RU2252968C1 - Method of sugar affination - Google Patents

Abstract

FIELD: sugar industry; methods of sugar affination.

SUBSTANCE: the invention is pertaining to the field of sugar industry, in particular, to methods of affination of the cane sugar raw and brown sugars of beet sugar production. The method provides for dilution of a concentrated sugar-containing solution up to a mass share of solids of 74-76 % and commixing of the sugar with a diluted affinating sugar-containing solution. The dilution of the sugar-containing solution is carried out with the help of an anolyte with pH 6.7-7.5 produced by treatment of a water solution of sodium chloride with amass share of 0.05-0.1 % in the anodic chamber of the diaphragm electrolyzer. The invention ensures an increase of efficiency of sugar purification because during the affination there is more full removal of non-sugars from the sugar crystals film. The method allows to increase purity of a brown sugar by 0.5-1.5 units and the cane sugar raw - by 0.3-1.1 units as compared with the known method.

EFFECT: the invention ensures significantly increased purity of a brown sugar and the cane sugar raw as compared with the known method.

2 ex, 2 tbl

Description

The invention relates to the sugar industry, and in particular to methods for refining raw cane sugar and yellow sugar beet sugar production.

There is a method of sugar refining, which involves mixing the latter with a sugar-containing refining solution with SV 74-76% and obtaining affinity massecuite (Sapronov AR Technology of sugar production. - M .: Kolos, 1998. - S.338-339).

The disadvantage of this method is the low efficiency of sugar purification.

The technical result of the invention is to improve the quality of sugar refining, namely increasing its purity and reducing color.

The technical result is achieved by the fact that in the proposed method of sugar refining, which involves mixing the latter with a sugar-containing refining solution with SV 74-76% and obtaining the refluxing massecuite, it is new that the sugar-containing refining solution is prepared by diluting the initial sugar-containing solution with anolyte with a pH of 6.7 -7.5 obtained by processing an aqueous solution of sodium chloride with a mass fraction of 0.05-0.1% in the anode chamber of the diaphragm electrolyzer.

The method is as follows. Get anolyte. For this, a 0.05-0.1% aqueous solution of sodium chloride is treated in the anode chamber of the diaphragm electrolyzer to a pH of 6.7-7.5.

The anolyte obtained in this way contains a complex complex of oxide products: O ₃ , HOCl, H ₂ O ₂ , Cl ^- , -ClO, ClO ₂ , Cl ₂ O, etc. Being present together in a solution, these components give the anolyte high bleaching and disinfecting properties. In addition, electrochemical treatment allows to obtain solutions with weakened hydrogen bonds between H ₂ O molecules and with a reduced viscosity. All this contributes to a more complete and effective course of many physicochemical processes in the anolyte environment.

It is known that the bulk of non-sugars and almost all reducing substances are in the outer layer of intercrystal solution adjacent to the sugar crystal.

Refining is a technological operation to improve the quality of yellow sugar and raw sugar by replacing a film of intercrystal solution on the surface of crystals by mixing sugar crystals with a sugar (refining) solution of higher purity. At the same time, the purity of the film increases, and the mass fraction of solids and viscosity decrease. As a result of refining, an affinity massecuite is obtained - a mixture of sugar crystals with intercrystal solution. By centrifuging the reflux massecuite with a less viscous intercrystal solution, the film of the latter on the surface of individual sugar crystals becomes thinner and the sugar purity is higher.

The positive effect when using anolyte as a refining solution can be explained by its high bleaching, disinfecting and dissolving effect.

An anolyte is diluted with a sugar-containing solution (for example, the first outflow of massecuite I crystallization or a mixture of outflows) to a mass fraction of solids (CB) of 74-76%, thereby obtaining an affinity solution.

The affinity is carried out by stirring sugar with a refining solution for 18-22 minutes at a temperature of 62-67 ° C.

The resulting reflux massecuite (a mixture of sugar crystals with intercrystal solution) is centrifuged to form refined sugar, the purity of which is higher than that of the original sugar.

For example, when the yellow sugar is refined with the last beet sugar product of the proposed method, after centrifugation, refined sugar is obtained with a color that is 15-23% lower than the color of the refined sugar obtained by the known method (Table 1). Table 1 also shows data on the quality of refined cane raw sugar refined by the proposed method, in comparison with the known. Table 2 shows the dependence of the quality indicators of refined sugar on the pH of the anolyte.

Example 1. Anolyte is prepared. To do this, sodium chloride is dissolved in water to a mass fraction of solids in a solution of 0.08%. The resulting solution is treated in the anode chamber of the diaphragm electrolyzer to a pH of 7.0 anolyte. An affinity solution is further prepared. For this, the first outflow of massecuite from the first crystallization is diluted with anolyte to CB = 74.0%. Yellow sugar of the last product (H = 92.2%, Cv = 64 conventional units) in the amount of 200 g is refined by mixing with 75 cm ^{3 of} refining solution. The resulting refill massecuite is stirred for 20 min at a temperature of 65 ° C and then centrifuged. Get refined sugar with a purity of 95.5% and a color of 28 srvc.

Example 2 (by the closest analogue). 200 g of yellow sugar of the last product (H = 92.2%, Cv = 64 conventional units) are refined by mixing with 75 cm ³ diluted with water to 74% CB of the first outflow of massecuite of the first crystallization. The resulting refill massecuite is stirred for 20 min at a temperature of 65 ° C and then centrifuged. Get refined sugar with a purity of 94.6% and color 35 srvc. units

Table 1 compares the effectiveness of the known and proposed methods for the purification of sugar. In the table. 2 shows the quality indicators of refined sugars obtained by the proposed method depending on the pH of the anolyte.

The use of the invention allows to increase the efficiency of sugar purification due to the fact that during refining, more complete removal of non-sugars from the film on sugar crystals occurs. The proposed method allows to increase the purity of yellow sugar by 0.5-1.5 units, and raw cane sugar by 0.3-1.1 units. in comparison with the known method.

Table 1
Sugar Quality Indicators Source sugar Sugar Quality Indicators Source After affinity The effect of bleaching,% Ah,% H% Chromaticity, conv. units H% Color, conventional units Known method Raw sugar 97.9-98.6 50-58 98.3-99.0 27.6-38.6 33.4-44.8 0.4 Yellow sugar of the last beet sugar product 91.6-94.8 55-65 94.4-96.9 30-38 41.5-45.5 2.1 The proposed method Raw sugar 97.9-98.6 50-58 98.6-99.4 22.7-34.1 41.2-54.6 0.7-1.5 Yellow sugar of the last beet sugar product 91.6-94.8 55-65 95.2-97.4 25-29 54.5-55.4 2.6-3.6

table 2
The effect of anolyte pH on the quality of refined sugars anolyte pH for affinity Sugar Quality Indicators Purity% Chromaticity, conv. units Yellow sugar 6.0 94.9 35.8 6.5 95.0 32,5 6.7 95.2 29.1 7.0 97.4 25.0 7.5 96.8 26.8 8.0 95.1 29.9 Refined Sugar 6.0 98.3 39.5 6.5 98.4 37.9 6.7 98.6 35.0 7.0 99,4 22.9 7.5 99.0 24.6 8.0 98.5 34.6

Claims (1)

A method of sugar refining, which involves mixing the latter with a sugar-containing refining solution with SV 74-76% and producing an affinity massecuite, characterized in that the sugar-containing refining solution is prepared by diluting the initial sugar-containing solution with anolyte with a pH of 6.7-7.5 obtained by treating an aqueous solution sodium chloride with a mass fraction of 0.05-0.1% in the anode chamber of the diaphragm electrolyzer.