Optimization of Pre-liming and Sulphitation pH of Cane Juice on Clarification
No Thumbnail Available
Date
2015-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
This study was conducted at Finchaa Sugar Factory to determine the optimum conditions of preliming and sulphitation pH which could result in best cane juice clarification. Two cane varieties, which cover about 70 % of total cane population of the estate namely, N - 14 and NCO - 334 were selected and studied. Mixed juice samples of five liters were taken and the pH was adjusted to constant pH 5.4. The phosphate content of the mixed juice differs from sample to sample and the deficiency was adjusted to 300 mg/l by adding a calculated amount of phosphoric acid in to the mixed juice in a clarification kit. When the temperature reached to 75 C, milk of lime (MOL) was added until the pH became according to the run order, followed by injection of SO2 gas till the pH of the juice became to the corresponding run order and then the 3 mg/L flocculants was added at 90°C. Mixing of the juice was terminated after the addition of the 3 mg/l flocculant (as per the factory norm) and then the juice heating process was continued until it gets boiled. The hot treated juice was flashed to remove dissolved air and after all these treatments, the juice sample was taken and placed in to separate graduated cylinders of 1000 ml capacity for settling. From the graduated cylinders, clear juice samples was taken and analyzed for Brix, Pol, reducing sugar, calcium oxide, color and turbidity. The response parameters determined include turbidity, ICUMSA color, purity rise, calcium oxide content and reducing sugar of clear juice. The data obtained from the comparative experiments were subjected to statistical analysis using JMP statistical and Central Composite Design (CCD )software whereby the significance was set at 5% level. Turbidity, color, and purity rise were used as a main parameter to evaluate the cane juice clarification efficiency. The superimposed of main parameter contour plots and the prediction profile with maximum desirability function gave the following optimized figures for N-14 cane variety. With optimum liming pH 8.792 and sulphiting pH 7.016 which gave a turbidity value of 618.6 IU, a color of 6646 IU and a purity rise of 1.68. The optimum liming pH and sulphiting pH for NCO – 334 cane variety were 8.920 and 7.001 respectively and gave a turbidity of 550 IU, a color of 5874 IU and purity rise of 1.85. In all cases NCO -334 seems superior and easy in juice clarification process. These optimum conditions can allow an increased productivity, low color sugar, minimize sugar loss at Finchaa sugar factory. Key words: Liming, Sulphiting, Flocullant, Turbidity, Purity rise and ICUMSA
Description
Keywords
Liming, Sulphiting, Flocullant, Turbidity, Purity rise and ICUMSA color