US 2022/0128298 A1 · Methods and Configurations for LNG Liquefaction

Abstract

Embodiments relate generally to systems and methods for pre-cooling a natural gas stream to a liquefaction plant. A system may include a compressor configured to receive a first natural gas stream at a first pressure and produce a second natural gas stream at a second pressure; an exchanger, wherein the exchanger is configured to receive the second natural gas stream as the second pressure and cool the second natural gas stream to produce a cooled natural gas stream; and an expander, wherein the expander is configured to receive the cooled natural gas stream and expand the cooled natural gas stream to produce a chilled natural gas stream from the second pressure to a third pressure. An LNG liquefaction plant system, wherein the refrigeration content of the external or internal refrigerant is used to liquefy and sub-cool a natural gas stream to produce liquefied natural gas (LNG) in a cold box or cryogenic exchanger. The refrigerant may be an external gas (N2) or an internal (CH4—BOG) refrigerant working fluid expanded and compressed in a twin compander arrangement and compressed by a refrigerant compressor, or an external single mixed refrigerant (SMR) working fluid compressed by a refrigerant compressor and expanded thru a JT valve.

Claims15

Dependent claims

A system for pre-cooling a natural gas stream for a liquefaction plant, the system comprising:

a first compressor operable to receive a first natural gas stream at a first pressure and produce a second natural gas stream at a second pressure;
a first exchanger, wherein the first exchanger is configured to receive the second natural gas stream at the second pressure and cool the second natural gas stream to produce a first cooled natural gas stream;
and
a second compressor operable to receive the first cooled natural gas stream at the second pressure and produce a third natural gas stream at a third pressure, wherein the third pressure is higher than the second pressure;
a second exchanger, wherein the second exchanger is configured to receive the third natural gas stream at the third pressure and cool the natural gas stream to produce a second cooled natural gas stream;
and
an expander, wherein the expander is operable to receive the second cooled natural gas stream and expand the second cooled natural gas stream from the third pressure to a fourth pressure to produce a chilled natural gas stream.

4 more elements

An LNG liquefaction plant system comprising:

a pre-cooling system comprising a first operable to receive a first natural gas stream at a first pressure and compress the first natural gas stream to produce a second natural gas stream at a second pressure, a first exchanger configured to cool the second natural gas stream at the second pressure to produce a first cooled natural gas stream, a second compressor operable to compress the first cooled natural gas stream to produce a third natural gas stream at a third pressure higher than the second pressure, a second exchanger configured to cool the third natural gas stream at the third pressure to produce a second cooled natural gas stream, and an expander operable to expand the second cooled natural gas stream from the third pressure to a fourth pressure to produce a chilled natural gas stream;
and
an LNG liquefaction system comprising a cryogenic exchanger including multiple stages of heat exchange and configured to receive a refrigerant working fluid for the multiple stages of heat exchange, wherein the LNG liquefaction system is operable to liquefy and subcool the chilled natural gas stream to produce LNG.

Dependencies are inferred from the claim text.

Methods and Configurations for LNG Liquefaction

Life of this patent

Methods and Configurations for LNG Liquefaction

Life of this patent

Abstract

Claims15