×

Liquefied natural gas processing

  • US 5,114,451 A
  • Filed: 03/12/1990
  • Issued: 05/19/1992
  • Est. Priority Date: 03/12/1990
  • Status: Expired due to Term
First Claim
Patent Images

1. In a process for the separation of liquefied natural gas containing methane, C2 components, C3 components and heavier hydrocarbon components, in which process(a) said liquefied natural gas stream is supplied to a fractionation column in one or more feed streams;

  • and(b) said liquefied natural gas is fractionated into a more volatile fraction containing a major portion of said methane and a relatively less volatile fraction containing a major portion of said C2 components, C3 components and heavier hydrocarbon components;

    the improvement wherein(1) a distillation stream is withdrawn from an upper region of said fractionation column and thereafter divided into said more volatile fraction and a recycle stream;

    (2) said recycle stream is compressed and thereafter said compressed recycle stream is directed in heat exchange relation with at least a portion of said liquefied natural gas whereby said compressed recycle stream is cooled sufficiently to substantially condense it, while said liquefied natural gas portion is heated;

    (3) said substantially condensed compressed recycle stream is supplied to said fractionation column at a top column feed position;

    (4) said heated liquefied natural gas portion is supplied to said fractionation column at a mid-column feed position; and

    (5) the quantity and pressure of said compressed recycle stream and the temperatures of said feed streams to said fractionation column are effective to maintain column overhead temperature at a temperature whereby the major portion of said C2 components, C3 components and heavier hydrocarbon components is recovered in said relatively less volatile fraction.

View all claims
  • 5 Assignments
Timeline View
Assignment View
    ×
    ×