Described are a method and apparatus for producing graphene by pyrolysis of hydrocarbons from a hydrocarbon feedstock and for recovering hydrogen gas which is a byproduct of the pyrolysis and which may be present in the hydrocarbon feedstock. The apparatus may comprise: an elongate reactor having: a first end and a second end, the first end being configured to receive a hydrocarbon feedstock; a channel defined therein for conveying a fluid between the first and second ends, wherein the fluid is a reaction mixture comprising the hydrocarbon feedstock; a terminal section attached to the second end, the terminal section being selectively permeable to hydrogen gas and impermeable to other components of the reaction mixture; and a hydrogen collection section attached to the second end to receive hydrogen gas from the terminal section, the hydrogen collection section being impermeable to hydrogen gas.

Recovering helium from a gaseous stream includes contacting an acid gas removal membrane with a gaseous stream to yield a permeate stream and a residual stream, removing a majority of the acid gas from the residual stream to yield a first acid gas stream and a helium depleted clean gas stream, removing a majority of the acid gas from the permeate stream to yield a second acid gas stream and a helium rich stream, and removing helium from the helium rich stream to yield a helium product stream and a helium depleted stream. A helium removal system for removing helium from a gaseous stream including hydrocarbon gas, acid gas, and helium includes a first processing zone including a first acid gas removal unit, a second processing zone including a second acid gas removal unit, a third processing zone, and a helium purification unit.

A gas separation membrane includes a gas separation layer that contains the polyimide compound having the structural portion represented by Formula (1). A gas separation module includes the gas separation membrane, a gas separator includes the gas separation module, and a gas separation method is performed using the gas separation membrane.

##STR00001## A.sup.1 and A.sup.2 represent a linking site, a hydrogen atom, a halogen atom, a carboxy group, a carbamoyl group, an acyl group, an acyloxy group, a sulfo group, a sulfamoyl group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyloxy group, an alkoxycarbonyl group, a non-fluorinated alkyl group, or an aryl group. Here, at least one of A.sup.1 or A.sup.2 represents a linking site.

A gas separation membrane includes a gas separation layer containing a polyimide compound, in which the polyimide compound has a repeating unit represented by Formula (I),

##STR00001## in Formula (I), R.sup.f1 to R.sup.f6 each independently represent a hydrogen atom or a substituent, a ring Ar.sup.1 and a ring Ar.sup.2 each independently represent an aromatic ring, A represents a single bond or a divalent linking group, and R represents a mother nucleus having a specific structure.

The gas separation membrane includes a separation layer containing a silsesquioxane compound, and a protective layer, in which a composition of the separation layer in a thickness direction is uniform.

An input stream of gaseous nitrogen and carbon dioxide is introduced into a first interior volume of a separation vessel that is divided into first and second interior volumes by a separation membrane that includes a metal layer. The metal layer selectively permits movement of nitrogen through the metal layer. An output stream of gaseous nitrogen and carbon dioxide is conveyed out of the first interior volume and into a reaction vessel. The volume fraction of carbon dioxide is greater in the output stream than in the input stream; the volume fraction of nitrogen is reduced in the output stream relative to the input stream. Nitrogen is removed from the second interior volume to maintain a gradient of nitrogen partial pressure across the separation membrane that causes net transport of nitrogen from the first interior volume through the separation membrane into the second interior volume.

Disclosed is an apparatus and method for mixing transmission and separation of hydrogen gas and natural gas recovered based on pressure energy. The method includes: (1) hydrogen compressed natural gas is introduced into the pressure energy recovery system; (2) the low-pressure hydrogen compressed natural gas is introduced into the separation system; (3) the low-hydrogen natural gas and the high concentration hydrogen gas are introduced into a first natural gas buffer tank and a first hydrogen gas buffer tank respectively; (4) the low-hydrogen natural gas and the high concentration hydrogen gas are introduced into the pressure boosting system; (5) the low-hydrogen natural gas and the high concentration hydrogen gas are respectively introduced into a natural gas user end. The method of the present invention is low in energy consumption, so as to realize pressure energy recovery, and energy consumption of hydrogen gas separation is greatly reduced.

A process for separating components or a fluid mixture using membranes comprising a selective layer made from copolymers of an amorphous per fluorinated dioxolane and a fluorovinyl monomer. The resulting membranes have superior selectivity performance for certain fluid components of interest while maintaining fast permeance compared to membranes prepared using conventional perfluoropolymers, such as Teflon? AF, Hyflon? AD, and Cytop?.

An input stream of gaseous nitrogen and carbon dioxide is introduced into a first interior volume of a separation vessel that is divided into first and second interior volumes by a separation membrane that includes a metal layer. The metal layer selectively permits movement of nitrogen through the metal layer. An output stream of gaseous nitrogen and carbon dioxide is conveyed out of the first interior volume and into a reaction vessel. The volume fraction of carbon dioxide is greater in the output stream than in the input stream; the volume fraction of nitrogen is reduced in the output stream relative to the input stream. Nitrogen is removed from the second interior volume to maintain a gradient of nitrogen partial pressure across the separation membrane that causes net transport of nitrogen from the first interior volume through the separation membrane into the second interior volume.

A portable oxygen generating system is provided that comprises a reaction chamber, a feed system for providing and controlling hydrogen peroxide solution to the reaction chamber, and a cooling/condensing system for cooling the hot oxygen and water vapor leaving the reactor and condensing and removing water. The portable chemical oxygen generation system produces humidified, breathable oxygen, that is substantially free of hydrogen peroxide and other contaminants, at a controlled flow and temperature over an extended period of time.