Embodiments of the invention are directed to methods, processes, and systems for safely and reliably purifying hydrogen from a gas mixture containing hydrogen and oxygen using a cryogenic separation method.

Systems and methods for separating one or more olefins are provided. In one or more embodiments, the method for separating one or more olefins can include separating at least a portion of one or more C.sub.3 and heavier hydrocarbons from a hydrocarbon containing C.sub.1 to C.sub.20 hydrocarbons to provide a first mixture that can include methane, ethane, ethylene, and/or acetylene. At least a portion of the first mixture can be hydrogenated to convert at least a portion of the acetylene to ethane and ethylene. At least a portion of the methane can be separated from the hydrogenated mixture to provide a second mixture that can include ethane and ethylene. At least a portion of the ethylene can be separated from the second mixture to provide a first product that can include at least 95 mol % ethylene and a second product that can include at least 95 mol % ethane.

This method includes introducing a downstream stream (140) of cracked gas from a downstream heat exchanger (58) in a downstream separator (60) and recovering, at the head of the downstream separator (60), a high-pressure fuel gas stream (144). The method includes the passage of the stream (144) of fuel through the downstream exchanger (58) and an intermediate exchanger (50, 54) to form a reheated high-pressure fuel stream (146), the expansion of the reheated high-pressure fuel stream (146) in at least a first dynamic expander (68) and the passage of the partially expanded fuel stream (148) from the intermediate exchanger (50, 54) in a second dynamic expander (70) to form an expanded fuel stream (152). The expanded fuel stream (152) from the second dynamic expander (70) is reheated in the downstream heat exchanger (58) and in the intermediate heat exchanger (50, 54).

One or more specific embodiments disclosed herein includes a method for separating hydrogen from an olefin hydrocarbon rich compressed effluent vapor stream, employing a single heat exchanger, multiple gas-liquid separators, multiple expander/compressor sets, and a rectifier attached to a liquid product drum.

Embodiments of apparatuses and methods for reforming of hydrocarbons including recovery of products are provided. In one example, a method comprises separating a reforming-zone effluent into a net gas phase stream and a liquid phase hydrocarbon stream. The net gas phase stream is separated for forming an H.sub.2-rich stream and a first liquid phase hydrocarbon stream. The H.sub.2-rich stream may be contacted with an adsorbent to form an H.sub.2-ultra rich stream and a gas stream. C.sub.3/C.sub.4 hydrocarbons are absorbed from the gas stream with the liquid phase hydrocarbon stream. The gas stream may be contacted with an H.sub.2/hydrocarbon separation membrane to separate the PSA tail gas stream and form an H.sub.2-rich permeate stream and an H.sub.2 depleted non-permeate residue stream.

The present invention relates to a process (100) for separatory processing of a starting mixture containing predominantly hydrogen, methane and hydrocarbons having two or two or more carbon atoms, wherein at least a portion of the starting mixture is cooled to form one or more condensates using one or more heat exchangers (101, 103, 105, 107) and at least a portion of the condensate(s) is subjected to a rectification to form a gaseous methane-rich fraction. It is provided that the gaseous methane-rich fraction is used to form a first fluid stream which is at least partly compressed, in an unchanged composition with respect to the gaseous methane-rich fraction, to a liquefaction pressure level of 35 to 45 bar, and at least partly liquefied by cooling, and in that the first fluid stream, or a second fluid stream formed using the first fluid stream, is expanded to a delivery pressure and heated in the or at least one of the heat exchanger(s) (101, 103, 105, 107). A corresponding plant likewise forms part of the subject matter of the invention.

This method comprises passing a residual stream into a flash drum to form a gaseous overhead flow and liquid bottom flow, and feeding the bottom flow into a distillation column,

It comprises cooling the overhead flow in a heat exchanger to form a cooled overhead flow.

It comprises the extraction of a gaseous overhead stream at the head of the distillation column, and the formation of at least one effluent stream from the overhead stream and/or from the top stream.

The separation of the cooled overhead flow flow comprises passing the cooled overhead flow into an absorber, and injecting a methane-rich stream into the absorber to place the cooled overhead flow in contact with the methane-rich stream.

A method for separating a hydrogen-containing hydrocarbon mixture (C2minus), which in addition to the hydrogen essentially contains hydrocarbons with two carbon atoms and methane, using a distillation column (10). Fluid (a, c, e) of the hydrocarbon mixture (C2minus) is cooled stepwise at a first pressure level, during which time first condensates (b, d) are separated from the fluid (a, c, e). Fluid (e) from the hydrocarbon mixture (C2minus) which remains gaseous after this is fed at the first pressure level into a C2 absorber (7), to which a liquid reflux (r) is added at the top, while a second condensate (f) is drawn off from the sump of the C2 absorber (7) and a gaseous top stream (g) containing predominantly methane and hydrogen is drawn off at the top of the C2 absorber (7). Fluid of the above-mentioned gaseous top stream (g) from the top of the C2 absorber (7) is cooled to a third temperature level and transferred at the first pressure level into a hydrogen separator (8) in which a methane-rich third condensate (i) is separated from the fluid of the gaseous top stream (g), leaving behind a gaseous, hydrogen-rich stream (h). Fluid of the first condensates (b, d) and fluid of the second condensate (f) is depressurized from the first pressure level to a second pressure level below the first pressure level and fed into the distillation column (10) which is operated at the second pressure level. Fluid (e) of the third condensate (i) which is separated in the hydrogen separator (8) from the fluid of the gaseous top stream (g) from the top of the C2 absorber is used as the reflux (r) added at the top of the C2 absorber (7) and transferred from the hydrogen separator to the C2 absorber solely by gravity. The invention also relates to a corresponding separating unit and a corresponding olefin apparatus.

A method of liquefying hydrogen, including dividing a hydrogen stream into at least a first fraction and a second fraction, introducing the first fraction into a refrigeration cycle of a hydrogen liquefaction unit, thereby liquefying a product hydrogen stream, withdrawing one or more warm hydrogen stream(s) from the hydrogen liquefaction unit, and returning the one or more warm hydrogen stream to the hydrogen stream, wherein the second fraction is combined with a high-pressure nitrogen stream to form an ammonia synthesis gas stream.

One or more specific embodiments disclosed herein includes a method for separating hydrogen from an olefin hydrocarbon rich compressed effluent vapor stream, employing a single heat exchanger, multiple gas-liquid separators, multiple expander/compressor sets, and a rectifier attached to a liquid product drum.