2nd International Conference on Small Scale LNG in Europe

Transcription

1 Two-Phase Expander Potential for Reduced Power Requirements in LNG Production Plants 2nd International Conference on Small Scale LNG in Europe Bergen, Norway 22 nd -24 th May 2007 Eginhard Berger and Manfred Boelt: The Linde Group -, Germany Dr. Hans Kimmel, Ebara, USA

2 The 2nd International Conference on Small Scale LNG in Europe Two-Phase Expander Potential for Reduced Power Requirements in LNG Production Plants Eginhard Berger, Manfred Boelt: The Linde Group -, Germany Dr. Hans Kimmel, Ebara, USA

3 Content: Basis of Comparison Options Current State of the Art and Development in Fluid Expansion for Refrigeration Expansion Options for the Linde Single Mixed Refrigerant Cycle Thermophysical Illustration of the LNG End Flash Options Heat Temperature Diagrams (Pinch Analysis) of the LNG Process Options TPE (Two-Phase Expander) Technology Economic Comparison of the Options Linde AG Division 2 Berger/GVP/ /GVP

4 LNG Process Comparison Basis: LiMuM (Linde Multi Stage Mixed Refrigerant) LNG Process Typical Natural Gas Composition Feed Gas: Pressure 60 bar, Temperature 30 C Comparison Options: JTE (Joule-Thomson Expansion) HE + JTE (Hydraulic Expander) + (Joule-Thomson Expansion) TPE (Two-Phase Expander) Linde AG Division 3 Berger/GVP/ /GVP

5 Technology Status: JTE (Joule-Thomson Expansion) Generally used in most of the existing LNG plants for refrigeration HE + JTE (Hydraulic Expander) + (Joule-Thomson Expansion) G Currently used in large LNG baseload plants TPE (Two-Phase Expander) G Currently used in a small LNG plant, Combination of Hydraulic and Gas Expander Linde AG Division 4 Berger/GVP/ /GVP

6 Natural Gas Mixed Refrigerant Cycle M Two-Phase Expanders Fuel a Large Potential for Reduced Power Requirement in LNG Production Plants Gas Precooling Cycle JTE Valve M LNG Linde AG Division 2 1 LNG JTE Valve Subcooling Cycle JTE Valve JTE (Joule-Thomson Expansion) Simplified Process Sketch LiMuM (Linde Multi Stage Mixed Refrigerant) LNG Process 5 Berger/GVP/ /GVP

7 Natural Gas Mixed Refrigerant Cycle M Two-Phase Expanders Fuel a Large Potential for Reduced Power Requirement in LNG Production Plants Gas M G Precooling Cycle Expander +JTE LNG Linde AG Division 1a 2 G LNG Expander +JTE 1 HE (Hydraulic Expander) + JTE (Joule-Thomson Expansion) G Subcooling Cycle Expander +JTE Simplified Process Sketch LiMuM (Linde Multi Stage Mixed Refrigerant) LNG Process 6 Berger/GVP/ /GVP

8 Natural Gas Mixed Refrigerant Cycle M Two-Phase Expanders Fuel a Large Potential for Reduced Power Requirement in LNG Production Plants Gas G Precooling Cycle Expander M LNG Linde AG Division 2 G LNG Expander 1 TPE (Two-Phase Expander) G Subcooling Cycle Expander Simplified Process Sketch LiMuM (Linde Multi Stage Mixed Refrigerant) LNG Process 7 Berger/GVP/ /GVP

9 60 1 Expansion Entry TPE (Two-Phase Expander) Pressure - Temperature Diagram Comparison of LNG End Flash 50 JTE (Joule-Thomson Expansion) 40 HE (Hydraulic Expander) P BAR 30 All Liquid JTE (Joule-Thomson Expansion) Two-Phase Envelope of a Typical Natural Gas All Gas 1a Expansion Outlet Temperature K Linde AG Division 8 Berger/GVP/ /GVP

10 Pressure - Temperature Diagram Section Expansion Entry 1 60 Comparison of LNG End Flash 50 All Liquid 40 P BAR 30 JTE (Joule-Thomson Expansion) TPE (Two-Phase Expander) HE (Hydraulic Expander) Two-Phase Envelope of a Typical Natural Gas JTE (Joule-Thomson Expansion) 1a Expansion Outlet Temperature K Linde AG Division 9 Berger/GVP/ /GVP

11 60 1 Expansion Entry Pressure - Enthalpy Diagram Comparison of LNG End Flash Section JTE (Joule-Thomson Expansion) 50 TPE (Two-Phase Expander) HE (Hydraulic Expander) All Gas 40 Pressure bar 30 All Liquid JTE (Joule-Thomson Expansion) Two-Phase Envelope of a Typical Natural Gas a Enthalpy J/mol 2 Expansion Outlet Linde AG Division 10 Berger/GVP/ /GVP

12 60 Comparison of LNG End Flash Section Pressure - Enthalpy Diagram 1 Expansion Entry All Gas 50 JTE (Joule-Thomson Expansion) HE (Hydraulic Expander) 40 Two-Phase Expanders a Large Potential for Reduced Power Requirement TPE in LNG Production Plants Pressure bar 30 All Liquid (Two-Phase Expander) JTE (Joule-Thomson Expansion) Two-Phase Envelope of a Typical Natural Gas Enthalpy J/mol Expansion Outlet 1a 2 Linde AG Division 11 Berger/GVP/ /GVP

13 Temperature - Specific Entropy Diagram 210 Comparison of LNG End Flash Section All Liquid Two-Phase Envelope of a Typical Natural Gas All Gas 170 Temperature K Expansion Entry 1 HE (Hydraulic Expander) + JTE (Joule-Thomson Expansion) TPE (Two-Phase Expander) JTE (Joule-Thomson Expansion) Expansion Outlet Entropy J/mol.K Linde AG Division 12 Berger/GVP/ /GVP

14 122,8 121,8 120,8 119,8 Expansion Entry All Liquid 1 Two-Phase Envelope of a Typical Natural Gas Temperature - Specific Entropy Diagram Section HE (Hydraulic Expander) 1a JTE (Joule-Thomson Expansion) Temperature K 118,8 117,8 116,8 JTE (Joule-Thomson Expansion) 115,8 114,8 113,8 TPE (Two-Phase Expander) 112,8 Comparison of LNG End Flash Section 111,8 85,8 86,0 86,2 86,4 86,6 86,8 87,0 Entropy J/mol.K 87,2 87,4 Expansion Outlet 87,6 2 87,8 88,0 Linde AG Division 13 Berger/GVP/ /GVP

15 Heat Temperature Diagrams (Pinch Analysis) ENTHALPY(SUM) OF HEAT EXCHANGER (MW) HEAT EXCHANGER : Q / T PROFILE FOR UNIT : E01 in LIMU32/CO01 HE + JTE (Hydraulic Expander + (Joule-Thompson Expansion) Two-Phase Expanders a Large Potential 0 for Reduced Power Requirement in LNG Production Plants ENTHALPY(SUM) OF HEAT EXCHANGER (MW) HEAT EXCHANGER : Q / T PROFILE FOR UNIT : E01 in LIMU19/CS01 JTE (Joule-Thompson Expansion) Date/Time : :33:22 T OF HEAT EXCHANGER (K) hot sum curve cold sum curve ENTHALPY(SUM) OF HEAT EXCHANGER (MW) HEAT EXCHANGER : Q / T PROFILE FOR UNIT : E01 in LIMU25/CO01 TPE (Two-Phase Expander) Date/Time : :28:41 T OF HEAT EXCHANGER (K) hot sum curve cold sum curve Date/Time : :36:30 T OF HEAT EXCHANGER (K) hot sum curve cold sum curve Linde AG Division 14 Berger/GVP/ /GVP

16 Result of theoretical calculations based on 80% efficiency for each expander (both for HE and for TPE) JTE (Joule-Thomson Expansion) HE + JTE (Hydraulic Expander) + (Joule-Thomson Expansion) TPE (Two-Phase Expander) kwh/nm Two-Phase Specicif power Expanders requirement a Large Potential for Reduced Power Requirement in LNG Production 0.243Plants kwh/nm3 Relative specific power requirement % Relative LNG production with a given power installation + expander / generator sets % Linde AG Division 15 Berger/GVP/ /GVP

17 Example of a Nm3/h LNG plant range JTE HE+JTE TPE LNG Production Nm3/h Two-Phase Basic power Expanders installed a Large (eg Potential all electric for drive) Reduced MW Power Requirement in LNG Production Plants Additional power by expanders Precooling expander MW Subcooling expander MW LNG expander MW Total installed power MW Linde AG Division 16 Berger/GVP/ /GVP

18 Theoretical economic assessment (table): Specific feed/fuel gas price: 0.02 /Nm3 (ab /MMBTU), LNG sales price: 0.15 /Nm3 (about 4 /MMBTU), Operation: 8000 h/a JTE HE+JTE TPE LNG Production Nm3/h Fuel gas consumption Nm3/h Annual feed gas cost Mill. /a Annual LNG sales revenues Mill. /a Power incl. expanders MW Investment cost: Power Mill Process Mill Total Mill Annual operating cost (10% of investment cost) Mill /a Annual profit before tax Mill /a Pay-out time (Investment cost / annual profit before tax) a Relaitve pay-out time % Linde AG Division 17 Berger/GVP/ /GVP

19 Theoretical economic assessment (bar chart): Rough Pay-out Time Investment Cost / Annual Profit before Tax Years 100% 96% 95% JTE HE+JTE TPE Options Linde AG Division 18 Berger/GVP/ /GVP

20 EBARA Hydraulic Expanders in the Snoehvit LNG Plant in Hammerfest Linde AG Division 19 Berger/GVP/ /GVP

21 Installation of Two-Phase LNG Expander at KRIO Polish Oil & Gas, Odolanow, Poland January Linde AG Division 20 Berger/GVP/ /GVP

22 Two-Phase Expander Full turbine section with nozzle and Runner iso transparent Linde AG Division 21 Berger/GVP/ /GVP

23 Two-Phase Expander Exducer with cut and translucent shroud Linde AG Division 22 Berger/GVP/ /GVP

24 Two-Phase Expander Hydraulic top and iso view Linde AG Division 23 Berger/GVP/ /GVP

25 Conclusion: Efficiency Improvement in LNG Plants is Mandatory for Environmental and Economical Reasons TPE is a Contribution to this Requirement TPE Provides Sensible Reduction in Specific Power Requirements in LNG Plants TPE: Hydraulic and Gas Expansion: a Combined Unit as a Logic Consequence of the Current Practice TPE is Applicable in Small LNG Baseload Plants TPE will become Beneficial in Particular with Large Capacity LNG Plants (Economy of Scale) Linde AG Division 24 Berger/GVP/ /GVP

26 Thank you for your attention Linde Process Concepts