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.

Provided are apparatus and systems for performing a swing adsorption process. This swing adsorption process may involve performing a startup mode process prior to beginning a normal operation mode process to remove contaminants from a gaseous feed stream. The startup mode process may be utilized for swing adsorption processes, such as TSA and/or PSA, which are utilized to remove one or more contaminants from a gaseous feed stream.

A process for altering the composition of a feed gas containing H.sub.2S equivalents is disclosed. The process comprises (a) contacting the feed gas with a solid adsorbent at a temperature of 250-500° C., to obtain a loaded adsorbent, (b) purging the loaded adsorbent with a purge gas comprising steam, thus producing a product stream which typically contains substantially equal levels of CO.sub.2 and H.sub.2S. The process further comprises a step (c) of regenerating the purged adsorbent by removal of water. The adsorbent comprises alumina and one or more alkali metals, such as potassium oxides, hydroxide or the like.

A method for regulating the regeneration time of an adsorption dryer, the method including the steps of: subjecting the adsorption dryer to an adsorption cycle; stopping the adsorption cycle after a preset adsorption time interval; and subsequently subjecting the adsorption dryer to a first regeneration cycle during a preset time interval. The method further includes maintaining the first regeneration cycle for an additional regeneration time interval if the measured pressure dew point or relative humidity is higher than a predetermined pressure dew point or relative humidity threshold; and/or stopping the first regeneration cycle if the outlet temperature is higher than or equal to a predetermined temperature threshold, and, if the time frame in which the adsorption dryer is subjected to the first regeneration cycle is greater than a minimum heat regeneration time interval.

Provided are apparatus and systems for performing a swing adsorption process. This swing adsorption process may involve passing streams through adsorbent bed units to remove contaminants, such as water, from the stream. As part of the process, the adsorbent bed unit may provide access to the adsorbent material within the adsorbent bed unit without having to remove one or more of valves, conduits and manifolds.

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.

Systems, devices and methods for submarine CO.sub.2 scrubbing are disclosed. The system may comprise an assembly including a sorbent, a scrubbing inlet configured to receive a first airflow during an adsorption mode. The first airflow may comprise air received from a cabin of a submarine. The assembly may be configured to flow the first airflow over and/or through the sorbent during the adsorption mode such that the sorbent removes a portion of CO.sub.2 entrained in the first airflow. The system may also include a scrubbing outlet configured to expel the scrubbed first airflow from the assembly into the cabin. The system may include an outside air inlet configured to receive a second airflow comprising outside air during a regeneration mode. The system may include a regeneration air outlet in configured to expel the second airflow after the second airflow has flowed over and/or through the sorbent during the regeneration mode.

Disclosed are metal organic frameworks (MOFs) for adsorbing guest species, methods for the separation of gases using the MOFs, and systems comprising the MOFs. The MOFs comprise a plurality of secondary building units (SBUs), each SBU comprising a repeating unit of one metal cation connected to another metal cation via a first moiety of an organic linker; a layer of connected adjacent SBUs in which a second moiety of the linker in a first SBU is connected to a metal cation of an adjacent SBU, and wherein adjacent layers are connected to each other via linker-to-linker bonding interactions

The present invention relates to a zeolite-based adsorbent comprising at least one zeolite of FAU structure of LSX type and comprising barium and/or potassium, in which the outer surface area of said zeolite-based adsorbent, measured by nitrogen adsorption, is between 20 m.sup.2.Math.g.sup.−1 and 100 m.sup.2.Math.g.sup.−1, limits inclusive. The present invention also relates to the use of such a zeolite-based adsorbent as an adsorption agent, and also to the process for separating para-xylene from aromatic isomer fractions containing 8 carbon atoms.

According to one aspect, there is provided a device (4) for providing supplemental oxygen to a subject (8), the device (4) comprising a subject interface (10) through which the subject (8) can inhale; a container (12) that has a first outlet (18) connected to the subject interface (10) to allow gas with an elevated oxygen level stored in the container (12) to be inhaled by the subject (8), a first inlet (24), and a material (15) for removing a specific gas from air passing through the container (12) to increase the oxygen content of the air passing through the container (12); and an air blower (14) that is connected to the first inlet (24) of the container (12) and that is configured to supply air into the container (12) as the subject (8) uses the device (4).