Non-Aqueous Solvent CO 2 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 9TH TRONDHEIM CONFERENCE ON CO 2 CAPTURE, TRANSPORT AND STORAGE TRONDHEIM, NORWAY June 12 - 14, 2017 www.rti.org RTI International is a registered trademark and a trade name of Research Triangle Institute.
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 CO 2 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
R&D Strategic Approach Path to Reducing ICOE and Breakdown of the Thermal Regeneration Cost of CO 2 Avoided Energy Load ▪ Primarily focus on reducing energy consumption – reboiler duty Heat of Heat of Reboiler Sensible ▪ Reduce capital expenditure Vaporization Absorption Heat Duty Heat ▪ Simplify process arrangement ▪ Materials of construction X solv Da D h abs D h vap C p Reboiler Duty Solvent [mol solv./ [mol CO 2 / [J/g K] [kJ/mol] [kJ/mol] [GJ/tonne CO 2 ] ▪ Limit operating cost increase mol sol’n ] mol solv.] 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 Oper. 11% For NAS, heat of vaporization of water Capital Power becomes a negligible term to the heat duty 33% 56% Process capable of achieving these criteria will have a lower energy penalty than SOTA processes 1 Rochelle, G. T. Amine Scrubbing for CO 2 Capture. Science 2009, 325, 1652- 4 1654.
NAS Process Exhaust Gas Condenser CO 2 Product Gas Wash Wash Lean Amine Section Section Cooler Knock-Out Drum Interstage Filter Coolers Interstage Heaters Flue Absorber Gas Solvent Rich/ Feed Lean HX Make Up Gas Reboiler 5
Bench Scale Test Unit Results Reboiler Heat Duty (GJ/T-CO 2 ) L/G (mass/mass) RTI non-aqueous solvents showing substantially reduced reboiler heat duties 6
Experimental Reboiler Duty Data Reboiler Heat Duty (GJ/T-CO 2 ) Conditions for Experimental Data • Absorber: 37-40 ° C • Regenerator: 87-98 ° C • Pressure: 2.5 bar • Interstage Heater Regeneration L/G (mass/mass) 7
Specific Reboiler Duty Comparison 4 3,5 3 SRD (GJ/T-CO 2 ) 36 – 42% 2,5 Reduction 2 1,5 1 0,5 0 MEA KS-1 Shell Cansolv DC- RTI NAS-5 103 (Petra Nova Carbon (SaskPower) Capture Project) Ref. for KS-1 Ref. Cansolv DC-103 8
Small-Pilot Testing with Coal-fired Flue Gas at SINTEF 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 • 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 9
MEA/H 2 O Baseline Testing at Tiller (Reboiler heat duty) 30 wt% MEA baseline testing at Tiller. 14 steady-state runs with varied parameters: • Liquid circulation rate • Absorber packing height Heat rate (MJ/kg CO 2 ) • CO 2 capture efficiency • • Inlet gas humidity • Flue gas velocity • Intercooling Reboiler Heat Duty (GJ/T-CO 2 ) 10
MEA/H 2 O Baseline Testing at Tiller (CO 2 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 Mimicked coal flue gas using propane burner Tiller Run 18 Run 22 Date 12.01.2017 16.03.2017 flue gas (runs 18, and 22 respectively) Hour 06:50-07:50 16:00-17:00 Solvent NAS NAS Source Mimicked Coal Coal Gas inlet ABS 110.0 110.0 SRD with account of heat loss amounts to CO 2 inlet ABS 14.87 14.42 about 2.8 GJ/t , assuming 1.5kW loss in the CO 2 outlet ABS 1.832 0.659 hot lines. CO 2 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 In the coming months, several modifications Rich Loading 0.273 0.290 Water Lean 7.9 6.841 will be made at Tiller to run NAS under Temp Liq Reboiler 99.3 104.8 optimum conditions 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 It is expected that the Tiller plant Temp Gas outlet modifications will bring the SRD further down DCC 24.7 23.7 (next slide). Temp Lean amine inlet 34.8 34.9 Temp Intercooling 38.1 38.7 13
NAS-Specific Components for SINTEF Plant 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. 14
Process Modeling Developed rate-based process model Aspen ENRTL-SR Thermodynamic and physical properties acquired experimentally: • Henry’s constant for CO 2 Liquid heat capacity • Vapor pressures • • Reference state properties • Heat of vaporization • Dissociation constants VLE • • Density D h abs • • Viscosity • Surface tension Thermal conductivity • • Dielectric constant • Diffusivity of CO 2 Used process model to direct bench- scale testing after initial runs 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 CO 2 Technology Centre Mongstad (TCM), Mongstad, Norway National Carbon Capture Center (NCCC), Alabama, USA 16
Leveraging the U.S. – Norway Collaboration Framework 17
RTI Novel CO 2 Solvents Lab Development Large, Bench-Scale Pilot Testing at SINTEF Future & Evaluation System Tiller Plant Demonstration (2010-2013) (RTI Facility, 2014-2016) (Norway, 2015-2018) (2017+) Solvent screening Demonstration of key Demonstration of all process Pre-commercial Demonstration process features components at in adiabatic e.g. at Technology Centre Lab-scale evaluation (≤ 2.0 GJ/T -CO 2 ) system pilot scale (~60 kWe) Mongstad, Norway (~10 MWe) of process Planning ongoing • Complete process unit with all • Optimize NAS formulation • Quantify solvent losses and components at minimum size required for • Develop critical process emissions confident scale-up components • Test campaign on coal derived • Collect critical process information to • Detailed solvent flue gas support detailed T&E assessments, degradation and • Collect critical process data to emissions monitoring, long-term testing to preliminary emissions support scale up, develop develop reliability, availability and studies (SINTEF engineering package maintainability (RAM) metrics NASCHAR project) • Detailed TEA and EH&S 18 assessments
Acknowledgments • Financial support provided by DOE NETL under DE- FE0026466 • DOE Project Manager: Steve Mascaro • RTI cost share and project partner SINTEF 19
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