In a hydrogen liquefaction process, a hydrogen-rich gas originating from an apparatus for separation by distillation and/or stripping and/or partial condensation, the gas exiting from the separation apparatus at a temperature of at most 103K containing at least 99.9 mol % of hydrogen and at a pressure between 20 and 30 bar, is sent to a hydrogen liquefier, without having heated the hydrogen-rich gas to a temperature above 0 C.

A method and apparatus for producing liquefied natural gas. A pretreated natural gas stream is compressed in at least two serially arranged compressors to a pressure of at least 1,500 psia and cooled. The resultant cooled compressed natural gas stream is expanded in at least one work producing natural gas expander to a pressure less than 2,000 psia and no greater than the pressure to which natural gas stream has been compressed, thereby forming a chilled natural gas stream that is separated into a refrigerant stream and a non-refrigerant stream. The refrigerant stream is warmed in a heat exchanger through heat exchange with one or more process streams associated with pretreating the natural gas stream, thereby generating a warmed refrigerant stream. The warmed refrigerant stream and the non-refrigerant stream are then liquefied.

In a process for the combined production of a) a hydrogen-enriched gas and a carbon monoxide-enriched gas and/or b) a mixture of hydrogen and carbon monoxide by cryogenic distillation and scrubbing, a still liquor is extracted from a scrubbing column and sent to a stripping column, a still liquor is extracted from the stripping column and sent to a separating column for carbon monoxide and methane and a cooling fluid is used at a pressure greater than that of the head of the separating column for cooling at least one fluid extracted at an intermediate level from the scrubbing column.

A system for conditioning a sour gas feed stream for a cryogenic distillation tower. A dehydration unit separates the sour gas feed stream into a first stream including water and a feed stream. A sequential cooling assembly is coupled to both the dehydration unit and the cryogenic distillation tower. The sequential cooling assembly includes: a first stage that separates the feed stream into a partially cooled feed stream and a second stream including acid gas; a second stage that cools the partially cooled feed stream into a cooled feed stream and a third stream including acid gas; and a cooled feed stream header coupled to a cryogenic distillation tower feed inlet. The first stage, the second stage, or both send at least one of the second and third streams to a bottom section of the cryogenic distillation tower.

A process for producing an olefin having N carbon atoms is proposed in which using a dehydrogenation a process gas is formed which contains at least the olefin having N carbon atoms, a paraffin having N carbon atoms and a hydrocarbon having N1 carbon atoms and in which using at least a portion of the process gas a separation input is formed which is subjected to a low temperature separation in which the separation input is cooled stepwise over a plurality of temperature levels and condensates are separated from the separation input, wherein the condensates are at least partly subjected to a first low temperature rectification to obtain a first gas fraction and a first liquid fraction, wherein the first gas fraction contains at least the olefin having N carbon atoms in a lower proportion than in the condensates and the hydrocarbon having N1 in a higher proportion than in the condensates. It is provided that the first gas fraction is at least partly subjected to a second low temperature rectification using a liquid reflux containing predominantly or exclusively the hydrocarbon having N1 carbon atoms in which the first gas fraction undergoes depletion in the olefin having N carbon atoms. A corresponding plant (100) likewise forms part of the subject matter of the invention.

This disclosure relates to a means of separating a gaseous mixture into both a purified stream and reject stream that can each be used for individual purposes. The disclosure will generally be connected to a gas supply such as a wellhead or gas pipe or other source where the gas makes contact with a membrane filter. The gaseous mixture should either have sufficient intrinsic pressure to be optimally filtered by the membrane filter or have the pressure boosted. Means of increasing the pressure includes ejectors, vacuum pumps and where the gas composition allows compressors. The retentave may be discharged into a pipeline, road or rail carriage or be liquefied. The permeate may be combusted through a combustion device to generate electricity and heat. Alternatively, the permeate may be discharged into a pipeline, road or rail carriage or stored for further use. The advantages of this disclosure include reduced capital and operational cost and a reduction in unnecessary environmental emissions.

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.

To obtain hydrogen from a gaseous C2minus feed, it is cooled from a first to a second temperature level at a first pressure level forming one or more condensates. A gaseous remainder is cooled to a third temperature level and subjected to a counterflow absorption at the first pressure level, obtaining a top gas rich in hydrogen and methane and a sump liquid. The former is heated and subjected to pressure swing adsorption at the first pressure level, forming a product stream rich in hydrogen and depleted in or free from methane. The condensate(s) and/or the sump liquid is/are expanded to and fed into a low pressure demethanizer at the second pressure level. The counterflow absorption is carried out using fluid taken from the demethanizer at the second pressure level, compressed in gaseous form to the first pressure level and cooled to the third temperature level.

Condensable vapors such as carbon dioxide are separated from light gases in a process stream. The systems and methods employ a circulating fluidized particle bed cooled by an out-bed heat exchanger to desublimate the solid form of condensable vapors from the process stream. Gas and solids may be sorted in a separator, and the solids may then be subcooled in a heat exchanger. The condensable vapors may be condensed on the bed particles or in the heat exchanger while the light gases from the process stream, which are not condensed, form a separated light-gas stream.

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.