Desired set points for all process conditions and reactor settings were tightly controlled
• Robust nature of system proven
Other Observations / Lessons• Attrition-resistance of sorbent is evident
from similar PSD for used sorbent, fines collection rate and no sorbent make-up
• Sorbent maintains excellent hydrodynamic / fluidization properties
• Good approach-to-equilibrium achieved in all reactor stages
• Quality data collected allowing for revision of economic analysis assumptions
CO2 Capture Efficiency
Sorbent Working Capacity
RTI International Updated Economic Analysis
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Summary• Basis: DOE/NETL’s Cost and Performance
Baseline for Fossil Energy Plants – updated with lab and bench-scale test data
• Total cost of CO2 captured ~ 45.0 $/T-CO2
• 43.3 $/T-CO2 achievable through use of unproven spent sorbent scrubbing strategy
• Still represents > 25% reduction in cost of CO2capture, significant energy and capital savings compared to SOTA aqueous amine solvents
Main Factors impacting TEA• Sorbent Cost• CO2 content in Regenerator• Sorbent working capacity• Regeneration temperature
Pathway to Cost Reductions• Adsorber/Regenerator Design• Heat recovery and integration• Sorbent stability and cost
Breakdown of Main Contributors to Cost of CO2 Captured
Preliminary Analysis
RTI International Updated Economic Analysis
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Summary• Basis: DOE/NETL’s Cost and Performance
Baseline for Fossil Energy Plants – updated with lab and bench-scale test data
• Total cost of CO2 captured ~ 45.0 $/T-CO2
• 43.3 $/T-CO2 achievable through use of unproven spent sorbent scrubbing strategy
• Still represents > 25% reduction in cost of CO2capture, significant energy and capital savings compared to SOTA aqueous amine solvents
Main Factors impacting TEA• Sorbent Cost• CO2 content in Regenerator• Sorbent working capacity• Regeneration temperature
Pathway to Cost Reductions• Adsorber/Regenerator Design• Heat recovery and integration• Sorbent stability and cost
Breakdown of Main Contributors to Cost of CO2 Captured
Preliminary AnalysisUpdated Analysis
RTI International Technology Roadmap
TCWS
TCWR
TCWS
TCWR
TCWS
TCWR
Flue Gas from Deep Desulfurization Wash
G [kg/h]
CO2 Absorber CO2-leanSorbent Feed
CO2-richSorbent Exit
S [kg/h]
Treated Flue Gas
2008 2025 2015 201820132011
Scale
Concept
Commercial / DemoBridge to Pilot Testing
Knowledge Gained:• Lessons learned from
bench-scale testing• Optimal process design
and operating conditions• Sorbent scale-up and
optimization
Additional Work:• More extensive
performance testing• Testing in flue gas• Application to multiple
CO2 sources• Sorbent cost reduction
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RTI International RTI-Norcem – Cement Plant Application
Objective Demonstrate the technical and economic feasibility of RTI’s advanced, solid sorbent CO2 capture process in an operating cement plant
Period of Performance:• 5/1/2013 to 12/31/2016
Two Phases
Phase I – Feasibility Review – Complete• Sorbent exposure to actual cement plant flue gas• Economic evaluation• Commercial design for cement application
Norcem’s Brevik Cement Plant(Source: Norcem)
Phase II – Demonstration – In Progress• Design, build, and test a prototype of RTI’s solid
sorbent CO2 capture technology• Evaluate CO2 capture performance• Update economics with pilot test data
RTI International Progress and Lessons Learned
RTI’s Lab-scale Test Unit in Norway
Economics• Economic indicators of 38 – 46
€/t-CO2 avoided show RTI’s technology is economically competitive in CO2 capture field
• RTI’s technology is a good candidate for waste heat utilization
Testing• Evaluated sorbent
performance with actual cement flue gas
• No critical failure in performance over 300+ cycles. Achieved desired capacities
Pilot Design• Design and engineering
leveraged lessons learned on DOE-funded project
• Process Hazard Analysis
• Install complete18
RTI International Phase II – Prototype Testing at Norcem
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Test site in 2014
FG Stack
Reactor Columns
System Enclosure
Blower
Caustic Scrubber
Gas Analysis “House”
RTI Prototype• Completed: Design, Engineering,
Construction, Shipment, Installation, Commissioning, and Training
• Baseline and Parametric testing currently underway at Norcem’s cement plant
• Parametric and long-term performance testing planned through Nov 2016
RTI International Project OutcomesAddressing Technology Challenges
• Heat management: Proved critical need for FMBR design through engineering analysis, lab-, and bench-scale testing
• Heat management technique in Bench system mimics commercial design• Solids handling: improved sorbent working capacities, fluidizable material,
and staged design reduce solids handling requirements• Bench testing provided correlations to flow control, pressure balancing• Physical strength: Bench testing proved excellent physical strength of
fluidizable sorbent – very little attrition losses• Performance stability: Excellent stability exhibited in bench testing• Sorbent now has thermal-, chemical, and leaching-stability
Sorbent Development
Economics
Process Development
Bridge to Pilot Testing• Bench testing, lab screening, and modeling collected critical
process design data for pilot design and detailed TEAs• Economics are attractive with pathway to meet DOE goalls• Sorbent manufacturing has been optimized – “Gen1” sorbent is
viable path forward; Gen2 sorbents exhibit great potential• Expanding potential market application through cement plant
testing and NGCC evaluations• Detailed economic assessments highlight areas for improvement:
• Expanded data collection, novel heat integration, sorbent cost, sorbent working capacity, further staging studies
Technology Challenges• Heat management / temperature control• Solids handling / solids circulation control• Physically strong / attrition-resistant• Stability of sorbent performance
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RTI International Acknowledgements
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• The U.S. DOE/National Energy Technology Laboratory• Bruce Lani• Lynn Brickett• John Litinski
• Masdar (Abu Dhabi Future Energy Company)
Funding provided by:
• DeVaughn Body• Luke Coleman• Justin Farmer• Ernie Johnson• Marty Lail• Martin Lee• Pradeep Sharma• JP Shen
• Xiao Jiang• Wenying Quan• Siddarth Sitamraju• Wenjia Wang• Tianyu ZhangRTI Team
PSU Team
MasdarTeam
• Alexander Ritschel• Mohammad Abu Zahra• Dang Viet Quang• Amaka Nwobi