An adsorption process for xenon recovery from a cryogenic liquid or gas stream is described wherein a bed of adsorbent is contacted with the aforementioned xenon containing liquid or gas stream and adsorbs the xenon selectively from this fluid stream. The adsorption bed is operated to at least near full breakthrough with xenon to enable a deep rejection of other stream components, prior to regeneration using the temperature swing method. Operating the adsorption bed to near full breakthrough with xenon, prior to regeneration, enables production of a high purity product from the adsorption bed and further enables oxygen to be used safely as a purge gas, even in cases where hydrocarbons are co-present in the feed stream.

The present invention discloses high selectivity copolyimide membranes for gas, vapor, and liquid separations. Gas permeation tests on these copolyimide membranes demonstrated that they not only showed high selectivity for CO.sub.2/CH.sub.4 separation, but also showed extremely high selectivities for H.sub.2/CH.sub.4 and He/CH.sub.4 separations. These copolyimide membranes can be used for a wide range of gas, vapor, and liquid separations such as separations of CO.sub.2/CH.sub.4, He/CH.sub.4, CO.sub.2/N.sub.2, olefin/paraffin separations (e.g. propylene/propane separation), H.sub.2/CH.sub.4, He/CH.sub.4, O.sub.2/N.sub.2, iso/normal paraffins, polar molecules such as H.sub.2O, H.sub.2S, and NH.sub.3 mixtures with CH.sub.4, N.sub.2, H.sub.2. The high selectivity copolyimide membranes have UV cross-linkable sulfonyl functional groups and can be used for the preparation of UV cross-linked high selectivity copolyimide membranes with enhanced selectivities. The invention also includes blend polymer membranes comprising the high selectivity copolyimide and polyethersulfone. The blend polymer membranes comprising the high selectivity copolyimide and polyethersulfone can be further UV cross-linked under UV radiation.

The present invention relates to a method for obtaining a hydrogen rich gas from an off gas. Further, the invention relates to a system for operating said method.

An exemplary single bed reversing blower adsorption based air separation unit is configured to follow the O.sub.2 load placed thereon by adjusting flow rates therethrough and power consumption. At least one and preferably multiple pressure sensors sense O.sub.2 pressure within an O.sub.2 storage region downstream of an adsorber vessel. These sensed pressures are utilized to generate control signals controlling flow rates at locations upstream of the compressor, such as at a reversible blower and an output compressor. Control loops for the blower and the compressor are independent of each other and have different time constants. Effective following of the O.sub.2 load is thus achieved without driving the air separation unit into operational conditions outside of design and also maintaining optimal power consumption for the O.sub.2 produced, such that efficiency is maintained over a large turndown ratio.

The present invention discloses multistage membrane apparatus and a method for separating gases from a crude gas stream a gas to be separated, a main remaining gas and optionally one or more further gas components, wherein in the apparatus comprises a feed stream separation stage, a first permeate separation stage and a second permeate separation stage, each stage being a membrane separation stage with gas separation membranes.

Disclosed is a segregating gas arrangement that generally comprises a gas segregation chamber, at least one cooling plate in the gas segregation chamber, and a carbon adsorber in an adsorption gas capturing chamber. The gas segregation chamber has a rim that when resting atop regolith defines a first interior environment. The cooling plates are in the gas segregation chamber, wherein the cooling plates are maintained at a first temperature above 5 K, which is a condensation temperature that higher temperature condensing gases will condense. The adsorption gas capturing chamber defines a second interior environment that is in communication with the first interior environment. The carbon adsorber is in the second interior environment and is maintained at a second temperature below 3 K. The carbon adsorber is configured to capture the low temperature condensing gas.

A structured adsorbent assembly is described, which is usefully employed for pressure swing adsorption (PSA) processing of ambient air to generate high purity oxygen. The structured adsorbent assembly in various implementations may include cellulosic carbon molecular sieve fibers formed by spinning of precursor cellulose followed by pyrolysis of the spun fibers, as an argon-selective adsorbent, or AgX zeolite contained on and/or in polymeric fibers, as an argon-selective adsorbent, and such argon-selective adsorbents may be in combination with nitrogen-selective adsorbent such as LiX zeolite contained on and/or in polymeric fibers. The structured adsorbent assembly may be employed in PSA systems and processes to achieve highly efficient and economic generation of high purity oxygen for applications such as distributed gasification power generation.

The adsorption based air separation unit includes an adsorber vessel containing media which selectively adsorbs water vapor and nitrogen preferentially over oxygen. The vessel includes an air entry spaced from an oxygen discharge. At least one dry air tap from the adsorber vessel is located between the entry and the discharge. When the adsorption media is fresh, air entering the adsorber vessel passes through enough of the adsorber vessel to have much of its water vapor removed and only some of its nitrogen removed. The vessel can include multiple taps sequentially further from the entry which can be selectively opened as the adsorption media becomes saturated with water vapor and nitrogen, so that dry air with much of its nitrogen still present can be further tapped from the adsorber vessel. The adsorber vessel thus facilitates production of both oxygen and dry air, such as for use as medical grade air.

An air separation unit includes an air inlet with a reversible blower downstream therefrom and an adsorption bed filled with adsorption media downstream of the reversible blower. The adsorption bed contains an adsorption media which preferentially adsorbs nitrogen over oxygen. An oxygen and argon output is located downstream of the absorption bed. At least a portion of the mixed gas of oxygen and argon is routed to a modular argon separator which separates out at least a portion of the argon to provide high purity oxygen to a high purity oxygen outlet. The argon separator can be configured as a molecular sieve filter to separate the argon from the oxygen or the argon separator can be in the form of a gas cooler and condenser which condenses liquid oxygen for storage and discharge as substantially pure oxygen.

A driving system for a reversing blower adsorption based air separation unit is configured to not only drive the reversing blower cyclically in a forward and in a reverse direction, but also to allow the reversing blower to coast during a portion of its operating cycle. While coasting, a pressure differential across the blower acts alone to switch the reversing blower between a forward and a reverse direction of operation. Less power is thus required. When coasting, the blower can also be configured to output power such as the drive motor functioning as an electric generator or by having a mechanical power input be driven by the blower for power generation and/or energy storage. Such a system beneficially utilizes the energy associated with the pressure differential across the blower for energy harvesting and to further accelerate cycle times for the reversing blower adsorption based air separation unit.