Exxon Research and Engineering Company

Air Products and Chemicals, Inc.

William M King

Man-Wing Tang

Harry F Shuey

William W Wight

C Glen Wensley

The method of preparing dried asymmetric cellulose acetate blend membranes through the use of at least one drying agent which is a hydrophobic organic compound, such as polysiloxanes, hydrocarbons, ethers, ketones, chlorohydrocarbons or nitrohydrocarbons. The membranes are dried from their aqueous state by direct evaporation of water. The resulting air dried membranes are suitable for the desalination of water by reverse osmosis, non-aqueous liquid separation, ultrafiltration, pervaporation, and for the separation of various gaseous mixtures into their constituent parts.

Air dried cellulose acetate membranes

In fabricating membrane elements, and especially spiral wound membrane elements, for the separation of extraction solvents, especially N-methyl-2-pyrrolidone (NMP) from extracted oil fractions (e.g., extract of raffinate), adhesive systems consisting of specific silicone elastomers in combination with specific primers have been identified which are useful in forming the bonds necessary to produce an element, as for example, in forming the edge-seal bonds of the membrane that is used to effect the separation, in bonding the membrane leaves to the metal or plastic components of the element, and in forming a protective outer-wrap for the element.

Adhesive system for use in preparing membrane elements for extraction

In fabricating a reverse osmosis spiral wound apparatus for the separation of organic fluid mixtures, especially for the separation of dewaxing solvents containing ketone from dewaxed oil by permeation through a permeable membrane such as pretreated regenerated cellulose or asymmetric polyimide a special epoxy adhesive formulation is used to form the membrane element edge seals which serve to define separate permeate zones and feed stream zones. This special adhesive formulation is characterized by having a relatively long pot life, (i.e. will not set too quickly) permitting it to be easily handled during application to the membrane edges in the course of element fabrication, as well as being flexible (trimable) and of proper viscosity.

Growing community of inventors

Los Alamitos, CA, United States of America

William M King