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过程工程学报 ›› 2021, Vol. 21 ›› Issue (1): 46-56.DOI: 10.12034/j.issn.1009-606X.220013

• 反应与分离 • 上一篇    下一篇

离子交换分离L-缬氨酸的传质动力学及动态穿透特征

陈建军, 张军伟*, 宋乾宁   

  1. 江南大学化学与材料工程学院,江苏 无锡 214122
  • 收稿日期:2020-01-08 修回日期:2020-03-30 出版日期:2021-01-22 发布日期:2021-01-21
  • 通讯作者: 张军伟
  • 基金资助:
    江苏省博士后基金项目;江南大学自主科研计划重点项目

Mass transfer dynamics and breakthrough characteristics of L-valine separation by ion exchange

Jianjun CHEN, Junwei ZHANG*, Qianning SONG   

  1. School of Chemical and Material Engineering, Jiangnan University, Wuxi, Jiangsu 214122, China
  • Received:2020-01-08 Revised:2020-03-30 Online:2021-01-22 Published:2021-01-21

摘要: 为了探讨离子交换分离L-缬氨酸的传质动力学及动态穿透特征,讨论了不同类型树脂的分离效能,研究了传质动力学及控制步骤,分析了固定床动态传质行为。结果表明,苯乙烯型强酸阳离子交换树脂有较佳的分离效能,吸附容量是其他树脂的5~8倍、选择性α为1.3~1.8;中性(或弱酸性)时,L-缬氨酸呈两性离子形态,有利于离子交换吸附。苯乙烯型强酸阳离子交换树脂001×7吸附分离L-缬氨酸,符合准二级动力学模型,初期受颗粒内与液膜两扩散共同控制,中后期受多个因素影响。Thomas和Yoon-Nelson模型适合描述L-缬氨酸和L-亮氨酸的动态穿透行为;流速增加,平衡吸附容量qe、体积吸附量N0和操作时间τ递减;料液浓度增加,平衡吸附容量qe和体积吸附量N0增加,但操作时间τ减少;床层高度的影响与料液浓度的影响呈相反趋势,高径比宜在5以下。

关键词: L-缬氨酸, 离子交换, 分离, 动力学, 穿透特征

Abstract: The separation effects of different types of resins, the mass transfer kinetics and the rate-controlling step, the breakthrough behavior in a fixed bed were studied respectively in order to investigate the kinetics and the dynamic breakthrough characteristics for the L-valine separated by ion exchange. The results showed that the adsorption capacity of strong acidic cation exchanger resin, with a better separation effect, were five to eight times that of other resins, meanwhile their selectivity was from 1.3 to 1.8. L-valine with amphoteric ionic sates in a neutral (or slightly acidic) solution, was beneficial to its exchange adsorption. Moreover, the pseudo-second order kinetic model was found to describe adsorption process of the L-valine well with 001×7 resin as a separation media, such a process was affected by the particle and the liquid film diffusions together at early stage and then by multiple factors at medium-latter stage. Thomas and Yoon-Nelson models could describe breakthrough behaviors of the L-valine and the L-leucine well. The equilibrium adsorption capacity qe, volume adsorption capacity N0 and operation time τ decreased gradually with enhancing flow rate of the L-valine feed, whereas the equilibrium adsorption capacity qe and volume adsorption capacity N0 increased but operation time τ decreased gradually with increasing feed concentration of the L-valine. The ratio of height to diameter should be less than 5 and had an opposite trend to the effect of feed concentration change of the L-valine.

Key words: L-valine, ion exchange, separation efficiency, dynamics, breakthrough characteristic