The feed gas compressor is the core boosting equipment at the front end of an LNG liquefaction unit. It boosts low-pressure raw natural gas such as wellhead gas, coalbed methane and associated gas to the operating pressure required by the pre-treatment unit, supplying a stable-pressure gas source for subsequent processes including acid removal, dehydration, mercury removal and liquefaction, so as to ensure continuous and stable operation of the whole liquefaction plant.
Working Principle
Low-pressure raw natural gas enters the unit and is pressurized through multi-stage compression. The natural gas heated by compression flows into interstage coolers for cooling, then passes through knockout drums to remove condensed free water and heavy hydrocarbons. The pressurized gas is delivered downstream to the pre-treatment and purification section.
The unit is equipped with an anti-surge system and interlock protections for vibration, temperature and oil pressure. Reciprocating types are widely adopted for small-flow skid-mounted units, while centrifugal types are selected for large-scale LNG plants.
Core Advantages
✅ Optional centrifugal or reciprocating type to suit different processing capacities
✅ Interstage cooling plus liquid knockout reduces inlet temperature and lowers the load of downstream purification
✅ Complete interlock protections against surge, vibration, overtemperature and abnormal oil pressure
✅ Skid-mounted integration with air coolers, inlet filters and instrument control system
✅ Variable frequency speed regulation to accommodate fluctuating source gas pressure
✅ Explosion-proof design for high-risk natural gas service conditions
Technical Parameters (Example)
Medium: Raw natural gas (coalbed methane / oilfield associated gas / wellhead gas)
Inlet Pressure: 0.05~0.8 MPa
Outlet Pressure: 3.0~8.0 MPa (customized according to liquefaction process)
Control Mode: Remote monitoring via DCS, automatic anti-surge regulation
Drive Type: Motor-driven
Applications
Skid-mounted LNG liquefaction stations, coalbed methane liquefaction, oilfield associated gas liquefaction, recovery and liquefaction projects for scattered natural gas
