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LIQUEFIED NATURAL GAS CARRIER (LNG)LIQUEFIED NATURAL GAS CARRIER (LNG)
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What is LNG ?
fiedLique Natural Gas
Natural Gas
At Minus 260 Fahrenheit (-162 C)
Reduces to 1/600 of its original volume
Natural Gas
OO
Vessel insulation is crucial !
OUTER HULL
INNER HULL
BALLAST WATER
Then 4 layers of insulation
2nd layer Insulation
2nd Membrane
1st layer Insulation
1st Membrane
1.8 metres (6 feet)
Membrane type LNG carrier tank layers of insulation
The membrane is where there have been “gluing” problems
So where are all the reserves of natural gas then ?
3%
25%
16%
15%4%
4%
3%
3%
3%
2%
22%
Russia
Iran
Qatar
Saudi Arabia
United Arab Emirates
United States
Nigeria
Venezuela
Algeria
Iraq
All other
Known reserves at 1 Jan 2011Source: http://www.aneki.com/countries2.php?
t=Countries_with_the_Largest_Natural_Gas_Reserves&table=fb167&places=*=*&order=desc&orderby=fb167.value&decimals=--
&dependency=independent&number=all&cntdn=asc&r=-67-68-69-70-71-72-73-74-76&c=&measures=Country--proven%20reserves%20of%20gas
%20%28cu%20m%29&units=--&file=gas
There are 2 methods for transporting the gas
…. by pipeline …….or a combination of both…
….or by sea…
..and the ships get bigger and bigger
PRISMATIC (Q - Max) TYPEMEMBRANE TYPE
Tanks fully incorporated into the ship’s hullTanks independent of the ship’s hullMOSS-ROSENBURG TYPE
Loading, carriage and discharging LNG carriers
Natural gas is cryogenically liquefied into LNG on-shore
Transferred from shore to vessel
1) Directly at the terminal
2) Offshore at a buoy mooring
LNG
PLANT
Cryogenic hose
Discharging is done EITHER :-
as LNG using cryogenic hoses (as with loading)
….. or by allowing LNG to vaporise on board (and then pumping as a gas)
STORAGE TANK
On board, LNG kept at boiling point (-162°C) to deliberately allow some “boil off”
“Boil off”
TEMPERATURE
Heat Heat
What is L G ?P
Liquefied Petroleum Gas
Propane (C3H8)
Butane (C4H10)
Ethanethiol (CH3CH2SH )
0
50
100
150
200
250
-42 -34 -29 -23 -18 -12 -6.6 -1 4.5 10 15.5 21.1 26.6 32.2 37.7 43.3
0% 30% 50% 70% 100%
Pounds per square inch
pressure required
Temperature (C)
% of butane in the LPQ
The greater the % of propane in the LPG, the more pressurized (or lower temperature) it needs to be, to remain liquefied
Odour added
Source: http://www.engineeringtoolbox.com
-0.5 ºC
-42 ºC
Liquefies at
Carriage of LPG
Semi-pressurized, semi-refrigerated ships have a cargo carrying capacity of 5,000 cubic metres under temperature and pressure condition of -10 degree Centigrade and 8.5 kg/ cm2 respectively.
Larger vessels can carry at temperature of -48 degree Centigrade.
As the boiling point of LPG is much higher than LNG, a re-liquefaction plant on the ship can load the cargo as gas and liquefy it onboard. Heating and cooling facilities are also provided for smooth discharging of the cargo
LNG CARRIER INSURANCE ISSUES
Current cost to build between $180,000,000 - $290,000,000
“Sloshing” Damage ClaimsBILL
$22,000,000 +
Containment Systems ClaimsBILL
$35,000,000 +
The only yards with repair capability…….
(152,000 cu.m.) (270,000 cu.m.)
……are too busy building new ones !
Insulation adhesive weakness claims Has led to Total Loss
L.N.G. CarriersJust one of 10 vessel types covered by Steve Harris during the Marsh Marine Insurance Weeks
For more information or a brochure, contact Marion J. Paul, Marsh Norwich U.K.Tel: + Intl 44 (0)1603 207098E-mail: [email protected]
