A method for recovering natural gas liquids from a recycle stream having natural gas is provided. In one embodiment, a carbon dioxide recycle stream that comprises carbon dioxide, natural gas, and natural gas liquids is received. The carbon dioxide recycle stream is separated into a purified carbon dioxide recycle stream and a natural gas liquids stream. The purified carbon dioxide recycle stream comprises the carbon dioxide and the natural gas, and the natural gas liquids stream comprises the natural gas liquids. In another embodiment, a system comprises piping and a separator. The piping is configured to receive a recycle stream, and the separator is coupled to the piping and is configured to separate the recycle stream into a purified recycle stream and a natural gas liquids stream.

The present disclosure provides a distillation tower that may include a stripper section constructed and arranged to separate a feed stream at a temperature and pressure at which the feed stream forms no solid; a controlled freeze zone section constructed and arranged to separate the feed stream at a temperature and pressure at which the feed stream forms a solid; a melt tray assembly in the controlled freeze zone section that includes a liquid; an underflow weir in the controlled freeze zone section that alters a flow of the liquid in the melt tray assembly; an overflow weir in the controlled freeze zone section that works with the underflow weir to alter the flow of the liquid in the melt tray assembly and is adjacent to the underflow weir; and a covering element in the controlled freeze zone section that is connected to and extends from the underflow weir.

Processes and devices for recovering natural gas liquid from a hydrocarbon containing gas are provided by introduction of compressed air to a vortex tube. The vortex tube generates a cold air stream that is introduced into a heat exchanger. A hydrocarbon containing gas of higher temperature than the cold air stream is introduced into the heat exchanger, so that the cold air stream in the heat exchanger cools the hydrocarbon containing gas to condense natural gas vapors in the hydrocarbon containing gas to liquid hydrocarbons. In this manner, liquid hydrocarbons and dry hydrocarbon containing gas are obtained.

Methods and systems for separating hydrocarbons using one or more dividing wall columns are provided. The method can include introducing a hydrocarbon fluid to a first dividing wall column. A first overhead comprising methane, ethane, or a combination thereof, a first intermediate comprising ethane, a second intermediate comprising ethane, and a first bottoms comprising one or more hydrocarbons having three or more carbon atoms per molecule can be recovered from the first dividing wall column. The first overhead can be introduced to a process for producing a liquefied natural gas. The first bottoms can be introduced to a second dividing wall column. A second overhead comprising propane, a third intermediate comprising butane, and a second bottoms comprising one or more hydrocarbons having five or more carbon atoms per molecule can be recovered from the second dividing wall column. The second overhead can be introduced to the process for producing a liquefied natural gas.

A method for separating nitrogen from an LNG stream with a nitrogen concentration of greater than 1 mol %. A pressurized LNG stream is produced at a liquefaction facility by liquefying natural gas, where the pressurized LNG stream has a nitrogen concentration of greater than 1 mol %. At least one liquid nitrogen (LIN) stream is received from storage tanks, the at least one LIN stream being produced at a different geographic location from the LNG facility. The pressurized LNG stream is separated in a separation vessel into a vapor stream and a liquid stream. The vapor stream has a nitrogen concentration greater than the nitrogen concentration of the pressurized LNG stream. The liquid stream has a nitrogen concentration less than the nitrogen concentration of the pressurized LNG stream. At least one of the one or more LIN streams is directed to the separation vessel.

A natural gas liquid plant is retrofitted with a bolt-on unit that includes an absorber that is coupled to an existing demethanizer by refrigeration produced at least in part by compression and expansion of the residue gas, wherein ethane recovery can be increased to at least 99% and propane recovery is at least 99%, and where a lower ethane recovery of 96% is required, the bolt-on unit does not require the absorber, which could be optimum solution for revamping an existing facility. Contemplated configurations are especially advantageous to be used as bolt-on upgrades to existing plants.

A purification method for feed air in cryogenic air separation of the present invention includes purifying the feed air for the cryogenic air separation by using a temperature swing adsorption method, wherein the whole region of a carbon dioxide adsorbent layer packed in an adsorption column is used as a mass transfer zone of a carbon dioxide. Also, a purification apparatus for feed air in cryogenic air separation of the present invention includes at least two adsorption columns; and a moisture adsorbent and a carbon dioxide adsorbent being laminated and packed in the adsorption columns, wherein the packed amount of the carbon dioxide adsorbent is the same as the amount of the carbon dioxide adsorbent in the region of the carbon dioxide adsorbent which a mass transfer zone of a carbon dioxide occupies at the end of an adsorption step, and a temperature swing adsorption method is used.

A method and apparatus for producing a purified liquid argon product in which liquid argon having oxygen impurities is produced in a cryogenic air separation plant by separating argon from oxygen within an argon column. An impure liquid argon stream, composed of part of the liquid argon, is purified in an adsorbent bed by adsorbing the oxygen impurities in an adsorbent to produce a purified liquid argon stream that constitutes the purified liquid argon product. During adsorption, the adsorbent bed is maintained at a reduced temperature with a coolant to prevent vaporization of the liquid argon. The bed is then regenerated by draining residual liquid argon from the adsorbent bed, introducing the residual liquid argon back into the air separation plant and then desorbing the oxygen impurities with a regeneration gas. After regeneration, the adsorbent bed is refilled with purified liquid argon prior to being brought back on-line.

The disclosure includes a process for treating a natural gas containing carbon dioxide wherein the natural gas is separated by a cryogenic process in order to provide, on the one hand, a stream of liquid carbon dioxide, containing hydrocarbons, and, on the other hand, purified natural gas; at least one part of the natural gas is cooled in a first heat exchanger and then in a second heat exchanger before the cryogenic process and/or before a reflux to the cryogenic process; at least one part of the stream of liquid carbon dioxide is recovered in order to provide a stream of recycled carbon dioxide; the stream of recycled carbon dioxide is divided into a first portion and a second portion; the first portion is expanded and then heated in the first heat exchanger, in order to provide a first stream of heated carbon dioxide; the second portion is cooled, then at least one part of the second portion is expanded and then heated in the second heat exchanger, in order to provide a second stream of heated carbon dioxide; at least some of the hydrocarbons contained in the first stream of heated carbon dioxide and in the second stream of heated carbon dioxide are recovered by liquid/gas separation.

A system and method for producing argon that uses a higher pressure column, a lower pressure column, and an argon column collectively configured to produce nitrogen, oxygen and argon products through the cryogenic separation of air. The present system and method also employs a once through argon condensing assembly that is disposed entirely within the lower pressure column that is configured to condense an argon rich vapor stream from the argon column against the oxygen-enriched liquid from the higher pressure column to produce an argon liquid product. The control system is configured for optimizing the production of argon product by ensuring an even flow split of the oxygen-enriched liquid is distributed to the argon condenser cores and by adjusting the flow rate of the argon removed from the argon condensing assembly to maintain the liquid/vapor balance in the argon condensing assembly within appropriate limits.