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 process for cryogenic separation of a feed stream containing methane and air gases in which: the feed stream is cooled in order to produce a cooled stream, at least one portion of the cooled stream is sent to one level of a distillation column, a bottom stream is drawn off from the distillation column, the bottom stream being enriched in methane relative to the feed stream, a stream enriched in oxygen and in nitrogen relative to the feed stream is drawn off from the distillation column, at least one noncombustible dilution stream that is more volatile than oxygen is introduced into the distillation column at at least one level lower than the one at which the cooled stream is introduced. The dilution stream is extracted from the feed stream. Facility for producing biomethane by purification of biogases derived from non-hazardous waste storage facilities (NHWSF) implementing the process.

Methods and systems for removing moisture from refrigerant that use a desiccant-based moisture removal unit can be used in the production of liquid natural gas (LNG). For example, a method can include: compressing a refrigerant; conveying at least a portion of the refrigerant to a moisture removal unit comprising a desiccant to form dehydrated refrigerant; cooling and condensing the dehydrated refrigerant to provide a cooled dehydrated liquid refrigerant; conveying the cooled dehydrated refrigerant to a heat exchanger; and passing a LNG stream rich in methane through the heat exchanger to cool at least part of the LNG stream by indirect heat exchange with the cooled dehydrated refrigerant.

A method for flexible production of argon from a cryogenic air separation unit is provided. The disclosed cryogenic air separation unit is capable of operating in a ‘no-argon’ or ‘low-argon’ mode when argon demand is low or non-existent and then switching to operating in a ‘high-argon’ mode when argon is needed. The recovery of the argon products from the air separation unit is adjusted by varying the percentages of dirty shelf nitrogen and clean shelf nitrogen in the reflux stream directed to the lower pressure column. The cryogenic air separation unit and associated method also provides an efficient argon production/rejection process that minimizes the power consumption when the cryogenic air separation unit is operating in a ‘no-argon’ or ‘low-argon’ mode yet maintains the capability to produce higher volumes of argon products at full design capacity to meet argon product demands.

A process for producing biomethane by scrubbing a biogas feed stream includes introducing the feed gas stream into a pretreatment unit wherein a CO.sub.2-depleted gas stream is partially separated from a CO.sub.2 stream and an oxygen stream and is compressed to a pressure P1 above 25 bar abs. Subjecting the CO.sub.2-depleted gas stream to cryogenic separation in a distillation column to separate a nitrogen stream and produce a CH.sub.4-enriched stream, the distillation column comprising n plates, n being an integer between 8 and 100. Recovering a pressurized CH.sub.4-enriched stream by pumping the CO.sub.2-depleted gas stream to a pressure P2 above 25 bar absolute.

An air gas separation plant comprising, in the direction of circulation of the air stream: a compression means that makes it possible to compress the air stream to a pressure P1 of between 1.15 bar abs and 2 bar abs, an adsorption unit of TSA type, and a cryogenic distillation unit, with the adsorption unit comprising at least two adsorbers A and B each having a parallelepipedal casing arranged horizontally and comprising: an air stream inlet and an air stream outlet, a fixed bed adsorbent mass, likewise of parallelepipedal shape, the faces of which are parallel to the faces of the casing; and a set of volumes allowing the air stream to pass through the adsorbent mass horizontally, over the entire cross-section and throughout the entire thickness thereof.

This specification relates to operating industrial facilities, for example, crude oil refining facilities or other industrial facilities that include operating plants that process natural gas or recover natural gas liquids.

This specification relates to operating industrial facilities, for example, crude oil refining facilities or other industrial facilities that include operating plants that process natural gas or recover natural gas liquids.

This specification relates to operating industrial facilities, for example, crude oil refining facilities or other industrial facilities that include operating plants that process natural gas or recover natural gas liquids.

A pretreatment system and method for a floating liquid natural gas (“FLNG”) facility are presented. The inlet natural gas stream flows through a membrane system to remove carbon dioxide and a heat exchanger, producing first and second cooled CO.sub.2-depleted non-permeate streams. The first cooled CO.sub.2-depleted non-permeate stream is routed to additional pretreatment equipment, while the second cooled CO.sub.2-depleted non-permeate stream is routed directly to a LNG train. Alternatively, the inlet natural gas stream may flow through a membrane system to produce a single cooled CO.sub.2-depleted non-permeate stream that is routed to the LNG train after sweetening and dehydration. Because the pretreatment system delivers the incoming gas stream to the LNG train at a lower temperature than conventional systems, less energy is needed to convert the gas stream to LNG. In addition, the pretreatment system has a smaller footprint than conventional pretreatment systems.