Recovery of natural gas liquids from a gas stream

A process comprising:

• providing a feed gas stream comprising methane and natural gas liquids in vapor form;
• splitting the feed gas stream into a first portion and a second portion;
• cooling the first portion of the feed gas stream in a first heat exchanger to obtain a cooled first portion of the feed gas stream;
• introducing the cooled first portion of the feed gas stream into a liquid-vapor separator;
• obtaining a vapor stream and a liquid stream from the liquid-vapor separator;
• splitting the vapor stream into a first portion and a second portion;
• conveying the second portion of the vapor stream directly from the liquid-vapor separator to a second heat exchanger;
• sub-cooling the second portion of the vapor stream in the second heat exchanger to obtain a liquefied vapor stream;
• introducing the liquefied vapor stream into a demethanizer column;
• wherein the second portion of the feed gas stream is circulated sequentially through a bottom reboiler and a top reboiler, each reboiler receiving one or more draw streams from the demethanizer column and returning one or more warmed draw streams to the demethanizer column;
• introducing the first portion of the vapor stream to at least one of an expansion valve or a turboexpander having an expansion side and a compression side connected by a shaft, the first portion of the vapor stream being introduced to the expansion side of the turboexpander;
• obtaining an expanded vapor stream from the expansion valve or the expansion side of the turboexpander;
• introducing the expanded vapor stream into the demethanizer column;
• introducing at least a first portion of the liquid stream into the demethanizer column;
• monitoring a temperature of at least one of the one or more warmed draw streams returning to the demethanizer column from the bottom reboiler and a temperature of the cooled first portion of the feed gas stream;
• estimating a temperature of the liquid-vapor separator based upon the temperature of the at least one of the one or more warmed draw streams returning to the demethanizer column from the bottom reboiler and the temperature of the cooled first portion of the feed gas stream;
• adjusting a split ratio between the first portion and the second portion of the feed gas stream if the temperature of the liquid-vapor separator is outside a desired range;
• obtaining from the demethanizer column an overhead stream lean in natural gas liquids and a bottoms stream rich in natural gas liquids;
• compressing the overhead stream in the compression side of the turboexpander to obtain a pre-conditioned sales gas stream;
• and
• processing the pre-conditioned sales gas stream in a sales gas conditioning sub-module to obtain a conditioned sales gas stream.