GERG Project 1.59
Calculation Models Of LNG Ageing During Ship Transportation
WHAT IS LNG? Liquefied Natural Gas is natural gas that has been cooled to the point that it condenses to a liquid.
NATURAL 70 GAS EQUILIBRIUM CURVE NG CRITICAL POINT 60 50 PRESSURE (bar) 40 30 LIQUID LIQUID + VAPOUR DEW POINT VAPOUR 20 BOILING POINT 10 LNG 0-180 -160-140 -120-100 -80-60 -40-20 0 20 TEMPERATURE ( C)
LNG: Changing Phase 1,35 1,30 CHANGES IN LNG STATE PRESSURE (bar) 1,25 1,20 1,15 1,10 LIQUID LNG BOILING POINT 1 2 3 4 LIQUID + VAPOUR 1,05 1,00-164 -163-163 -162-162 -161-161 -160-160 TEMPERATURE ( C)
MOLECULAR MASS 100 90 80 70 60 50 40 30 20 10 0 LNG: Boiling Points C6 C5 C4 C3 C2 C1-200 -150-100 -50 0 50 100 TEMPERATURE (ºC)
BOG Methane T GAS P GAS Nitrogen BOG Q COMPOSITION IS T LÍQUIDO CHANGING...
BOG Methane T GAS P GAS Nitrogen BOG Q COMPOSITION IS T LÍQUIDO CHANGING...
BOG Methane T GAS P GAS Nitrogen BOG Q COMPOSITION IS T LÍQUIDO CHANGING...
BOG Methane T GAS P GAS Nitrogen BOG Q COMPOSITION T IS LÍQUIDO CHANGING...
BOG Methane T GAS P GAS Nitrogen BOG Q COMPOSITION IS T CHANGING... LÍQUIDO
BOG Methane T GAS P GAS Nitrogen BOG Q COMPOSITION IS T LÍQUIDO CHANGING...
CONCLUSION: LNG composition s changes when the time pass.
LNG Qualities LNG LNG LNG Composition (%) Light Medium Heavy Methane(C1) 98,00 92,00 86,98 Ethane (C2) 1,40 6,00 9,35 Propane (C3) 0,40 1,00 2,33 Butane (C4) 0,10 0,00 0,63 Nitrogen (N2) 0,10 1,00 0,71 CV [kwh/m3](n) 11,290 11,650 12,340 Density [kg/m3(n)] 427,742 445,694 464,831 Variation of density (%) - 4,2 8,7
MOLAS Project is intended to predict LNG composition during ship transportation from loading point (Origin) to unloading point (Destination). The aim of MOLAS Application is to know LNG composition at Destination just before unloading,, and from it, to calculate its main properties: Heat Value, Wobbe Index and liquid density.
What MOLAS is made of? Physical Model imodel Data Base
Main Menu
Physical Model Based on Mass Balance & Thermodynamic Equilibrium between liquid and vapour phase
Main Menu
imodel Based on Artificial Neuronal Networks
imodel Model: Details
Physical Model: Results
Data Base Stores relevant information
Data Base: Registers
Physical Model Testing & Errors imodel Summary
Errors: Physical Model 0,7 0,6 0,5 Qatar Nigeria Limit Egypt T & T 0,4 0,3 0,2 0,1 0,0 C 1 Density HHV(mass) Energy HHV(vol) Wobbe Index
Errors: imodel 0,7 0,6 Qatar Egypt Nigeria T & T 0,5 Limit 0,4 0,3 0,2 0,1 0,0 C1 Density HVV(mass) Energy HVV(vol) Wobbe Index
imodel vs Physical Model % 80,00 70,00 60,00 50,00 40,00 30,00 20,00 10,00 0,00 Qatar T & T Nigeria C 1 Density HHV(mass) Energy
SUMMARY Physical Model: 37 cases studied 92% doesn t exceed the methane limit 95% doesn t exceed the energy limit imodel: 21 cases studied 95% doesn t exceed the methane limit 100% doesn t exceed the energy limit
Areas of Application Operational Area Prevent stratification (density) Quality Area Quality Specifications (WI, HV, etc.) Economical Area Energy to be unloading (HV) Administration Area Store information (Data Base)
Conclusions MOLAS Application is a user friendly, powerful and reliable tool that runs on a desktop and allows knowing LNG composition to be unloaded at Destination and, therefore, the most essential LNG properties, with errors that are within uncertainty accepted in LNG industry. The results provided by MOLAS Application, can help Terminal Operators to manage Regasification Plants in a more safety and efficient manner, can help Engineers and Technicians to take necessary actions on natural gas to sent out so that can comply with Bratislava, Quality 18th Specifications. and 19th of September 2008
Thank very much for your attention