According to an exemplary embodiment of the present invention, a pressure swing adsorption process of a hydrogen production system is provided.

The hydrogen production system comprises a desulfurization process for removing sulfur components from raw natural gas; a reforming reaction process for producing a reformed gas containing hydrogen generated by the reaction of natural gas through the desulfurization process and steam; and a pressure swing adsorption process of concentrating the hydrogen using a pressure swing adsorption from the reformed gas.

In a desorption step of the pressure swing adsorption process, a cocurrent depressurization and a countercurrent depressurization are simultaneously performed.

The present invention discloses polymeric ionic liquid (PIL) composition comprising a polymer selected from PBI or ABPBI and their derivatives or analogues covalently attached to fluorescence moiety selected from poly aromatic hydrocarbons, preferably pyrene or anthracene. Further, the invention discloses a process for preparing said composition with enhanced fluorescence and stability. Also, disclosed herein is the use of said fluorescent PIL in detection of explosives, as membranes for gas permeation and as chemo sensors.

Novel carbon molecular sieve (CMS) compositions comprising carbonized vinylidene chloride copolymer having micropores with an average micropore size ranging from 3.0 to 5.0. These materials offer capability in separations of gas mixtures including, for example, propane/propylene; nitrogen/methane; and ethane/ethylene. Such may be prepared by a process wherein vinylidene chloride copolymer beads, melt extruded film or fiber are pretreated to form a precursor that is finally carbonized at high temperature. Preselection or knowledge of precursor crystallinity and attained maximum pyrolysis temperature enables preselection or knowledge of a average micropore size, according to the equation ?=6.09+(0.0275?C)?(0.00233?T), wherein ? is the average micropore size in Angstroms, C is the crystallinity percentage and T is the attained maximum pyrolysis temperature in degrees Celsius, provided that crystallinity percentage ranges from 25 to 75 and temperature in degrees Celsius ranges from 800 to 1700. The beads, fibers or film may be ground, post-pyrolysis, and combined with a non-coating binder to form extruded pellets, or alternatively the fibers may be woven, either before or after pre-treatment, to form a woven fiber sheet which is thereafter pyrolyzed to form a woven fiber adsorbent.

Embodiments of methods and apparatuses for recovery of ethylene from FCC absorber off-gas comprising a heavy cut comprising ethylene, ethane and heavier hydrocarbons and a light cut comprising hydrogen, nitrogen and methane. An exemplary method includes passing the FCC absorber off-gas to an adsorption zone containing an adsorbent selective for the adsorption of the light cut, the adsorption zone adsorbing at least a portion of the light cut and recovering an adsorption zone effluent stream comprising the heavy cut. The adsorption zone effluent is passed to a demethanizer column to provide an overhead stream comprising hydrogen, nitrogen, methane, ethylene and ethane and a net bottoms stream comprising ethylene, ethane and the heavier hydrocarbons.

In embodiments of the present disclosure, a CMS hollow fiber membranes may be prepared to have an ultrathin (e.g. 2 microns or less) separation layer. A precursor hollow fiber may be prepared as dual layer fibers having a thin sheath layer and a core layer. During pyrolysis, the sheath layer is transformed into an ultrathin separation layer. Porosity of the core layer substrate is well-maintained during pyrolysis, thereby enabling high permeance of the CMS hollow fiber membrane. Additionally, in some embodiments, the sheath layer of the precursor hollow fibers may be hybridized prior to pyrolysis. By hybridizing the sheath layer prior to pyrolysis, a CMS hollow fiber may having an improved separation factor, including for example increased carbon dioxide/methane selectivity, may be provided.

A method of obtaining helium from a helium-containing feed gas. Helium-containing feed gas is fed to a prepurifying unit that uses a pressure swing adsorption process to remove undesirable components from the helium-containing feed gas and obtain a prepurified feed gas. The prepurified feed gas is fed to a membrane unit connected downstream of the prepurifying unit and that has at least one membrane more readily permeable to helium than to at least one further component present in the prepurified feed gas. A pressurized low-helium retentate stream that has not passed through the membrane is fed to the prepurifying unit. The pressurized low-helium retentate is used to displace helium-rich gas from an adsorber that is to be regenerated into an already regenerated adsorber.

A method for filtering gas includes providing a gas filtration structure, and the gas filtration structure includes a porous support and a first gas filtration film pair on the porous support, wherein the first gas filtration film pair includes a first hydrogen permeation layer and a first calcinated layered double hydroxide (c-LDH) layer, and the first hydrogen permeation layer is disposed between the porous support and the first c-LDH layer. The method also provides a hydrogen-containing mixture gas over the first gas filtration film pair, and collects hydrogen under the porous support.

A process for the production of a gas stream with a hydrogen concentration equal to or greater than 99.9% utilizing a pressure swing adsorption unit with a main gas stream having at least 70 mol % of hydrogen, wherein a secondary stream, representing less than 20% of the molar flow rate of the main gas stream and having a hydrogen content of less than 25 mol %, is introduced into the main gas stream upstream of the PSA is presented.

An adsorption apparatus and associated method for capturing a target gaseous adsorbate from an atmospheric air based gaseous feed stream. The adsorption apparatus includes a housing enclosing at least one adsorption element for adsorbing the target gaseous adsorbate, at least one substrate coated with an adsorptive composite coating that comprises at least 50 wt % metal organic framework and at least one binder, the housing having an inlet through which the gaseous feed stream can flow to the adsorption element and an outlet through which gas can flow out from the housing; and a desorption arrangement in contact with and/or surrounding the at least one adsorption element.

To reduce the emission of carbon dioxide and improve the energy efficiency in a hydrogen supply system. The hydrogen supply system (1) comprises: a reformer (5) for performing steam reforming of a hydrocarbon; a shift reaction unit (6) for producing a gas containing hydrogen and carbon dioxide by causing a water gas shift reaction of a gas obtained from the reformer; a first absorber (36) for absorbing the carbon dioxide contained in the gas obtained from the shift reaction unit in an absorption liquid; a hydrogenation reaction unit (8) for producing a hydrogenated aromatic compound by causing a hydrogenation reaction of an aromatic compound with a gas that has passed through the first absorber; and a regenerator (37) for separating the carbon dioxide from the absorption liquid by re-circulating the absorption liquid from the first absorber and heating the absorption liquid with heat generated from the hydrogenation reaction.