Natural gas treatment with LNG production

09EN
Process Description
Feedstock – natural gas enters inlet separator 1, where the preliminary separation of the methanol-water solution and mechanical impurities takes place. The separated NG is cooled in a recuperative heat exchanger 2, fed to a reducing device 3 and directed to a low-temperature separator 4. Hydrocarbon condensate from separators 1 and 4 is fed to the fractionation unit 5, where it is separated into off-gas and gas condensate. Gas from separator 4 is sequentially heated in the recuperative heat exchangers 6 and 2 and separated into 2 streams. The first stream is discharged from the unit as commercial gas. The second stream enters the intake of compressor 7, is cooled in ACU 9 and supplied to the treatment and dehydration unit 10. Treated and dehydrated gasis cooled in the heat exchanger 6, supplied to the inlet of expander 8 connected to compressor 7, partially liquefied and supplied to separator 11 for LNG separation. Separation gas is heated in a recuperative heat exchanger 6 and removed from the unit.

Process features
  • Minimization of methanol losses
  • Elimination of process discharges to the flare
  • Pre-cooling of separated gas due to the main stream of commercial gas
  • As for the LNG unit: capital costs are 3-4 times less, operating costs are 10-12 times less in comparison with LNG production units from piped natural gas

Technical Specification
  • Gas feedstock pressure is 4.0-12.0 MPa
  • Applicable for the line of CGTU with unit capacity of up to 10 million nm³/day of commercial gas
  • Gas condensate withdrawal up to 99.9% of the potential
  • LNG withdrawal up to 8 t from 1 million nm³ of commercial gas (subject to approval). It is regulated as required

Patents of the Russian Federation No.
2705160, 2717668, 2730289, 2732998, 2736031, 2739038,
2741026, 2744138, 2757211, 2758364, 2758754.

Development level, industrial application
Developed design concepts
Completed feasibility study