Patent GB-390716-A (GB)
Title: Process for concentrating one or more components in liquid systems containing three or more components
IPC: B01D11/04
Filed: 1932-09-02
Abstract: A process for concentrating one or more components in homogeneous liquid systems containing three or more components comprises treating the liquid mixture with the component or components to be enriched in the form of a washing liquid which is only partially miscible with the mixture under the conditions of treatment.  If the component or components to be enriched are liquids, and only partially miscible with the mixture, they may be used alone or with diluting agents which do not destroy the partial miscibility, otherwise they are used dissolved in solvents, or mixed with substances so that a liquid only partially miscible with the poly-component mixture is obtained. Similarly, substances may be added to the latter to ensure partial miscibility, or to reduce an existing partial miscibility.  These substances may be added during a countercurrent washing, if desired in several portions.  The temperature used, generally a low one, may be such as to reduce miscibility.  The components to be concentrated pass from the washing liquid to the poly-component system and/or undesirable components pass from the latter to the washing liquid. This latter may be returned to a preceding extraction process or worked up separately.  Examples describe: (1) the production of anhydrous alcohol by dissolving 95 per cent alcohol in a kerosene fraction and treating with water-free alcohol in countercurrent. Anhydrous alcohol dissolved in kerosene, from which it is separated by distillation, is obtained, together with some 80 per cent alcohol which may be rectified and serve as starting product.  (2) The treatment of a solution containing oleic acid, acetic acid, and water with a countercurrent of pure acetic acid.  High boiling hydrocarbons are added to the liquid mixture, or glycerine, for example, to the acetic acid, to destroy complete miscibility.  A mixture of oleic acid, acetic acid, and glycerine, from which acetic acid is obtained by distillation, is obtained, together with an 85 per cent acetic acid containing glycerine, which acid may be brought to the concentration of the starting product in known manner.  The oleic acid containing glycerine may be used for dissolving more acetic acid.  (3) The treatment with acetic acid of an aqueous acetic acid-chloroform mixture obtained by extracting 10 per cent acetic acid with chloroform.  Pure acetic acid cannot be used since it is completely miscible with the liquid mixture, but at a certain dilution a region of immiscibility appears and the use of an aqueous acetic acid of a concentration less than this limiting value results in a concentrating of the acid dissolved in chloroform.  In the example, the washing liquid is a suitable aqueous acetic acid saturated with chloroform.  Two solutions are obtained, one containing concentrated acetic acid in chloroform, separable by distillation, the second dilute acetic with small amounts of chloroform which is returned to the original extraction process.  The addition of gasolene to the mixture, prior to or during the washing, enables a more concentrated acetic acid to be used as washing liquid and consequently gives a more concentrated product.ALSO:Anhydrous alcohol is obtained by dissolving 95 per cent alcohol in a kerosene fraction and treating with water-free alcohol in countercurrent. There results anhydrous alcohol dissolved in kerosene, from which it is separated by distillation, and alcohol of about 80 per cent strength which may be rectified and serve as starting product.ALSO:A process for concentrating one or more components in homogeneous liquid systems containing three or more components comprises treating the liquid mixture with the component or components to be enriched in the form of a washing liquid which is only partially miscible with the mixture under the conditions of treatment.  If the component or components to be enriched are liquids, and only partially miscible with the mixture, they may be used alone or with diluting agents which do not destroy the partial miscibility, otherwise they are used dissolved in solvents, or mixed with substances so that a liquid only partially miscible with the poly-component mixture is obtained. Similarly, substances may be added to the latter to ensure partial miscibility, or to reduce an existing partial miscibility.  These substances may be added during a counter-current washing, if desired in several portions.  The temperature used, generally a low one, may be such as to reduce miscibility.  The components to be concentrated pass from the washing liquid to the poly-component system and undesirable components may pass from the latter or to the washing liquid.  This latter may be returned to a preceding extraction process or worked up separately. Examples describe: (1) the production of anhydrous alcohol by dissolving 95 per cent alcohol in a kerosene fraction and treating with water-free alcohol in counter-current.  Anhydrous alcohol dissolved in kerosene, from which it is separated by distillation, is obtained, together with some 80 per cent alcohol which may be rectified and serve as starting product.  (2) The treatment of a solution containing oleic acid, acetic acid, and water with a counter-current of pure acetic acid. High boiling hydrocarbons are added to the liquid mixture, or glycerine, for example, to the acetic acid, to destroy complete miscibility.  A mixture of oleic acid, acetic acid, and glycerine, from which acetic acid is obtained by distillation, is obtained, together with an 85 per cent acetic acid containing glycerine, which acid may be brought to the concentration of the starting product in known manner.  The oleic acid containing glycerine may be used for dissolving more acetic acid.  (3) The treatment with acetic acid of an aqueous acetic acid and chloroform mixture obtained by extracting 10 per cent acetic acid with chloroform.  Pure acetic acid cannot be used since it is completely miscible with the liquid mixture, but at a certain dilution a region of immiscibility appears and the use of an aqueous acetic acid of a concentration less than this limiting value results in a concentrating of the acid dissolved in chloroform. In the example, the washing liquid is a suitable aqueous acetic acid saturated with chloroform.  Two solutions are obtained, one containing concentrated acetic acid in chloroform, separable by distillation, the second dilute acetic with small amounts of chloroform which is returned to the original extraction process. The addition of gasolene to the mixture, prior to or during the p washing, enables a more concentrated acetic acid to be used as washing liquid and consequently gives a more concentrated product.