A single compressor is used to separately compress permeate from cascaded first and second gas separation membrane-based separation units and residue from a fourth gas separation membrane-based separation unit in order to avoid too high a CO2 partial pressure in the compressed permeate. After the permeates from the first and second stages are compressed, the compressed stream is fed to a third gas separation membrane-based separation unit.

Described herein are separation articles such as, for example, films, membranes and the like separating at least one component from a gaseous mixture comprising two or more components comprising difluoromethane (HFC-32, CH.sub.2F.sub.2) and pentafluoroethane (HFC-125, C.sub.2F.sub.5H). The disclosed articles include a “selective layer” that is selectively permeable for the desired component to be separated from the gas mixture. The selective layer is composed of an amorphous fluorinated copolymer. Optionally, the article may include other layers which serve various purposes such as, for example, a porous support layer, a “gutter layer,” which allows the permeate gas to pass from the selective layer to the porous layer with minimal flow impedance, and a protective layer, which protects the selective layer from fouling. Each component of the separation articles described herein and methods for making and using the same are provided below.

The gas separation membrane element contains a gas separation membrane, and a sealing portion for preventing mixture of a source gas and a specific gas permeated through a gas separation membrane. The gas separation membrane has a first porous layer including a porous membrane, and a hydrophilic resin composition layer disposed on the first porous layer. The sealing portion is a region in which a cured material of a sealant penetrates in at least the first porous layer in the gas separation membrane, and a thermal expansion coefficient A of the sealing portion and a thermal expansion coefficient B of a material forming the first porous layer satisfy a relation (I):
0.35≤A/B≤1.0  (I).

The gas separation membrane element contains a gas separation membrane, and a sealing portion for preventing mixture of a source gas and a specific gas permeated through a gas separation membrane. The gas separation membrane has a first porous layer including a porous membrane, and a hydrophilic resin composition layer disposed on the first porous layer. The sealing portion is a region in which a cured material of a sealant penetrates in at least the first porous layer in the gas separation membrane, and a thermal expansion coefficient A of the sealing portion and a thermal expansion coefficient B of a material forming the first porous layer satisfy a relation (I):
0.35≤A/B≤1.0  (I).

A CMS membrane module includes plurality of hollow fiber CMS membranes that are enclosed within an open cylindrical shell whose ends are embedded in tubesheets. The shell is concentrically disposed within an open cylindrical pressure vessel whose open ends are covered by and secured by end caps. The shell includes a feed fluid inlet formed therein between the tubesheets and a retentate outlet in between one of the tubesheets and an adjacent end cap. A retentate seal is formed between the shell and the pressure vessel at a position between the tubesheets. A permeate seal is formed between the pressure vessel and the tubesheet that is adjacent a permeate port of the module. A structure made up of the CMS membranes, shell, tubesheets, and seals is slidable within the pressure vessel and not fixed in place in relation to the pressure vessel and end caps.

Methods and systems for recovering sulfur dioxide from a Claus unit process emissions stream are provided. The method comprises the steps of generating a process emissions stream from a thermal oxidizer or other combustion device, introducing the emissions stream to an SO.sub.2 removal system, introducing the SO.sub.2 rich stream from the SO.sub.2 removal system to a CO.sub.2 removal system, and introducing an enriched SO.sub.2 stream back to the Claus unit. The SO.sub.2 removal system can include one or more SO.sub.2 selective membranes. The CO.sub.2 removal system can include one or more CO.sub.2 selective membranes.

A sanitizing spray system includes a Nitrogen generation system that produces Nitrogen used as a carrier gas source for spraying an alcohol-based disinfecting and sanitizing composition without flashing.

A sanitizing spray system includes a Nitrogen generation system that produces Nitrogen used as a carrier gas source for spraying an alcohol-based disinfecting and sanitizing composition without flashing.

A crosslinked microporous membrane (crosslinked polymer) composition useful in gas separation, the membrane comprising: (i) an aromatic polymer containing a multiplicity of benzene rings; and (ii) a multiplicity of fluorinated aromatic moieties, each fluorinated aromatic moiety containing at least two separate methylene (—CH.sub.2—) linkages connected to benzene rings on the aromatic polymer; wherein the cross-linked microporous membrane possesses micropores having a pore size of up to 2 nm. Also described are methods for producing the crosslinked polymer and a microporous carbon material produced by pyrolysis of the crosslinked polymer membrane. Also described are methods for using the crosslinked polymer and microporous carbon material for gas or liquid separation, filtration, or purification.

Hollow fiber membranes, membrane contactors, and related production and use methods. The asymmetric hollow fiber membranes include a porous substrate having a multiplicity of pores and including at least one semi-crystalline thermoplastic polyolefin (co)polymer. A skin layer including at least one polydiorganosiloxane polyoxamide copolymer overlays the porous substrate. The skin layer is less porous than the porous substrate and forms an outer surface of the asymmetric hollow fiber membrane, while the porous substrate forms an inner surface of the hollow fiber membrane. The skin layer is preferably nonporous.