Patent GB-923109-A (GB)
Title: Improvements in and relating to sugar purification
IPC: C13B20/14
Filed: 1961-05-09
Abstract: In a process for the purification of sugar (see Group VI) an ion-exchange absorption material comprises a substrate of asbestos fibre or kieselguhr having a surface layer of a cellulose derivative containing basic amino, substituted amino or quaternary ammonium groups or heterocyclic nitrogen radicals.ALSO:A process for the purification of a sugar solution comprises passing the sugar solution or syrup through a bed or mat of an ion-exchange absorption material comprising a substrate of inert material having a surface thereon of a cellulose derivative which contains basic amino, substituted amino, quaternary ammonium groups or heterocyclic nitrogen radicals.  The substrate may be of cellulosic, asbestos or synthetic fibre or of keiselguhr.  When cellulose is the substrate, the surface layer may be obtained by chemical modification of the surface of the fibres to form amino-derivatives of cellulose, e.g. aminoalkyl cellulose or substituted aminoalkyl derivatives such as diethylaminoethyl, dimethylaminoethyl- and piperidinoalkyl cellulose.  These derivatives may be treated with alkyl halides, sulphates or toluenesulphonates to form quaternary ammonium groups.  Instead of forming the surface layer chemically, a cellulose derivative may be applied to the substrate to form a layer thereon.  Regeneration of the bed or mat may be carried out by flushing with, e.g. potassium and sodium hydroxides and/or sodium chloride, and is economically effected by dividing the regenerant solution into two fractions, and rinsing the bed with hot water between treatment with each fraction. In an example, sugar solutions, e.g. "green syrup" are filtered through a 2 inch deep bed of cellulose fibres having a surface of the diethylaminoethyl derivative; 80 to 90% of the colour is removed. Colloidal material, e.g. proteins may also be removed.  The process may be made selective by passing the sugar solutions successively through similar beds which have been regenerated in different ways.ALSO:A process for the purification of a sugar solution comprises passing the sugar solution or syrup through a bed or mat of an ion-exchange absorption material comprising a substrate of inert material having a surface thereon of a cellulose derivative which contains basic amino, substituted amino, quaternary ammonium groups or heterocyclic nitrogen radicals.  The substrate may be of cellulosic, asbestos or synthetic fibre or of kieselguhr.  When cellulose is the substrate, the surface layer may be obtained by chemical modification of the surface of the fibres to form aminoderivatives of cellulose e.g. aminoalkyl cellulose or substituted aminoalkyl derivatives such as diethylaminoethyl-, dimethylaminoethyl-and piperidinoalkyl cellulose.  These derivatives may be treated with alkyl halides, sulphates or toluene-sulphonates to form quaternary ammonium groups.  Instead of forming the surface layer chemically, a cellulose derivative may be applied to the substrate to form a layer thereon, Regeneration of the bed or mat may be carried out by flushing with e.g. potassium and sodium hydroxides and/or sodium chloride, and is economically effected by dividing the regenerant solution into two fractions, and rinsing the bed with hot water between treatment with each fraction.  In an example, sugar solutions e.g. "green syrup" are filtered through a 2 inch deep bed of cellulose fibres having a surface of the diethylaminoethyl derivative; 80% to 90% of the colour is removed.  Colloidal material e.g. proteins may also be removed.  The process may be made selective by passing the sugar solutions successively through similar beds which have been regenerated in different ways.ALSO:A process for the purification of a sugar solution comprises passing the sugar solution or syrup through a bed or mat of an ion-exchange absorption material comprising a substrate of inert material having a surface thereon of a cellulose derivative which contains basic amino, substituted amino, quaternary ammonium groups or heterocyclic nitrogen radicals.  The substrate may be of cellulosic, asbestos or synthetic fibre or of kieselguhr.  When cellulose is the substrate, the surface layer may be obtained by chemical modification of the surface of the fibres to form amino-derivatives of cellulose e.g. aminoalkyl cellulose or substituted aminoalkyl derivatives such as diethylaminoethyl-, dimethylaminoethyl- and piperidinoalkyl cellulose.  These derivatives may be treated with alkyl halides, sulphates or toluene-sulphonates to form quaternary ammonium groups.  Instead of forming the surface layer chemically, a cellulose derivative may be applied to the substrate to form a layer thereon. Regeneration of the bed or mat may be carried out by flushing with e.g. potassium and sodium hydroxides and/or sodium chloride, and is economically effected by dividing the regenerant solution into two fractions, and rinsing the bed with hot water between treatment with each fraction.  In an example, sugar solutions e.g. "green syrup," are filtered through a two-inch-deep bed of cellulose fibres having a surface of the diethylaminoethyl derivative; 80% to 90% of the colour is removed.  Colloidal material e.g. proteins, may also be removed.  The process may be made selective by passing the sugar solutions successively through similar beds which have been regenerated in different ways.