LNG Liquefaction Plant Operations: Refrigeration Cycles, Cryogenic Equipment and Train Start-Up – Dubai, 23 Aug – 3 Sep 2027

Programme overview

Introduction:

LNG liquefaction plant operations fail quietly before they fail loudly: a drifting mixed refrigerant composition, a warm-end pinch in the main cryogenic exchanger or a rushed cool-down cuts production, raises specific power and can crack cold equipment. This Core Concept course takes engineers inside the liquefaction train, from feed gas pre-treatment and refrigeration cycles through spiral-wound and plate-fin exchangers, compressors, tanks and boil-off gas, to cool-down, start-up, trips and hazards. Participants produce a Train Start-Up and Performance Review Plan for a case LNG plant.

Course Objectives:

• Interpret LNG cooling curves, flash behaviour and feed gas composition to set the operating basis of a liquefaction train
• Verify that acid gas, water, mercury and heavy hydrocarbon removal meets the limits that prevent freeze-out and exchanger damage
• Compare propane-precooled mixed refrigerant, cascade, single mixed refrigerant and expander cycles on specific power, turndown and equipment count
• Diagnose exchanger pinch points, refrigerant composition drift and compressor operating point problems from plant data
• Plan cool-down, start-up, shutdown and trip response steps that protect cryogenic materials, tanks and personnel from LNG hazards
• Produce a Train Start-Up and Performance Review Plan with efficiency and reliability KPIs for a case LNG plant

Target Audience:

• Process engineers accountable for liquefaction train heat and material balance and refrigerant performance
• Operations engineers and shift leads who run cool-down, start-up, rundown and shutdown of LNG trains
• Mechanical and rotating equipment engineers responsible for refrigerant compressors, drivers and cryogenic exchangers
• HSE and process safety engineers who assess cryogenic spill, rollover and vapour cloud scenarios at liquefaction sites
• Reliability engineers who track train availability, trips and bad actors on cold section equipment

Course Outline:

Day 1: LNG Properties, Cryogenic Behaviour and Liquefaction Train Basis

• Methane-Rich LNG Composition, Minus 162 Degree Boiling Point and Density Behaviour
• Temperature-Enthalpy Cooling Curves for Precooling, Liquefaction and Subcooling Zones
• Joule-Thomson Expansion, Flash Gas and End Flash Nitrogen Rejection
• Feed Gas Composition Envelope: Lean, Rich and Nitrogen-Bearing Cases
• Liquefaction Train Block Flow Diagram from Inlet Receiving to Rundown

Day 2: Feed Gas Pre-Treatment for the Cold Section

• Amine Acid Gas Removal Unit and CO2 Slip Limits That Prevent Freeze-Out
• Molecular Sieve Dehydration Bed Cycle, Regeneration Gas and Breakthrough Signs
• Mercury Guard Bed Duty and Protection of Brazed Aluminium Equipment
• Scrub Column and NGL Extraction to Remove Heavy Hydrocarbons and Benzene
• Cold Section Entry Gas Specification Sheet

Day 3: Liquefaction Refrigeration Cycle Families

• Propane-Precooled Mixed Refrigerant Cycle Flow Scheme and Pressure Levels
• Pure-Component Cascade Cycle with Propane, Ethylene and Methane Loops
• Single Mixed Refrigerant Cycle for Mid-Scale and Modular Trains
• Nitrogen and Methane Expander Cycles for Small-Scale and Floating Units
• Cycle Selection Matrix: Specific Power, Equipment Count and Turndown

Day 4: Cryogenic Heat Exchangers, Refrigerant Compressors and Train Control

• Spiral-Wound Main Cryogenic Exchanger Bundles, Shell-Side Distribution and Warm-End Approach
• Brazed Aluminium Plate-Fin Cores: Thermal Stress Limits and Core Leak Detection
• Refrigerant Compressor Maps, Anti-Surge Control and Gas Turbine or Electric Motor Drivers
• Mixed Refrigerant Make-Up, Composition Trimming and Light-to-Heavy Ratio Control
• Advanced Process Control of LNG Rundown Temperature and Production Rate

Day 5: Week-One Case: Refrigeration Loop Diagnosis on a Case Train

• Case Train Data Pack: Heat and Material Balance, Cooling Curves and Compressor Logs
• Cooling Curve Gap Analysis to Locate Exchanger Pinch Points
• Mixed Refrigerant Composition Correction from Sample Chromatograph Results
• Compressor Operating Point Plot Against Surge and Stonewall Lines
• Week-One Diagnosis Memo and Peer Challenge

Day 6: LNG Storage Tanks, Boil-Off Gas Recovery and Loading Interface

• Full-Containment Tank: Nickel Steel Inner Tank, Prestressed Concrete Wall and Suspended Deck
• Membrane Tank Corrugated Stainless Liner and Insulation Panel System
• Tank Heat Leak, Boil-Off Rate Estimation and Stratification Monitoring
• Boil-Off Gas Compressor, Fuel Gas Header and Reliquefaction Return Routes
• Jetty Loading Arm Sequence, Vapour Return Balancing and Ship-Shore ESD Link

Day 7: LNG Hazards, Process Safety and Safeguards

• Tank Rollover Mechanism, Density Layering and Mixing Countermeasures
• Rapid Phase Transition on LNG Contact with Water and Spill Direction Channels
• Vapour Cloud Dispersion, Pool Fire Radiation and Impoundment Basins
• Cryogenic Burns, Asphyxiation Risk and Cold-Work Protective Equipment
• Emergency Shutdown Hierarchy, Fire and Gas Detection and Cause and Effect Review

Day 8: Cryogenic Materials, Cool-Down, Start-Up and Shutdown Sequences

• Cryogenic Materials: Austenitic Stainless, Nickel Steel and Aluminium Alloys
• Piping Thermal Contraction, Cold Spring and Support Movement Checks
• Controlled Cool-Down Rate Procedures for Exchangers, Piping and Tanks
• Train Start-Up Sequence from Refrigerant Charging to First LNG Rundown
• Planned Shutdown, Warm-Up, Deriming and Shift Handover Communication

Day 9: Trip Response, Troubleshooting and Liquefaction Performance KPIs

• Compressor Trip, Driver Loss and Exchanger Flow Maldistribution Scenarios
• Freeze-Out, Hydrate and Fouling Diagnosis from Differential Pressure Trends
• Specific Power Consumption and Refrigeration Efficiency Tracking
• Train Availability, Production Uptime and Flaring Loss KPIs
• Reliability Bad Actor Ranking and Root Cause Analysis Records

Day 10: Capstone: Train Start-Up and Performance Review Plan

• Capstone Brief: Case LNG Plant Train Data, Constraints and Outage History
• Start-Up Plan Drafting: Cool-Down Steps, Hold Points and Permissives
• Performance Review Section: KPI Baselines, Targets and Efficiency Actions
• Hazard Safeguard and Trip Response Annex for the Case Train
• Plan Presentation to a Peer Panel and Revision Log

Skills You Will Gain:

• Cooling Curve Interpretation
• Pre-Treatment Specification Checking
• Refrigeration Cycle Comparison
• Mixed Refrigerant Composition Control
• Cryogenic Exchanger Diagnostics
• Cool-Down Procedure Planning
• Cryogenic Hazard Safeguarding
• Liquefaction Performance Benchmarking

Why Attend This Course:

• Return with a Train Start-Up and Performance Review Plan built on a case LNG plant and challenged by a peer panel
• Read compressor maps, exchanger temperature profiles and refrigerant samples together to find lost production
• Run cool-down and restart after a trip without thermal shock to spiral-wound bundles, plate-fin cores or cold piping
• Compare liquefaction practice with process, rotating equipment and safety engineers from other trains and operators

Conclusion:

Steady LNG rundown depends on clean feed gas, a well-tuned refrigerant loop, healthy cryogenic exchangers and compressors, and disciplined cool-down and restart. Week one covers LNG properties, pre-treatment, refrigeration cycle families, exchangers, compressors and control, then tests them on a case train. Week two adds tanks and boil-off gas, the loading interface, cryogenic hazards, materials, start-up and shutdown sequences, trip troubleshooting and performance KPIs. The final day produces a Train Start-Up and Performance Review Plan for a case LNG plant.