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www.rti.orgRTI International is a registered trademark and a trade name of Research Triangle Institute.
Non-Aqueous Solvent CO2 Capture Process
S. James Zhou, Jak Tanthana, Paul Mobley, Aravind Rabindran, Mustapha Soukri, Vijay
Gupta, Thomas Gohndrone, Markus Lesemann, and Marty Lail
Andrew Tobiesen, Thor Mejdell, Ugochukwu E. Aronu, Andreas Grimstvedt,
Kai Hjarbo, Lars Hovdahl
TRONDHEIM, NORWAY
June 12 - 14, 2017
9TH TRONDHEIM CONFERENCE ON CO2 CAPTURE,
TRANSPORT AND STORAGE
Presentation Overview
▪ Overview and Objectives
▪ Summary
▪ Results and Discussion
▪ Next Steps / Technology Development Pathway
2
Overview and Objectives
Objective: Continue the advancement of the
NAS CO2 Capture Process
• Increase solvent performance
• Design and build unique process modifications for
Non-aqueous solvent
• Perform pilot testing of NAS on coal-derived flue gas
• Techno-economic and EHS evaluation
3
Path to Reducing ICOE and
Cost of CO2 Avoided▪ Primarily focus on reducing energy
consumption – reboiler duty
▪ Reduce capital expenditure
▪ Simplify process arrangement
▪ Materials of construction
▪ Limit operating cost increase
R&D Strategic Approach
41 Rochelle, G. T. Amine Scrubbing for CO2 Capture. Science 2009, 325, 1652-
1654.
Breakdown of the Thermal Regeneration
Energy Load
Sensible
Heat
Heat of
Vaporization
Heat of
AbsorptionReboiler
Heat Duty
SolventCp
[J/g K]
Dhabs
[kJ/mol]
Dhvap
[kJ/mol]
Xsolv
[mol solv./
mol sol’n]
Da
[mol CO2/
mol solv.]
Reboiler Duty
[GJ/tonne CO2]
MEA (30%) 3.8 85 40 0.11 0.34 3.22
Lower Energy
Solvent System
NAS 1.3 65 1 0.3 0.3 1.71
For NAS, heat of vaporization of water
becomes a negligible term to the heat duty
Process capable of achieving these criteria
will have a lower energy penalty than SOTA
processes
Oper.
11%
Power
56%
Capital
33%
NAS Process
5
Wash
Section
Wash
Section
Exhaust
Gas
Interstage
Coolers
Flue
Gas
Feed
Gas
Filter
Absorber
Solvent
Make Up
Lean Amine
Cooler
Condenser
Interstage
Heaters
Reboiler
CO2 Product
Gas
Knock-Out
Drum
Rich/
Lean HX
Bench Scale Test Unit Results
6
RTI non-aqueous solvents showing substantially reduced reboiler heat duties
Reb
oil
er H
eat
Du
ty (
GJ/T
-CO
2)
L/G (mass/mass)
Experimental Reboiler Duty Data
7
Conditions for Experimental Data • Absorber: 37-40°C
• Regenerator: 87-98°C
• Pressure: 2.5 bar
• Interstage Heater Regeneration
Reb
oil
er H
eat
Du
ty (
GJ/T
-CO
2)
L/G (mass/mass)
Specific Reboiler Duty Comparison
8
0
0,5
1
1,5
2
2,5
3
3,5
4
MEA KS-1 Shell Cansolv DC-103
RTI NAS-5
SR
D (
GJ/T
-CO
2)
(SaskPower)(Petra Nova Carbon
Capture Project)
36 – 42%
Reduction
Ref. for KS-1 Ref. Cansolv DC-103
Small-Pilot Testing with Coal-fired Flue Gas at SINTEF
9
• Compare MEA and NAS in
conventional system
• Water balance
• Confirm reboiler heat duty
• Emission measurement
• MEA baseline testing completed at Tiller plant
• NAS baseline testing completed
• 400 hours of testing with propane+coal flue gas
• Confirmed the reduction in reboiler duty
Objective: • Design and build unique process modifications for
SINTEF’s Tiller plant
• Demonstrate RTI NAS process on coal-derived flue gas
• Finalize NAS solvent formulations
• Techno-economic and EHS evaluation
MEA/H2O Baseline Testing at Tiller (Reboiler heat duty)
30 wt% MEA baseline testing at Tiller. 14 steady-state runs with varied parameters:• Liquid circulation rate
• Heat rate (MJ/kg CO2)
• Inlet gas humidity
• Intercooling
• Absorber packing height
• CO2 capture efficiency
• Flue gas velocityR
eboil
er H
eat
Du
ty (
GJ/T
-CO
2)
10
MEA/H2O Baseline Testing at Tiller (CO2 capture rate)
11
NAS Baseline Testing in SINTEF’s Tiller Plant
Temperature profiles for NAS-3 baseline testing at SINTEF’s Tiller Plant
12
NAS Baseline Testing Results at Tiller
13
Tiller Run 18 Run 22
Date 12.01.2017 16.03.2017
Hour 06:50-07:50 16:00-17:00
Solvent NAS NAS
Source Mimicked Coal Coal
Gas inlet ABS 110.0 110.0
CO2 inlet ABS 14.87 14.42
CO2 outlet ABS 1.832 0.659
CO2 recovery 89.3 % 96.1 %
Liquid inlet Absorber 18.00 18.00
L/G ratio 8.5 8.4
Lean amine (tit) 2.695 2.348
Lean Loading 0.121 0.074
Rich Loading 0.273 0.290
Water Lean 7.9 6.841
Temp Liq Reboiler 99.3 104.8
Desorber press top 100.68 97.08
Reboiler duty 17.82 17.80
Preheat rich flow 2.53 2.53
SRD (w/ heat loss) 3.06 2.90
Temp Gas outlet
DCC 24.7 23.7
Temp Lean amine
inlet 34.8 34.9
Temp Intercooling 38.1 38.7
Mimicked coal flue gas using propane burner
flue gas (runs 18, and 22 respectively)
SRD with account of heat loss amounts to
about 2.8 GJ/t, assuming 1.5kW loss in the
hot lines.
In the coming months, several modifications
will be made at Tiller to run NAS under
optimum conditions
It is expected that the Tiller plant
modifications will bring the SRD further down
(next slide).
NAS-Specific Components for SINTEF Plant
14
Customized changes for the NAS solvents
Installation of:
• Two additional absorber inter-coolers (total of three intercoolers)
• Improved water-wash (additional water wash section)
• Two custom made regenerative "inter-heaters"
• One additional cross-flow heat exchanger (that can work in series, or bypass, with the
current).
Improved solvent:
• To run NAS-5, capable of operating with lower L/G ratios.
Plant modification to Tiller is expected to be completed by mid
September 2017.
Developed rate-based process model
Aspen ENRTL-SR
Thermodynamic and physical
properties acquired experimentally:• Henry’s constant for CO2
• Liquid heat capacity
• Vapor pressures
• Reference state properties
• Heat of vaporization
• Dissociation constants
• VLE
• Density
• Dhabs
• Viscosity
• Surface tension
• Thermal conductivity
• Dielectric constant
• Diffusivity of CO2
Used process model to direct bench-
scale testing after initial runs
Process Modeling
15
Next Steps: Large Pilot Testing
• Large pilot testing for non-aqueous solvent technology targeted for 2018+
• ~ 1 - 10 MW equivalent
• Range of flue gas compositions (including coal, NGCC, etc)
• Extended operation with finalized NAS formulation and process design
• Technology Center Mongstad and U.S. National Carbon Capture Center
are potentially suitable sites
16CO2 Technology Centre Mongstad (TCM), Mongstad, Norway National Carbon Capture Center (NCCC), Alabama, USA
17
Leveraging the U.S. – Norway Collaboration Framework
Pilot Testing at SINTEF
Tiller Plant
(Norway, 2015-2018)
Demonstration of all process
components at in adiabatic
system pilot scale (~60 kWe)
• Quantify solvent losses and
emissions
• Test campaign on coal derived
flue gas
• Collect critical process data to
support scale up, develop
engineering package
RTI Novel CO2 Solvents
Large, Bench-Scale
System
(RTI Facility, 2014-2016)
Demonstration of key
process features
(≤ 2.0 GJ/T-CO2)
• Optimize NAS formulation
• Develop critical process
components
• Detailed solvent
degradation and
preliminary emissions
studies (SINTEF
NASCHAR project)
• Detailed TEA and EH&S
assessments
Lab Development
& Evaluation
(2010-2013)
Solvent screening
Lab-scale evaluation
of process
Future
Demonstration
(2017+)
Pre-commercial Demonstration
e.g. at Technology Centre
Mongstad, Norway (~10 MWe)
Planning ongoing
• Complete process unit with all
components at minimum size required for
confident scale-up
• Collect critical process information to
support detailed T&E assessments,
emissions monitoring, long-term testing to
develop reliability, availability and
maintainability (RAM) metrics
18
Acknowledgments
• Financial support provided by DOE NETL under DE-
FE0026466
• DOE Project Manager: Steve Mascaro
• RTI cost share and project partner SINTEF
19