Configurations and methods for retrofitting an NGL recovery plant
AssigneeFluor Technologies Corporation
InventorJohn Mak
Life of this patent
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Abstract
Devices and methods for retrofitting a natural gas liquids plant are contemplated to extend recovery of C3+ hydrocarbons from various feed gases to recovery of C2+ and C3+ hydrocarbons. In especially preferred aspects, dedicated C2+ exchangers are integrated to exclusively cool the feed gas to produce a cooled absorber feed and to produce two separate absorber reflux streams. During C2+ recovery, absorber reflux is provided by a portion of the residue gas and a portion of the feed gas, while during C3+ recovery absorber and distillation column reflux are provided by the distillation column overhead product.
Claims9
A method of retrofitting a natural gas liquids plant for recovery of C2+ hydrocarbons, wherein the natural gas liquids plant has an absorber, a downstream distillation column, and a C3+ recovery exchanger that is configured to cool a feed gas and to cool an overhead product from the distillation column to thereby form a reflux stream for the absorber, and wherein a bottom product of the absorber is fed to the downstream distillation column, comprising:
- installing a bypass circuit for the C3+ recovery exchanger that includes first and second dedicated C2+ recovery exchangers;
- wherein the first C2+ recovery exchanger uses refrigeration content from an absorber overhead product to produce an ultra-lean reflux stream from a portion of compressed residue gas and a reflux stream from a portion of the feed gas;
- wherein the second C2+ recovery exchanger uses refrigeration content from the absorber bottom product to produce a cooled feed gas from another portion of the feed gas;
- and
- installing a bypass that routes the overhead product from the distillation column to the absorber as a stripping vapor.
A method of retrofitting a natural gas liquids plant for recovery of C2+ hydrocarbons, wherein the natural gas liquids plant has an absorber, a downstream distillation column, and a C3+ recovery exchanger that is configured to cool a feed gas and to cool an overhead product from the distillation column to thereby form a reflux stream for the absorber, and wherein a bottom product of the absorber is fed to the downstream distillation column, comprising:
- installing first and second dedicated C2+ recovery exchangers, piping, and a plurality of switching valves such that:
- (a) flow of the feed gas is routable exclusively to the C3+ recovery exchanger or the first and second C2+ recovery exchangers;
- wherein the C3+ recovery exchanger is configured to produce a cooled feed gas from the feed gas, wherein the first C2+ recovery exchanger is configured to produce a feed gas reflux stream from a first portion of the feed gas, and wherein the second C2+ recovery exchanger is configured to produce a cooled feed gas from a second portion of the feed gas;
- (b) flow of the bottom product of the absorber is routable exclusively to the C3+ recovery exchanger or the second C2+ recovery exchanger to provide refrigeration content to the C3+ recovery exchanger or the second C2+ recovery exchanger;
- (c) flow of an overhead product of the absorber is routable exclusively to the first C2+ recovery exchanger to provide refrigeration content to generate for the absorber an ultra-lean reflux stream from a portion of compressed residue gas;
- and
- (d) flow of an overhead product of the distillation column is routable exclusively to the absorber as a stripping vapor, or to the absorber as the reflux stream for the absorber and the distillation column as a distillation column reflux.
Dependencies are inferred from the claim text.