Cavitand compositions that comprise void spaces are disclosed. The void spaces may be empty, which means that voids are free of guest molecules or atoms, or the void spaces may comprise guest molecules or atoms that are normally in their gas phase at standard temperature and pressure. These cavitands may be useful for industrial applications, such as the separation or storage of gasses. Novel cavitand compounds are also disclosed.

The present invention relates to an extraction unit for extracting hydrogen from a gas mixture, including a tube or vessel, including a transit channel for passing a gas mixture in a feed-through direction from a receiving opening to a dispensing opening, which tube or vessel is arranged to be received in-line in a gas transport pipe, at least one membrane-electrode assembly arranged in the tube or vessel with at least one anode, a membrane and a cathode. The assembly is arranged such that an anode surface faces the transit channel and that a cathode surface faces away from the transit channel to a drain separated from the feed-through channel. The anode and the cathode are provided with a connector for an electrical voltage source.

In an aspect, a hydrogen separation unit includes an electrochemical cell stack that includes a separator stack located in between an anode side and a cathode side; a mixed gas conduit for receiving a mixed gas stream to the anode side; an anode removal conduit for removing a helium rich stream from the anode side; and a cathode removal conduit for removing a hydrogen rich stream from the cathode side. The separation stack includes a plurality of electrochemical cells, each of which includes a proton exchange membrane located in between an anode and a cathode. The proton exchange membrane can include a cation. The separation stack can be a cascading separation stack.

Processes and apparatuses for recovering a high purity carbon dioxide stream. A first separation zone that may include a cryogenic fractionation column provides the high-purity CO.sub.2 stream. A vapor stream from the cryogenic fractionation column is passed to a second separation zone to separate the CO.sub.2 from the other components. The second separation zone may include a pressure swing adsorption unit or a solvent separation unit. The second separation zone provides a hydrogen enriched gas stream that may be used in a gas turbine. The second stream from the second separation zone includes carbon dioxide and, after a pressure increase in a compressor, may be recycled to the first separation zone.

Described are composite adsorption media that contain two or more different types of adsorbent material in binder, that may preferably be prepared by additive manufacturing techniques, as well as methods of preparing the structures by additive manufacturing methods.

The present invention provides a composite body having, on a porous substrate and in the interstices of the substrate that includes fibers, preferably of an electrically nonconductive material, a porous layer (1) composed of oxide particles bonded to one another and partly to the substrate that include at least one oxide selected from oxides of the elements Al, Zr, Ti and Si, preferably selected from Al.sub.2O.sub.3, ZrO.sub.2, TiO.sub.2 and SiO.sub.2, and having, at least on one side, a further porous layer (2) including oxide particles bonded to one another and partly to layer (1) that include at least one oxide selected from oxides of the elements Al, Zr, Ti and Si, preferably selected from Al.sub.2O.sub.3, ZrO.sub.2, TiO.sub.2 and SiO.sub.2, where the oxide particles present in layer (1) have a greater median particle size than the oxide particles present in layer (2), which is characterized in that the median particle size (d.sub.50) of the oxide particles in layer (1) is from 0.5 to 4 μm and the median particle size (d.sub.50) of the oxide particles in layer (2) is from 0.015 to 0.15 μm, preferably 0.04 to 0.06 μm, a process for producing corresponding composite bodies and for the use thereof, especially in gas separation.

Novel methods for pretreating a rare-gas-containing stream exiting an etch chamber followed by recovering the rare gas from the pre-treated, rare-gas containing stream are disclosed. More particularly, the invention relates to the pretreatment and recovery of a rare gas, such as xenon or krypton, from a nitrogen-based exhaust stream with specific gaseous impurities generated during an etch process that is performed as part of a semiconductor fabrication process.

A process for separating components of a fluid mixture using membranes comprising a selective layer made from copolymers of perfluorinated dioxolanes. The resulting membranes have superior selectivity performance for fluid pairs of interest while maintaining fast fluid permeance compared to membranes prepared using conventional perfluoropolymers, such as Teflon® AF, Hyfion® AD, and Cytop®.

Novel methods for pretreating a rare-gas-containing stream exiting an etch chamber followed by recovering the rare gas from the pre-treated, rare-gas containing stream are disclosed. More particularly, the invention relates to the pretreatment and recovery of a rare gas, such as xenon or krypton, from a nitrogen-based exhaust stream with specific gaseous impurities generated during an etch process that is performed as part of a semiconductor fabrication process.

This disclosure relates to the adsorption and separation of fluid components, such as oxygen, in a feed stream, such as air, using zeolite ITQ-55 as the adsorbent. A process is disclosed for adsorbing oxygen from a feed stream containing oxygen, nitrogen and argon. The process comprises passing the feed stream through a bed of an adsorbent comprising zeolite ITQ-55 to adsorb oxygen from the feed stream, carrying out an equalization step to improve recovery, thereby producing a nitrogen product stream depleted in oxygen as well as a waste stream can be collected to have enriched oxygen. The kinetic selectivity and related mass transfer rates can be tuned by varying the mean crystal particle size of zeolite ITQ-55 within the range of from about 0.1 microns to about 40 microns, or by varying the adsorption temperature within the range from about -195° C. to about 30° C., or by varying the adsorption pressure within the range from about 1 bar (~14.7 psi) to about 30 bar (~435 psi), or combinations thereof. The feed stream is exposed to the zeolite ITQ-55 at effective conditions for performing a rapid cycle of kinetic separation, in which oxygen exhibits greater kinetic selectivity than nitrogen and argon.