LNG LIQUEFACTION, SHIP AND REGASIFICATION GAS MANAGEMENT PROGRAM DEPT. OF CHEMICAL ENGINEERING UNIVERSITY OF INONESIA

What is LNG? Source: IELE

Typical properties of LNG LNG is simply natural gas that has been cooled to its liquid state at atmospheric pressure: - 162.2 C and 14.7 psia LNG is transported at ambient pressures. Liquefying natural gas, which reduces the gas into a practical size for transportation and storage, reduces the volume that the gas occupies more than 600 times LNG is considered a flammable liquid LNG vapor is colorless, odorless, and non-toxic LNG vapor typically appears as a visible white cloud, because its cold temperature condenses water vapor present in the atmosphere. The lower and upper flammability limits of methane are 5.5% and 14% by volume at a temperature of 25 C

Natural Gas Components

Composition Comparison Source: IELE

LNG Heating Values LNG Heating Values depends on the content of heavy hydrocarbons (C 3, C 4 ) and varies between sources Heating Values requirement also varies between markets: Japan: 1,120 1,150 BTU/Cft Europe: 990 1,070 BTU/Cft USA: 1,020-1,075 BTU/Cft Heating Values has thus to be adjusted to each market It can be reduced by extraction of C 3 /C 4 at liquefaction plant, mixed with lower BTU gas, or inject nitrogen It can be increased by adding propane (Japan)

LNG Heat Content (Btu/cft)

Specific Gravity and Wobbe Index The Specific Gravity of gas is defined as the ratio: Density of gas/density of air. Density of air is 1.29 kg/m3, Specific Gravity of air is 1.0. The Specific Gravity of natural gas is in the range of 0.55 to 0.60. The heat efficiency of a burner is measured by the Wobbe Index of gas, defined as: Gross Calorific Value/ (Specific Gravity) 1/2

Natural Gas problem is Volume For the same energy content:

LNG Plant

Types of LNG plant 1. Land-based LNG LNG fuelling station (0.5-10 mmscfd, 0,004-0.08 MTPA) Peak Shaving LNG Plant (5-20 mmscfd, 0.04 0.15 MTPA) Decentralize LNG Plant (50-250 mmscfd, 0.3 1.7 MTPA) Based Load LNG Plant (300-1000 mmscfd, 2 8 MTPA) 2. Offshore-based LNG Floating LNG (150-300 mmscfd, 1-2 MTPA)

Based load plant

Peak shaving plant

Peak shaving principle

Satellite LNG Storage

Decentralize LNG plant Capacity: 130 tpd, 0.04 MTPA

LNG satellite

LNG satellite principle

LNG fuelling stations

LNG trailers

LNG tank for vehicle

LNG tank for heavy vehicles

Floating LNG

Liquefaction Process

Basic refrigeration cycles

Natural gas/refrigerant cooling curve

Vapor pressure vs. temperature

Baseload liquefaction processes Air Products propane pre-cooled MR (PPMR) uses nitrogen, methane, ethane, propane. Gas feed initially cooled by propane chiller to - 35 C. Liquid/vapor streams chilled further before flashed across J-T valves to provide cooling for final gas liquefaction. Used in 82% of baseload plants and APCI also moving into small and medium-scale plant Phillips original optimized cascade LNG process uses propane/ethylene circuits, methane flash circuit, brazed-aluminum heat exchangers and core-in-kettle exchangers Statoil/Linde LNG Technology Alliance s mixed-fluid cascade process uses three MR cycles to pre-cool, liquefy, sub-cool purified gas. Linde makes proprietary spiral wound heat exchanger (SWHE) Shell s dual MR process has two separate MR cooling cycles using SWHEs and process configuration similar to PPMR process. Shell also has single MR process IFP/Axens Liquefin produces LNG at very high capacities and is two-mr process for new LNG baseload projects of 6 MTPA train sizes

Base load LNG Lisensor

LNG Production Scheme

Liquefaction Technologies 1. Mixed Refrigerant Process (MCR) - Refrigerant= a mix of propane, ethane, methane - Feed gas pre-cooled at -35/-60 o C - Main cooling in Heat Exchanger (Spirally Wound or Plate Find) 2. Cascade Process - Cooling in three stages - Propane to -35 o C - Ethylene to -105 o C - Methane to -161 o C - Heat Exchangers: Plate Fin

Schematic Mix Refrigerant System

Mixed Refrigerant Cycle Process (Liquefin)

Mixed Refrigerant Cycle Process (APCI)

LNG Process: Badak

Mixed Refrigerant Cycle Process (Statoil/Linde)

Optimized Cascade Process (Phillips)

Expander Cycle

LNG process selection Cascade Cycle Liquefaction Cycle Single Stagemixed Refrigerant Cycle Mixed Refrigerant With Pre-Cooler Propane Cycle Multi Stage Mixed Refrigerant Cycle Single Expander Cycle Single Expander With Pre-Coolore Propane Cycle Double Expander Cycle Source: LNG 2000 Smi Conference, England, February 2000. Power Consumption Relative to Cascade Cycle 1.00 1.25 1.15 1.05 2.00 1.70 1.70

Main exchange line typical arrangements Front View

Main exchange line typical arrangements Top View

Plate Fin Heat Exchanger

Australia North West Shelf Liquefaction Plant

Badak Liquefaction Plant, Indonesia

Liquefaction Process Trend Improvement of Cascade Process using Plate Fin Exchangers New Technology using MCR Process by Axens/IFP, Linde (Liquefin) Use of larger Gas Turbine Use of Electrical Drivers instead of Gas Turbine Increase of capacity for a single train, up to 8 Tons of LNG

Small and Mid-Scale Liquefaction Processes (1) Black & Veatch s PRICO process uses single-mr loop/single refrigeration compression system: nitrogen, methane, ethane, propane, iso-pentane. MR compressed/partially condensed prior to entering cold box w/pfhe cores. Used for peakshaving, vehicle fuel supply, gas distribution systems: 4 to >180 MMscfd. MR system used for baseload, peakshaving. BV has 16 operating plants: 4 to 360 MMscfd and nine projects under development. Linde LE s advanced single-flow for mid-scale 0.2-1.0-MTPA plants. Liquefaction occurs in SWHE. Basic single-flow for small <0.2 MTPA plants such as peakshaving or mini-lng. Precooling, liquefaction & sub-cooling occurs in 1 or 2 PFHE(s). Kryopak s EXP - single-cycle turbo-expander refrigeration uses inlet process gas as refrigerant. No mixed refrigerant (MR) required. PCMR - pre-cooled MR: nitrogen, methane, ethane, butanes w/ conventional refrigeration circuit for pre-cooling. SCMR - single-cycle MR: nitrogen, methane, ethane, butanes and pentane

Small and Mid-Scale Liquefaction Processes (2) Chart Energy & Chemicals provides process design thru engineering, construction, startup to meet small-plant requirements. Designed cold boxes for Phillips Cascade Process and provides aluminum plate and core-in-kettle heat exchangers. Mustang Engineering s LNG Smart requires no refrigerant production. Eliminates MRs. Uses inlet gas as sole refrigerant medium. Gas enters multistage process via compression, turbo-expansion. Hamworthy offers small-scale plant using closed nitrogen expansion loop providing required cold duty to liquefy gas. Mini-LNG plant uses pipeline or landfill gas

General Scheme of a SS plant (Closed-loop)

General Scheme of a SS plant (Open-loop)

Mixed Refrigerant Cycle Process (Black & Veatch Prico)

Mid-Scale LNG Process Source: Verghese

Small Scale Plants, Process, Efficiency and Capacity

LNG process selection for small and mid scale (SMS) Criteria Expander Liquid Refrig. Compactness Weight Inherent safety Suitable for marine environment Ease of operations Ease of start-up Equipment count Availability Cycle robustness Efficiency

LNG process selection for SMS Criteria Cascade MRC Use guarantee technology Yes Yes Overall Location Needed Area High High Refrigerant Tank Risks Yes Yes Vessel movement Sensitivity Average Average Operation Simplicity Average Low Start-up/Shutdon Simplicity Average Low Changing Gas Feed Flexibility High Average Total Investment Cost High High Source: LNG 2000 Smi Conference, England, February 2000 Expander Yes Low No Low High High High Low

Mid-Range (MR) LNG (GasConsult Ltd and Energy and Power Consultant Ltd) LNG outputs from 300,000 1 million tpy LNG (approximately 50-150 mmscfd feed gas). Estimated investment and production costs 30% lower than with scaled down conventional mixed refrigerant cycle process effectively matching large scale mixed refrigerant economic at a small scale. Potential application include stranded natural gas and associated gas, upgrading existing LNG facilities and peak shaving. Refrigerant can be obtained directly from feed gas without columns or storage. Low hydrocarbon inventory enhances safety offshore and onshore. Process consists of proven equipment. Recycle type will be simple to operate with convenient turndown. Modular construction enables rapid installation in remote environments or offshore applications.

Coldbox of MRLNG

LNG Smart TM (Mustang) LNG Smart TM tank design

LNG Smart TM (Mustang)

Offshore Facilities Source: Moss Maritime FLNG: Floating LNG FSRU: Floating Storage Regasification Unit

LNG Shipping

Characteristics of LNG Tanker Fleet Two types of tanker design: Membrane design and Kväerner-Moss spherical design Existing Fleet (2004): 141 Ships; on order: 52 ships Current capacity of LNG ships on order: 135,000 to 145,000 m 3 Membrane ships are increasing their share: 63% of all ships on order compared to 43% in existing fleet.

Choice of containment system

Moss vs. Membrane Ship Illustration of Dimensions and Tonnage

LNG Ship Maximum Capacity Progression

Kväerner-Moss Ship built in 1990 135,000 m 3 276 m

Membrane ship built in 2004 (Madrid) 138,000 m 3 124 m

Kväerner-Moss Ship Structure

Membrane Ship Structure

Structure of Membrane hull

LNG tankers

LNG Tanker Fleet (2004)

Comparative Characteristics of LNG Tank Systems

LNG Receiving Terminal

LNG Receiving Terminal Facilities Jetty for berth and unloading Monitoring dolphins, manifold unloading arms, security systems Storage tanks Design: single, double or full containment, or membrane Regasifying facility: vaporizers Connection to pipeline system

LNG Receiving Terminal

LNG Marine Terminal Scheme Source: IELE

Cold Utilization (1)

Cold Utilization (2) Air Filter & Chiller Seawater Solution Heater Seawater Gas Turbine TG Compressor Air 7 ºC Air Inlet 17 ºC 12 ºC Gas Turbine GAS TG Compressor 2 ºC Air 7 ºC Air Filter & Chiller LNG Vaporizer Air Inlet 17 ºC 2 ºC LNG 12 ºC By-pass Tanque Solución Solution Tank Solution Pumps

Vaporizers Open Rack Vaporisers (ORV) are common worldwide and use seawater to heat and vaporise the LNG in an open, falling film type arrangement. In general, for using ORVs the preferred seawater temperature is always above 8 C. The seawater is chlorinated to protect the surface of the tube panel against bio-fouling and to prevent marine growth inside the piping. Submerged Combustion Vaporisers (SCV) use send-out gas as fuel for the combustion that provides vaporising heat. The SCV vaporizes LNG contained inside stainless steel tubes in a submerged water bath with a combustion burner. In the baseload terminal SCV, the fuel gas is burned in a large single burner rather than multiple smaller burners because it is more economical and it achieves low NOx and CO levels. The hot flue gases are sparged into a bath of water where the LNG vaporization coils are located. Due to the high cost of the seawater system ORV installations tend to have a higher installed capital cost while the SCV installations have a higher operating cost because of the fuel charge.

Vaporizers Shell and Tube Vaporizers (STV): The STV and Intermediate Fluid STV type are generally smaller in size and cost competitive compared to an ORV or SCV system. Heat is usually supplied to the LNG vaporizer by a closed circuit with a suitable heat transfer medium. They are mainly used when a suitable heat source is available. Design of these types of vaporizer systems requires a stable LNG flow at design and turndown conditions with provisions to prevent the potential for freeze-up within the vaporizer. The design of Double Tube Bundle STV incorporates both a lower and an upperset of tube bundles, and uses an intermediate heat transfer fluid (e.g. propane, isobutane, freon, ammonia) between the LNG (upper tubes) and the seawater or glycol water (lower tubes) inside a single shell. A small shell and tube superheater is required to heat the vapor to 5 C. Combined Heat and Power unit with Submerged Combustion Vaporize (CHP-SCV): In order to decrease the gas auto-consumption of SCVs, as well as to increase the efficiency and economics of the entire regasification process, the receiving terminal can be modified to use a cogeneration concept that offers energy saving and environmental advantages. This has been implemented at the Zeebrugge LNG Terminal Cogeneration Project. The heart of the CHP facility is a gas turbine type LM6000 that generates 40 MW of electrical power. The hot exhaust gases from the turbine pass through a heat recovery tower and transfer their heat to raise the temperature of a closed hot water circuit. This hot water will then be circulated and injected in the water bath of the vaporizers and transfer its heat to regasify the LNG.

ORV

Open rack type

SCR

Shell and Tube Vaporiser

Loading arms

LNG Storage Facility Several components, that: - allow unloading ships without delay - provide storage for compensating delay in ships arrival - provide storage for facing seasonal variations - provide strategic storage, if possible Current storage capacities: - Japan Sodegaura: 2,700,000 m 3 including strategic storage - Korea Incheon: 2,200,000 m 3 including seasonal demand - France Fos: 150,000 m 3 including including size of ships 70,000 m 3

Above ground-lng Storage

In Ground, Underground LNG storage

LNG Tank Containment

LNG Storage Tank Schematic

LNG Storage Tank 140,000 m 3 double containment

LNG Receiving Terminal

Offshore LNG Terminals

FSRU Gravity Based Structure Source: Brian Raine, LNG Journal

LNG Safety