lng training brazil

1

LNG Training Course

Brazil

December 2007

Sven Lataire

2

Terminal & Transportation Services


Gas Competence Center


Production ServicesProduction Services

Gas Competence CenterTechnical Center

Europe, Middle East, Africa



Gas Competence CenterAsia, Oceania


Gas Competence CenterAmerica


SpainSpain

FranceFrance

BelgiumBelgium

QatarQatar

PortugalPortugal

ItalyItaly

UKUK

EgyptEgypt

AlgeriaAlgeria

NigeriaNigeria

TurkeyTurkey

OmanOman

GreeceGreece

NorwayNorway

Eq.GuineaEq.Guinea

RussiaRussia

UAEUAE

LibyaLibya

3


Lake CharlesLake Charles

Cove PointCove Point

BostonBoston

SavannahSavannah

TrinidadTrinidad

MexicoMexico

CanadaCanada



USAUSA








4



AustraliaAustralia

MalaysiaMalaysia

KoreaKorea

TaiwanTaiwan

JapanJapan

IndiaIndia

ChinaChina










5

LNG TRAINING PROGRAM

� Day 1

• Welcome & Introduction LNG

• Types of gastankers – Design Criteria LNG tankers

• LNG Terminology/Analysis/behaviour & change of cargo

• Custody Transfer– Ship side: Types of Custody Transfer Instruments

– Shore Side: Principles of LNG Sampling

• LNG Video / Accidents

• Energy calculations

• Lay out and Equipment of LNG vessels

• Cargo handling: Preparation

• Cargo handling: Loading and discharging

• Measurement/Verification/Accuracy

1. Types of GastankersDesign Criteria LNG Tankers

7

Criteria for classification

� Gas carriers can be classified according to different criteria

• Ship survival capability and cargo tank location

– IMO Code

• Pressure / temperature conditions

– Types of gas carriers

» Fully press – Semi Press – Fully ref - …..

• Cargo containment system

– Types of tanks

» Spheric – Rectangular

» Integral – independent - membrane - ……

9




– IMO Code





– Types of tanks



10

IMO code

� IMO: International Maritime Organization

a United Nations agency that issues international tradestandards for shipping

� IMO code

• survival capability

• flooding/dammage

• location of cargo tanks

• survival requirements

• design criteria

11

IMO code

IMO code

Specifies the required type of ship for each product

4 categories:

• IG

• IIG

• IIPG

• IIIG

�Hazard rating of the cargo

�IG = greatest hazard, e.g.: chlorine

�IIG, IIPG, IIIG: progressivelydecreasing hazards

12

IMO code

Location of cargo tanks in ships of types IIG, IIPG and IIIG

13

IMO code

Location of cargo tanks in a ship of type IG

14




– IMO Code





– Types of tanks



16

T/P conditions

� Types of gascarriers

Classification according to pressure / temperature conditions

• Fully pressurised Ships

• Semi pressurised Ships

• Ethylene Ships

• Fully refrigerated LPG Ships

• LNG Ships

17

T/P conditions – Fully Pressurized

� Fully pressurized ships

• Type ‘C’ tanks ( carbon steel )

• Design pressure 18 barg (Max 20 Bar)

• Cargo transported at ambient temp

• Tanks are heavy due to their design pressure

• Result: Cargo Capacity - max 6000 m3

• No cooling units

• No insulation

• No secondary barrier is required

• Primarily used to carry LPG and Ammonia

18

T/P conditions – Fully Pressurized

19

T/P conditions – Semi Pressurized

� Semi pressurized ships

• Type ‘C’ tanks

• Max working pressure: 5 to 7 barg

• Temperature min 50 degr C

• Capacity from 3000 to 20000 m3

• Refrigeration units

• Insulation


• Used to carry a wide variety of gases ( LPG Vinyl Chloride, Propylene and butadiene )

20

T/P conditions – Semi Pressurized

21

T/P conditions – Ethylene Ships

� Ethylene Ships

• Semi pressurized type vessel

• Type ‘C’ tanks

• Temperature: - 104°C


• Thermal insulation

• High capacity reliquefaction

• Capacity range: 1000 to 12000 m3

22

T/P conditions – Ethylene Ships

23

� Fully refrigerated ships

• Cargo carries at approx.atmospheric pressure

• Type ‘A’ tank

• Maximum working pressure: 0,7 barg

• Temperature: - 50°C

• Capacity range: 20000 to 100000 m3

• Provided with longitudinal bulkhead

• Thermal insulation

• Reliquefaction equipment

• Secondary barrier is required

T/P conditions – Fully Refrigerated

24

T/P conditions – Fully Refrigerated

25

� LNG carriers

• Fully refrigerated type

• Maximum working pressure: 0,25 Barg

• Temperature minimum - 165 degr C

• No cooling units

• Dual firing

• Heavy insulation

T/P conditions – LNG carriers

26




– IMO Code





– Types of tanks

» Spherical – Rectangular


28

cargo containment system

� Types of tanks (IMO)

• by construction - integral

- independent

- semi membrane

- membrane

• by shape - cylindrical/spheric

- rectangular

29

� Integral tanks

• design pressure max 1.25 Bar

• if strenghtened max 1.7 Bar

• A structural part of the ship’s hull

• simple design

• temperature not below -10 degr. C

• applied for Butane

cargo containment system – by construction

30

� Independent, self-suppporting tanks• type A

– recognized standards/classical construction

– Max design pressure 0.7 barg

– secondary barrier

– Cargo: fully ref and near atm.press ( below 0,25 barg )

• type B– Partial secondary barrier in the form of a dip tray

– When prismatic: limited to 0,7 barg

– Hold space: dry air or inert gas

– Almost exclusively applied to LNG ships

– Can be spherical or prismatic

• type C– cylindrical/spherical

– Always used for semi or fully press.vessels

– No secondary barrier is required

– In case of fully press – Max design pressure 18 barg

– In case of semi press – working pressure 5 to 7 barg


31

Type ‘A’ tank

32

Type ‘B’ tank

33

Type ‘C’ tank

34

Type ‘C’ tank

35

Cargo containment system – by construction

� Semi-membrane tanks

• A Variation of the tank membrane system

• differences

– Primary barrier is much thicker

– Tank is self supporting when empty

– Not used for LNG

36

� Membrane tanks

• Three principle types:

– Gaz Transport: NO96

– Technigaz: Mark III

– GTT: Combined System 1 (CS1)


37

LNG carriers

� Basic features of LNG vessels

• All LNG hulls requires specially designed insulation

– Minimise heat transfer and boil off

– Protect hull steel from low temp embrittlement

• LNG is kept in a sort of metallic container

– To contain the LNG cargo

– To protect the insulation

• Cargo carried at –162 degr C

• A LNG tanker has no compressors on board like LPG

• Dual firing

• Capacity between 130000 – 150000 m3 ( new ships are edging up to 266000 m3 )

38

LNG carriers

� Type of LNG carriers• Self supporting Spherical Type ‘B’

» ( Kvaerner Moss system )

• LNG ship: Technigaz system» ( Single Membrane )

• LNG ship: Gaz transport system» ( Dual Membrane )

• LNG ship: Gaz transport & Technigaz system» (Combined system 1 )

• Self-supporting Prismatic Type ‘B’» ( only a few were built )

� Gas transport and Technigas have now merged to form GTT and are developing new membrane designs. In 2001 GTT launched the new on board LNG containment system : CS1 ( Combined System 1 )

39

Cargo containment system – by shape

� Kvaerner Moss Design

• Consists of an Independent Spherical Tank

• Type ‘B’

– Most common: Spherical tank

– Requires only a partial sec.barrier ( dip tray )

– Hold space: dry inert gas or dry air

– Tank can be spherical or prismatic

40

LNG carrier

41

Spherical type ‘B’ tank

42

Kvaerner Moss Design

43

SPHERICAL TYPE ‘B’ TANK

44

MEMBRANE SHIP

� Technigaz: Mark III

� Gaztransport: N°96

� GTT: CS1

45


� Technigaz system

• Primary barrier: 1.2 mm thick stainless steel

• Raised corrugations or waffles (expansion/contraction)

• Insulation consists of reinforced cellular foam

• Secondary barrier: fibreglass cloth/aluminiumlaminate within the foam

46

Technigaz membrane system

47

Technigaz membrane system

48

MEMBRANE SHIP

� Technigaz: Mark III


� GTT: CS1

49


� Gaz Transport system

• Based on a very thin invar barrier - 0.7 to 1.5 mm

• Membrane is supported through insulation

• Inner hull forms the load bearing structure

• Not self-supporting

• System is provided with sec barrier

• Barriers consists of perlite filled plywood boxes

50

Gaz transport

51

Gaz Transport

52

MEMBRANE SHIP

� Techinigaz: Mark III


� GTT: CS1

53


� Containment combined system

• Combination of the two other existing techniques

• Reinforced polyurethane foam insulation is used

• Prim membrane is made of invar

• Sec membrane is made of composite aluminium-glass fiber called triplex

Calculations shows savings of some 15% on the containment system or about 3% on the total costof the vessel

54

Containment combined system

55

Containment system – existing LNG fleet

56

Containment system – new buildings

57

MOSS VS MEMBRANE

� The membrane technology offers the most cost-effective containment system

• Membrane systems achieves a higher and more efficient deadweight to lightweight ratio for any given hull form

• Membrane systems requires lower effective power and less fuel consumption ( lower operating costs )

• Membrane vessels have less registered tonnage, which reduces port charges and canal dues

• Membrane vessels costs less to dry-dock than a sphere vessel

� Conclusion

• Membrane system require less steel, smaller scale equipments, lower investment from the shipbuilder,

58

LNGX CARRIER

59

LNG carrier

� Kvaerner Masa-Yards has developed a new generation of Moss-type LNG carrier

� Improvements

• Increased cargo capacity

• No boil off due to new compact size reliquefactionplant

• Reduced fuel costs through diesel electric machinery

• Fully azimuthing electric propulsion: excellent manoeuvrability

• Reduced need for harbour tug

2. Properties of LNG

From NG to LNG

• Natural gas

• LNG production

62

Natural gas: origin

� Origin of natural gas?

• Plankton and micro-organisms died and sankto the bottom

• Thick layers of organic material

• Organic material covered with sediment layers

• Temperature increase due to processes goingon in the earth

Pressure increase due to mud layers

⇒⇒⇒⇒ FORMATION OF NATURAL GAS

63

Natural gas: sources

� Natural gas may be found in:

• Underground wells, which are mainly gas bearing

– Non-associated gas

• Condensate reservoirs

– Pentanes and heavier Hydrocarbons

• Large oil fields

– Associated gas

– Natural gas may be either in solution with the crude oil or as a gas-cap above it

64

Natural gas: composition

� Most important component?

⇒ methane : 1 carbon atom + 4 hydrogen atoms

http://encarta.msn.com/encyclopedia_761568077/Methane.html

65


� Hydrocarbons?

• Family of organic compounds

• Composed entirely of Carbon and Hydrogen:

CnH2n+2 with n = amount of carbon atoms

DecaneCH3-(CH2)8-CH3C10H22

NonaneCH3-(CH2)7-CH3C9H20

OctaneCH3-(CH2)6-CH3C8H18

HeptaneCH3-(CH2)5-CH3C7H16

HexaneCH3-(CH2)4-CH3C6H14

PentaneCH3-(CH2)3-CH3C5H12

ButaneCH3-(CH2)2-CH3C4H10

PropaneCH3-CH2-CH3C3H8

EthaneCH3-CH3C2H6

MethaneCH4CH4

66


� Composition of natural gas?

• may vary widely

• Typical composition

traceAr, He, Ne, XeRare gases

0-5%H2SHydrogen Sulphide

0-5%N2Nitrogen

0-0.2%O2Oxygen

0-8%CO2Carbon Dioxide

C4H10Butane

0-20%C3H8Propane

C2H6Ethane

70-97%CH4Methane

http://www.naturalgas.org/overview/background.asp

67


� Natural gas• Contains smaller quantities of heavier hydrocarbons

– Known as natural gas liquids – NGL

• Contains amounts of water, Carbon dioxide, nitrogen and other non-hydrocarbon Substances

� NGL• made up of ethane, propane, butane, pentane, hexane

and heavier fractions

• Proportion varies from one location to another

• Percentage smaller in gas wells

� LNG• Mainly methane and ethane, liquefied at cryogenic

temperature

� Condensate• A liquid/hydrocarbon mixture , which may be recovered

at the surface from some non-associated gas reservoirs

68


� Constituents of natural gas

From NG to LNG

• Natural gas

• LNG production

70

LNG production: overview

Raw feed gas

Condensate removal

Acid gas removal

Dehydration

Fractionation

Liquefaction

LNG storage

NGL storage

Pentane-plus storage

Fuel to plant

to jetties

CO2

H2S

water

-162°C

McGuire and White, Liquefied gas handling principles,2000

71

LNG production

� Raw feed gas

� Condensate removal

� Acid gas removal

• CO2

freezing point CO2 > atmospheric boiling point LNG

⇒ Cargo contamination

⇒ operational difficulties (clogging of pumps, filters and valves)

• H2S

causes atmospheric pollution when being burnt in a fuel

72

LNG production

� Dehydration (water removal)

• to avoid the formation of ice

freezing point water > atmospheric boiling point LNG

⇒ cargo contamination

⇒ operational difficulties (clogging of pumps, filters and valves)

• to avoid hydrate formation

hydrocarbons + water → hydrates

hydrates are crystalline substances

⇒ operational difficulties

� NGL fractionation

• NG: Natural gas

• GTL: Gas To Liquids

• CNG: Compressed Natural Gas

� Liquefaction and storage

73

LNG properties

74

LNG: Properties

• Temp: ± -160°C/-260 °F

• Volume liquid = 1/600 volume gas @ STP

• Density = ± 450 kg/m³ (~ composition/temperature)

• Colorless

• Odorless

• Non-toxic

• Non corrosive

• Safety/ hazard � later

• Composition

• ~ source

• changes during transport

75

Composition changes during transport

� Influence on the

• Molecular mass LNG

• GHVmass

• GHVvolume

• Density

� Effect high Nitrogen content

76

LNG composition change: Example

0.0122Nitrogen

0.0002n-Pentane

0.0017Iso Pentane

0.0554n-Butane

0.0735Iso Butane

0.3648Propane

2.4270Ethane

97.0651Methane

Load portComponent

�Composition load port: � discharge port

0.0056

0.0003

0.0036

0.1267

0.1590

0.6465

3.2654

95.7928

DifferenceDischarge Port

77

Change during transport

� Properties of the main Components

0,0

4756,0

4008,7

4000,9

3262,4

3252,0

2516,2

1769,7

1010,0

Hvi(BTU/SCF)

0

20944

21085

21044

21300

21232

21654

22334

23892

Hmi(BTU/LB)

28,013

86,175

72,149

72,149

58,122

58,122

44,096

30,069

16,042

Mi (g/mol)

-195,9Nitrogen

69Hexane

36N-Pentane

28Iso Pentane

-0,5N-Butane

-11,7Iso Butane

-42,1Propane

-88,6Ethane

-162Methane

Boiling Point (°C)

Component

78

Change during transport: cause

� Components with lowest boiling points will evaporate first

-195,9Nitrogen

69Hexane

36N-Pentane

28Iso Pentane

-0,5N-Butane

-11,7Iso Butane

-42,1Propane

-88,6Ethane

-162Methane

Boiling Point (°C)

Component

Temp LNG = -160 °C

Product becomes richer

79

Change during transport: Mavg

� Components with lowest BP have lowest Mi

28,013-195,9Nitrogen

86,17569Hexane

72,14936N-Pentane

72,14928Iso Pentane

58,122-0,5N-Butane

58,122-11,7Iso Butane

44,096-42,1Propane

30,069-88,6Ethane

16,042-162Methane

Mi (g/mol)

Boiling Point (°C)

Component

80

Change during transport: Mavg

16.8016.54Mavg [kg/kmol]

0.00560.0122Nitrogen

0.0000

0.0039

0.1267

0.1590

0.6465

3.2654

95.7928

Discharge port

0.0002

0.0017

0.0554

0.0735

0.3648

2.4270

97.0651

Load port

n-Pentane

Iso Pentane

n-Butane

Iso Butane

Propane

Ethane

Methane

Component

81

Change during transport: density

� Density ~ composition and temperature

� Calculation density @ fixed temperature= -160 °C

� Calculation Klosek-Mckinley

82

Change during transport: density @ -160 °C

430.59Density [kg/m³]

0.0122Nitrogen

0.0002n-Pentane

0.0017Iso Pentane

0.0554n-Butane

0.0735Iso Butane

0.3648Propane

2.4270Ethane

97.0651Methane

Load PortComponent

435.49

0.0056

0.0000

0.0039

0.1267

0.1590

0.6465

3.2654

95.7928

Discharge Port

83

Change during transport: GHVmass

� Hydrocarbons with lowest BP have highest Hmi

� Calculation GHV mass: ISO 6976 @ 15°C

0

20944

21085

21044

21300

21232

21654

22334

23892

Hmi (BTU/LB)

-195,9Nitrogen

69Hexane

36N-Pentane

28Iso Pentane

-0,5N-Butane

-11,7Iso Butane

-42,1Propane

-88,6Ethane

-162Methane

Boiling Point (°C)Component

84

Change during transport: GHVmass

55.3267GHVmass [MJ/kg]

0.0122Nitrogen

0.0002n-Pentane

0.0017Iso Pentane

0.0554n-Butane

0.0735Iso Butane

0.3648Propane

2.4270Ethane

97.0651Methane

Load PortComponent

55.2029

0.0056

0.0000

0.0039

0.1267

0.1590

0.6465

3.2654

95.7928

Discharge Port

85

Change during transport: GHVvolume

� Hydrocarbons with lowest BP have lowest Hvi

� Calculation GHVvolume: ISO 6976 @ 15°C (ideal gas)

0,0

4756,0

4008,7

4000,9

3262,4

3252,0

2516,2

1769,7

1010,0

Hvi (BTU/SCF)

-195,9Nitrogen

69Hexane

36N-Pentane

28Iso Pentane

-0,5N-Butane

-11,7Iso Butane

-42,1Propane

-88,6Ethane

-162Methane

Boiling Point (°C)Component

86

Change during transport: GHVvolume

38.703GHVvol [MJ/m³]

0.0122Nitrogen

0.0002n-Pentane

0.0017Iso Pentane

0.0554n-Butane

0.0735Iso Butane

0.3648Propane

2.4270Ethane

97.0651Methane

Load PortComponent

39.242

0.0056

0.0000

0.0039

0.1267

0.1590

0.6465

3.2654

95.7928

Discharge Port

87

Change during transport: High Nitrogen content

� Cargo with high N2 content!!

• Methane may increase due to a high decrease in Nitrogen

• In this case the molar GHV (mass based) may also increase

=> Behaviour of GHV (mass based) during transport depends highly on the composition of the cargo!!

88

Change during transport: High Nitrogen content

41,552Hv (ISO 6976 - 0°C) [MJ/m³]

54,4845Hm (ISO 6976 - 0°C) [MJ/kg]

442,2649Density @ -160°C [kg/m³]

0,8100Nitrogen

0,0000N-Hexane

0,0000N-Pentane

0,0000Iso Pentane

0,0200N-Butane

0,0200Iso-Butane

0,3500Propane

5,9800Ethane

92,8200Methane

Load Port

41,789

54,8025

441,9915

0,4400

0,0000

0,0000

0,0000

0,0200

0,0200

0,3800

6,2200

92,9200

Discharge Port

89

Change during transport: overview

� Components with lowest BP evaporate first

• Percentage nitrogen and methane will decrease

• All other percentages (heaviest components) will increase

� Consequences

• Molecular weight of mix will increase

• Density will increase

• Molar GHV on volume basis will increase

• Molar GHV on mass basis will decrease

� Remark: High nitrogen content

• Density may decrease

• Molar GHV on mass basis may decrease

• Molar GHV on volume basis will increase

90

Change during transport: Quantity

� Change in Quality

� Change in Quantity• Gas used as a fuel: dual - firing

• Determined by experience– Weather ?

– Direction waves ? ( motion of the ship ? )

– Cargo handling ? (Gas – Gas, Fuel – Fuel, TK pressure …)

– Length voyage ? ( at anchor, drifting )

– Composition ?

– Volume Vessel

– Age Vessel

– Insulation

– Etc

• Has to comply with the limit described in Charter Party– Exception Gas – Gas

91

Change during transport

� Prediction based on experience

3. Custody Transfer Instruments

93

Role of CTS

Custody Transfer System

94

Components for CTS

� Temperature gauging system

• Temperature sensors

• Temperature indication system

� Pressure gauging system

• Combined test for pressure sensor and indication system

� Trim List inclinometer

• Trim List sensor

• Trim List interface

� Level Measurement system

95

Level Measurement system

� Types

• Float gauge

• Capacitance gauge

• Radar system

� Two types are installed

• Primary system

• Secondary system

96


� Float gauge• Serving as a secondary gauge

• Float hanging on a ribbon

• Recording rotation of cycles on drum

• Local and remote readout

• Accuracy in range of ± 4 mm to ± 8 mm

• Corrections to be applied

– Trim

– List

– Density of LNG, Affects float buoyancy

– Correction for thermal contraction/expansion of wire

• Commercial manufactures

– Whessoe

– Enraf

97

FLOAT GAUGE

98

FLOAT GAUGE

99


� Capacitance gauge• Consists of two concentric aluminium tubes

• LNG will fill the space between the tubes

• Level to be determined by measuring the change in capacitance

• Accuracy ± 7.5 mm


– Trim

– List

100

CAPACITANCE GAUGE

101

CAPACITANCE GAUGE

1. Outer aluminium tube

2. Inner aluminium tube

3. Concentric electrical insulator

4. Isolation of inner tube sections by a gap

or dielectic plug

5. Isolation from the tank bottom

6. Bolting together the sections of the outer

tube making a single electrical conductor

7. Transfer line of the signals from the

outer tube and each centre of the inner

tube to a control junction box outside the

cargo tank

8. LNG cargo tank

102


� Microwave gauge• The same principle as a ship’s radar

• Transmitter mounted on top cargo tank

• Emits radar waves to surface of liquid

• Signal reflects

• Signal received by transmitter’s antenna

• Sent back to the control panel and processed

• Accuracy better than ± 7.5 mm


– Trim

– List

103

RADAR GAUGE

104

RADAR GAUGE

Limitation of CT Instruments

106

Limitation of CT Instruments

� During Cooling Down

• Cooling down creating a kind of fog

• Limits cooling down should be respected

� Measuring Heel

• Level indicating liquid, however it’s out of the measurable range

4. Principles of LNG sampling

108

Traditional sampling

� Traditional Liquid Gas sampling

• Sample points/pipes

• Liquid filling of container

• Vapor sampling

109

LNG sampling

� Spot sampling

Vapor Liquid

Sprayline

?

110


� Traditional Sampling points are of No use

� Sampling creates boiling effect

� Boiling creates fractionation

Top 1Middle 2 Bottom 3Sump 4

1

2

34

111

Problem

� Fractionation effect

� Boiling Points

• N2 = -196 C

• C1 = -162 C

• C2 = - 88 C

• C3 = - 42 C

• C4 = - 5 C

• C5 = 36 C…………..

112

Problem

� Gas volume/liquid volume effect

• N2 = 205

• C1 = 619

• C2 = 619

• C3 = 413

• C4 = 311

• C5 = 311

113


� Traditional Liquid Gas sampling

• NOT POSSIBLE FOR LNG

• Fractionation effect

• Gas volume/liquid volume effect

114

Solution

� Sampling LNG

• VAPOR?

• LIQUID?

• VAPORIZED LIQUID?

115

Solution

� Sampling LNG ?

• VAPOR SAMPLE = Possible, but useless

• LIQUID SAMPLE = Not possible

Due to LNG critical P/T values

• VAPORIZED LIQUID = Yes, only alternative

116

LNG sampling

� Sampling features

• Sampling variables/Controled conditions

• Sample location/frequency

• Sampling point– Shape

– Flow rate

– Location

• insulation sampling line

• Sample Vaporizer– Outlet Temp

– Inlet Temp

5. Energy Calculation(Klosek McKinley density routine)

118

Transferred energy

• Etransferred = energy transferred from loading facilities to LNG carrier of

from LNG carrier to unloading facilities

• DLNG = Density of LNG loaded or unloaded (kg/m³)

• VLNG = Volume of LNG loaded or unloaded (m³)

• GHV = Gross Heating Value of LNG loaded or unloaded (MJ/kg or

MMBTU/kg): quantity of heat produced by complete combustion in air of a unit of

volume or mass of the gas, at a constant absolute pressure of 1,01325 bar and at a

temperature T

• Egas displaced = quantity of energy in gaseous form displaced during loading

or unloading (MMBTU)

displacedgasLNGLNGLNGdtransferre EGHVVDE ** −=

119

KMK Density

� Klosek McKinley density

• Easy to apply

• Requires only the LNG temperature and composition to betaken into account

• Application limits:

– min 60% CH4

– max 4% C4

– Max 4% N2

– Temp. < 115 K

120

KMK Density

� Klosek Mc Kinley density calculation routine - revised

• Mixture molar mass determined by composition and dependent of temperature

• Mixture True Molar volume = mixture pseudo molar volume –volume reduction

volumetruemixture

massmolarmixtureDensity

=

121

Mixture true volume

� Mixture true volume?

V1 = 100 liter of ping-pong balls

V2 = 100 liter of footballs

volume of the mixture?

volumetruemixture

massmolarmixturedensity

=

122

Mixture true volume

+

V1 = 100 L V2 = 100 L

Vtot = ??? L ??

123

Mixture true volume

124

Mixture true volume

125

KMK Density

� The determination of the Mixture Molar Mass (ISO 6976-95)

Molar Molecular Molar

Fraction Mass Mass

Components (Xi)-g/mol (Mi)-g/mol (Xi * Mi)-g/mol

Methane 0,89235 16,0430 14,315971

Ethane 0,08267 30,0700 2.485887

Propane 0,01313 44,0970 0,578994

Iso Butane 0,00167 58,1230 0,097065

N-Butane 0,00277 58,1230 0,161001

Iso Pentane 0,00011 72,1500 0,007937

N-Pentane 0,00000 72,1500 0,00000

N-Hexane 0,00000 86,1770 0,00000

Nitrogen 0,00730 28,0130 0,204499

Oxygen 0,00000 31,9990 0,00000

Carbon Dioxide 0,00000 44,0100 0,00000

1,00000 17.851353 = mixture molar mass

126

KMK Density

� The determination of the Mixture Pseudo Molar Volume

Molar Molecular Vol. Molar Vol.

Fraction m3 / kmole m3 / kmole

Components (Xi) (Vi) (Xi * Vi)

Methane 0,892350 0,038046 0,033950

Ethane 0,082670 0,047877 0,003958

Propane 0,013130 0,062427 0,000820

Iso Butane 0,001670 0,078274 0,000131

N-Butane 0,002770 0,076801 0,000213

Iso Pentane 0,000110 0,091637 0,000010

Nitrogen 0,007300 0,046491 0,000339

1,000000 0,039421 = mixture pseudo molar volume

127

KMK Density

� Determination of the Mixture True Molar Volume

True mixture Molar volume = Σ ( Xi * Vi ) - Xm * C

Xm * C = volume reduction factor

With C = K1 + ((K2 – K1) * Xn/0,0425)

K1 and K2 correction factors depending on the mixture

molecular weight and the LNG liquid temperature

Xn molar fraction of nitrogen

Xm molar fraction of methane

128

KMK Density

� Determination of the Mixture True Molar Volume

True mixture Molar volume = Σ Σ Σ Σ ( Xi * Vi ) - Xm * C

C = K1 + ((K2 – K1) * (Xn/0,0425))

K1 and K2 at 112.38 and with MM 17.851353 g/mol

K1 = 0.000376 l/mol

K2 = 0.000609 l/mol

C = 0.000376 + ((0.000609 - 0.000376) x (0.0073/0.0425)

C = 0.000416

Xm*C = 0.89235 x 0.000416 = 0.000371

True Molar Volume = 0.03941 – 0.000371 = 0.039050 l/mol

129

KMK Density

� Klosek – McKinley density calculation routine -revised

Density = mixture molar mass

mixture true molar volume

Density = 17.851353 = 457.140922 kg/m³

0.039050

5. Quantity calculation routine (Energy)

131

Transferred energy








temperature T




132

Quantity calculation

� Liquid Quantity?

Expressed in Energy terms:

Liquid mass x GCV liquid (mass)

GCV: Gross Calorific Value

units? Kg x MJ/kg = MJ

MJ →→→→ BTU →→→→ MMBTU

133

Heating values

� Heating values?

• Vapour

• Liquid

134

Heating values

� Heating values?

• GHV (Gross heating value)

• HHV (Higher heating value)

• GCV (Gross calorific value)

135

Measurements

� Temperature of LNG liquid and vapour phase

� Level

• Corrections on level measurement

– Trim

– List

– Temperature

• Determine volume from gauge tables

� Pressure

136

Quality and quantity

� Volume before/after loading

� Laboratory analysis

• Density of LNG

• GCV of gas displaced

• GCV of LNG

E = (VLNG * DLNG * GCVLNG) – Egas displaced

137

Composition calculation

� Xi molar fraction: ratio of the number of moles of the component to the total number of moles in a mixture

• Gas chromatograph

� Mi (kg/kmol) molecular weight• norm

� Xi*Mi (kg/kmol) molar mass

� Vi (m³/kmol) molecular volume• norm

• Interpolation for T

� Vi*Xi (m³/kmol) molar volume

� Hmi (MJ/kg) molecular GHV: quantity of heat produced bycomplete combusion in air of a unit of volume or mass of the gas, at a constant absolute pressure of 1.01325 bar and at a temperature T

• Norm

� Xi*Hmi*Mi (MJ/kg) molar GHV

138

Tables Vi (norm: NBSI report 77-867)

0,027950 0,027650 0,027300 0,027200 0,027000 0,026700 0,026400 Carbon Dioxide

0,033670 0,032750 0,031910 0,031510 0,031150 0,030450 0,029800 Oxygen

0,055877 0,051921 0,048488 0,046995 0,045702 0,043543 0,041779 Nitrogen

0,106020 0,105570 0,105122 0,104899 0,104677 0,104236 0,103800 N-Hexane

0,092643 0,092217 0,091794 0,091583 0,091373 0,090953 0,090535 N-Pentane

0,092817 0,092377 0,091939 0,091721 0,091504 0,091071 0,090641 Iso Pentane

0,077847 0,077456 0,077068 0,076876 0,076684 0,076303 0,075926 N-Butane

0,079374 0,078962 0,078554 0,078352 0,078151 0,077751 0,077356 Iso Butane

0,063417 0,063045 0,062678 0,062497 0,062316 0,061957 0,061602 Propane

0,048805 0,048455 0,048111 0,047942 0,047774 0,047442 0,047116 Ethane

0,039579 0,038983 0,038419 0,038148 0,037884 0,037375 0,036890 Methane

-150-154-158-160-162-166-170Temperature

139

Determination Vi at Tliq = -162.39°C

0.0269710.0270000.027600Carbon dioxide

0.0310820.0311500.030450Oxygen

0.0454910.0457020.043543Nitrogen

0.1046340.1046770.104236N-Hexane

0.0913320.0913730.090953N-Pentane

0.0914620.0915040.091071Iso-Pentane

0.0766470.0766840.076303N-Butane

0.0781120.0781510.077751Iso Butane

0.0622810.0623160.061957Propane

0.0477420.0477740.047442Ethane

0.0378340.0378840.037375Methane

Vi at -162.39°CVi at -162°CVi at -166°CComponent

)(*))/()(( 112121 TTTTVVVV TTTT −−−+=

037834.0))166(39.162(*))166(162(

)037375.0037884.0(037375.0 =−−−

−−−

−+

140

Composition calculation

976.96670.03952218.2101.0000TOTALS:

0.00000.0000.0000000.0269710.00044.0100.0000Carbon Dioxide

0.00000.0000.0000000.0310820.00031.9990.0000Oxygen

0.00000.0000.0005640.0454910.33628.0130.0120Nitrogen

0.000048.7190.0000000.1046340.00086.1780.0000N-Hexane

0.000049.0530.0000000.0913320.00072.1510.0000N-Pentane

0.000048.9440.0000000.0914620.00072.1510.0000Iso-Pentane

12.094749.5440.0003220.0766470.24458.1240.0042N-Butane

8.901549.4020.0002420.0781120.18058.1240.0031Iso Butane

45.776950.3930.0012830.0622810.90844.0970.0206Propane

126.786951.9260.0038770.0477422.44230.0700.0812Ethane

783.406755.5600.0332520.03783414.10016.0430.8789Methane

Xi*Mi*Hmi

MJ/kg

Hmi

MJ/kg

Vi*Xi

m³/kmol

Vi

m³/kmol

Xi*Mi kg/kmol

Mi kg/kmol

Xicomponents

GC norm Multiply 2 previous columnsNorm + interpolationMultiply 1st and 4th columnnormMultiply 1st, 2nd, 6th column

141

Density calculation

� Revised Klosek McKinley density calculation

0.0425

Density = Σ ( Xi * Mi )

Σ ( Xi * Vi ) – [(k1 + (k2 – k1)*Xn) * Xm]

• k1 and k2 correction factors depending on molar mass and the T of

the LNG

• Xm molar fraction of methane

• Xn molar fraction of nitrogen

Application limits:

• min 60 % CH4

• max 4 % C4

• max 4 % N2

• T < 115 K

142

Tables k1 (norm: NBSI Report 77-867)

0,002238 0,002043 0,001867 0,001790 0,001714 0,001567 0,001435 30,00,001782 0,001619 0,001475 0,001407 0,001339 0,001220 0,001116 25,00,000976 0,000881 0,000793 0,000757 0,000721 0,000654 0,000590 20,00,000932 0,000842 0,000757 0,000722 0,000688 0,000622 0,000561 19,80,000888 0,000803 0,000721 0,000688 0,000655 0,000590 0,000532 19,60,000844 0,000763 0,000685 0,000653 0,000622 0,000558 0,000503 19,40,000800 0,000724 0,000649 0,000619 0,000589 0,000526 0,000474 19,20,000757 0,000685 0,000613 0,000584 0,000556 0,000494 0,000445 19,00,000717 0,000645 0,000575 0,000548 0,000523 0,000467 0,000421 18,80,000677 0,000605 0,000537 0,000513 0,000489 0,000440 0,000397 18,60,000637 0,000566 0,000499 0,000477 0,000456 0,000412 0,000373 18,40,000597 0,000526 0,000460 0,000441 0,000423 0,000385 0,000349 18,20,000557 0,000486 0,000422 0,000405 0,000389 0,000357 0,000325 18,00,000502 0,000438 0,000382 0,000366 0,000351 0,000321 0,000293 17,80,000447 0,000390 0,000342 0,000327 0,000312 0,000286 0,000260 17,60,000392 0,000342 0,000301 0,000287 0,000274 0,000250 0,000228 17,40,000337 0,000293 0,000261 0,000248 0,000235 0,000214 0,000195 17,20,000282 0,000245 0,000221 0,000209 0,000197 0,000179 0,000163 17,00,000135 0,000118 0,000106 0,000100 0,000094 0,000086 0,000078 16,5

-0,000012 -0,000010 -0,000009 -0,000009 -0,000008 -0,000007 -0,000007 16,0

-150-154-158-160-162-166-170

143

Determination of k1 at Tliq = -162.39°C

0.0004560.00041218.4 g/mol

0.0004230.00038518.2 g/mol

-162°C-166°CTliq

Σ(Xi*Mi)

)(*))/()(( 112121 TTTTkkkk TTTT −−−+=

000419.0))166(39.162(*))166(162(

)000385.0000423.0(000385.0 =

−−−

−−−

−+

Interpolation for temperature for both molar masses:

000452.0))166(39.162(*))166(162(

)000412.0000456.0(000412.0 =

−−−

−−−

−+

Σ(Xi*Mi) = 18.2 g/mol

Σ(Xi*Mi) = 18.4 g/mol

144

Determination of k1 at Tliq = -162.39°C and Σ(Xi*Mi) = 18.210 g/mol

Interpolation for molar mass (MM) at Tliq = -162.39°C

0.000456

0.000423

-162°C

0.000452

0.000419

-162.39°C

0.00041218.4 g/mol

0.00038518.2 g/mol

-166°CTliq

Σ(Xi*Mi)

)(*))/()((112121 ∑∑∑∑ −−

∑−

∑+

∑=

∑MMMMMMMMkkkk

MMMMMMMM

000421.0)2.18210.18(*)2.184.18(

)000419.0000452.0(000419.01 =

−

−

−+=k

145

Tables k2 (norm: NBSI Report 77-867)

0,003723 0,003230 0,002806 0,002631 0,002459 0,002172 0,001934 30,00,002734 0,002374 0,002014 0,001893 0,001777 0,001562 0,001383 25,00,001619 0,001382 0,001158 0,001065 0,000973 0,000823 0,000709 20,00,001573 0,001342 0,001118 0,001029 0,000941 0,000794 0,000681 19,80,001526 0,001302 0,001078 0,000992 0,000908 0,000765 0,000652 19,60,001480 0,001262 0,001038 0,000956 0,000876 0,000737 0,000623 19,40,001434 0,001222 0,000998 0,000920 0,000844 0,000708 0,000594 19,20,001388 0,001182 0,000958 0,000883 0,000811 0,000679 0,000566 19,00,001320 0,001121 0,000912 0,000841 0,000773 0,000642 0,000531 18,80,001252 0,001061 0,000865 0,000799 0,000735 0,000605 0,000496 18,60,001184 0,001000 0,000819 0,000756 0,000696 0,000567 0,000460 18,40,001116 0,000939 0,000772 0,000714 0,000658 0,000530 0,000425 18,20,001049 0,000878 0,000726 0,000672 0,000620 0,000493 0,000390 18,00,000973 0,000816 0,000664 0,000613 0,000564 0,000449 0,000354 17,80,000897 0,000754 0,000602 0,000554 0,000508 0,000406 0,000318 17,60,000821 0,000692 0,000540 0,000495 0,000452 0,000362 0,000282 17,40,000745 0,000630 0,000478 0,000436 0,000397 0,000318 0,000246 17,20,000669 0,000568 0,000416 0,000377 0,000341 0,000274 0,000210 17,00,000315 0,000269 0,000196 0,000178 0,000162 0,000131 0,000101 16,5-0,000039 -0,000031 -0,000024 -0,000021 -0,000017 -0,000012 -0,000009 16,0

-150-154-158-160-162-166-170

146

0.0006960.00056718.4 g/mol

0.0006580.00053018.2 g/mol

-162°C-166°CTliq

Σ(Xi*Mi)

Determination of k2 at Tliq = -162.39°C and Σ(Xi*Mi) = 18.210 g/mol

Interpolation for temperature and Σ(Xi*Mi)

Same as for k1

k2 = 0.00674

147

Density calculation

0.0425


Σ ( Xi * Vi ) – [(k1 + (k2 – k1)*Xn) * Xm]

Σ (Xi * Mi) = 18.210

Σ (Xi * Vi) = 0.039522

k1 = 0.000421

k2 = 0.000647

Xn = 0.0120

Xm = 0.8789

⇒ Density = 465.78 kg/m³

constant

148

Higher heating values

∑∑

=)*(

)**(

MiXi

MiHmiXiHm

kgMJHm /53.6500210.18

9667.976==

149

Consumed energy

� Energy of gas consumed

• E gas consumed =

V gas.metered x GCV gas

(GCV gas => MMBTU/m3) – (ISO 6976)

150

BTU quantity delivered

MMBTUVDH

Q LNGmtotal 904749

12.1055

400.38201*78.465*6500.53

12.1055

**===

MMBTUP

TVQ

vap

LNGr 366312.1055

7.37*

25.1013*

15.273

15.288* =

+=

MMBTUQQQ rtotalnet 9010863663904749 =−=−=

Conversion factor MJ → MMBTU

GCV of 100% CH4 at 1013.25mbar and 15°CStandard temperature

Standard pressure

5. Quantity calculation routine :- Wobbe index

152

Wobbe index

� Interchangeable?

substitute gas yields same results in the combustion process as the original gas

� Determining interchangeability?

Wobbe index: measure of the energy flow through a nozzle

Qv = flow rate

P = static pressure

DP = differential pressure

SG = specific gravity

T = temperature

C = constant based on geometry

5,0)*/*(* TSGDPPCQv =

153

Wobbe index

� Energy flow would be:

HV = Heating Value

� For constant pressure and T:

⇒ for the same pressure at the burner, gases of equal Wobbe Index will generate heat at equal rates per unit of burner port area.

5,0)*/*(*** TSGDPPCHVHVQE v ==

indexWobbeSG

HVE ~

5,0=

154

Wobbe index (norm: ISO 6976:1995)

density gas relative

H index wobbe

gas v=

mix

vi

Z

HXi∑=

)*(H gas v

2))*((1 ∑−= imix bXiZ

Hvi = ideal calorific value on a volumetric basis of component i

Z = compression factor

Root bi = summation factor

mix

airair

ii

rZ

ZMM

X

D∑

=*

*()

155

0,628743,598000,000000,996864Z=100,0000TOTALS:

0,00000,00000,000000,000000,00000,081900,00000,0000Carbon

Dioxide

0,00000,00000,000000,000000,00000,031600,00000,0000Oxygen

0,01160,96720,000000,000000,00030,0224028,01401,1980Nitrogen

0,00002,97540,00000187,300000,00000,3286086,17600,0000N-Hexane

0,00002,49110,00000157,870000,00000,2864072,14980,0000N-Pentane

0,00002,49110,00000157,570000,00000,2510072,14980,0000Iso-Pentane

0,00842,00680,53700128,480000,00090,2069058,12300,4180N- Butane

0,00632,00680,40210128,070000,00060,2049058,12300,3140Iso Butane

0,03131,52252,0373099,090000,00300,1453044,09622,0560Propane

0,08431,03825,6616069,690000,00810,1000030,07008,1240Ethane

0,48680,553934,9600039,777000,04310,0490016,043087,8900Methane

Xi*Mi/MairMi/MairMJ/m³Xi*Hvi

MJ/m³ HviXi*Root(Bi)Root(Bi)MiXi

Components

Mair=28.9626

normGC

(1)*(3) (1)*(5) (1)*(7)(2)/28.9626

156

Wobbe index

3

gas v /74.43996864.0

59800.43)*(H mMJ

Z

HXi

mix

vi===

∑

6303.0996864.0

99941.0*6287.0**(

D)

r ===∑

mix

airair

ii

Z

ZMM

X

³/09.556306.0

74.43

density gas relative

H index wobbe

gas vmMJ===

5. Quantity calculation routine :- Exercise

158

Exercise

• Tliq = -159.5°C

• Tvap = - 112.8

• P = 1195 mbar

• V = 126589 m³

Composition:

0.0000Carbon dioxide

0.0000Oxygen

0.0008Nitrogen

0.0000N-Hexane

0.0000N-Pentane

0.0004Iso-Pentane

0.0032N-Butane

0.0029Iso butane

0.0191Propane

0.0416Ethane

0.9320Methane

Molar fractioncomponent

159

Exercise

� Calculate with previous methods

• Density

• Hm

• Qtotal

• Qr

• Qnet

160

Exercise

1. Density

a) Σ (Xi*Mi)

17.4511.0000TOTALS

0.00044.0100.0000Carbon dioxide

0.00031.9990.0000Oxygen

0.02228.0130.0008Nitrogen

0.00086.1780.0000N-Hexane

0.00072.1510.0000N-Pentane

0.02972.1510.0004Iso-Pentane

0.18658.1240.0032N-Butane

0.16958.1240.0029Iso butane

0.84244.0970.0191Propane

1.25130.0700.0416Ethane

14.95216.0430.9320Methane

Xi*MiMiXicomponent

161

Exercise

0,027300

0,031910

0,048488

0,105122

0,091794

0,091939

0,077068

0,078554

0,062678

0,048111

0,038419

-158

0.027225

0.031610

0.047368

0.104955

0.091636

0.091776

0.076924

0.078403

0.062542

0.047984

0.038216

-159.5

0,027200 Carbon Dioxide

0,031510 Oxygen

0,046995 Nitrogen

0,104899 N-Hexane

0,091583 N-Pentane

0,091721 Iso Pentane

0,076876 N-Butane

0,078352 Iso Butane

0,062497 Propane

0,047942 Ethane

0,038148 Methane

-160Temperature

1. Density

b) Interpolation for Vi and calculation Σ (Xi * Vi)

162

Exercise

0.027225

0.031610

0.047368

0.104955

0.091636

0.091776

0.076924

0.078403

0.062542

0.047984

0.038216

Vi

0.0000

0.0000

0.0008

0.0000

0.0000

0.0004

0.0032

0.0029

0.0191

0.0416

0.9320

Xi

0.039356TOTALS

0.000000Carbon dioxide

0.000000Oxygen

0.000038Nitrogen

0.000000N-Hexane

0.000000N-Pentane

0.000037Iso-Pentane

0.000246N-Butane

0.000227Iso butane

0.001195Propane

0.001996Ethane

0.035617Methane

Xi*Vicomponent

163

Exercise

0,000342

0,000301

-158

0.000331

0.000291

-159.5

0,000327 17,6

0,000287 17,4

-160

1. Density

c) Interpolation for k1 and k2

k1 = 0.000301

0,000602

0,000540

-158

0.000566

0.000506

-159.5

0,000554 17,6

0,000495 17,4

-160

k2 = 0.000521

164

Exercise

1. Density

d) Calculation of density

0.0425


Σ ( Xi * Vi ) – [(k1 + (k2 – k1)*Xn) * Xm]

³/64.446

9320.0*0425.0

0008.0*)000301.0000521.0(000301.0039356.0

451.17mkgdensity =

−+−

=

165

Exercise

2. Calculation Hm

957.0905TOTALS

0.00000.000Carbon Dioxide

0.00000.000Oxygen

0.00000.000Nitrogen

0.000048.719N-hexane

0.000049.053N-Pentane

1.412548.944Iso-Pentane

9.215049.544N-Butane

8.327249.402Iso Butane

42.443650.393Propane

64.954951.926Ethane

830.737355.560Methane

Xi*Hmi*MiHmicomponent

166

Exercise

kgMJMiXi

MiHmiXiHm /8445.54

451.17

0905.957

)*(

)**(===

∑∑

167

Exercise

MMBTUVDH

Q LNGmtotal 2939109

12.1055

126598*64.446*8445.54

12.1055

**===

MMBTU

P

TVQ

vap

LNGr

9586

12.1055

7.37*

25.1013

1195*

8.11215.273

15.288

12.1055

7.37*

25.1013*

15.273

15.288* =

−=

+=

3. Calculation Qtotaal, Qr, Qnet

MMBTUQQQ rtotalnet 292952395862939109 =−=−=

6. Lay out and equipment of LNG vessels

169

� Lay-out & equipment LNG

• Cargo piping system

– Liquid Header

– Vapour Header

– Stripping header

– Gas header

– Gas to Engine

– Vent line

– Inerting line

– N2 line ( prim. and sec barrier )

170

LAY OUT

7. Cargo Handling: Preparation

172

� Readiness• Pre – arrival tests

– Test of main fire pump and emergency fire pump

– Test of all fire and spray valves

– Test of gas detector

– Test of Emergency Shut Down

– Closing time manifold valves

– Test of H, HH, VH and EH levels cargo tanks and automatic closing of filling valves

– Megger-Ohm test of Cargo pumps

– Ship / Shore Connection

173

� Readiness

• Preparation of a ship before loading– After dry dock

» Inserting dry air ( bottom in – top out )

» Inerting the tanks ( Bottom in – top out )

o Why: to get out the flammable range

» Gas filling ( top in – bottom out )

o Why: carbondioxide freezes and produces white powder

– Cooling down» Why: limiting boil off & capacity of nitrogen generator & to

avoid metal cracks

• After ballast voyage– Long voyage

» Gathering LNG into one tank

» Before arrival: cooling down

– Short voyage» LNG in all tanks

» Before arrival: cooling down

174

Leaving Drydock

175

INSERTING DRY AIR

176

Inserting dry air

� Bottom in – Top out

� Drying tanks: What’s the danger of wet air inside?• Forming ice

• Formation of corrosive agents

� Measurement• Dewpoint meter

• Dewpoint : - 40°C

� Time needed:• +/- 20 hours

177

Wet air – dry air

� Density

• Mass divided by volume (m/V)

• Increases when

– Mass increases while volume remains constant

– Volume decreases while mass remains constant

� Composition of air (T = 15°C; P = 101325 Pa)

0.0000087 %XeXenon

0.00005 %HHydrogen

0.000114 %KrKrypton

0.000524 %HeHelium

0.0002 %CH4Methane

0.001818 %NeNeon

0.0314 %CO2Carbon Dioxide

0.934 %ArArgon

20.9476 %O2Oxygen

78.084 %N2Nitrogen

Percent by volumeSymbolName

178

Wet air – dry air

� Density of air

• Varies with T and moisture

– T increase – higher molecular motion – expansion of volume

» DECREASE IN DENSITY

– Two most abundant elements in air : O2 and N2

» O2 = 32 g/mol

» N2 = 28 g/mol

» H2O = 18 g/mol

H2O is a relatively light gas when compared with O2 and N2

When water vapor increases, the amount of O2 and N2 per unit volume will decrease – mass is decreasing

» DECREASE IN DENSITY

179

Wet air – dry air

D = density in kg/m³

Rdry air = R / Mair = 8.314510/0.028965 = 287,05 J/kg K

Rwater vapor = R/Mwater vapor = 8.314510/0.01801646 = 461.495

J/kg K

Pdry air = partial pressure of dry air in Pa

Pwater vapor = partial pressure of water vapor in Pa

T = temperature in K

Partial pressure = Molar fraction * total pressure

TR

P

TR

P

** D

rwater vapo

rwater vapo

airdry

airdry +=

180

Example calculation density air

Ptotal = 101325 Pa

T = 15 °C = 15 + 273.15 K = 288.15 K

• Dry air:

• Wet air:

Xwater vapor = 0.15

Xdry air = 0.85

³/ 2250.115.288*05.287

101325

* D

airdry

airdry mkg

TR

P===

³/ 1555.115.288*495.461

101325*15.0

15.288*05.287

101325*85.0

** D

rwater vapo

rwater vapo

airdry

airdry mkg

TR

P

TR

P=+=+=

181

INERTING

182

Flammable range

183

Inerting

� Bottom in – Top out

� Why:

• To get out the flammable range

� Specification:

• Oxygen content less than 1%

• Dewpoint below –40°C

� Remaining lines

• Nitrogen

184

GAS FILLING: STAGE 1

185

Gas Filling: Stage 1

� Top in – bottom out

� Why:

• Unlike N2 inert gas contains 15% carbondioxide

• Freezes and forms white powder

• Block valves, filters, nozzles

� Stage 1

• 5% methane

� Stage 2

• 80% Methane

• CO2 less than 1%

� Time needed

• 14h to 16h

186

GAS FILLING: STAGE 2

187

COOLING DOWN

188

Cooling down

� Limited

• To avoid active pump tower stress

• More boil off than the HD can handle

• To remain in the capacity of the nitrogen system (barriers)

� 6 Temp sensors

• Average lowest 4: -130°C

� First time loading

• More boil off (adjacent spaces still hot )

� Time needed

• +/- 10 hours

189

Entering drydock

190

LNG STRIPPING PUMP

� Stripping pump

• +/- 2 cm

� Heating up

• Recirculation heated vapour by two HD

• Excessive vapour: ventmast

� Purging

• Till hydrocarbon content is less than 1,5%

• +/- 20 hours

� Dry air

• Ready

– 20% O2

– Less than 0,2 volume% Methane

– Dewpoint below –40°C

191

TANK WARM UP

192

INERTING

193

AERATION

8. Cargo Handling & Control- loading- discharge

195

� Arrival in port• Connecting + Purging

• Safety meeting + checklist

• Stop gasburning

• ESD tests– Ship – Shore

– Shore – Ship

• Custody Transfer Inspection and Certification – Manifold closed

• Cooling down liquid lines + shore arms

• Start loading

• Loading completed

• Draining + purging

• Custody Transfer Inspection and Certification– Manifold closed

• Start gasburning

• Disconnecting

196

CARGO LINES COOL DOWN

197

LOADING WITH VAPOUR RETURN

198

CARGO LINES COOL DOWN

199

DISCHARGING WITH VAPOUR RETURN

200

� Custody transfer

• Ship side

– Survey or push on the button

• Surveyor

– Calculation primary system

– Calculation secondary system

– Calculation heel

– Calculation boil off

– Pressure

– Temperature

– Witnessing sampling

– Anticipate on any potential non-conformities

– Time-log and statements of facts

201


• Density

– Difference between density departure and density arrival

– Light product evaporates first

• GCV / GHV

– Gross Calorific Value / Gross heating Value

– GCV of gas corresponds to the quantity of heat produced by complete combustion in air of a unit of volume or mass of the gas

– Unit: BTU ( British Thermal Unit )

• Vapour return

202


• LNG report

– Summary of findings

– Certificate of analysis

– Calculation density, BTU,…

– Quantity calculation

» Primary

» Secondary

– Fuel oil bunkers

– Diesel oil bunkers

– General notes

» Vessel operation

» Shore operation

– Time log

– Note of protest

203

CUSTODY TRANSFER ( SHIP )

204


205


206

CUSTODY TRANSFER: SGS

CONTRACT # 1Page 1

TRUNKLINE LNG / LAKE CHARLES, LA

SGS Office :

2

3

4

SUMMARY OF FINDINGS

LNG QUANTITY REPORT

CLOSING CUSTODY TRANSFER REPORT - PRIMARY

CLOSING CUSTODY TRANSFER REPORT - SECONDARY

OPENING CUSTODY TRANSFER REPORT - PRIMARY

OPENING CUSTODY TRANSFER REPORT - SECONDARY

CERTIFICATE OF ANALYSIS

FUEL OIL BUNKER REPORT

DIESEL OIL BUNKER REPORT

GENERAL NOTES ON SHORE OPERATIONS

GENERAL NOTES ON VESSEL OPERATIONS

TIME LOG

LETTER OF PROTEST

Phone Number : 337-625-1455

:DATESSGS FILE #

:

R.U.R. / GDF INTL.1223

LIQUEFIED NATURAL GASDISCHARGE REPORT

:VESSEL NAME LNG HILLI258:

Date

29/jan/04

Lake Charles, La

TERMINAL / PORT

REFERENCE #

:::

CLIENTS

JANUARY 27-28, 2004710847

VOYAGE #

PAGEDOCUMENTS ENCLOSED

5

6

7

8

9

10

11

12

13.1-4

14.1-4

SGS NORTH AMERICA INC.

4701 EAST NAPOLEON STREET

SULPHUR, LOUISIANA 70663

ISSUANCE OF THIS CERTIFICATE DOES NOT EXONERATE BUYERS OR SELLERS FROM EXERCISING ALL THEIR RIGHTS AND

DISCHARGING ALL THEIR LIABILITIES UNDER THE CONTRACT OF SALE. STIPULATIONS TO THE CONTRARY ARE NOT

BINDING ON US. THE COMPANY'S RESPONSIBILITY UNDER THI

THIS CERTIFICATE REFLECTS OUR FINDINGS AT THE TIME AND PLACE INDICATED AND IS ISSUED IN PURSUANCE OF

PRINCIPALS INSTRUCTIONS AND IN CONFORMITY WITH OUR GENERAL CONDITIONS OF BUSINESS DERIVED FROM THOSE

OF THE INTERNATIONAL FEDERATION OF INSPECTION AGENCIE

Larry Wallace

9. The economical consequences in using different LNG standards

208

� Typical values

• 138000 m³

• 60000 tons of LNG

• 3130000 MMBTU

• US $ 6,807 / MMBTU

• 21 305 910 US $ / cargo

209

Transferred energy








temperature T




210

Displaced energy

• Egas displaced = energy of the gas which is

– sent back onshore by the LNG carrier when loading

– Received by the LNG carrier when unloading

• Tvap = mean value of the temperatures of the probes not immersed in LNG (°C)

• Pvap = absolute pressure in the tanks (bar)

• GHVgas = GCV of the gas in gaseous state contained in the ship’s tanks (MJ/m³

or MMBTU/m³)

gasvap

vapLNGdisplacedgas GHV

P

TVE *

01325.1*

15.273

15.273*

+=

211

Using different LNG standards

� International standards

• NBS Measurement Study – 1985

• ISO 13398 LNG procedure for Custody transfer on board ships

• G.I.I.G.N.L. LNG Custody Transfer Handbook

• ISO – GPA – IP – ASTM

• Klosek McKinley revised

212

Using different standards

� Xi, Xn, Xm determined by analysis in gas chromatograph• Xi: Molar fraction of the ith component

• Xn: Molar fraction of Nitrogen

• Xm: Molar fraction of Methane

� Mi by standard• Molecular mass of the ith component

� Vi by standard and dependent on Tliq

• Molecular volume of the ith component

� K1, k2 by standard and dependent on Tliq and molar mass• Correction factors for Nitrogen and Methane

0.0425


Σ ( Xi * Vi ) – [(k1 + (k2 – k1)*Xn) * Xm]

213


0,0002820,0001340,03848916,6750ISO 6578 & ISO 6578

0,0002360,0001300,03848516,6750ISO 6578 & NBS TN 1030

0,0002770,0001340,03848516,6750ISO 6578 & NBS IR 77-867

0,0002820,0001350,03848916,6754ISO 6976 & ISO 6578

0,0002360,0001300,03848516,6754ISO 6976 & NBS TN 1030

0,0002770,0001340,03848516,6754ISO 6976 & NBS IR 77-867

0,0002810,0001340,03848916,6744GPA 2145 & ISO 6578

0,0002360,0001300,03848516,6744GPA 2145 & NBS TN 1030

0,0002760,0001340,03848516,6744GPA 2145 & NBS IR 77-867

K2 factorK1 factorΣ(Xi*Vi)Σ(Xi*Mi)Used standard

214


434,7074ISO 6578ISO 6578

434,7078NBS TN 1030ISO 6578

434,7506NBS IR 77-867ISO 6578

434,7190ISO 6578ISO 6976

434,7194NBS TN 1030ISO 6976

434,7622NBS IR 77-867ISO 6976

434,6906ISO 6578GPA 2145

434,6911NBS TN 1030GPA 2145

434,7339NBS IR 77-867GPA 2145

Density (kg/m³)Used standard (k1, k2, Vi)Used standard (Mi)

MIN

MAX

Difference between min and max = 0,0716 kg/m³

⇒⇒⇒⇒ US $ 3540

215


� Xi determined by analysis in gas chromatograph

� Hmi by standard

• Molecular Gross Heating Value

� Mi by standard

∑∑

=)*(

)**(

MiXi

MiHmiXiHm

216


44,009844,010044,010Carbon Dioxide

28,013428,013528,013Nitrogen

86,176686,177086,175N-Hexane

72,149872,150072,149Iso Pentane

72,149872,150072,149N-Pentane

58,123058,123058,122Iso Butane

58,123058,123058,122N-Butane

44,096244,097044,096Propane

30,069430,070030,069Ethane

16,042616,043016,042Methane

Mi (ISO 6578)Mi (ISO 6976)Mi (GPA 2145)Component

217

Using Different LNG Standards

0,0000,0000,000Carbon Dioxide

0,0000,0000,000Nitrogen

48,71648,72048,717N-Hexane

48,93948,95048,950Iso Pentane

49,05149,04049,046N-Pentane

49,39749,39049,389Iso Butane

49,54149,55049,547N-Butane

50,38950,37050,370Propane

51,92551,95051,952Ethane

55,55855,57455,576Methane

Hmi (ISO 6578)Hmi (ISO 6976)Hmi (GPA 2145)Component

218


921,5721

921,5947

921,3032

Σ (Xi*Mi*Hmi)

16,6744GPA 2145

16,6754ISO 6976

16,6750ISO 6578

Σ (Xi*Mi)Used standard

219


55,2686GPA 2145

55,2667ISO 6976

55,2506ISO 6578

GHV (MJ/kg)Used standard

MIN

MAX

Difference between min and max = 0,018 MJ/kg

⇒⇒⇒⇒ US $ 7011

220


� Combination of D and GHV to calculate Etransferred

⇒ 27 different results between 3131171 MMBTU and 3132717 MMBTU

⇒⇒⇒⇒ US $ 10524

221

3132209,441610197,03563142406,4771434,7074ISO 6578 & ISO 657855,2667ISO 6976138000,000

3132212,458610197,03563142409,4941434,7078ISO 6578 & NBS TN 103055,2667ISO 6976138000,000

3132521,977210197,03563142719,0128434,7506ISO 6578 & NBS IR 77-86755,2667ISO 6976138000,000

3132293,312010197,03563142490,3476434,7190ISO 6976 & ISO 657855,2667ISO 6976138000,000

3132296,055710197,03563142493,0913434,7194ISO 6976 & NBS TN 103055,2667ISO 6976138000,000

3132605,770610197,03563142802,8061434,7622ISO 6976 & NBS IR 77-86755,2667ISO 6976138000,000

3132087,994710197,03563142285,0303434,6906GPA 2145 & ISO 657855,2667ISO 6976138000,000

3132091,407410197,03563142288,4429434,6911GPA 2145 & NBS TN 103055,2667ISO 6976138000,000

3132400,641910197,03563142597,6775434,7339GPA 2145 & NBS IR 77-86755,2667ISO 6976138000,000

3132320,919510197,03563142517,9551434,7074ISO 6578 & ISO 657855,2686GPA 2145138000,000

3132323,936610197,03563142520,9722434,7078ISO 6578 & NBS TN 103055,2686GPA 2145138000,000

3132633,466310197,03563142830,5018434,7506ISO 6578 & NBS IR 77-86755,2686GPA 2145138000,000

3132404,792910197,03563142601,8285434,7190ISO 6976 & ISO 657855,2686GPA 2145138000,000

3132407,536710197,03563142604,5723434,7194ISO 6976 & NBS TN 103055,2686GPA 2145138000,000

3132717,262610197,03563142914,2982434,7622ISO 6976 & NBS IR 77-86755,2686GPA 2145138000,000

3132199,468410197,03563142396,5039434,6906GPA 2145 & ISO 657855,2686GPA 2145138000,000

3132202,881110197,03563142399,9167434,6911GPA 2145 & NBS TN 103055,2686GPA 2145138000,000

3132512,126710197,03563142709,1622434,7339GPA 2145 & NBS IR 77-86755,2686GPA 2145138000,000

Qnet (MMBTU)Qr(MMBTU)

Qtotal(MMBTU)

D (kg/m³)Hm (Mj/kgV (m³)

222

3131292,524410197,03563141489,5600434,7074ISO 6578 & ISO 657855,2506ISO 6578138000,000

3131295,540510197,03563141492,5761434,7078ISO 6578 & NBS TN 103055,2506ISO 6578138000,000

3131604,968910197,03563141802,0045434,7506ISO 6578 & NBS IR 77-86755,2506ISO 6578138000,000

3131376,370410197,03563141573,4059434,7190ISO 6976 & ISO 657855,2506ISO 6578138000,000

3131379,113310197,03563141576,1488434,7194ISO 6976 & NBS TN 103055,2506ISO 6578138000,000

3131688,737810197,03563141885,7734434,7622ISO 6976 & NBS IR 77-86755,2506ISO 6578138000,000

3131171,113010197,03563141368,1486434,6906GPA 2145 & ISO 657855,2506ISO 6578138000,000

3131174,524710197,03563141371,5602434,6911GPA 2145 & NBS TN 103055,2506ISO 6578138000,000

3131483,669010197,03563141680,7046434,7339GPA 2145 & NBS IR 77-86755,2506ISO 6578138000,000

Qnet (MMBTU)Qr(MMBTU)

Qtotal(MMBTU)

D (kg/m³)Hm (Mj/kgV (m³)

223

Using same standard under different conditions

� Calculation of GHV according ISO 6976

• 0°C

• 15°C

• 20°C

• 25°C

Difference in energy value is 8180 MMBTU

⇒⇒⇒⇒ US $ 55681

224

� Typical values

• 138000 m³

• 60000 tons of LNG

• 3130000 MMBTU

• HH: US $ 6,807 / MMBTU

• 21 305 910 US $ / cargo

The economical losses due to the inaccuracy of the custody transfer system

226

Level measurements

� Usually 2 level gauges per tank

• Primary

• Secondary

• Mechanical float gauge principle

• Automatic gauging principle (capacitance or radar)

• Accuracy according to the industry: ± 7,5 mm

~ 9,5 tons

~ US $ 3369

227

Temperature measurement

� Temperature gauging devices

• Built in thermo wells or installed as single probes

• Usually 5 or 6 probes

• Mostly of a resistance type – PT 100 systems

• Accuracy as good as ± 0,3°C

~ 3137 MMBTU

⇒⇒⇒⇒ US $ 21354

228

Pressure measurement

� Pressure readouts

• For safety reasons and for monitoring the boil-off process

• Represent no major error

• Accuracy is about ± 1% of full scale

229

Overall inaccuracy

± 0.60 %± 0.49 %TOTAL INACCURACY OBTAINED by QUADRATIC COMBINATION OF MEASUREMENTS

± 0.41 %± 0.35 %Overall GCV inaccuracy

± 0.04 %± 0.04 %GCV of the components (NBS)

± 0.1 %± 0.03 %Calibration gas (NBS) (weighting process)

± 0.3 %± 0.3 %Inaccuracy sampling (NBS)

GROSS CALORIFIC VALUE

± 0.31 %± 0.27 %Overall density inaccuracy

± 0.20 %± 0.15 %Temperature measurement

± 0.09 %± 0.09 %Gas analysis (NBS)

± 0.10 %± 0.10 %NBS estimate of LNG measurement

DENSITY

± 0.30%± 0.21%Liquid + vapour boil-off + vapour displaced

VOLUME

SGSSurvey

INDUSTRYperception

Inaccuracy of Measurement

230

Overall inaccuracy

� In Energy value this inaccuracy represents according:

61 mio US$50 mio US$Est. loss over 20 years contract

128 kUS$104 kUS$Energy value in US $

± 0,60%± 0,49%Inaccuracy

REAL WORLDINDUSTRY

Identifying the possible technical risks and economical consequences during the custody transfer measurement and analysis

232

� Cargo value based on measurement parameters

• Level

• Pressure

• Temperature

• Volume calibration

• Sampling

• Gas testing

• Cargo (vapour/liquid) remainders

• Vapors displaced/boil-off

233

Measurement ignorance

� Full or empty liquid lines on board

(before/after – loading/discharge)

average vessel: 46 tons

→ US$ 16403

� Vapour phase accounted before/after discharge/loading

difference: 192 tons

→ US$ 68463

234

Measurement errors - Density

� Parameters influenced by T

• k1

• k2

• Vi

� E.g.

• Actual Tliquid = -161°C

– D = 434.7074 kg/m³

– E = 3131292.5244 MMBTU

• Measured Tliquid = -160.5°C

– D = 434.0052 kg/m³

– E = 3126218.1013 MMBTU

( )Xm

XnkkkViXi

MiXiD

*0425.0

*121)*(

)*(

∑

∑

−+−

=

∆E = 5074 MMBTU

∆∆∆∆$ = US $ 34539

235

� Influenced by• Measurement of trim

• Measurement of list

• Measurement of level

• T (only for float gauge)

• D (only for float gauge)

� E.g. (list = -1°to port, level = 26700 mm) – TANK 1• Actual trim = -2m by stern

– V = 21902.804 m³

– E = 496986.1335 MMBTU

• Measured trim = -1.80 by stern– V = 21905.200 m³

– E = 497040.5000 MMBTU

∆E = 54 MMBTU

∆∆∆∆$ = US $ 367

Measurement errors - Volume

236


� E.g. (list = -1°to port, level = 26700 mm) – TANK 2,3 or 4

• Actual trim = -2m by stern

– V = 40287.587 m³

– E = 914146.5217 MMBTU

• Measured trim = -1.80 by stern

– V = 40300.456 m³

– E = 914438.5261 MMBTU

� Total loss

367 + (3 * 1988) = US $ 6331

∆E = 292 MMBTU∆∆∆∆$ = US $ 1988*3 (3 tanks) = US $ 5964

237


� E.g. (list = -1°to port, trim = -2m by stern) – TANK 1• Actual level = 26700 mm

– V = 21902.804 m³

– E = 496986.1335 MMBTU

• Measured level = 26600 mm– V = 21872.256 m³

– E = 496292.9834 MMBTU

� E.g. (list = -1°to port, trim = -2m by stern) – TANK 2,3 or 4• Actual level = 26700 mm

– V = 40287.587 m³

– E = 914146.5217 MMBTU

• Measured level = 26600 mm– V = 40229.466 m³

– E = 912827.7257 MMBTU

� Max loss: US $ 31.633

∆E = 693 MMBTU

∆∆∆∆$ = US $ 4717

∆E = 1318 MMBTU

∆∆∆∆$ = US $ 8972

*3 (3 tanks) = US $ 26916

238

Measurement errors - Displaced energy

� Influenced by

• Tvap

• Pvap

• VLNG

� E.g.

• Actual Tvap = -115°C

– Edisplaced = 10197.0356 MMBTU

– Etransferred = 3131292.5244 MMBTU

• Measured Tvap = -114.5°C



∆E = 32 MMBTU

∆∆∆∆$ = US $ 218

239

Measurement errors - Displaced energy

� E.g.

• Actual Pvap = 1150 mbar



• Measured Pvap = 1140 mbar



∆E = 89 MMBTU

∆∆∆∆$ = US $ 606

240

Measurement errors

� Accuracy and correctness of measurement parameters

US$ 60689 MMBTUPvap = 1140 mbarPvap = 1150 mbar

US$ 21832 MMBTUTvap = -114,5°CTvap = -115°C

US$ 8.972(tank 2,3 or 4)

1318 MMBTULevel = 26600 mmLevel = 26700 mm

US$ 4.717 (tank 1)693 MMBTULevel = 26600 mmLevel = 26700 mm

US$ 1.988(tank 2,3 or 4)

292 MMBTUTrim = -1,8m by sternTrim = -2m by stern

US$ 368 (tank 1)54 MMBTUTrim = -1,8m by sternTrim = -2m by stern

US$ 34.5395074 MMBTUTliq = -160,5°CTliq = -161°C

Difference in ValueDifference in Etransferred

Measured ParameterActual Parameter

241

Measurement errors

� Estimated loss over 20 years contract (2 voyages/month)

35.197.440TOTAL

290.880∆ Pvap = 10 mbar

104.640∆ Tvap = 0,5°C

15.183.840∆ Level = 10 cm

3.039.360∆ Trim = 20 cm

16.578.720∆ Tliq = 0,5°C

Loss (US $)Parameter

10. LNG Safety

243

WISH YOU A SAFE OPERATION

Thank you Sven

lng training brazil

Documents

imo code imo

preparation cargo handling

middle east

ships of types iig

classification gas carriers

required type of ship

ig iig iipg iiighazard

international tradestandards