regasification Hamworthy

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Hamworthy Gas Systems AS

• LNG reliquefaction systems - Why LNG reliquefaction - Concept description

• LNG regassification systems - Concept description

LNG Journal Conference – Norshipping 9 June 2005





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The LNG value chain

Natural gas is the fastest growing energy sourceApprox. 25% of gas export as LNG LNG world trade growth 15% in 2004

New challenges for LNG transportation

LNG: a mean for concentrating and transporting energy

Hamworthy PLC

international operationshigh technology products and systemstotal commitment to innovationfocus on specialist shipsemphasis on system design and integrationemphasis on procurement rather than own manufacturing of all equipment80% of sales for the production and transportation of oil and gasdemand is driven by increasing environmental, safety and noise regulation

and expansion in world trade and energy transportationmore than 40 years delivery reference to gas shipsawarded all contracts for LNG reliquefaction systems for QG LNG Carriers

with slow speed diesel propulsion system

How do we fit in ?

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LNG carriers’ propulsion system today

• Boil-Of-Gas (BOG) is a result of the LNG warming up during transportation.• All BOG now used as fuel in steam turbine propulsion systems.• Reliabil ity in existing system considered to be very high.• Proven system with low lubrication and maintenance cost

• Low efficiency of turbines high fuel consumption/cost• Valuable cargo used as fuel• Lack of crew to operate steam turbines• Power required by large LNG carriers at boundary of existing turbine design• Limited redundancy• 2 suppliers

Why change ?

Alternative to to-days practice

• BOG reliquefaction system in combination with 2 stroke diesel engine(s)• The Moss RS reliquefies BOG and send LNG back to the cargo tanks

• Results in economical and technical advantages

• Hamworthy has worldwide rights to the patented Moss RS TM

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Slow speed diesel with BOG reliquefaction

✪ High overall efficiency✪ Proven propulsion system with high level of reliability✪ Proven solutions for large LNG C✪ Reduced CO2 emissions✪ Crew availalble✪ Well known technology for shipyards & owners (design, installation and operation)✪ Twin screw system; Propulsion redundancy, reduced propeller load, lower power consumption, improved manoeuvrability✪ Reliquefaction of BOG increase amount of cargo delivered

✬ Separate auxiliary generator high total installed power NOx & SOx emissions Bunkering for some routes need to be established

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LNG Reliquefaction system

Pattern for ship’s using BOG & LNG as fuel for propulsion

Two principle different solutions available for LNG carrier propulsion:1. Use BOG & LNG as fuel e.g steam turbines, dual-fuel diesel electric, gas engines

Laden BallastBallast

Maximum

Minimum

LNG level in tanks

Minimum heel required for cool down of tanks

2. Use efficient slow speed diesel engines and BOG reliquefact ion, sell all LNG loaded onboard

Fuel used during roundtrip(Natural BOG & forced)

Additional LNG delivered with Slow Speed diesel andBOG Reliquefaction System

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LNG Reliquefaction systemLNG & HFO prices

HFO always been competitive compared with natural gas prices in Europe, USA and Japan.Gas price in Europe and USA in average (1994-2001) 110% higher than HFO pricesJapanese gas prices has been 160 % of HFO pricesThe gas prices has increased considerably compared with HFO the last years

0,00

1,00

2,00

3,00

4,00

5,00

6,00

7,00

199 7 199 8 199 9 200 0 200 1 200 2 200 3 200 4 200 5

$/m

BTU

Japan CIFEU CIFUS Henry HubHFO price

Future price difference ??

Propulsion alternatives & energy consumptions

30

40

50

Source: Man B&W

Best efficiency, Lowest total fuel consumption,Lowest value fuel (HFO)

Lowest efficiency, Highest total fuel consumption,High value fuel (LNG) + HFO

Improved efficiency, High value fuel (LNG)

Improved efficiency, High value fuel (LNG or MDO)

Propulsion type Relat ive energy cons.Main + aux system (%)

Slow Speed diesel 66Diesel electric 72Gas turbines 84Conventional steam turbine 100

Example made byshipowner

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Relative increase annual LNG deliveriesLNG sales price 3.5 $/Mbtu

0,00 %0,50 %1,00 %1,50 %2,00 %2,50 %3,00 %3,50 %4,00 %

Steam turbine Diesel

Avg. BOR 0,08%/day Avg. BOR 0,10%/day Avg. BOR 0,12%/day

3.4 M$4.3 M$

5.5 M$

Slow speed diesel and reliquefaction system (RS) compared with alternatives;• Lowest total operating cost (efficient propulsion using HFO, maintenance and lube oil)• Additional sale of LNG

Investment level for newbuildings with alternative propulsion; ??• Traditional size vessels, reason to believe steam still lowest.• Slow speed diesel and RS competitive, in particular for large LNG Carriers

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Source: MAN B&W (150 k m3 LNG C)

Environmental impact – emission levels

60 000 t/year

Note;Entire LNG chainshould be takeninto accountfor environmentalimpact evaluations.

Avoid sub-optimisation !

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LNG liquefaction

Snurrevarden LNG plant - Norway

• The feasibility of the Reliquefaction technology to be used onboard LNG C has been demonstrated• First free-standing small scale (micro) LNG plant in Scandinavia• Hamworthy EPCIC contract with GASNOR for small scale LNG plant• LNG production capacity 60 ton/day (2500 kg/hr)• Unmanned operation• The plant produced first LNG on 15th March 2003

CO2 removal

H2O removal

Storage tank

Gas engine

LPG separator &Gas condensation (LNG)

Cooling cyclecompressor

Instrument air &Nitrogen

Onshore plant vs installation on LNG carrier;- LNG production capacity 60 ton/day (2500kg/hr)- Pre-treatment of feed gas, removal of CO2 & water (not on LNG carriers)

- Feed gas pressure to be reduced – no need for low duty compressors

Main equipment same as for the ships;- Similar 3 stage centrifugal compressor with expander for refrigeration cycle- Similar cold box type (plate fin heat exchanger)- Same control system principles

Snurrevarden LNG plant has resulted in awards of – LNG RS for LNG Carriers !


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Snurrevarden LNG plant - Norway

Succesful operat ion in more than 2 years

Unmanned operations

Contractual requirement free regulat ion from 1.670 kg / hr to max capacity 2.500 kg/hr

After commissioning:Free regulation from 0 kg/hrup to max capacity

Max achieved capacity = 2.831 kg/hr

Different capacitiesstudied;

BOG compositionNitrogen 0-30 mol%Methane 70-100 mol%

BOG rates (BOR):0,08- 0,16%/24 hours

Boil-off mass flowdependant on BOR &tank size:2000-11000 kg/hr

LNG Reliquefaction systemProcess description

• Nitrogen cycle

The system consist of ;• Cargo cycle

Vent or GCU

• Auxiliary system

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LNG Reliquefaction systemGeneral arrangement – membrane ship

BOG compressors3 stage centrifugalcompressor withexpander & el motor

Pre-coolerCold box& separator

N2 reservoir (on roof)


General arrangement – Spherical tanks

Low and high duty compressors

3 stage centrifugalcompressor withexpander &electric motor

SeparatorCold box

N2 reservoir

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LNG Reliquefaction systemCargo cycle

To enable stabletemp at inlet coldbox, BOG ispre-cooled upstreamcompressors

BOG from the cargotanks (1.06-1.15 bar a)by convent ional LDcompressors.

Discharge pressure from BOG compressor is4,5 bar and the BOG is cooled and condensed toLNG at this pressure in a 3-stream plate-fincryogenic heat exchanger (cold box).

Non-condensibles,mainly N2, are removedin a separator ( 4,5 bar)and exited to a flare(GCU) or vent mast.Part ial reliq (if N2>12%) results in ;-reduced power req.-tank pressure control From the separator,

the LNG flows back tothe cargo tanks

Vent or GCU

LNG Reliquefaction systemNitrogen cycle (cooling cycle)

The gas is led to the “warm” part of the cryogenicH/E where it is pre-cooled (–110°C) and send to theexpander

The RS system needs to have sufficient capacity to cater for heat ingress to the cargo tanks,vapour header and LBOG piping, in adition to heat introduced by BOG compressors

The gas expanded toa pressure of 14.5 barand temp of –163°C.Gas then introducedinto the “cold” part ofthe cryogenic H/Ewhere it cools andreliquefies the boil-offgas to LNG.

N2 at 13.5 barcompressed to 57 barin 3-stage centrifugalcompressor withwater cooling.

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RS - Power requirement versus BOG rate (100% C1)

0 1000 2000 3000 4000 5000 6000

2400290031003600430050006000

BOG

- kg/h

r

BOG compressor N2-compressor

kW


New concept with 20 % reduction in power consumptionnow developed

IACS Rules for Redundancy for RS

Spare capacity of RS unit, or

Auxiliary boiler(s) for BOG, or

Gas oxidiser (GCU) for the BOG, or

Controlled venting

Redundancy considerations


Different configurations/alternatives

• 2x100% capacity with 1 cold box

• 1x100% capacity with gas oxidizer (GCU)

• QGII ;2x100% capacity with GCU

• Different configurations studied for newprojects resulting in operational flexibility

VENT

TO TANKS

2 3

1 E

G

-200-1000+100

-200-100

0+100

-200-1000+100

-200-1000+100

MAXMIN

-200-1000+100

MAXMIN

-200-1000+100

-200-1000+100

-200-1000+100

-200-1000+100

RESE

RVOIR

BY-PASS

SUCTIO N THROTTLE

NITR

OGEN

RECYCLING

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LNG Reliquefaction system Gas combustion unit or thermal oxidizer as redundancy

Pre-qualification of Hamworthy asa supplier to Qatar Gas involved ;-extensive process discussions-qualifications of our sub-suppliersanddevelopment of a Dynamic model.

Typical dynamic simulation cases;

1. Start-up from warm condition2. Normal operation (3.5 t/hr)3. Stand-by operation4. Ballast (40% capacity, warm BOG (-40degC))5. Normal shut down6. Emergency shut down7. Varying N2 content in BOG

Dynamic simulation model of RS

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Dynamic simulation model


Process/systemSystemstatus

Risk area

Comfort factorsRisk mitigation

The system only use proven components - first class, high quality with extensive reference

Low duty compressors used on all LNG carriers

Cold box (plate fin heat exchanger) widely used in onshore cryogenic installations.

Refrigeration & cargo cycle in has been proven in operation.

Analysis concludes 99.98 % availability

Approval in principle by several class societies

Independant HAZOP/HAZID with owners & class

Hamworthy has supplied a small scale LNG plant based on same principles. Operational experience since Mar 2003.

Proven or unproven ?

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Summary


• Slow speed diesel engines in combination with reliquefaction system, results in improved economy

• LNG business is conservative and typical attitude has for a long time been; “We do not want to be the first, but first to follow” This is now possible !

• Expect several alternative propulsion systems to be used in the future. Selection dependant on trade, size of vessels, charterer’s and owners’ preference, etc

• Hamworthy continues improving the system; - Reduced power consumption - Improved redundancy configurations - Improved project execution models





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LNG Vaporization/gasification system

• Increased import & spot/short term LNG trading in the future

• Capacity in existing import terminals booked/limited

• Permission to build new terminals in US/Europe difficult

• Vaporization plant onboard LNG carriers or Floating Storage Units will not need “terminals”

Not in my back yard !!

Regass unit

LNG regasification system

Process/system

Regasification units on;• Floating Storage Regasification Unit (FSRU) permanently anchored receiving LNG from LNG carriers or• Shuttle Regasification Vessels overlapping at unloading site in order to ensure continuous send-out

3 alternative Hamworthy systems: - Steam based (closed loops) - Seawater, alternatively with steam back-up - Cascade system

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LNGfromtanks

Naturalgas topipeline

The 2 stage regasificationsystem is placed on skidson deck. No’s of skidsdependant on send-outcapacity and redundancyrequirements

General description of Hamworthy’s Cascade system

1st stage :Booster pumppressurize the LNGbefore it is heatedagainst propane(-163 -10°C)

Closedpropaneloop

LNG regasification system General description of Hamworthy’s Cascade system

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Seawater

2nd stage :Seawater used for finalvaporization. In caseswith low seawatertemperature, steam tobe used

LNG regasification system General description of Hamworthy’s Cascade system

Cascade LNG regasification system

LNG boosterpump

LNG/propaneheat exchanger(PCHE)

Propane pump

Seawater out

Seawater In

NG out

LNG/seawater heat exchanger

Propane

2 Propane /Seawater HX

LNG in

•Compact unit•Reduced risk for freezing up the system

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Studies ofdifferent type ofsystems for FSRU’s& SRV’swith shell & tubetype system using;

-seawater,-steam,-intermediate media heated by steam

or cascade system

Pressure &capacity ranges;

40-130 bar 50-1100 t/hr


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Cascade LNG regasification system Joint industry project (Høegh LNG and Hamworthy) – test plant of the cascade system

• HAZID performed (designer, operator, DNV)

• DNV technolgy qualification ongoing as part of JIP

• Test plant to be operational autumn 2005

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Thank you for attention


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Documents

regasification Hamworthy