Embodiments of the present invention provide for the deposition of spacing elements for spiral wound elements which promote mixing within the feed space during element operation thereby improving element performance and reducing concentration polarization and potential for biological fouling.

Embodiments provide methods and structures for purification or volume reduction of a brine by an advanced vacuum distillation process (AVMD) to achieve higher flux by passage of vapors through an AVMD distillation unit. In one example, brine is circulated in a tank. The tank may include one or more membrane pouches that are submerged in the circulating brine or placed above the water level of the hot circulating brine. In other embodiments the membrane pouches are outside of the tank that includes the hot circulating brine but still in communication with it. The circulating brine is heated, allowing creation of water vapor. Using a vacuum, the water vapor is drawn through the membrane, where it may be condensed and subjected to further beneficial use. This process can concentrate to levels to generate crystals or solids, which can be separated and utilized.

A gas separation element comprising a membrane sheet and a permeate spacer, wherein the membrane sheet comprises a porous support and a discriminating layer, CHARACTERISED IN THAT: (a) the permeate spacer has an open space volume of at least 0.0004 m.sup.3/m.sup.2; and (b) the membrane sheet has an aspect ratio of at least 1.5.

Provided is a spiral membrane element that has a restricted outer diameter and is capable of being decreased in operation energy therefor. The element is a spiral membrane element including plural membrane leaves in each of which a permeation-side flow-channel member is interposed between opposed separation membranes a supply-side flow-channel member interposed between any two of the membrane leaves a perforated central pipe on which the membrane leaves and the supply-side flow-channel member are wound and a sealing part that prevents a supply-side flow-channel member from being mixed with a permeation-side flow-channel member. This element has an efficiency index E of 0.005 to 0.10, and the thickness of the supply-side flow-channel member is from 10 to 110 mil.

A gas separation element comprising a membrane sheet and a permeate spacer, wherein the membrane sheet comprises a porous support and a discriminating layer, CHARACTERISED IN THAT:

(a) the porous support comprises less than 10 mg/m.sup.2 of monovalent metal ions; and
(b) the discriminating layer has an average thickness of at least 0.7 μm.

The present invention relates to a spiral wound membrane element designs that utilize entrance and exit points in the feed space channel and utilize barriers on the perimeter of the feed space as well as barriers in the feed space area to direct fluid flow in the membrane element.

A gas separation membrane module includes a center pipe; a plurality of separation membranes each having a feed surface and a permeate surface, the separation membranes arranged such that the feed surfaces face each other and the permeate surfaces face each other; a feed channel material arranged between the feed surfaces; and a permeate channel material arranged between the permeate surfaces, wherein the separation membranes, the feed channel material, and the permeate channel material are wound around the center pipe, an average pore size on a front surface and an average pore size on a back surface of the feed channel material are each 0.95 mm or less, and an average pore size on a front surface and an averaged pore size on a back surface of the permeate channel material are each 0.95 mm or less.

The present invention provides compact spiral-wound filter elements having cassette-like performance. The invention further provides filtration systems (e.g., TFF systems) and processes (e.g., SPTFF processes) employing compact spiral-wound filter elements having cassette-like performance.

A process for separating a feed gas comprising a polar gas and a non-polar gas into a permeate gas and a retentate gas, one of which is enriched in the polar gas and the other of which is depleted in the polar gas, the process comprising passing the feed gas through a gas separation module comprising: (i) a feed carrier comprising a membrane envelope and a feed spacer located within the membrane envelope; and (ii) a permeate carrier comprising: (a) a macroporous sheet; and (b) a protective sheet; and wherein: i) the feed gas is fed along the feed spacer of the feed carrier and a part of the feed gas passes through the membrane envelope and into the permeate carrier to give the permeate gas and a part of the feed gas is rejected by the membrane to give the retentate gas; ii) the protective sheet shields at least a part of the membrane envelope from contact with the macroporous sheet; and iii) the protective sheet comprises a non-woven material.

Embodiments of the present invention provide the integration of arbitrary flow directing patterns, deposited or integrated on or into the porous permeate spacer in a spiral-wound membrane separation element.