In the last years membrane processes for gas separation are gaining a larger acceptance in industry and in the market are competing with consolidated operations such as pressure swing absorption and cryogenic distillation. The key for new applications of membranes in challenging and harsh environments (e.g., petrochemistry) is the development of new tough, high performance materials. The modular nature of membrane operations is intrinsically fit for process intensification, and this versatility might be a decisive factor to impose membrane processes in most gas separation fields, in a similar way as today membranes represent the main technology for water treatment. This review highlights the most promising areas of research in gas separation, by considering the materials for membranes, the industrial applications of membrane gas separations, and finally the opportunities for the integration of membrane gas separation units in hybrid systems for the intensification of processes.

Membrane Gas Separation: A Review/State of the Art

Membrane gas separation applications in natural gas processing

Disclosed are improved polymer materials. Also disclosed are fine fiber materials that can be made from the improved polymeric materials in the form of microfiber and nanofiber structures. The microfiber and nanofiber structures can be used in a variety of useful applications including the formation of filter materials.

Polymer, polymer microfiber, polymer nanofiber and applications including filter structures

Pharmaceutical composition unit dosage forms adapted for enteral or topical administration are described, comprising a safe and effective amount of a pharmaceutically active medicament compound dissolved or uniformly dispersed in a flexible, water-soluble film carrier therefor. Admixtures of medicament and carrier are drawn into a film, which can be cut to desired unit dosage content.

Medicament carriers in the form of film having active substance incorporated therein

The present invention provides a method for purifying a gas by contacting the gas with a liquid ionic compound. Natural gas may be purified, removing water and carbon dioxide, by contacting the natural gas with a liquid ionic compound.

Purification of gas with liquid ionic compounds

There is disclosed a method of forming membranes on the order of 10-200A (0.001 to 0.01 Mu ) thick, particularly for use in reverse osmosis processes where solvents are caused to flow from a more concentrated solution to a more dilute solution through the membrane. The membrane is formed from a plurality of monomolecular layers of a polymer material alone, and in mixtures, which can be crosslinked, if desired.

Membrane method and product

Semi-permeable membranes are made from polyamides, especially N-alkoxyalkyl polyamides, and water-soluble polyvinyl alcohols The membranes are preferably formed as fibers The membranes can be made from compositions containing the polymer components and a di(lower alkyl) sulfoxide, eg dimethyl sulfoxide The membranes may contain complex-forming metal components The membranes are useful for separating chemicals from their mixtures by techniques using an aqueous liquid barrier and complex-forming metals, eg for the separation of aliphatically-unsaturated hydrocarbons such as ethylene from close-boiling hydrocarbons

Semi-permeable membrane compositions based on blends of polyamides and polyvinyl alcohols

There is described the preparation of hydrophilic, semi-permeable film membranes having an increase in pores and containing complex-forming metals. The films can be formed from solutions having film-forming material and pore-forming material dissolved in a solvent. The films can be useful for separating a component, e.g. an aliphatically-unsaturated hydrocarbon, from mixtures by the combined use of liquid barrier permeation and metal complexing techniques. The liquid barrier is at least partially within the hydrophilic film membrane during use, and the barrier contains complex-forming metal ions in aqueous solution. The metal ions may be, for example, noble metal, nickel, mercurous, cuprous or other metal ions, and mixtures of these metal ions, and the aqueous solution may contain other cations. The separation of ethylene from ethane and methane is of particular interest.

Process of separating complexable materials employing semipermeable polymer film

Method for the manufacture of membrane separation units suitable for the separation of components from mixtures containing them. These separation units can be made from elongated anisotropic hollow fiber membranes and can be used for the separation of olefinic compounds from saturated materials.

Method of converting membrane separation units

Novel gas separation film membranes are made by grafting alpha-olefinic, polymerizable monomers having hydrophilic functional groups and having, e.g., about from 2 to about 12 carbon atoms, to nylon, and forming a film from the resulting copolymers. A complex-forming metal component which is active in the presence of water is provided in the film. The invention also includes the process of separating components from gaseous mixtures using the membranes. Of particular interest is the separation of aliphatically-unsaturated hydrocarbons from mixtures, for example, the separation of ethylene from one or more of ethane, methane and hydrogen.

Edward F. Steigelmann

Papers

Membrane method and product

Semi-permeable membrane compositions based on blends of polyamides and polyvinyl alcohols

Process of separating complexable materials employing semipermeable polymer film

Method of converting membrane separation units

Process for separating a material from a mixture of mixture which comprises employing a solid water-insoluble, hydrophilic, semi permeable membrane