CARBON CAPTURE IN A NATURAL GAS COMBINED CYCLE (NGCC) 4.1 Overview Maria Elena Diego m.diegodepaz@sheffield.ac.uk
Before starting… Some thoughts from yesterday ’s discussion: ✓ Implementation of CCS requires investments, but… ✓ Many scenarios show that the cost of cutting emissions without CCS would be substantially higher ✓ Strong policy drivers and regulatory framework development are much needed to create a favorable CCS market and facilitate its deployment • Example: Sleipner project
Before starting… EXAMPLE: Sleipner project – North Sea ✓ Started in 1996 ✓ CO 2 is removed from natural gas (~9.5% CO 2 ) and inject it in an offshore deep saline formation at ~ 900 m depth ✓ Injection rate ~ 1Mt CO 2 /yr The 1991 Norwegian CO 2 tax was a driver for this project (offshore oil and gas activities) ✓ This tax was avoided by implementing CCS (NOK 1 million/day)* *https://sequestration.mit.edu/tools/projects/sleipner.html
Outline 1. Gas-based power generation context 2. Integration of NGCCs with PCC 3. NGCCs and CO 2 capture experience
1. Gas-based power generation context ✓ Increased capacity and share in the global energy mix (electricity generation) The use of natural gas as a fuel is expected to substantially contribute to the supply of the increasing electricity demand worldwide in the next few decades, accounting for 16 to 24% of the total share by 2040* *IEA. World Energy Outlook 2017; BP Energy Outlook, 2017. IEA. World Energy Outlook 2017
1. Gas-based power generation context IEA. World Energy Outlook 2017.
1. Gas-based power generation context ✓ CO 2 emissions of NGCC systems are lower than other fossil fuel-based power generation options, e.g., coal: 750-900 kg CO 2 /MWh 350-400 kg CO 2 /MWh NGCC Coal-fired power plant Natural gas can be used to replace more intensive fuels, but further CO 2 emissions reductions are needed ZEP, 2017. Future CCS technologies
2. Integration of NGCCs with PCC ✓ Coupling NGCC plants with post-combustion CCS systems is challenging (large excess air): • Large volumes of flue gas • Low CO 2 concentration (~3-4%vol.) • High O 2 content in the flue gas (~12-13%vol.) ✓ Energy requirements of post-combustion solvent scrubbing systems reduce with increasing CO 2 concentrations in the flue gas • Higher CO 2 levels increase the driving force in the absorption column
2. Integration of NGCCs with PCC Li H, Ditaranto M, Berstad D. Technologies for increasing CO 2 concentration in exhaust gas from natural gas-fired power production with post-combustion, amine-based CO 2 capture. Energy 2011; 36: 1124-33 ZEP, 2017. Future CCS technologies. Zhang Y, Ji X, Lu X. Energy consumption analysis for CO 2 separation from gas mixtures. Appl Energy 2014; 130: 237-43
2. Integration of NGCCs with PCC ✓ New alternatives are being investigated: • Supplementary firing • Humidified gas turbine cycles • Exhaust gas recirculation (EGR) • Selective exhaust gas recirculation (S-EGR) ✓ These options aim at increasing the CO 2 content: • Increased driving force • Oxidative degradation (O 2 content) • Reduced costs
2. Integration of NGCCs with PCC ✓ Post-combustion • Several reports and studies – DoE/NETL, IEA, …
2. Integration of NGCCs with PCC ✓ Important considerations • Current level of knowledge & experience - less than coal • Boundary conditions (configuration, engine, fuel price, etc) ✓ These reports assess the NGCC system in terms of: • Performance • Costs (for comparative purposes)
2. Integration of NGCCs with PCC ✓ Important considerations • Current level of knowledge & experience - less than coal • Boundary conditions (configuration, engine, fuel price, etc) ✓ These reports assess the NGCC system in terms of: • Performance • Costs (for comparative purposes) Amine-based solvents
2. Integration of NGCC with PCC • Capacity factor = 0.85 • 90% CO 2 capture efficiency • Advanced solvent (2.96 GJ/t CO 2 ) • 2x2x1 configuration • HRSG - 3 pressure levels with reheat (175/28/4 bar, 567ºC)
650 MW (gross) 634 MW (net) Efficiency 57.4% (LHV) GT ST 420 MW 230 MW HRSG DOE/NETL (2013). Current and Future Technologies for Natural Gas Combined Cycle (NGCC) Power Plants
ACP CO 2 COMPRESSION ST GT HRSG DOE/NETL (2013). Current and Future Technologies for Natural Gas Combined Cycle (NGCC) Power Plants
ACP CO 2 COMPRESSION ST GT HRSG DOE/NETL (2013). Current and Future Technologies for Natural Gas Combined Cycle (NGCC) Power Plants
ACP CO 2 COMPRESSION ST GT HRSG DOE/NETL (2013). Current and Future Technologies for Natural Gas Combined Cycle (NGCC) Power Plants
ACP 67 kg/s 3.4 bar, 292ºC DOE/NETL (2013). Current and Future Technologies for Natural Gas Combined Cycle (NGCC) Power Plants
WITHOUT CO 2 CAPTURE WITH CO 2 CAPTURE Efficiency Efficiency 50.1% (LHV) 57.4% (LHV) DOE/NETL (2013). Current and Future Technologies for Natural Gas Combined Cycle (NGCC) Power Plants
2. Integration of NGCC with CCS 354 kg CO 2 /MWh-net 41 kg CO 2 /MWh-net
2. Integration of NGCCs with PCC • Different costing methodologies DOE/NETL (2011). Quality Guidelines for Energy System Studies: Cost Estimation Methodology for NETL Assessments of Power Plant Performance.
2. Integration of NGCCs with PCC WITHOUT CO 2 CAPTURE - CAPEX 2011 US dollars DOE/NETL (2013). Current and Future Technologies for Natural Gas Combined Cycle (NGCC) Power Plants
2. Integration of NGCCs with PCC WITH CO 2 CAPTURE - CAPEX 2011 US dollars DOE/NETL (2013). Current and Future Technologies for Natural Gas Combined Cycle (NGCC) Power Plants
2. Integration of NGCCs with PCC 2011 US dollars WITHOUT CO 2 CAPTURE - OPEX WITH CO 2 CAPTURE - OPEX ✓ FOM = $25.0/kW-net ✓ FOM = $46.5/kW-net ✓ VOM = $0.00174/kWh-net ✓ VOM = $0.00315/kWh-net ✓ Fuel costs = $0.04/kW-net ✓ Fuel costs = $0.05/kW-net Natural gas price: Comparative $5.81/GJ purposes $6.13/MMBtu DOE/NETL (2013). Current and Future Technologies for Natural Gas Combined Cycle (NGCC) Power Plants
2. Integration of NGCCs with PCC 2011 US dollars WITHOUT CO 2 CAPTURE - OPEX WITH CO 2 CAPTURE - OPEX DOE/NETL (2013). Current and Future Technologies for Natural Gas Combined Cycle (NGCC) Power Plants
2. Integration of NGCCs with PCC DOE/NETL (2013). Current and Future Technologies for Natural Gas Combined Cycle (NGCC) Power Plants
DOE/NETL (2013). Current and Future Technologies for Natural Gas Combined Cycle (NGCC) Power Plants
DOE/NETL (2013). Current and Future Technologies for Natural Gas Combined Cycle (NGCC) Power Plants
DOE/NETL (2013). Current and Future Technologies for Natural Gas Combined Cycle (NGCC) Power Plants
2. Integration of NGCCs with PCC Considerations: ✓ Comparative purposes ✓ High-level cost analysis (variations of ± 30%) ✓ CO 2 compression, transport and storage costs are included ✓ Contribution from EOR is not considered in this study ✓ Process contingencies for the CO 2 capture stage (20% BEC) Cost reduction of CO 2 capture options: ✓ R&D, process optimization ✓ Demonstration at larger scales of operation (pilot and demo plants)
2. Integration of NGCCs with CCS LEARNING CURVE DOE/NETL (2012). Technology learning curve (FOAK to NOAK).
3. NGCCs and CO 2 capture experience ✓ Less experience has been gained in gas CCS compared to coal CCS options ✓ Specific challenges: • Larger flue gas flowrates with lower CO 2 concentration (absorber design) • Higher O 2 content in the flue gas (oxidative degradation of the solvent) • Environmental impacts • Higher temperatures of operation (NO x ) • Flexible operation DOE/NETL. Carbon Capture opportunities for natural gas fired power systems..
3. NGCCs and CO 2 capture experience ✓ Bellingham (Massachusetts) - Technical feasibility of CO 2 capture in NGCCs • Fluor Econamine FG+ • Slipstream - 40 MW from NGCC • CO 2 concentration = 3.5%vol. • O 2 concentration = 13-14%vol. • Operation from 1994 to 2005 Source: Fluor
3. NGCCs and CO 2 capture experience ✓ There are only a limited number of pilot plants that treat flue gases directly derived from gas combustion processes: • Technology Centre Mongstad (TCM) - Norway ➢ Capacity of 20 kt CO 2 /yr from a natural gas-fired combined heat and power (CHP) plant ➢ 3.5%vol. CO 2 ➢ 30%wt. & 40%wt. MEA de Cazenove, T., R. H. B. Bouma, E. L. V. Goetheer, P. J. van Os and E. S. Hamborg (2016). "Aerosol Measurement Technique: Demonstration at CO 2 Technology Centre Mongstad." Energy Procedia 86: 160-170
3. NGCCs and CO 2 capture experience ✓ There are only a limited number of pilot plants that treat flue gases directly derived from gas combustion processes: • Technology Centre Mongstad (TCM)
3. NGCCs and CO 2 capture experience ✓ There are only a limited number of pilot plants that treat flue gases directly derived from gas combustion processes: • Sulzer CCS pilot plant - Switzerland ➢ Capacity of up to 150 kg/h of flue gas from a commercial gas fired burner ➢ 3.8%vol. CO 2 Notz, R., H. P. Mangalapally and H. Hasse (2012). "Post combustion CO 2 capture by reactive absorption: Pilot plant description and results of systematic studies with MEA." International Journal of Greenhouse Gas Control 6: 84-112
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