Study On Sulfur-Free Clarification Process With Cationic Bagasse Clarifying Agent

The white granulated sugar which made from traditional sulfitation process contains high content of SO₂, with poor qualities, and along with the establishment of new standard about white granulated sugar, its disadvantages become even more obvious. For the sake of joining international market, the sulfurous acid processe should be improved, then the qualities of white granulated sugar will be enhanced, as well as, the sugar-refinery products value and profit will be also improved. Based on the situation of our country, the transitional new clarified processes, equipment and methods should be tried out to improve the current condition.In this paper, the approach we explore is a novel sulfur-free clarification technics which is the combination of defecation process and cationic bagasse clarifying agent. It contribute to the gradual clarification of the sugar juice. In addition, a series of tests were carried out to study adsorption kinetics and rebirth of cationic bagasse clarifying agent, as well as the stability of sugar juice which was obtained by the new technics described above. In virtue of no accession of SO₂, we can gain sulfur-free sugar product. Besides, low cost is another merit we think a lot of. So it is remarked that this novel sulfur-free clarification technics might serve as a promising industrial protocol for sugar juice clarifying approach. The main research contents and results of the thesis are reported as follows:1. According to the monofactorial tests, four important factors including cationic bagasse clarifying agent dosage, react temperature, contact time and pH value were focus to ascertain their influence on defecatation effect. Whereafter, on the basis of monofactorial tests, the orthogonal design and results were presented in the paper. And the optimal clarification condition was found as follows: the cationic bagasse clarifying agent dosage 0.4g per 100mL preclarified sugar juice, react temperature 80°C, contact time 40min and pH8.2. According to static adsorption test, it indicate that liquid-film pervasion is the main control step of decoloration reaction. Namely, the retain-time of the exchange matters which are at the interphase is controled by the exchange velocity (k) that equal to 5.57×10^-3s^-1 numerically. Also, the decoloration process of catinic bagasse clarifying agent follows Freundish isothermal equation. And according to dynamic adsorption test, it educes that along with the enhance of velocity, the decoloration rate of sugar juice becomes much lower and when the length-diameter ratio increases the decoloration effect can be advanced. 3. The optimal clarification condition: combined regeneration agent of 1%HC1 and 10%NaCl which bears the merit of low loss on exchange capacity. On account of decalescence during regeneration at 80℃we can achieve regeneration of cationic bagasse clarifying agent preferably. Yet if the temperature is too high, meybe cause the decline of decoloration effect as a result of chemical decompose and mutative structure.4. Thermal stability of clarified sugar juice and disposal of pigment waste: the sugar juice which is not decolored by cationic bagasse clarifying agent possesse a trait of poor thermal stability and when it heats gradually the color value may increase soon. However, the sugar juice which is decolored by cationic bagasse clarifying agent is stable which means the removal of pigment is complete and there give birth to no pigment on the condition of high temperature. The pigment waste contains no sucrose, so it can be used to wash boilers, and meet the need of protection of environment.