Applied Research Of Activated Carbon In The Purification Of Sugarcane Industry

For the past few years, the domestic sugar products is becoming more and more high quality requirements, the urgent need for sugar mills is to find an effective and practical method to sugar decolorization. Because of the favorable decolorization effect of activated carbon, using activated carbon becomes one of the effective ways to sugar decolorization. Different conditions carbon on the effect of color, pH, purity, ash, viscosity,colloid and calcium, magnesium, iron, zinc ion concentration of sugar liquor were studied, and the best purification process conditions was determined; carbon column adsorption process on the effect ofpH, purity, ash, color and sucrose content of sugar liquor were studied; powder charcoal filter separation technology was studied. The results are as follows:(1) In the single factor test, it’s hard to remove color when the decolorization ratio of powdered carbon with mixed juice was among 80%-85%, and for syrup was 70%-75%.(2) The most optimum dosage to decolorization of No.2 powdered carbon with mixed juice was 0.3%, with syrup was 0.8%, the reaction time was 25 mines, reaction temperature was 80℃; While, as for No.6 powdered carbon, with mixed juice was 15%, with syrup was 25%, the reaction time was 30 mines, reaction temperature was 75℃.(3) Activated carbon cannot remove calcium ion, its elimination ratio to magnesium ion was not too high------only 10%, but higher to iron ion and zinc ion, especially much higher to iron ion when in alkali condition. Under the most suitable conditions, elimination ratio of iron ion and zinc ion in No.2 powdered carbon with mixed juice could reach 65%, to iron ion in No.2 powdered carbon with syrup was only 35%; while the elimination ratio of iron ion in No.6 powdered carbon with mixed juice could reach over 75%, to zinc ion was over 60%, but to iron ion in No.6 powdered carbon with syrup was only about 30%, to zinc ion was about 50%.(4) Carbon column adsorption process has a greater initial impact to sugar pH value, ash content, color value, turbidity, and apparent purity. It gets smaller with the decrease of activated carbon capacity. Carbon column equipped with 50g No.6 powdered carbon, the brix of the 100ML initial filtering floating juice, which initial brix was 17.30Bx, decrease into 4.90Bx, pH value decrease into 1.33, ash content increase into 1.068g/100g, turbidity increase into 325.147 MAU, apparent purity increase into 5.71AP, and the color value reduce into 1193IU.(5) After adsorption decolorizing carbon column, some sugar liquor still remained in activated carbon pore,50g No.6 powdered carbon can absorb 75mL sugar liquor in carbon column. This part of sugar liquor contains 7.34% cane sugar of total juice, and they need to be washed and taken back. When the ratio is 1:3 between activated carbon weight and rinse water volume, it benefit for taking back sugar and energy saving, and decrease the sugar total loss into 1.74%.(6) A good way to powder charcoal filtering is to select a more suitable kind of filtration separation medium------PE filter plate. The experiment shows that filtration flux can reach 180L/h-m2 when accuracy is 0.45 mm.