Open loop liquefaction process with NGL recovery

A system for removing natural gas liquids from and liquefying a natural gas feed stream, the system comprising:

• one or more expansion devices and/or heat exchanger sections arranged and configured to expanding and/or cool a natural gas feed stream to form an expanded and/or cooled natural gas feed stream;
• a distillation column having one or more separation sections, the distillation column being arranged and configured to receive the expanded and/or cooled natural gas feed stream into the distillation column below at least one of said separation sections and separate expanded and/or cooled natural gas feed stream into a natural gas liquids stream withdrawn from the bottom of the distillation column and a natural gas vapor stream withdrawn from the top of the distillation column;
• one or more conduits, heat exchanger sections and compression stages arranged and configured to receive and warm the natural gas vapor stream and a first expanded refrigerant stream, compress the resulting warmed streams and combine said streams to form a compressed refrigerant, wherein the one or more conduits, heat exchanger sections and compression stages and are arranged and configured such that the natural gas vapor stream and first expanded refrigerant stream are combined prior to, during or after being warmed and compressed;
• one or more conduits arranged and configured to pass a first portion of the compressed refrigerant and a second portion of the compressed refrigerant through the one or more heat exchanger sections so as to cool the first portion of the compressed refrigerant and the second portion of the compressed refrigerant via indirect heat exchange with the natural gas vapor stream and the first expanded refrigerant stream, to form respectively a first cold refrigerant stream and a second cold refrigerant stream, the first and second portions of the compressed refrigerant being cooled against the natural gas vapor stream and the first expanded refrigerant stream and the first portion of the compressed refrigerant being then further cooled against the natural gas vapor stream and the first expanded refrigerant stream such that the first cold refrigerant stream is formed at a lower temperature than the second cold refrigerant stream;
• one or more expansion and separation devices arranged and configured to expand the first cold refrigerant stream, expand the second cold refrigerant stream, and combine and separate the resulting expanded streams into vapor and liquid phases to form a first liquefied natural gas stream from the liquid phase and the first expanded refrigerant stream from the vapor phase;
• and
• one or more conduits and expansion devices arranged and configured to receive a reflux stream and expand and introduce the reflux stream into the top of the distillation column to provide reflux to the distillation column, wherein the reflux stream is formed from a portion of the first liquefied natural gas stream, a portion of the liquid phase separated in step (f), a portion of the first cold refrigerant stream withdrawn from said stream prior to said stream being separated in step (f), a further portion of the compressed refrigerant that has been cooled via indirect heat exchange with the natural gas vapor stream and the first expanded refrigerant stream that are being warmed in step (d), and/or a portion of a liquefied natural gas stream or liquefied natural gas product derived from the first liquefied natural gas stream.