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Gas fractionation

 Natural gas and oil-well gas are processed by the method of low-temperature gas separation. The cold source is, as a rule, a turbo-expander unit.

 
 Plant capacity in terms of source gas
 0.5–3.0 billion cub.nm/year 
 Mini-plant capacity
 6–50 thou. cub.nm/hour
 The lightest component recovery ratio  
 up to 0.98
 
 
Depending on the source gas composition, the following target products can be produced:
  • combustible natural gas (according to State Standard GOST 5542-87, 27577-87)
  • ethane fraction (Technical Specifications TU 0272-022-00151638-99)
  • propane-butane mixture, technical grade (GOST 20448-90)
  • propane and propane-butane, automobile grade (GOST 27578-87)
  • wide fraction of light hydrocarbons
  • natural gasoline, stable (TU 39-1340-89)
  • isobutane (TU 38.101 497-79)
  • normal butane (TU 38.101 492-79)
  • isopentane (TU 38.101494-79)
  • normal pentane (TU 38.101 493-79)
  • pentane-hexane fraction
 
A typical natural and oil-well gas processing plant comprises the following units:
  • Source gas preparation unit – designed for gas re-compressing (at a low pressure), drying from moisture and cleaning from solid and other impurities
  • Cooling unit – for cooling and partial condensation of source gas and recovery of heavy components
  • Demethanizing unit – for separation of stripped gas used for local needs or returned to the gas-main pipeline
  • Gas fractionating unit – for production of required target products
  • Heat-carrying media unit – for heating bottom product of columns
  • Compressor unit – for re-compressing of stripped gas to the gas-main pipeline pressure
  • Furnace unit – for heating adsorber regeneration gas
  • Final product storage facility
 
Monitoring and control of the plant are provided by an automated control system.
 
For the method of oil-well gas separation comprising preliminary separation of source mixture, adsorption drying, successive cooling in heat exchangers, etc., LENNIICHIMMASH Ltd has patent RU 2225971 "A method for oil-well gas separation". The patent effective date is March 3, 2003.