Natural Gas Refrigeration Systems

Refrigeration system used to process oil and natural gas. The PETROGAS Refrigeration Type Liquids Recovery Mini-Plant is a modular process skid designed to mechanically condense natural gas liquids at temperatures as low as -40°F by using commercial refrigerants.

The portability of the Mini-Plant enables it to be quickly and inexpensively installed and moved when no longer needed. The operating pressures may vary from ambient to 1000 psig.

Process Design

The process flow is similar for all size units. The incoming gas/vapor stream enters an interchanger where the gas/vapor stream is pre-cooled by the cold outlet gas. A chemical injection pump injects atomized methanol into the gas vapor stream to prevent the formation of ice. The gas/vapor stream passes through a chiller where the temperature of the gas/vapor stream is lowered to that required to condense the designated vapors from the gas by indirect contact with a refrigerant.

The gas and condensed vapors then flow from the chiller into a separator where the condensed vapors are collected in the bottom. The gas, free of the vapors, flows from the separator, passes through the interchanger, and exits the unit. The recovered liquids flow, or are pumped, from the bottom of the Separator to storage.

If control of the recovered liquid vapor pressure and/or composition is required, a stabilizer may be added to split the lighter components (ethane, propane, and butane) from the heavier gasoline. The recovered liquids flow from the separator into the stabilizer column. Control of the stabilizer column's operating pressure and temperature results in the distillation of the undesired lighter components from the heavier components.

Temperature control is achieved by the use of an electric or natural gas-fired reboiler. The heavier components flow from the stabilizer column bottom to storage. The lighter components flow overhead as vapors and can be used as a fuel or re-injected into the natural gas stream.


Gas processing and refrigeration unit used int he processing of natural gas and oil. All PETROGAS Refrigeration Systems are skid mounted and completely factory assembled, including all required equipment, instrumentation, piping and electrical components. The unit is charged with refrigerant and tested prior to shipment.
The BASIC SYSTEM consists of the following components:

  • Inlet/outlet gas interchanger
  • Separator
  • Gas chiller
  • Methanol injection pump (if required)
  • Refrigeration compressor, electric or gas engine drive
  • Liquid product booster pump (if required)
  • Refrigerant condenser, air cooled
  • Liquid product booster pump (if required)
  • Cryogenic refrigeration system
  • Electrical and control systems
  • Emergency shutdown system

The STABILIZING SYSTEM consists of the following additional components:

  • Stabilizer Column
  • Pressure control system
  • Reboiler (electric or gas)
  • Liquid discharge system
  • Re-circulation pump (if required)
  • Integrated control system
  • Reflux system

Model Specifications

Model Number R-100 R-300 R-400 R-500 R-1000 R-1500
Nominal Capacity (mcfd) 100 300 400 500 1000 1500
Operating Temp Min. -40°F -40°F -40°F -40°F -40°F -40°F
Est. Shipping Weight (lbs.) 2000 4000 5000 8000 20,000 25,000
Skid Dimension (WxLxH, ft.) 4x8x8 6x10x10


6x10x10 8x28x10 8x21x10


The PETROGAS Refrigeration System can usually be installed in less than 1 day. Installation requires unloading of the unit and setting it on a level, stable foundation. The skid is designed to structurally support the unit and to equally distribute the weight of the skid components. No piers or special foundations are required.

The upper section of the Stabilizer, removed for shipment, is installed by bolting together body flanges. Gas inlet and outlet lines, and a line to the product storage tank, need to be connected. Purchaser will provide the designated electric power to the control panel.


A PETROGAS factory-trained technician, if required, can be provided to supervise the initial startup, adjustment of the equipment, and the training of operators, at an additional cost