Evonik Degussa Gmbh

Evonik Membrance Extraction Technology Limited

Fui Wen Lim

Andrew Timothy Boam

Andrew Guy Livingston

The present invention relates to a method for curing adhesives used in the manufacture of membrane modules containing polymeric membranes, particularly polyimide based membranes used for the nanofiltration or ultrafiltration of solutes dissolved in organic solvents using microwaves. To maximise the chemical resistance of the adhesive used in these organic solvent applications, it must be as fully reacted and crosslinked ('cured') as possible. Typically, thermal processing (heating) of the entire membrane module is used to cure the adhesives. However, the time and temperature required to achieve this high degree of completion of reaction may damage the separation performance of the membrane contained within the membrane module. In one particular aspect, this process utilises microwaves to preferentially promote the curing of epoxy adhesives over the general heating of the membrane module.

Membrane module

There is provided a process for reducing the free fatty acid content of natural oils by contacting the crude natural oil with a solvent to produce an oil product phase substantially depleted in free fatty acids and a free fatty acid rich solvent phase containing the extracted free fatty acids and some of the glycerides, and processing the free fatty acid rich solvent phase with a membrane to recover the glycerides from the solvent phase, comprising the steps of: (a) contacting the crude natural oil with an immiscible solvent; (b) separating the deacidifed natural oil phase from the solvent phase; (c) providing a selectively permeable membrane having a first surface and a second surface; (d) transferring a portion of the solvent and a portion of the free fatty acids and a lesser portion of the glycerides from the first surface to the second surface across the membrane by contacting the free fatty acid rich solvent phase with the first surface, wherein the pressure at the first surface is greater than the pressure at the second surface, and wherein the membrane is a selectively permeable membrane such that the membrane rejections of the free fatty acids (RFFA) and glycerides (RGLY) are greater than 0%, and the membrane rejection (RGLY) of the glycerides is at least 5% greater than the membrane rejection (RFFA) of the free fatty acids.

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London, United Kingdom

Fui Wen Lim