×

Lean reflux process for high recovery of ethane and heavier components

  • US 6,244,070 B1
  • Filed: 12/03/1999
  • Issued: 06/12/2001
  • Est. Priority Date: 12/03/1999
  • Status: Expired due to Term
First Claim
Patent Images

1. A process for recovering components of a hydrocarbon-containing feed gas via a cryogenic distillation column wherein its reflux components are cryogenically generated by a separate lean reflux absorber, comprising:

  • a) deriving a top feed portion and a bottom feed portion to said lean reflux absorber by dividing a feed gas stream into a top feed portion, a bottom feed portion, and a first gas portion, and thereafter cooling and separating said first gas portion into a first liquid phase comprising condensed components and a main vapor portion;

    b) condensing said top feed portion and thereafter introducing it to the top of said lean reflux absorber comprising one or more mass transfer stages;

    c) introducing said bottom feed portion to said lean reflux absorber at a location below said condensed top feed portion;

    d) rectifying within said lean reflux absorber to produce a lean vapor phase from an upper region of said lean reflux absorber, and a bottom fluid stream comprising the remaining components from the bottom of said lean reflux absorber;

    e) condensing said lean vapor phase to form a lean reflux stream for top feed to said cryogenic distillation column;

    f) expanding and lowering the pressure of;

    (i) said lean reflux stream and supplying it as reflux to the top of said cryogenic distillation column, (ii) said bottom fluid stream and supplying it as a first middle feed to a middle region of said cryogenic distillation column at a point below top reflux, (iii) said main vapor portion and supplying it as a second middle feed to the middle region of said cryogenic distillation column at a point below the top reflux and at least the same as or above the first liquid phase, if present, and (iv) said first liquid phase, if present, and supplying it as a third middle feed to the middle region of said cryogenic distillation column at a point not higher than the second middle feed, and g) recovering natural gas liquid product from the bottom of said cryogenic distillation column.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×