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THE NEXT GENERATION OF LNG PLANTS

LA NOUVELLE GENERATION DES USINES DE LIQUEFACTION

Murtaza KhakooLNG Technology Project Manager

BP ExplorationChertsey Road, Sunbury

Middlesex TW16 7LN, UK

Beatrice FischerSenior Process Engineer

Institut Francais du Petrole (IFP)1 et 4 avenue de Bois-Preau

92852 Rueil-Malmaison, France

Jean-Christophe RaillardProject Manager

Gaz de France (GdF)Roche Maurice B.P. 12417

44024 Nantes, France

ABSTRACT

Trinidad and Tobago’s Atlantic LNG plant has demonstrated how an innovativeapproach to project implementation can achieve lower capital costs and a reduction in thetime from conception to start-up. As a result, it is now the industry benchmark on bothcounts despite using previous generation LNG technology.

To meet the growing pressures in the LNG market over the next decade, furthersubstantial reductions in full chain LNG costs will be required. With the liquefaction unitcomprising nearly 50% of LNG plant cost, this is an obvious target for further costreduction. Improvements in liquefaction process efficiency offered by a new technologyand additional cost reduction innovations can lead to an overall unit cost reduction of upto 25% for the next generation of LNG plants.

With this objective, a collaborative alliance and industrial pre-project developmentprogram has been undertaken to capture innovations and cost reductions whileconfirming the expected benefits of a new LNG technology based on two different butcomplementary processes developed by Gaz de France (GdF) and IFP. These have beenrigorously and critically investigated and objectively compared with current establishedprocesses. The scope of the program, conducted with the participation of engineeringcompanies and major equipment fabricators, has included the development ofengineering definitions and cost estimates to demonstrate clearly the benefits of theseprocesses. The program has shown that it is possible to design and construct a unit thatcan produce from 2 to 5 million tonnes per annum using single or dual Frame 7EA gasturbine drivers.

This paper presents the significant findings and comparative conclusions of thiscollaborative work, addresses the key issues of innovation, efficiency and operability anddiscusses the potential commercial impact and timing of the project implementation ofthe Next Generation of LNG plants.

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RESUME

La réalisation de l’usine de liquéfaction de Trinidad et Tobago, dans le cadre duprojet “Atlantic LNG”, a permis de montrer comment une démarche innovante peutconduire à une réduction des coûts d’investissement ainsi que de la durée du temps deconstruction. Cette usine constitue ainsi une référence pour l’industrie sur ces deux plans,bien que basée sur un procédé de génération antérieure aux procédés qui peuvent êtreconçus à présent.

Pour faire face à la demande croissante de GNL prévue au cours des dix prochainesannées, des réductions substantielles de coût sont requises sur l’ensemble de la chaîneGNL. L’unité de liquéfaction, qui représente près de 50 % des coûts d’investissement,doit faire l’objet d’une attention particulière. Les gains d’efficacité rendus possibles parla mise en œuvre de nouveaux procédés ainsi que de nouvelles innovations techniquespermettent d’envisager une réduction supplémentaire de 25 % sur le coût du GNL produitpar la nouvelle génération d’usines de liquéfaction.

Avec cet objectif en vue, un programme de développement a été entrepris sur la based’un pré-projet élaboré conjointement en vue de confirmer les gains résultant de la miseen œuvre de deux procédés différents mais complémentaires développés par Gaz deFrance et IFP. Ceux-ci ont été examinés selon une procédure rigoureuse, visant à établirune comparaison objective avec les procédés couramment utilisés à l’heure actuelle.Dans ce but, le programme de travail, mené avec la participation de sociétés d’ingénierieet de fournisseurs d’équipements, a pris en compte les évaluations nécessaires pourdisposer des conclusions économiques escomptées. Ce programme a montré qu’il estpossible de concevoir et réaliser une unité produisant de 2 à 5 millions de tonnes par anutilisant une seule ou deux turbines identiques de type "Frame 7".

La présentation résume les principaux résultats et les conclusions en termes decomparaison de ce travail conjoint, précise les facteurs clés de réussite sur le plan del’innovation, des performances et de l’opérabilité et analyse l’impact commercialpotentiel ainsi que les perspectives de mise en œuvre de cette nouvelle générationd’unités de liquéfaction.

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THE NEXT GENERATION OF LNG PLANTS

INTRODUCTION

Gas will continue to be the fuel of choice providing it can compete on deliveredprices compared to alternatives like diesel and coal. A major share of this gas is suppliedby long distance pipelines and LNG. LNG has the advantage of no geographical orpolitical barriers, but to increase its market share, a significant reduction in cost has to beachieved in order to deliver low cost LNG for any scale, from small (~0.5mtpa) to large(~5mtpa). This will lead to a rapid growth in the international LNG trade and to thepossibility of new grass-root projects with shorter transport distance.

With the liquefaction unit accounting for nearly 50% of LNG plant cost, this is anobvious target for further cost reduction. The challenge of this alliance project was tobring the investment cost down without compromising operability, safety and reliability -all of which are considered essential. The technologies which are selected therefore haveto rely upon simple and robust concepts which are easy to operate. The equipmentincorporated should also be inherently safe, well-proven and widely available.

Two main concepts have been considered in the development of the CII (IntegralIncorporated Cascade) Technologies :

− CII-1 for smaller capacity trains, in the range of 1 to 2mtpa of LNG, requiring lowerinvestment and better adapted for some quick start projects and

− CII-2 for large-size liquefaction trains producing 4mtpa of LNG or more to benefitfrom scale effects.

The innovative and efficient liquefaction processes described in this paper result inhigher LNG production for a given unit of power. When combined with cost reductionsfrom state-of-the-art rotating and heat transfer equipment and appropriately correctengineering design, there is a significant reduction in the LNG production unit cost.

THE CHALLENGE

Trinidad and Tobago

The Atlantic LNG plant is the first grassroots LNG export project in the WesternHemisphere since 1969 [1]. The plant began production in 1999, less than 7 years afterproject inception. The plant has now exported in excess of 100 cargos of LNG and iscurrently undergoing expansion with the addition of two almost identical trains.

Prior to Atlantic LNG’s first train in Trinidad, the capital costs of greenfield LNGfacilities lay in the range of 300 to 400 US$/tpa of LNG production. Trinidad has set anew benchmark at just over 200 US$/tpa. The addition of Trains 2 and 3 currently beingundertaken is projected to set an even lower benchmark in LNG plant cost at around 150US$/tpa.

The breakthrough in Trinidad was achieved by challenging the use of traditional LNGtechnology and by using unique project management, contract strategy and execution foran LNG facility. The plant which uses the Phillip’s Cascade system with 6 GE Frame 5gas turbines for its drivers and an air cooling system, maintains a high level of reliabilityand flexibility.

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Targets

With this background of an aggressive new benchmark in execution and cost set bythe Trinidad LNG project, the target for the current BP/IFP/Gaz de France project was toreduce the unit cost of LNG production even further through:

• Increased LNG output: This is achieved in the CII processes through a higherefficiency liquefaction cycle which incorporates cascades of dual mixed refrigerantscircuits and through the use of specific equipment like plate-fin exchangers. Cycledevelopment and optimisation targeted in excess of 15% additional LNG productionfor a given power compared to conventional processes.

• Cost reductions: With compressors, gas turbines and exchangers representingbetween 70 and 80 % of the direct cost of a liquefaction unit, cost reductions throughtechnical improvements and optimal utilisation of these and other plant items weretargeted. The pre-project development team working in conjunction with inputs fromthe engineering companies and the equipment vendors incorporated many costreductions into the CII liquefaction and LNG plant design.

A critical factor in the optimisation and cost reduction effort was to ensure thatoperability, reliability and safety are preserved. Review and value improvement sessionswere incorporated at key stages of the project – at completion of process design andduring operability assessment.

Process Benchmarking

The key factors in the validation of the benefit from the new LNG process is to ensurethat proper benchmarks of both the achieved process efficiency and the resultant LNGplant costs are made.

• Efficiency Benchmark: This relates to the theoretical power required to produce aunit of LNG production and is frequently the most improperly benchmarked numberin the industry. To make proper comparison requires comparable designs to beproduced taking into consideration many factors including : sink temperatures (air orwater-cooled); cold box outlet temperature (sub-cooled or warm into tanks);economic heat exchanger LMTD and pinch temperatures; driver power including allderating factors, margins and compressor efficiency.

• Cost Benchmark: This is perhaps the hardest to achieve and can be facilitated by atleast two approaches :− Comparison of theoretical costs produced from a combination of “factored” costs

for the liquefaction unit including sections of the plant affected by the specificprocess technology,

− Comparing a detailed cost estimate for the whole LNG plant including allpretreating units, export systems etc. with an actual plant cost.

Both approaches have been adopted in the BP/IFP/Gaz de France project - the firstfor comparison of liquefaction technologies and the second for comparison with Trinidadproject information. To ensure congruence, the Trinidad Train 1 design was used as theCase Study with much of the actual plant parameters outside the liquefaction unit and the

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scope of the engineering maintained as per actual project to facilitate a comparison afteradjustment to capacity differences.

THE PROJECT

CII Technology

The CII concept has been aimed at providing operators with liquefaction processesthat combine the advantages of simplicity and reliability together with a high efficiencyin order to maximize LNG output.

This is achieved by exploiting the full improvement potential resulting from optimaluse of mixed refrigerants and compact designs incorporating plate-fin heat exchangers.

The CII-1 version uses a single cascade, incorporating two sub-cascades. A lowspecific power consumption is obtained by the fractionation of the single refrigerant intooptimised heavy and light mixtures [2] [3][5].

The CII-2 version is a dual mixed refrigerant process incorporating specific patentedfeatures for increasing the simplicity and at the same time the efficiency of the system[4][5]. The CII-2 process involves two refrigeration cycles of equivalent power, usingfully condensed mixed refrigerants.

Scope

A comprehensive scope of work was implemented to develop the CII liquefactionunit design and engineering, to enable cost comparisons, to evaluate specific processcharacteristics and to demonstrate the performance, operability and benefits.

The Trinidad Train 1 design parameters together with the use of Frame 7 gas turbinedrives (one for Gaz de France CII/1 and two for IFP CII/2 process) were the only givensin the design premise. The development of an optimised process design formed a key partof the study and delivered a comprehensive process data book incorporating optionevaluations and all the normal process engineering information.

These formed the basis for evaluation of sensitivities to site conditions (dailytemperature variations, pressure), feed composition variation and mixed refrigerantcomposition drift. In addition, piping and instrument diagrams (P&ID) were developed toassess operability and maintenance aspects.

For key items of equipment, such as the machinery (compressors, turbines) and heatexchangers, specifications were developed in consultation with equipment vendors inparticular the cold box design where detailed design incorporating 3-D layout and pipestressing of significant lines were made. A subcontract to an engineering companydeveloped detailed layouts and cost estimates.

The final step was to generate generic designs of competing processes and developequipment and costs for comparison with the new technologies.

Approach and Organisation

The project has been operated with an integrated Core Team involving BP as anOperator and IFP together with Gaz de France as technology providers. An Extended

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Team was formed with vendors and engineering companies to provide an optimised anddetailed design information for the liquefaction units.

These vendors included providers of plate-fin heat exchangers (Chart Marston /Nordon Cryogenie), of rotating equipment (Nuovo Pignone and Sulzer/Elliott) and alsoliquid turbine and air-cooler suppliers.

A flexible and proactive approach to communications, periodic review meetings andtargeted value improvements steps was facilitated by design to ensure innovations fromall contributors were captured in the study.

THE RESULTS

CII-1 Process

The CII-1 LNG process is a fully integrated cascade process, designed with aninnovative arrangement of proven and efficient technologies. Under the Trinidad siteconditions, the annual capacity delivered by a single LNG train is 2mtpa. The processflow scheme (Figure 1) incorporates the following main features:

• Simple compression line:The single refrigerant is compressed in two compressors casings: one axial type with

a suction flow rate of 250 000 m3/h (actual) and a two stage, back-to-back centrifugalcompressor for the mid and high pressure duties. This simple, ambient temperaturecompression line is driven by a single Fr 7EA gas turbine.

• Simple cryogenic heat exchange line:The integrated heat exchanger line, shown in Figure 2, is made up of brazed

aluminium plate fin heat exchangers (PFHE) which are more cost effective thanalternatives in similar duties. One of the innovative features of CII-1 is its two butt-welded PFHE cores, forming a dual-core, inside which natural gas is pre-cooled,liquefied and sub-cooled. Five dual-cores are parallel-mounted inside each of fouridentical and modular cold boxes. These together with an additional cold box for thePFHE interconnecting pipework permits a high degree of prefabrication which reducesonsite work and the schedule for assembly and installation of the main heat exchanger.The cross section of the cold boxes (hence the footprint) are also minimised by selectinga PFHE configuration which maximises the cold box height within transportation limit.

• Simple process control:The control of the process is defined to automatically track the best energy efficiency

conditions when changes in feed composition, pressure, flow rate or ambient conditionvary without specific refrigerant make-up or venting.

The CII-1 refrigerant is a mixture of five components: C5, C4, C2, C1 and nitrogen.The refrigerating duty is achieved by expansion of three different streams at threetemperature levels (-30°C, -110°C and –160°C). These three flow rates are automaticallyset by the system to achieve the required cold duty of the corresponding heat exchangezone. Consequently, the composition of the “circulating MR” is automatically optimisedfor the cooling duty required.

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MR Fractionation

Scrubber

LNG to storage

DRY FEED

Frame 7

MCHEL

Figure 1. CII-1 Process Flow Scheme.

This “auto-internal loop adjustment” is performed by the transfer of liquid hold-upbetween the four vessels of the CII-1 process, which contain a liquid buffer of variousvolatilities. Three of these four vessels are operated with “floating levels”. The positiveor negative difference between the actual levels and the reference levels enables directcalculation, by software, of the quantities of C5, C4, and/or C2 that should be injectedinto the loop to compensate for leaks.

The operating stability of the MR fractionation column, which contains less than 4meters of packing, is maintained by the control of the temperature of the reflux drum.

• Efficiency:The performance of the CII-1 process has been compared with a typical Single Mixed

Refrigerant (SMR) process ensuring similarity in all parameters that impact theefficiency.

The reference SMR scheme considered provides all the required cooling duty by asingle expansion of the mixed refrigerant at the cold-end of the cryogenic plate-fin heatexchange line [6]. The SMR is compressed in an axial and a centrifugal casing, withpartial condensation at the inter-stage ambient chilling, and is expanded through a liquidexpander.

Comparative process design work has shown that the controlled fractionation of themixed refrigerant in the CII-1 process reduces the specific power consumption byapproximately 10%. Also, the fractionation of the CII-1 MR removes all the C5 from thehigh pressure, light refrigerant, which flows to the coldest part of the exchange line andavoids potential C5 freeze-out. Consequently the LNG can be sub-cooled to a greater

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extent and the end-flash is limited to the LNG tank boil-off thereby avoiding a large,costly end-flash compression line.

Figure 2. CII-1 Integrated Heat Exchanger Line

CII-2 Process

The CII-2 process incorporates two multi-component refrigerant circuits and in thisparticular design, each driven by a Fr 7EA gas turbine. Specific features of the CII/2process are :

− A balanced power on the two cycles : makes it possible to use two identical gasturbines, getting all the positive features of the cascade process with much lessrotating equipment. It avoids the difficulty, encountered with the C3/MR cycle, ofhaving to transmit driver power from the precooling to the cryogenic cycle orreversely the compression load.

− No integrated cascade : this is the main novelty of the process. As the mixedrefrigerant of the second cycle is fully condensed, the two cycles become very similarand the two mixed refrigerants can be used in a similar way to the pure refrigerantsused in the cascade process. As a consequence, the design of the heat-exchange line issimpler, there is no phase separation (no separation drum required) and the regulationbecomes easier. Thus, changing the flow-rate in any branch does not change thecomposition in any other part of the system, as the mixture composition is the sameeverywhere. With an integrated cascade requiring a phase separation, the fluidmixture composition varies all along the cycle.

− Compact and modular heat-exchange line : the CII-2 process has also been definedto make the best use of plate-fin heat-exchangers and to simplify their design. Asingle heat exchange line is used to cool gas from ambient temperature down tocryogenic temperatures.

Figure 3 presents the process flow schematic specific for the Trinidad Case Study.

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DRY FEED

Demethanizer

LNG to endflash system

Mainexchange line

C2+ ToC2/C3+ fract.

Liquid turbines

1st Frame 7 -prerefrigerationcycle

2nd Frame 7 -cryogenic cycle

Figure 3. Simplified Trinidad CII-2 Process Flow Scheme

• Compression LineThe two compression lines are each driven by a Frame 7. The pre-refrigerationcompression line consists of one centrifugal compressor with two lateral entries. Thecryogenic compression line is composed of one axial compressor followed by acentrifugal compressor with one intermediate inter-stage cooling step.

• Heat Exchanger LineThe heat-exchange line comprises 4 cold boxes, with two cold boxes located on each sideof the distribution pipes (see Figure 4). To limit the numbers of two-phase distributiondevices, the concept of the process is such that all fluids entering the main exchange line,except the outlets of Joule-Thomson valves, are in a single phase - vapour or liquid. Thefirst mixed refrigerant (MR1) is sub-cooled at the inlet of the main exchange line,whereas the second mixed refrigerant (MR2) is in vapour phase at the inlet of the firstcore, and in liquid phase at the inlet of the second.

• EfficiencyThe capacity obtained with an end flash scheme is 4.5mtpa. Comparison with a standardpropane cooled mixed refrigerant (C3-MR) process, with equivalent assumptions (endflash, two liquid turbines, exchanger pinch/LMTD etc) has been undertaken. To use thefull power of the two Frame 7 gas turbines, the C3-MR process has to balance theprecooling and the cryogenic cycle compression requirements to available driver powers–the assessment of impact on operability (start-up, transients etc) was excluded from scopeof this study.

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Figure 4. Overall Layout of the Main Exchange Line

Despite this assumption, the LNG production capacity obtained with the two Frame 7gas turbines is lower by approximately 10% compared to that of the CII-2 process,although the difference is expected to be higher if the two processes are compared fromtheir optimal design points, particularly with respect to the main heat exchangerparameters.

From the investment cost standpoint, significant savings result from the use of theplate-fin heat-exchange line. The pressure drops and stream arrangement in the CII-2process are optimised so as to have no lost volume in the PFHE. A good exchangecoefficient is thus obtained so that the overall core volume is very low, despite a largeheat transfer area. The second important saving point is the air coolers, whose area andcost are also very significantly reduced from condensing a multi-component refrigerantcompared to the single component propane in C3-MR.

The above, coupled with other cost reduction ideas identified in this and previousstudies [7], and currently not used in the Trinidad LNG plant, lead to a projected capitalcost reduction of 10-15 % for the process units. Taking into account the increasedcapacity, this results in a overall reduction of about 20-25 % per tonne of LNG produced.

Influence of Site Conditions

As the main study was based on an actual and a single design point, it was importantto assess the response and performance of the process technology to varied conditions,namely: different site temperature, feed composition and pressure.

The influence of each of the parameters has therefore been evaluated separately,while keeping all other parameters constant. The key findings discussed below show thatboth processes can be designed to accept a variety of feed gases, and the response toprocess condition changes are not different to any of the established processes.

• Site TemperatureTwo extreme air temperatures: 10°C and 45°C were evaluated in the design mode,

while keeping the Trinidad gas composition and pressure constant. Two advantages arenoticed in going to lower ambient temperatures : an increase in available turbine power

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and lower air cooler outlet temperatures – which combine to give a large benefit,compared to the 26°C base case.

The use of sea water coolers has also been investigated whilst maintaining the samegas turbine power (no change in ambient). This gives an increase in LNG capacity due tolower condensing pressure of the refrigerant but is not as pronounced in Trinidad becausethe air and sea water temperature are similar.

Table 1. Summary of CII sensitivities to temperatures

Case Base Case Cold climate Warm climate Medium coolerAmbient cooler Air Air Air Sea watercooler temperature 26°C 10°C 45°C 25°C

CII-1 / CII-2 CII-1 / CII-2 CII-1 / CII-2 CII-1 / CII-2Specific consumption, % 100 / 100 87 / 91 117 / 117 95 / 97Available Driver Power, % 100 / 100(1) 110 / 110(1) 88 / 87 (1) 100 / 100LNG capacity, % 100 / 100 127 / 122 76 / 75 105 / 104

Note 1: Includes fuel gas compressor for CII-2 case

• PressureA higher feed gas pressure (55 bar a instead of 42 bar a) gives a higher capacity due

to the reduction of the required liquefaction duty and to the transfer of energetic lossesfrom the LNG sub-cooling heat-exchange zone to the natural gas condensing zone (seeTable 2).

• Feed CompositionThe ability to design for other feedstocks was made to confirm process flexibility.

Two feed compositions were considered :− Higher Nitrogen Content : Since nitrogen content in Trinidad gas is very low, a

hypothetical design based on 4 % nitrogen was made which required the addition of anitrogen rejection tower to both processes.

− Rich Gas Case : A hypothetical LPG case with 21% C2+ in the feed (7% in Trinidad)was considered and required minimum changes to process scheme. Compared to thebase case, the LNG capacity was decreased, but the overall liquid outlet capacity wasincreased.

Table 2. CII Sensitivity to Press & Feed Compositions

Case Base Case High pressure N2 rich LPG richNG feed pressure 42 bar 55 bar 42 bar 42 barNG composition (N2 /C2

+) <0.1% / 6.7% <0.1% / 6.7% 4 % / 6.6% <0.1% / 21%

CII-1 / CII-2 CII-1 / CII-2 CII-1 / CII-2 CII-1 / CII-2Specific consumption, % 100 / 100 88 / 93 100 / 105 111 / 127LNG capacity, % 100 / 100 113 / 107 108 (1) / 98 93 / 78 C2 + LPG capacity 4 / 5 4 / 5 5 / 5 38 / 42

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Note 1: For CII-1, in the N2 rich case, a flash gas compressor must be introduced in order toproduce the high pressure fuel-gas from the overhead product of the nitrogen removal tower.This additional compression power leads to an increase in the LNG production capacity.

For CII-2, as an end-flash scheme was already used in the base case, the capacityobtained with the high nitrogen case is very similar.

These studies have confirmed the robustness of the CII technologies and the ability tocope with a range of feed gas compositions and conditions.

Operability

An important aspect in adopting a new process technology is understanding theoperability, reliability/availability and flexibility of the process. To achieve this, controlphilosophies, P&I diagrams and operating procedures for start-up, shut-down, warm-up,turndown etc. were developed by IFP/Gaz de France. A P&I Review session was thenconvened to assess the control philosophy and operational procedures, and ensure thatoperational upsets and potential hazards were adequately catered for in the design.

A reliability review showed that most of the major equipment items (plate finexchanger, compressors, vessels etc) are not different to those in other gas plants andwould have similar reliability. Availability was primarily governed by the gas turbineselected and in this respect, the CII process technologies are therefore similar to existingLNG plants.

The operational flexibility to cater for day/night temperature variations, as well as theeffect of leaks from the mixed refrigerant circuit have been checked in rating mode:− For day/night variation, the process temperatures have been determined using the

designed surface areas of the cryogenic and ambient heat exchangers. For both CII-1and CII-2, during the night and the day, the actual capacity changes by about 4 % ofthe average daily capacity – this is therefore the prize for any optimisation packagetracking the daily ambient temperature variation.

− The effect of mixed refrigerant drift was also checked by simulation and the deficit ina major component was noted to have negligible effects on the resulting capacity.

KEY BENEFITS

Efficiency

With the same gas turbine, both the CII-1 and CII-2 achieve significantly higher LNGoutput than their respective competing process. The improved efficiency of the newliquefaction processes has been demonstrated.

Compact Layout

Both CII-1 and CII-2 use a plate-fin heat-exchange line that is assembled into fourcold boxes and laid adjacent to the gas turbine driver-compressor sets with aircoolersinstalled on the compressor housing. This compact layout leads to significant reduction inlow temperature, large diameter pipework giving significant cost savings.

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Costs

Comparative factored costs of the CII processes with corresponding establishedprocesses show the possibility of combining a lower cost with an increased in LNGproduction.

At the time of writing this paper, a detailed cost estimate based on a Trinidad locationis being prepared using on major equipment costing, construction factors adjusted to takeinto account the compact layout (from 3D model), overall plot layout, utilities, offsitesincluding storage and export system. The aim is to make comparison with the existingTrinidad Train 1 data and current indications are that these will show significantreduction in unit cost – within the limitations of the approach used.

Schedules

The critical path of conventional LNG plant projects has been the delivery ofcompressor-drive, main heat exchanger and storage / export system. Pre-ordering ofcompressors has been previously adopted and shifted the critical path to the mainexchanger. The CII processes employ plate fin heat exchangers with many potentialsuppliers for the large number of cores thus removing this item as a constraint in projectschedule. New ideas are being pursued to target the next schedule constraints(storage/export systems), and the overall reduction in schedule will undoubtedly result insignificant cost reductions.

Project Strategy

The philosophy adopted from the outset is to ensure that the process technology hasthe ability to use multi-sourced equipment. Also direct link of the CII technologies to anyspecific engineering contractors has been avoided to maximise leverage in theengineering, procurement and construction phases. This ensures that potential licenseescan maximise the potential saving possible from a favourable contract strategy.

OVERALL CONCLUSIONS

The study results have confirmed that the CII processes have potential for:• improvement in process efficiency and hence more LNG production for a given

driver configuration• use of standardised and multi-sourced process equipment• incorporate majority of cost reduction ideas that have been previously studied and

implemented with minimal impact to the design and operation of current LNG plants• leverage to reduce cost from equipment supply, engineering and project schedule

This now gives the project’s partners increased confidence in the CII technologies toproceed with the industrialization phase, involving both CII-1 and CII-2 processes. Theprocesses can be adapted to operators’ requirements, and as they involve only well-proven equipment, they can be implemented rapidly to commercial projects.

Having completed the evaluation, BP will now consider putting forward the CIItechnologies to their current and emerging projects. The intention is to get the projects’buy-in to take up to FEED level of definition, in competition with established

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technologies, before opening to a number of contractors for EPC of the plant with theleast LNG unit cost.

BP believe that through application of innovative technologies for liquefactioncoupled with equally innovative project strategies, it will be able to deliver LNG projectsat even lower cost than the current Trinidad benchmark.

REFERENCES CITED

(1) Bob WilliamsUpstart LNG ProjectOil & Gas Journal, December 16, 1996

(2) Duremberg C., Flesch E., Raillard J.C. Cost Reduction of the LNG chain: Development of a New Liquefaction Process Eurogas 1996, Trondheim, Norway, June 3-5, 1996 (3) Flesch E., Raillard J.C. CII Liquefaction Process: 2 cascades into 1 LNG12, Perth, Australia, May 4-7, 1998 - Session 3, Paper 3-4 (4) Streicher C., Rojey A., Fischer B., Chabrelie M.F., Maisonnier G.

New Options for Natural Gas LiquefactionGastech 1998, Dubai, November 29-December 2 - Session 10, Paper 10-2

(5) Flesch E., Raillard J.C., Burin des Roziers T., Streicher C., Rojey A. and Fischer B.New Trends in LNG Process DesignEuropean GPA meeting, London, February 19th, 1999

(6) K.J. Vink, R. Klein NagelvoortComparison of Baseload Liquefaction ProcessesLNG12, Perth, Australia, May 4-7, 1998 - Session 3, Paper 3-6

(7) P.J. Nutall, S. TakamiSmall LNG Plants: Overcoming the Economies of ScaleGastech 1998, Dubai, November 29-December 2 - Session 10, Paper 10-1