Praxair Technology, Inc.

L'air Liquide, Societe Anonyme a Directoire Et Conseil De Surveillance Pour L'etude Et L'exploitation Des Procedes Georges Claude

Union Carbide Industrial Gases Technology Corporation

James Timothy Macheras

Benjamin Bikson

Joyce K Nelson

Salvatore Giglia

Yong Ding

Cheryl Ann Ford

Thomas Anthony Bolan

A method for fabricating a composite membrane includes coating a substrate, such as, for example, an asymmetrical porous hollow fiber substrate, with a solution which includes a perfluorinated polymer and a perfluorinated solvent. Prior to coating, the substrate is impregnated with an impregnation fluid which is immiscible with the perfluorinated solvent. The method of the invention further includes removing the perfluorinated solvent and the impregnation fluid. A composite membrane includes a porous asymmetric hollow fiber substrate having an outer surface coated with a perfluoropolymer coating. Separation devices which include composite membranes and methods of separating a fluid mixture into a fraction enriched in a first component and a fraction depleted in that component also are described.

Method of preparing composite gas separation membranes from perfluoropolymers

The invention relates to preparation and uses of novel polymeric materials, polyimide amic acid salts (PIAAS). The use of these materials for the fabrication of fluid separation membranes is further disclosed.

Polyimide amic acid salts and polyimide membranes formed therefrom

Tubesheet materials for hollow fiber membrane module are disclosed using materials to provide for improved performance at high temperatures. The tubesheets are cast from a mixture of solidifiable resinous components that are designed to provide desirable processing characteristics to the mixture in its initial liquid state, as well as improved thermal properties its final cured casting state.

High temperature membrane module tubesheet composed of thermoset resin blends

Multicomponent hollow fiber membrane tubesheets are disclosed that provide for improved membrane performance, particularly at high operating pressures. The multicomponent tubesheets have an epoxy resin having, when cured, different degrees of hardness in different portions of the tubesheet. Methods for producing such multicomponent tubesheets are also provided.

Hollow fiber membrane tubesheets of variable epoxy composition and hardness

Improved anisotropic fluid separation membranes are prepared from blends of polymers with surface energy differences. The membranes are formulated by processes wherein low surface energy polymer with desirable fluid separation and permeation characteristics is preferentially concentrated in the surface discriminating layer of the membrane.

Method of preparing membranes from blends of polymers

A process for the preparation of anisotropic hollow fibers useful as permselective separation membranes and for producing composite membranes thereof, involves extruding a spinning dope through a spinneret that extends into a coagulation chamber maintained at subatmospheric pressure, conveying the nascent hollow fiber through a column that extends into the reduced pressure chamber, and contains at least two different abutting liquids arranged in sequence. An apparatus for conducting the process includes the vacuum chamber, the spinneret and the column that extends into the vacuum chamber and is equipped with entrance and exit ports for introduction and removal of at least two abutting liquid coagulation media.

Method and apparatus for spinning hollow fiber membranes

Anisotropic fluid separation membranes having an integral discriminating layer are formed from blends of two types of polyimides. The first type is a phenylindane containing polyimide. The second type consists of polyimides formed from the reaction of benzophenone tetracarboxylic dianhydride (BTDA) and optionally pyromellitic dianhydride (PMDA), with toluene diisocyanate (TDI) and/or 4,4'-methylene-bis-phenylisocyanate (MDI). The ratio of Type 1 polymer to Type 2 polymer is 1 or less. The blend membranes are particularly useful for gas separation.

Fluid separation membranes prepared from blends of polyimide polymers

Improved fluid separation membranes are prepared from the blends of polyetherimide with phenylindane containing polyimides, wherein the amount of phenylindane containing polyimide in the blend is low. The present invention provides for highly anisotropic membranes particularly useful for gas separation applications and for preparation of composite membranes thereof.

Method of preparing membranes from blends of polyetherimide and

A process for producing highly asymmetric hollow fibers useful as permselective gas separation membranes and for producing composite membranes thereof by extruding the spinning dope through a tube-in-orifice spinneret into a gas-filled chamber maintained at reduced pressure and then conveying the extruded hollow fiber through a liquid bath to solidify the extrudate.

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Quincy, MA, United States of America

James Timothy Macheras