At present, in the sugar industry, especially in the subsequent processes of starch sugar, although the sugar solution has undergone decolorization and separation processes with activated carbon, the color and odor of the final product are difficult to satisfy. Specifically, the sugar solution has a pungent acidic (or alkaline) taste, and the color turns yellow. The final product after concentration and drying also has poor whiteness. It has a significant impact on the quality of the product. To address these issues, Shandong Xiwang Group Starch Sugar Co., Ltd. Dextrin Factory 1 took the lead in selecting Suqing DA201-CII resin for experiments to remove these phenomena and achieve the goal of improving product quality. For the sake of safety, a factory first conducted a small trial and selected several products for comparative simulation experiments. The results showed that the various indicators of Suqing brand DA201-CII resin were the best. Subsequently, a medium-sized test was conducted.
Choose two φ 1000mm separation columns were added with 1.5 cubic meters of DA201-CII resin, and then soaked in 2-3 times alkaline salt water (2% NaOH+8% NaCl) for 12 hours. Clean with clean water until the pH of the effluent is neutral, and then use it for backup. The optimal flow rate for operation is 2-3 times the resin volume.
1、 The quality of the feed liquid imported from DA201-CII is generally:
1. The pH value between 4.5 and 6.5 is optimal;
2. The conductivity is generally around 300us/cm (with significant fluctuations in the actual range of 100-1000); 3. The chromaticity is generally around 50HZ;
4. The transmittance is around 92%;
5. The color is slightly yellow;
6. Odor: pungent sour or alkaline taste;
2、 Quality of discharge:
1. Conductivity: theoretically the same as imported;
2. PH value: In the initial stage of operation, due to the incomplete cleaning of the alkali, the pH value of the discharged material may be around 10, but after 3 hours, it is basically below 6.5; When approaching failure, due to the release of adsorbed acidity, the pH value begins to slowly decrease; But 90% of the time is within a good range;
3. Chromaticity: The pilot test showed that the chromaticity of DA201-CII discharge was less than 20HZ (most of which were less than 15HZ), showing a very significant improvement;
4. Odor: After passing through DA201-CII resin, the discharged sugar solution has no acid or alkali odor except for obvious sugar taste (which is also the most important aspect for users);
5. Color: The discharge liquid is clearly transparent, clear, and looks good compared to the imported liquid;
6. The export transmittance is on average 4-5% higher than the import transmittance;
3、 DA201-CII resin regeneration
1. Backwashing: Use pure water to backwash the DA201-CII resin layer, maintaining a backwashing expansion rate of 80-100% as much as possible until the backwashed water clarifies (preferably with a transmittance greater than 95%);
2. Regeneration: Inject 2% NaOH+5% NaCl mixed solution twice the resin volume, with a flow rate of 2-3m/h, and soak for 2 hours;
3. Replacement: Use deionized water to replace and clean the resin layer at the same flow rate and regeneration direction, with a suitable time of 60-90 minutes;
4. Washing: Use pure water to clean the DA201-CII resin in the direction of operation and at the flow rate of deionized water until the pH value of the effluent is around 7.
4、 Precautions during operation:
1. During operation, the quality of the discharged material is greatly affected by the imported material liquid (mainly on the periodic feed volume), and it is necessary to ensure the stability of the imported material liquid quality as much as possible.
2. The judgment of the quality of the discharged odor varies among different operators, and it is best to use an odor detector for scientific detection to avoid human influence on the results.
3. It should be noted that due to the significant decrease in odor, chromaticity, and absorbance of the sugar solution after being treated with deodorized resin, various careless factors can have an impact on product quality. For example, the quality of the regenerated cleaning water is initially cleaned by using steam condensation water recovered from evaporated concentrated sugar solution to clean the resin layer. However, it is found that the final product still contains a certain odor (the method to identify the odor is to take 20 grams of the finished product, dilute it with water to 100ml, boil it, and smell the odor. Good odors have obvious sugar taste and few impurities; bad odors have more impurities and less sugar taste).