| The clear juice is the key process in the sugar production process,and the cleaning effect and speed determine the quality and production efficiency of the product.The traditional sulphurous acid process for sugar production uses sulfur dioxide as a detergent,which has problems such as pollution of the environment,corrosion equipment and sulfur residues.Therefore,the development of new technologies for the production of sulfur-free(sulfurous acid)sugar has become an urgent issue in the sugar cane sugar industry.In this paper,four new sulphur-free sulphur-free cleaning techniques and processes were studied.Based on the optimization of process conditions,the cleaning performance and related mechanisms were mainly investigated.The following is the main research content and results:1.Developed a new process for clarification and decolorization of syrup by the phospho-sucrose calcium method.The effects of syrup pH,reaction temperature,pH value of reaction liquor and reaction time on the clarification effect of syrup were investigated by decolorization rate and turbidity removal rate,and the optimal process conditions were obtained by orthogonal test.To: adjust the pH of the syrup to 3.00 with phosphoric acid,the reaction temperature is 35°C,neutralize with a calcium sucrose solution to a pH of 7.20,react for 5min,add a flocculant,and stir it to form a flocculation.Under this condition,the decolorization rate can reach 61.8 % and the turbidity removal rate reaches 96.6 %.The decolorization and turbidity removal effects under the same conditions are better than the phosphoric acid-lime method.2.Based on the micro-soil enhanced flocculation technology and the principle of heterogeneous nucleation in water treatment,the strengthening effect of micro-sand on the calcium phosphate-sucrose process was studied.The effect of the dosage of micro-sand and flocculant on the flocculation sedimentation velocity was investigated.The optimal dosing method of micro-sand was determined,and the formation mechanism of flocs was discussed.On this basis,taking the sedimentation time as the index,the effects of three factors of micro-sand,micro-sand dosage and polyacrylamide dosage on the flocculation and sedimentation process were investigated,and the process conditions were optimized by response surface analysis.It shows that the micro-sand particle size is 80-100?m,the micro-sand dosage is 0.4g,the polyacrylamide dosage is 5mg/kg,and the sedimentation time is only 4.5min.Compareded with the phosphoric acid-sucrose calcium process,the flocs formed by the micro-sand strengthening are larger and denser,and the sedimentation performance is better.3.Developed a new process for clarification and decolorization of syrup by sulfuric acid-phosphoric acid-sucrose calcium method.Based on the decolorization rate and turbidity removal rate,the effects of five factors,such as phosphoric acid dosage,pre-ash pH value,ash pH value,reaction temperature and PAM dosage,on the clarification effect of syrup were investigated,and the optimal results were obtained by orthogonal test.The process conditions were: the amount of phosphoric acid was400mg/kg,the pH of the ash was 11.30,the pH of the pre-ash was 7.2,the reaction temperature was 65°C,and the amount of PAM was 3mg/kg.Under this condition,the decolorization rate was 62.8% and the turbidity removal rate was 96.2%.The mechanism of clarification decolorization was discussed in combination with infrared spectrum and scanning electron microscopy.4.A new process for clarification and decolorization of syrup by magnesium carbonate-lime milk method was proposed.Magnesium carbonate was prepared by precipitation method,and the effect of self-made magnesium carbonate and lime milk on the clarification and decolorization of sugar juice was investigated.The effects of pH value,magnesium carbonate dosage and temperature on the decolorization rate of sugar juice were investigated by decolorization rate.The clarification and decolorization process of sugar juice was optimized by response surface analysis method: pH was 11.0,and the amount of magnesium carbonate was 0.2 g and a temperature of 50°C.Under this condition,the decolorization rate of the juice reached 83.9%,and the turbidity removal rate reached 95.9%.The results show that the magnesium carbonate-lime milk system has good clarification and decolorization performance for sugar juice,and the process is simple,green and environmentally friendly,and has certain application prospects in the sugar industry. |
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