LNG regasification is the process of warming LNG from -162°C back into gas so it can enter a pipeline network — the last link in the LNG chain, and the exact reverse of what a liquefaction plant does. Global regasification capacity in 2026 stands at ~1,100 MTPA, significantly exceeding liquefaction capacity (~520 MTPA), creating a buyer's market. Regasification terminals use specialized vaporizers that extract heat from seawater, ambient air, or combustion to safely warm LNG at rates up to 1,000 MMcf/d per terminal.
Where LNG regasification happens
Regasification takes place at an import terminal, and import terminals come in two forms. Onshore terminals are fixed installations with large storage tanks and a vaporizer hall, built over three to five years and sized for decades of service. FSRUs — floating storage and regasification units — are converted or purpose-built ships that do the same job while moored at a jetty, and can be in service within a year. Europe added several after 2022 for precisely that reason.
Either way the equipment is the same in principle: tanks that hold the liquid at -162°C, cryogenic pumps that raise it to pipeline pressure, and vaporizers that add the heat. Where they differ is in scale, in how the heat is sourced, and in how quickly they can be built. Terminal locations and capacities worldwide are mapped on the global LNG terminals page.
The Regasification Process
Regasification reverses liquefaction through controlled heat addition:
Process Steps
- Unloading: LNG transferred from carrier to storage tanks (6-12 hours for 174,000 m³ vessel)
- Storage: LNG held in insulated tanks at -162°C, atmospheric pressure
- Sendout: LNG pumped from storage through vaporizers
- Vaporization: Heat applied to convert LNG to gas (primary focus of this article)
- Odorization: Mercaptan odorant added (natural gas is odorless; smell aids leak detection)
- Metering & Pressure Control: Gas measured and pressurized (50-100 bar) for pipeline injection
Energy Requirements
Heat Needed per Tonne LNG:
- Sensible Heat: Warming from -162°C to 15°C: ~220 kJ/kg
- Latent Heat: Phase change (liquid → gas): ~510 kJ/kg
- Total: ~730 kJ/kg (0.2 kWh/kg)
This is far less than the 250-300 kWh/tonne required for liquefaction (cooling consumes ~100x more energy than warming).
Vaporizer Technologies
| Type | Heat Source | Efficiency | CAPEX | Market Share |
|---|---|---|---|---|
| ORV (Open Rack Vaporizer) | Seawater | 99%+ (free heat) | Low | ~55% |
| SCV (Submerged Combustion) | Natural gas combustion | ~85% (fuel cost) | Medium | ~20% |
| AAV (Ambient Air Vaporizer) | Atmospheric air | 99%+ (free heat) | Very Low | ~15% |
| IFV (Intermediate Fluid) | Propane/glycol loop | ~90% | High | ~5% |
| HOIV (Heat Exchanger) | Industrial waste heat | 99%+ (free heat) | Medium | ~5% |
1. Open Rack Vaporizer (ORV) - Industry Standard
Operating Principle:
- LNG flows through aluminum tubes arranged in vertical panels ("racks")
- Seawater cascades over tubes from top, transferring heat
- LNG vaporizes as it rises through tubes; exits as gas at ~5-10°C
- Discharge seawater is ~4-6°C colder than intake
Design Specifications:
- Tube Material: Aluminum alloy (5083 or 5052) - excellent low-temp properties
- Typical Size: 12m high × 4m wide panel; 10-20 panels per vaporizer
- Capacity: 150-250 tonnes/hour per vaporizer unit
- Seawater Flow: ~4,000 m³/h per 200 tonne/h unit
Advantages:
- Zero fuel cost (uses ambient seawater heat)
- High reliability (no moving parts in heat exchanger)
- Low operating cost (~$0.10-0.15/MMBtu)
- Proven technology (used since 1970s)
Disadvantages:
- Location-dependent: Requires coastal site with deep water access
- Environmental concerns: Discharge water 4-6°C colder affects marine life (requires mitigation)
- Cold climate issues: Seawater can freeze in extreme cold; requires SCV backup
- Corrosion: Seawater is corrosive; requires cathodic protection and regular maintenance
Seawater Intake Requirements:
Example: 1,000 MMcf/d (7 MTPA) Terminal
- LNG throughput: ~300 tonnes/hour
- Heat required: ~220 MW thermal
- Seawater flow: ~20,000 m³/h (5.5 m³/s)
- Temperature drop: 5-6°C
2. Submerged Combustion Vaporizer (SCV)
Operating Principle:
- Natural gas burned underwater in combustion chamber
- Hot combustion gases (1,800°C) bubble through water bath
- Water heated to 30-60°C
- LNG flows through submerged tubes, absorbing heat from hot water
Design Specifications:
- Fuel Consumption: ~1.5-2.0% of throughput gas
- Capacity: 100-300 tonnes/hour per unit
- Efficiency: 85-90% (some heat lost to atmosphere)
- Water Bath: 500-1,000 m³ per unit
Advantages:
- Location-flexible: Can be built inland (no seawater needed)
- Works in any climate (no freezing risk)
- Compact footprint vs. ORV
- Fast startup (15-30 minutes vs. hours for ORV)
Disadvantages:
- Fuel cost: ~$0.30-0.50/MMBtu operating expense
- CO₂ emissions: ~0.5 kg CO₂/MMBtu (climate concern)
- Water vapor plume: Visible steam discharge (aesthetic/regulatory issue)
Typical Use Cases:
- Peak Shaving: Backup to ORV during winter demand spikes
- Inland Terminals: Where seawater unavailable
- FSRU: Floating terminals use SCV for flexibility
3. Ambient Air Vaporizer (AAV)
Operating Principle:
- LNG flows through finned aluminum tubes
- Natural air convection (or fans) transfers ambient heat to tubes
- No external energy input required (passive system)
Design Specifications:
- Tube Array: Vertical or horizontal configuration with extensive fin area
- Capacity: 10-50 tonnes/hour per unit (smaller than ORV/SCV)
- Footprint: Large - requires 10-20x more space than ORV for same capacity
Advantages:
- Zero operating cost (no fuel, no pumps in passive design)
- Extremely simple and reliable
- No environmental discharge (no seawater, no emissions)
- Ideal for small-scale LNG (trucking terminals, peak shaving)
Disadvantages:
- Large land requirement (prohibitive for large terminals)
- Climate-dependent: Capacity drops significantly in cold weather
- Icing: Frost/ice buildup on fins reduces efficiency; periodic defrosting needed
- Scaling limitation: Not practical above ~100 MMcf/d due to footprint
Best Applications:
- Small-scale LNG terminals (trucking, satellite stations)
- Peak shaving facilities (seasonal use)
- Remote locations where simplicity valued over efficiency
4. Intermediate Fluid Vaporizer (IFV)
Operating Principle:
- Closed-loop system using propane or glycol as heat transfer fluid
- Intermediate fluid heated by seawater, combustion, or waste heat
- LNG vaporized in separate heat exchanger (no direct contact)
Advantages:
- Prevents LNG contact with seawater (safety/environmental benefit)
- Can use multiple heat sources simultaneously
- Better temperature control than ORV
Disadvantages:
- High CAPEX: Requires additional equipment (pumps, heat exchangers)
- Maintenance: More complex than ORV
- Efficiency loss: Two-stage heat transfer reduces overall efficiency
Import Terminal Operations
Typical Terminal Layout
A modern 7 MTPA (~1,000 MMcf/d) import terminal includes:
- Ship Unloading Berth: Jetty with 4-6 unloading arms (1,200-1,500 m³/h per arm)
- Storage Tanks: 2-4 tanks, each 180,000-200,000 m³ capacity
- Sendout Pumps: High-pressure cryogenic pumps (150-300 bar discharge)
- Vaporizers: 4-8 ORV units + 2-3 SCV (backup/peak)
- Metering & Odorization: Gas quality adjustment and measurement
- Pipeline Connection: High-pressure (50-100 bar) tie-in to transmission grid
Unloading Process
| Phase | Duration | Description |
|---|---|---|
| Berthing & Connection | 2-3 hours | Ship moors; loading arms connected; safety checks |
| Cooldown | 1-2 hours | Pipelines pre-cooled with LNG vapor to prevent thermal shock |
| Cargo Transfer | 10-14 hours | LNG pumped at 8,000-12,000 m³/h (174,000 m³ cargo) |
| Disconnection | 1-2 hours | Arms drained, disconnected; ship prepares to depart |
| Total Port Time | 14-20 hours | Varies by cargo size and terminal efficiency |
BOG Handling at Import Terminals
Boil-off gas generated during unloading and storage must be managed:
- BOG Compressor: Compress BOG to 50-80 bar, inject into sendout pipeline
- Reliquefaction: Some terminals have small reliquefaction units to return BOG to storage
- Flare (Emergency): Burn excess BOG if system capacity exceeded (avoided due to emissions)
Sendout Flexibility
Modern terminals can modulate sendout from 10% to 110% of design capacity:
- Base Load: Continuous sendout at ~70-80% capacity
- Peak Mode: 100-110% during winter demand or pipeline maintenance
- Minimum Sendout: 10-15% to maintain system operability
Cold Energy Recovery
LNG at -162°C contains significant cold energy (~830 kJ/kg) that is typically wasted during regasification. Some terminals capture this for value-added applications:
Cold Energy Applications
| Application | Energy Use | Value | Adoption |
|---|---|---|---|
| Power Generation | Cryogenic turbine (Rankine cycle) | 5-7 kWh/tonne LNG | ~15% of terminals |
| Air Separation | Liquefy air to separate N₂/O₂ | High (co-located with industrial users) | ~5% |
| Cold Storage | Refrigerate warehouses | Medium (logistics hubs) | ~5% |
| Desalination | Freeze desalination process | Medium (water-scarce regions) | <5% |
| CO₂ Capture | Liquefy CO₂ for sequestration | High (with CCS infrastructure) | Pilot stage |
Power Generation Example
Direct Expansion Turbine:
- LNG pumped to high pressure (80-100 bar)
- Expanded through turbine while vaporizing (like steam turbine)
- Generates ~5-7 kWh per tonne LNG
- Economic Value: $0.30-0.50/MMBtu at $0.10/kWh electricity price
Challenge: High CAPEX ($50-100M for 7 MTPA terminal); payback 10-15 years.
Why Cold Recovery Isn't Universal
- Low value: 5-7 kWh/tonne only worth ~$0.50-0.70/tonne
- High CAPEX: Equipment costs $50-150M for large terminal
- Complexity: Adds operational risk and maintenance burden
- Location: Requires nearby customer for cold energy or grid connection for power
Safety Systems
LNG Rollover Prevention
Rollover is rapid vaporization caused by density stratification in storage tanks:
- Cause: Different LNG compositions (e.g., Qatar heavy LNG layered over Australian light LNG)
- Risk: Sudden BOG surge can overpressure tank
- Prevention: Blend incompatible cargoes slowly; use multiple fill points; recirculation pumps
Emergency Shutdown (ESD) Systems
Triple-redundant safety systems at import terminals:
- Level 1: Automated process shutdown (leak detection, overpressure)
- Level 2: Tank isolation (emergency valves close in <30 seconds)
- Level 3: Ship quick-release couplings (vessel can disconnect in emergency)
Fire Protection
- Water Curtains: High-pressure spray to disperse LNG vapor clouds
- Dry Chemical: Powder suppression for confined fires
- Foam Systems: Cover LNG pools to prevent vaporization
Regasification Economics (2026)
Terminal Construction Costs
| Component | Cost (7 MTPA Terminal) | % of Total |
|---|---|---|
| Storage Tanks (3×180,000 m³) | $300-400M | 40-50% |
| Vaporizers & Sendout Equipment | $150-200M | 20-25% |
| Jetty & Unloading Arms | $100-150M | 15-20% |
| Utilities, Piping, Instrumentation | $100-150M | 15-20% |
| Total CAPEX | $650-900M | 100% |
Operating Costs
- Vaporization (ORV): $0.10-0.15/MMBtu
- Vaporization (SCV): $0.30-0.50/MMBtu (fuel cost)
- Labor & Maintenance: $0.05-0.10/MMBtu
- Total Regas Fee: $0.30-0.60/MMBtu (typical terminal tariff)
Comparison: Land-Based vs. FSRU
| Parameter | Land-Based Terminal | FSRU |
|---|---|---|
| CAPEX | $650-900M (7 MTPA) | $200-350M (5 MTPA) |
| Development Time | 4-6 years | 12-18 months |
| Operating Cost | $0.30-0.50/MMBtu | $0.50-0.80/MMBtu (lease + opex) |
| Flexibility | Permanent | Relocatable |
| Capacity | Up to 30+ MTPA | 3-6 MTPA typical |
Key Takeaways
- Regasification requires ~730 kJ/kg heat input, ~100x less energy than liquefaction
- Open Rack Vaporizers (ORV) dominate (55% share) due to zero fuel cost
- Typical terminal: $650-900M CAPEX for 7 MTPA capacity
- Regasification fee: $0.30-0.60/MMBtu (ORV-based terminal)
- Global regasification capacity: ~1,100 MTPA vs. 520 MTPA liquefaction (2026)
- Cold energy recovery adds $0.30-0.50/MMBtu value but high CAPEX
- FSRUs offer 3x faster deployment than land terminals (12-18 months vs. 4-6 years)
- Ship unloading: 14-20 hours for 174,000 m³ cargo