Sugar manufacturing technique for improving yield and reducing color value of white sugar

Abstract

The invention relates to an improved sugar manufacturing technique adopting the alkaline sulfite method, and particularly relates to a sugar manufacturing technique for improving the yield and reducing the color value of white sugar. According to the sugar manufacturing technique, the appropriate pH value is controlled at three technique points, and the timing of adding phosphoric acid in the conventional method is changed; the reaction time is increased in the step of the phosphoric acid reaction, so that phosphoric acid can completely react with calcium salt in clear syrup; the color value of clear syrup obtained by adopting the sugar manufacturing technique can be reduced from 2000 IU to 1700-1900 IU, and the yield is improved.

Description

technical field [0001] The invention belongs to the technical field of sugar production, and relates to an alkaline sulphite sugar production process, in particular to a sugar production process which improves yield and reduces the color value of white sugar. Background technique [0002] The traditional sulfite sugar production process is: control the pH value of the neutralized juice at 6.8-7.2, heat it to 98-102°C and enter the settler to separate the mud juice from the clear juice; the clear juice is evaporated and concentrated to a Brix of 60-65BX °The rough syrup of about °, the pH value of the rough syrup naturally drops during the evaporation process, and the drop range is usually between 0.4-0.8, to pH 6.3-6.8, and then enters the syrup floating process. [0003] The syrup flotation process is to add phosphoric acid, lime milk and flocculant to the coarse syrup to control the pH value at about 6.0-6.5, and use the calcium phosphate produced by phosphoric acid and li...

AI Technical Summary

Problems solved by technology

[0008] In order to solve the above sugar loss problem, the alkaline sulfite process has appeared in recent years, which increases the pH value of the neutralized juice to 7.8-8.2, which is close to the isoelectric point of pH8.2-8.4, so the clear mixed juice of the alkaline sulfite process Poor purity and scouring recovery have been greatly improved

[0009] However, since the clear juice enters the concentration stage of the evaporation process, the maximum steam temperature reaches 128-138°C, high temperature and alkaline conditions will intensify the Maillard reaction in the syrup, produce a large number of new pigments, and increase the color value of white sugar

[0010] Therefore, the increase of the color value of white sugar due to alkaline high-temperature conditions is the biggest obstacle to improve the recovery rate of scouring by using alkaline sulfite method

[0011] 3. The current syrup floating process cannot solve the problems of sugar purity and color reduction

[0012] At present, the addition point of phosphoric acid and lime in the syrup flotation process is at the coarse syrup stage, and the reaction between phosphoric acid, lime, and impurities requires ionization under water medium conditions to generate acid and alkali ions. After the syrup is concentrated, the water content has been greatly reduced. , the concentration of syrup is high, the viscosity is high, and the clarification chemical speed is very slow, resulting in poor clarification effect of syrup

Based on the above reasons, although the floating of the existing syrup can reduce the turbidity, viscosity, and sulfur dioxide of the sugar syrup, it has little effect on improving the purity and reducing the color value of the white sugar.

[0013] 4. The utilization rate of phosphoric acid in the current sulfite process is not high

At present, the addition point of phosphoric acid is mainly in the mixed juice box of the pressing workshop. The sugarcane juice at this stage contains a lot of sugarcane bran, sediment, and impurities, which affects the removal efficiency of calcium phosphate on pigments.

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