A method for producing liquefied natural gas (LNG) from a natural gas stream having a nitrogen concentration of greater than 1 mol %. At least one liquid nitrogen (LIN) stream is received at an LNG liquefaction facility. The LIN streams may be produced at a different geographic location from the LNG liquefaction facility. A natural gas stream is liquefied by indirect heat exchange with a nitrogen vent stream to form a pressurized LNG stream. The pressurized LNG stream has a nitrogen concentration of greater than 1 mol %. The pressurized LNG stream is directed to one or more stages of a column to produce an LNG stream and the nitrogen vent stream. The column has upper stages and lower stages. The LIN streams are directed to one or more upper stages of the column.

Plant and process for the production of liquid methane from a feed gas stream comprising at least methane and carbon dioxide. A feed gas stream is injected into a CO.sub.2 crystallizer in countercurrent fashion against a stream of predominantly liquid methane, thereby crystallizing amounts of carbon dioxide from the feed gas stream. Gaseous methane recovered from the CO.sub.2 crystallizer is liquefied at a liquefaction exchanger.

The present disclosure provides a gas liquefaction separator, a gas liquefaction recovery system, and a method for separating and recovering ethylene oxide. The gas liquefaction separator includes a housing, a blocking plate, a gas baffle, and a liquid collector, the latter three being located inside the housing. The liquid collector—an outer edge of which is connected to an inner wall of the housing—is located below the gas baffle, which is located below the blocking plate. The liquid collector includes a first flow guide surface, on a bottom portion of which is disposed a first hole. The gas baffle—an upper surface of which forms a second flow guide surface and an outer edge of which has a protrusion(s)—is connected to the first flow guide surface through the protrusion(s), thereby forming a second hole between the outer edge of the gas baffle and the first flow guide surface.

A method and system for liquefying a natural gas feed stream and removing nitrogen therefrom.

Xenon and/or krypton is separated from a liquid oxygen stream comprising oxygen and xenon and/or krypton in a process comprising providing at least a portion of the liquid oxygen stream as a reflux liquid to the top of a rare gas recovery column operated at a pressure of between 5 to 25 bara, vaporizing a reboiler liquid in the reboiling zone in the bottom of the rare gas recovery column to produce a mixture of a rising vapor and a xenon and/or krypton-enriched liquid stream; and contacting the rising vapor with the reflux liquid in at least one distillation zone of the column to effect stripping xenon and/or krypton from the rising vapor to the reflux liquid. The process provides a recovery of xenon of greater than 90% and a krypton recovery of 15% to 90%.

The present disclosure provides a gas liquefaction separator, a gas liquefaction recovery system, and a method for separating and recovering ethylene oxide. The gas liquefaction separator includes a housing, a blocking plate, a gas baffle, and a liquid collector, the latter three being located inside the housing. The liquid collector—an outer edge of which is connected to an inner wall of the housing—is located below the gas baffle, which is located below the blocking plate. The liquid collector includes a first flow guide surface, on a bottom portion of which is disposed a first hole. The gas baffle—an upper surface of which forms a second flow guide surface and an outer edge of which has a protrusion(s)—is connected to the first flow guide surface through the protrusion(s), thereby forming a second hole between the outer edge of the gas baffle and the first flow guide surface.

A system and method for removing nitrogen from natural gas using two fractionating columns, that may be stacked, and a plurality of separators and heat exchangers, with horsepower requirements that are 50-80% of requirements for prior art systems. The fractionating columns operate at different pressures. A feed stream is separated with a vapor portion feeding the first column to produce a first column bottoms stream that is split into multiple portions at different pressures and first column overhead stream that is cooled and separated into vapor and liquid portions to control subcooling of the vapor portion prior to feeding the second column. Heat exchange between first column and second column streams provides first column reflux and reboil heat for a second column ascending vapor stream. Three sales gas streams are produced, each at a different pressure.

A system and method for removing nitrogen from natural gas using two fractionating columns, that may be stacked, and a plurality of separators and heat exchangers, with horsepower requirements that are 50-80% of requirements for prior art systems. The fractionating columns operate at different pressures. A feed stream is separated with a vapor portion feeding the first column to produce a first column bottoms stream that is split into multiple portions at different pressures and first column overhead stream that is split or separated into two portions at least one of which is subcooled prior to feeding the top of the second column. Optional heat exchange between first column and second column streams provides first column reflux and reboil heat for a second column ascending vapor stream. Three sales gas streams are produced, each at a different pressure.

Methods and systems for producing a product natural gas employing a natural gas liquids (NGL) recovery unit followed by removing nitrogen in a nitrogen rejection unit (NRU) operatively connected with the NGL recovery unit by a pressure management sub-system (PMSS). In one embodiment, the PMSS includes a first conduit fluidly connecting the top of a demethanizer column (or an existing conduit connected to the top of the demethanizer) to a separator, a second conduit fluidly connecting the separator to a pump, the pump connected to a distillation column in the NRU by a third conduit, in another embodiment, the PMSS includes a first conduit fluidly connecting an NGL expander to a separator, allowing natural gas vapors and nitrogen to be fed to the NRU column through a second conduit. Alternatively, the PMSS allows mixture from the NGL recovery unit expander to be fed directly via the first conduit to the NRU distillation column.

Disclosed is a method of discharging lubricant oil from a BOG reliquefaction system configured to reliquefy BOG by compressing the BOG by a compressor, cooling the compressed BOG through heat exchange with non-compressed BOG by a heat exchanger, and reducing a pressure of fluid cooled through heat exchange by a pressure reducer. In the lubricant oil discharge method, the compressor comprises at least one oil-lubrication type cylinder and it is determined that it is time to discharge condensed or solidified lubricant oil, if at least one of preset conditions is satisfied.