树脂的绿色再生是离子交换技术应用于制糖工业的关键。本文研究了醇溶制糖色素存在条件下传统氯化钠再生剂对糖汁脱钙树脂的再生,探讨醇溶制糖色素对钙型树脂再生的影响,以及钙的解吸性质及动力学。结果表明,醇溶色素的存在,促进了传统氯化钠再生剂对糖汁脱钙树脂的复苏,可能的原因是醇溶酚类色素与钙盐的螯合作用促进了树脂的再生;使用动边界模型描述了钙型树脂的解吸过程,发现解吸过程的速度控制步骤为颗粒扩散,表观活化能Ea为36.90 k J/mol,反应级数为1.14,表观频率因子k0为1679 min^-1,解吸过程可用假二级动力学模型描述(R^2〉0.99);钙型树脂的解吸过程与Freundlich等温模型拟合性良好,说明钙型树脂的解吸属于表面不均一性单分子层或多分子层扩散。研究为减少再生剂氯化钠的使用,实现糖用树脂绿色再生提供思路。
Environmentally friendly regeneration of resins is of the reason to use ion-exchange technique in the sugar industry.Here,the regeneration of syrup decalcification resin using conventional sodium chloride as the regeneration agent in the presence of alcohol-soluble pigments was evaluated.The desorption properties,desorption kinetics of decalcification resin,and effect of alcohol-soluble pigments on resin regeneration were evaluated.The results showed that the presence of alcohol-soluble pigments contributed to the recovery of decalcification resin,which is likely because the chelation of alcohol-soluble phenolic pigments and calcium salts promotes the regeneration of decalcification resin.The moving boundary model was used to describe the desorption kinetics of resin decalcification,and the results showed that the rate-determining step of the desorption process was particle diffusion.The reaction order was 1.14,apparent activation energy was 36.90 k J/mol,and apparent frequency factor k0 was 1679 min^-1.Further analysis of the kinetics showed that the desorption process could be described by a pseudo-second-order kinetic model(R^2〉0.99).Moreover,the desorption behavior of resin decalcification fit well with the Freundlich isotherm model,showing that the desorption process in this resin occurred through mono-or multi-molecular layer diffusion on heterogeneous surfaces.This study provides a novel approach for reducing the use of sodium chloride and for regenerating resins more efficiently and in an environmentally friendly manner in the sugar industry.