Carbon Capture Options for LNG Liquefaction

Transcription

1 Carbon Capture Options for LNG Liquefaction ME-Tech 25 January 2011, Dubai Chris Sharratt Manager, Midstream Business Solutions Group Images: Courtesy of Woodside Energy Ltd

2 Outline LNG liquefaction sources of CO 2 and capture potential Overview of capture technologies and options for LNG integration: Pre-combustion Oxyfuel combustion Post-combustion FW case study Results and conclusions

3 FW LNG liquefaction experience includes: >150 LNG studies, pre-feeds and FEEDs since mid-90 s EPC/EPCM includes Oman LNG, Qalhat LNG, North West Shelf Phase V Expansion, Pluto LNG FW carbon capture experience includes: >50 CCS studies and pre-feeds since mid-90 s Hydrogen Power Abu Dhabi, Kingsnorth and DF1 FEEDs

4 Sources of CO 2 and Capture Potential LNG liquefaction typically y accounts for 75% of LNG supply ppy chain CO 2 emissions CO 2 from feed gas: Prevent freeze out in MCHE 99%+ CO 2 captured in AGRU All operational LNG plants (except Snohvit) currently vent to atmosphere CO 2 from fuel combustion: Majority of CO 2 emissions Viable opportunity to capture ~90% CO 2 Focus on CO 2 capture from flue gases G tonne CO 2 / tonne LN Specific CO 2 Emissions Fuel Feed Gas

5 Capture of CO 2 generated from fuel combustion Three process routes considered for CO 2 capture from flue gases: Pre-combustion Oxyfuel combustion Post-combustion Each method will be presented with example flow scheme and description Options for integration into a LNG liquefaction facility will be highlighted

6 Pre-combustion Drying & Air ASU Nitrogen CO Compression 2 Export Oxygen Water / Steam Hydrocarbon Gasifier / Feedstock Reformer Shift Reactor Heat Recovery AGR Process SRU & Tail TilGas Treating Sulfur HP MP LP Steam HP Hydrogen Generate H 2 fuel stream via syngas (CO & H 2 ) from hydrocarbon feed CO 2 removed from syngas and H 2 used as fuel for: direct gas turbine (GT) drivers CCGT power plant; electric motor (EM) drivers boiler plant; steam turbine (ST) drivers Not considered for the case study

7 Oxyfuel combustion Air Oxygen ASU Nitrogen Flue Gas Recycle Limestone Slurry Drying & Compression CO 2 Export Hydrocarbon Feedstock Oxyfuel Boiler Particle Sulfur Cooler / Condenser Ash Fly Ash Gypsum Water CO 2 concentrated in flue gas stream Integrated into LNG facility using: direct GT drivers CCGT power plant; EM drivers common boiler plant; ST drivers Not considered for the case study

8 Post-combustion Vent Lean Solvent Drying & Compression CO 2 Export Flue Gas Direct Contact Cooler Absorber HEX Stripper Excess Water Blower Reboiler CO 2 removed from flue gases by solvent in absorber Integrated into LNG facility with flue gasses from: direct GT drivers CCGT power plant; EM drivers common boiler plant; ST drivers Considered in the case study

9 Post-combustion Case Study Post-combustion case study Case Study Basis Base case & four options Simulations for each Sized equipment lists for each Parameter Development No. of Trains Feed Gas Composition Liquefaction Technology Basis Greenfield One Nitrogen 4.00 mole% CO mole% Methane mole% l% Ethane 0.01 mole% C3MR Capital cost estimate Cooling Media Air (24 o C) CO 2 Capture Technology Post combustion (MEA) Economic evaluation CO 2 Export Pressure 150 barg

10 Case Study Base Case CO 2 Vent GT Flue Gas Vent Feed Inlet Facilities Acid Gas Dehydration & Mercury Liquefaction & End Flash Gas LNG Storage LNG GTG Flue Gas Vent Fuel EFG Power Generation Fuel Fuel Gas BOG System Refrigeration Compressor Drivers Electric Power Generation Heat Integration CO 2 Capture & Export Base Case 2 x Frame 7 GTs each with 8 MW helpers 4 x Frame 5 open cycle GTGs WHRU on one GT No

11 Option 1; Full cogen, no CC CO 2 Vent GT Flue Gas Vent Feed Inlet Facilities Acid Gas Dehydration & Mercury Liquefaction & End Flash Gas LNG Storage LNG Fuel EFG Fuel Gas BOG System Option 1 Refrigeration Compressor Drivers 2 x Frame 7 GTs each with 8 MW helpers Electric Power Generation STGs Heat Integration HRSGs on GT drives; cogen all heat & power CO 2 Capture & Export No

12 Option 2; Partial cogen with CC CO 2 Export CO2 Drying & Compression CO 2 CO 2 Post Combustion Capture GT Flue Gas Vent CO 2 GT Flue Gas Feed Inlet Facilities Acid Gas Dehydration & Mercury Liquefaction & End Flash Gas LNG Storage LNG Fuel EFG GT Flue Gas Vent Power Generation Fuel Fuel Gas BOG System Option 2 Refrigeration Compressor Drivers Electric Power Generation Heat Integration 2 x Frame 7 GTs each with 8 MW helpers 3 x Frame 5 simple cycle GTGs plus STGs HRSGs on GT drives; cogen all heat & some power CO 2 Capture & Export 100% from feed gas; 90% for GT driver flue gas; 0% from GTG flue gas

13 Option 3; Full cogen with CC CO 2 Export CO2 Drying & Compression CO 2 CO 2 Post Combustion Capture GT Flue Gas Vent CO 2 GT Flue Gas Feed Inlet Facilities Acid Gas Dehydration & Mercury Liquefaction & End Flash Gas LNG Storage LNG Fuel EFG Fuel Gas BOG System Option 3 Refrigeration Compressor Drivers Electric Power Generation Heat Integration CO 2 Capture & Export 2 x Frame 7 GTs each with 8 MW helpers STGs HRSGs on GT drives with supplementary firing; cogen all heat & power 100% from feed gas; 90% for GT driver flue gas

14 Option 4; EM drive with CCGT and CC Feed Inlet Facilities Acid Gas Dehydration & Liquefaction & Mercury LNG Storage End Flash Gas LNG CO 2 Flue Gas Vent EFG CO 2 Export CO2 Drying & Compression CO 2 CO2 Post Combustion Capture CCGT Power Generation Fuel Fuel Gas BOG System Option 4 Refrigeration Compressor Drivers 3 x 65 MW electric motors Electric Power Generation CCGT 2x Frame 7 plus STGs Heat Integration CCGT provides steam for all process duties CO 2 Capture & Export 100% from feed gas; 90% for CCGT flue gas

15 Results 3500 CO 2 Balance Base Case Option 1 Option 2 Option 3 Option 4 CO2 from feed CO2 from fuel CO2 capture from feed CO2 capture from fuel Total CO2 emissions Parameter Base Case Option 1 Option 2 Option 3 Option 4 LNG Production (tpd) 13,560 13,560 13,560 13,560 13,590 Overall Thermal Efficiency (%) Specific CO 2 Emissions (te CO 2 /te LNG) 91.9% 94.2% 92.6% 92.9% 93.1%

16 Capital Cost Estimates

17 Economic Evaluation Basis Feed gas cost 3.5US$/MMBtu LNG cost normalized for zero NPV at 10% discount rate over 25 years Availability; 91% for Base Case and Options 1, 2 & 3, 93% for Option 4 CO 2 emissions charge in range 0 to 160 US$/tonne CO 2 emitted Capital and operating cost for CO 2 export pipeline and storage excluded

18 LNG Cost v CO 2 Emissions Charge

19 Summary CCS applied to LNG liquefaction facilities could reduce total CO 2 emissions from typically greater than 0.20 tonne CO 2 /tonne LNG to approximately tonne CO 2 /tonne LNG For the post-combustion case study undertaken: heat recovery optimization without capture (Option 1) becomes attractive at CO 2 emission charge of approx. 35 US$/tonne CO 2 EM driver case with capture (Option 4) becomes attractive at emissions charge of approx. 60 US$/tonne CO 2

20 Thank you. Any questions? Web: