A method for preparing a palladium-gold alloy layer on a substrate by electrodepositing said coating surface with an aqueous electroplating solution comprising of an aqueous solution of a soluble palladium compound and a soluble gold complex, wherein the ratio of gold to palladium to in the solution is from 5 to 40 w/w %. Also taught is a substrate such as a vanadium or vanadium alloy gas separation membrane coated with a palladium-gold alloy layer.

Disclosed herein are membrane-based onboard gas separation methods and systems, and in particular membrane-based onboard air separation methods and systems for ships and offshore installations, in which a vacuum is applied on the permeate side of the membrane separator unit in order to reduce the energy consumption of the process.

A system for separating carbon dioxide from a carrier gas includes a CO.sub.2 enrichment subsystem that receives a carrier gas stream and produces an enriched carbon dioxide fluid stream. The system also includes a CO.sub.2 polishing subsystem in fluid communication with the CO.sub.2 enrichment subsystem that produces a carbon dioxide rich fluid stream. In a corresponding method, a carrier gas is received in a CO.sub.2 enrichment subsystem and an enriched carbon dioxide fluid stream is produced. The enriched carbon dioxide fluid stream is directed to a CO.sub.2 polishing subsystem wherein a stream further enriched in carbon dioxide is produced.

Described herein are articles for separating gases. The article includes an amorphous fluorinated copolymer containing, one or more types of fluorinated dioxolane ring monomers, and one or more types of fluorinated non-dioxolane ring monomers, optionally with crosslinking between the fluorinated copolymer chains. The copolymers of fluorinated dioxolane ring monomers and fluorinated non-dioxolane ring monomers show a large differential in the permeability of certain gases compared with other gases. The resulting polymer membranes have superior selectivity and reliability performance in certain gas separations compared with previous compositions known to the art. Methods for making and using the article described are also provided,

A membrane assembly includes a tube container having an inlet conduit and a first outlet conduit both oriented in a radial direction, and a second outlet conduit oriented in an axial direction; and a hollow fiber membrane element disposed inside the tube container, the hollow first membrane element comprising a first adapter with an axial permeate fluid passage in a center thereof and an inlet gas passage in a peripheral portion thereof; and a second adapter with an axial permeate fluid passage in a center thereof and a non-permeate fluid passage in a peripheral portion thereof.

A membrane assembly includes a tube container having an inlet conduit and a first outlet conduit both oriented in a radial direction, and a second outlet conduit oriented in an axial direction; and a hollow fiber membrane element disposed inside the tube container, the hollow first membrane element comprising a first adapter with an axial permeate fluid passage in a center thereof and an inlet gas passage in a peripheral portion thereof; and a second adapter with an axial permeate fluid passage in a center thereof and a non-permeate fluid passage in a peripheral portion thereof.

The invention relates to a gas-liquid separator (2) for separating at least one liquid component, in particular H.sub.2O, from a gaseous component, in particular H.sub.2, the separator comprising at least one container (6) which is supplied with a medium via an inlet (16), at least the liquid component of the medium being separated in at least one container (6) and the separated component of the medium being discharged from the at least one container (6) via a discharge valve (46) with the remaining gaseous component of the medium, in particular H.sub.2, being recirculated into an outflow line (5) via a first outlet (18). According to the invention, in addition to the liquid component, in particular H.sub.2O, a gaseous component N.sub.2 is separated from the medium by the gas-liquid separator (2).

The invention relates to a gas-liquid separator (2) for separating at least one liquid component, in particular H.sub.2O, from a gaseous component, in particular H.sub.2, the separator comprising at least one container (6) which is supplied with a medium via an inlet (16), at least the liquid component of the medium being separated in at least one container (6) and the separated component of the medium being discharged from the at least one container (6) via a discharge valve (46) with the remaining gaseous component of the medium, in particular H.sub.2, being recirculated into an outflow line (5) via a first outlet (18). According to the invention, in addition to the liquid component, in particular H.sub.2O, a gaseous component N.sub.2 is separated from the medium by the gas-liquid separator (2).

Process for producing biomethane from a biogas stream including methane, carbon dioxide and at least one impurity chosen from ammonia, volatile organic compounds, water, sulfur-based impurities (H.sub.2S) and siloxanes. A biogas stream is dried, the at least one impurity is at least partially removed by solidification and removal of the impurity. The methane and the carbon dioxide contained in the biogas obtained from the second step are separated so as to produce a biomethane stream and a CO.sub.2 stream.

A gas sensor includes a support structure with a cavity, a sensing element sensitive to a gas and arranged in the cavity, and a filter spanning the cavity. The filter is a size selective filter.