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Emerging Technology Allows Greater Flexibility for the Design and Operation of FLNG

Emerging Technology Allows Greater Flexibility for the Design and Operation of FLNG. Worldwide Higher Heating Value (HHV) Specifications. Spot sales complicated by differences in LNG specification Lean LNG gives more marketing flexibility Easier for user to add LPG than N 2.

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Emerging Technology Allows Greater Flexibility for the Design and Operation of FLNG

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  1. Emerging Technology Allows Greater Flexibility for the Design and Operation of FLNG

  2. Worldwide Higher Heating Value (HHV) Specifications • Spot sales complicated by differences in LNG specification • Lean LNG gives more marketing flexibility • Easier for user to add LPG than N2

  3. Typical LNG Flowsheet

  4. Transportation Study Results for Conventional Floating LNG (FLNG) • Based on Qmax LNG Vessels • Length 400m, breadth 80m, displacement 550,000Te • High Plant Utilisation Rate Required • Need Spare Storage Capacity to allow for loading delays • LNG Storage Capacity 350,000 m3 • LPG Storage Capacity 80,000 m3 • Condensate Storage Capacity 160,000 m3

  5. Liquefaction Plant LPG Storage LNG Storage Condensate Storage Flare tower Accommodation Seawater intake reservoir Machinery Space Floating LNG Hull Layout • Comparable to the Worlds Largest Ship • Knock Nevis; Length 458m - Breadth 69m • Larger than Very Large Crude Carriers • Length 333m - Breadth 58m

  6. Ship to Ship LNG Transfer Time Log • 2 – 3 day window for transfers • Difficult operation for two huge vessels • LPG & condensate needs additional transfer equipment & operations

  7. Issues with Higher Hydrocarbons (C2+) on FLNG • LPG marketable, but adds complexity and reduces LNG storage (or increases vessel size) • LPG system increases fire risk by ~30% • C2 content of LPG limited to 2% (vapour pressure) • Excess C2 may exceed fuel gas demand • C2 –rich fuel gas may exceed NOx emission limit on gas turbine • ‘Slopping’ on FLNG can create variable Boil Off Gas, hence variable Fuel Gas composition & Wobbe Number • Impact on Fuel Gas burners

  8. Catalytic De-Richment • Catalytic De-Richment (CDR) converts higher hydrocarbons (ethane up to naphtha) to methane • Well established technology developed for substitute natural gas (SNG) • Overall reactions: 4C2H6 + 9H2O  7CH4 + 7H2O + CO2 2C3H8 + 7H2O  5CH4 + 5H2O + CO2 4C4H10 + 19H2O  13CH4 + 13H2O + 3CO2 C5H12 + 6H2O  4CH4 + 4H2O +CO2

  9. LNG Plant with Catalytic De-richment

  10. Catalytic De-richment Reactors & reactions

  11. Typical CDR Operating Conditions* Temp 275 °C: Press 30 bara: Steam/Carbon 0.833 * Patented catalyst

  12. Potential Increase in LNG from Heavy Gases

  13. Catalytic De-Richment • Catalytic De-Richment (CDR) converts higher hydrocarbons to methane • Increased LNG production • Simplified FLNG design • Well established technology • Reduces flaring where ethane in excess of fuel gas demand • Generates constant Wobbe number fuel gas • Lean LNG gives more marketing flexibility

  14. Mercury Distribution

  15. Why Must Mercury be Removed? • Avoid corrosion of equipment using aluminium alloys, copper alloys and some other alloys • LME (liquid metal embrittlement) • Amalgam corrosion • Process cheaper mercury-distressed crudes • Avoid emissions to environment • Comply with HSE directives & protect employees • Feb ’09 UN Environment Programme – World-wide treaty to limit Hg exposure LME

  16. 2004 Moomba Explosion • Losses: • Caused by LME of aluminium heat exchanger inlet, by Hg • Leading insurers put the insured loss at A$320million (USD245 million) • Energy crisis in NSW & South Australia • Supplies were limited to 30-40% capacity • Cutbacks by major industrial customer • Job layoffs

  17. PURASPEC Mercury Removal Technology • Uses variable valency metal sulphide • Hg + MxSy → MxSy-1 + HgS • Metal sulphide can be generated in situ from mixed metal oxide (patented co-removal of H2S & Hg) • Grades for gas and liquid hydrocarbons (LPG, condensate etc) • Can be used on saturated gas

  18. Full Cradle to Grave Service • Optimisation of Mercury Removal Unit (MRU) design with customer • Data sheets and vessel drawings • Low PD radial flow designs possible • Provision of most suitable absorbent • Supervised loading and discharge • Recycling of spent absorbent • Absorbents are made from materials compatible with smelters • Only audited, approved smelters used • Certificate proves environmentally safe disposal

  19. Recommended location of MRU Typical location of (carbon) MRU Regeneration Medium Compression Export Export Fuel Gas 4% 5% 25% 20% Cooling/ Al Heat Exchanger 19% Molecular Sieve/ Glycol Unit Separation Amine System <10 nanogram / Nm3 inlet specification NGL’s 90% 15% 65% LP Compression Amine Gas Oil 90% 100% 2% NGL’s Multiphase flow Separation Waste Water Water Glycol 2% 8% Wells Amine Overboard Oil Storage/ Export Mercury Distribution – Gas Processing Plant Mercury Survey Results 4%

  20. Fit and Forget Technology • Intervention only required for charging and discharging • High mercury capacity gives long bed life • Sharp absorption profile means bed can cope with high excursions in mercury in feed and in the flow rate of feed

  21. FPSO SE ASIA MRU on FPSO

  22. Oil & Gas Platform Gulf of Thailand Offshore MRU

  23. Conclusions • Catalytic De-Richment can be used to increase LNG production • Free up space for LNG storage or reduce size of vessel • Simplifies FLNG design and improves safety • Potentially reduce the need for flaring • Mercury removal essential • Location upstream of acid gas & water removal maximises protection of equipment, people and environment

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